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INDEX INTRODUCTION TO PROJECT VENUE – CENTURY RAYON, SHAHAD RAYON – HISTORY & UTILITY METHOD OF RAYON PRODUCTION YARN VISCOSE PROCESS OF RAYON YARN PRODUCTION EFFLUENT TREATMENT TOTAL QUALITY MANAGEMENT IN PRODUCTION POLLUTION ANALYSIS PHYSICAL PARAMETER CHEMICAL PARAMETER WATER ANALYSIS PREPARATION OF STANDARD SOLUTIONS (NaOH, H 2 SO 4 , Na 2 S 2 O 3 .5H 2 O) GENERAL SAFETY IN LABORATORY 1

RAYON PRODUCTION

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Page 1: RAYON PRODUCTION

INDEX INTRODUCTION TO PROJECT VENUE – CENTURY RAYON, SHAHAD

RAYON – HISTORY & UTILITY

METHOD OF RAYON PRODUCTION

YARN

VISCOSE PROCESS OF RAYON YARN PRODUCTION

EFFLUENT TREATMENT

TOTAL QUALITY MANAGEMENT IN PRODUCTIONPOLLUTION ANALYSIS

PHYSICAL PARAMETERCHEMICAL PARAMETER

WATER ANALYSISPREPARATION OF STANDARD SOLUTIONS(NaOH, H2SO4, Na2S2O3.5H2O)

GENERAL

SAFETY IN LABORATORY

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CENTURY RAYON is a division of Century Textiles & Industries Limited, which belongs to B. K. Birla Group of Companies, one of the largest industrial houses in India. The division is situated at Shahad, about 60 Kms, North of Mumbai, on the bank of Ulhas River.

Rayon division at Shahad commenced its operations in 1956 with an industrial production capacity of 5.5 Tons of Viscose filament yarn per day. Today, it is the largest producer of viscose filament yarn in the country, having the capacity of 45 tons per day.

Century Rayon commenced Caustic Soda production for its captive consumption way back in the year 1964 with 30 TDP mercury cell plant. In the year 1993, the company installed pollution free membrane cell plant and discontinued mercury cell plant. Today, it produces 55 TDP of Caustic Soda & allied chemicals. Century Rayon also produces Carbon-disulphide, Sulphuric Acid which are the basic raw materials for producing viscose filament yarn.

It’s now one of the largest manufacturer & exporter of Viscose Filament Pot Spun Yarn, Continuous Spun Yarn, & Tyre Yarn. All these plants are accredited with ISO 9001: 2000 Certification. Century Rayon commands 28% of the Indian Viscose Filament Yarn market. The financial annual turnover exceeds INR 400 crores (approx US $ 90 Million).

PLANT PRODUCT CAPACITYRayon (Estd.1056) Viscose Rayon Filament Yarn 16,000 MT/annumTyre Yarn/ Cord (Est. 1963) High Tenacity Tyre Yarn 6,500 MT/annumCSY (Est. 1998) Continuous Spun Yarn 2.500 MT/annum

Inn 1963, the rayon Division diversified in to production of high tenacity viscose tyre yarn/cord. The plant was installed in collaboration with Algemene Kuntzidjeunu NV of Holland & Galansztoff AG of Germany. Today the plant is operating at 18 TPD production capacity.

In the year 1998, the “State of Art” machines for production of Continuous Spinning Yarn were installed. Continuous Spun Yarn has many advantages over conventional pot spun viscose filament yarn. The plant was expanded to capacity of 7 TPD in year 2003.

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RAYONRayon is one of the most peculiar fabrics in commercial use today. Strictly speaking it is not an artificial fiber, because it is derived from naturally occurring cellulose. It is not, however, a natural fabric because cellulose requires extensive processing to become RAYON. Rayon is usually classified as manufactured fiber and considered to be “Regenerated Cellulose”.

Skeins of artificial silk produced by the viscose above shows the first attempt to make colored

Spinning syndicate Silks.

Rayon is the oldest manufactured fiber, having been in production since the 1880’s in France, where it was originally developed as a cheap alternative to silk. DuPont Chemicals acquired the rights to the process in the 1920’s and quickly turned rayon into a household world, churning out yards of the cheap, versatile fabric. Rayon drapes well, is easy to dye, and is highly absorbent, although it tends to age poorly. Many rayon products yellow with age and pill or form small balls and areas of roughness where the fabric is most heavily worn.

Rayon is a manufactured regenerated cellulose fiber, because it is produced from naturally occurring polymers, it is neither a truly synthetic fiber nor a natural fiber; it is a semi-synthetic fiber. Rayon is known by the names Viscose Rayon and art silk in the textile industry. It usually has a high luster quality giving it a bright shine. Rayon contains the chemical element carbon, hydrogen, and oxygen.

Cellulose is treated with alkali and carbon disulfide to yield viscose.

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RAYONUSES OF RAYON:-Some major rayon fiber includes apparel (E.g. Blouses, Dresses, Jackets, Lingerie, Linings, Scarves, Suits, Ties, Hats, and Socks) furnishings (E.g. Bed spreads, Blankets, Window Treatments, Upholstery, Slipcovers) industrial uses (E.g. Medical surgery products, Non woven products, tire cord), and other uses (E.g. Yarn, Feminine hygiene products, Diapers)

A sample of rayon from skirt, blouse, shirt with different texture.

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RAYONHISTORY:-

NitrocelluloseThe fact that Nitrocellulose is soluble in organic solvents such as Ether & Acetone, made it possible for Georges Audemars to develop the first “Artificial Silk” about 1885, but his method was impractical for commercial use. The commercial production started in 1891, but it was flammable, and more expensive than acetate or cuprammonium rayon. Because of this, production was stopped before World War I, for example in Germany. Briefly, it became known as “Mother-in-law silk”.Nathan Rosenstein invented the spunize process by which he turned rayon from hard fiber to a fabric. His allowed Rayon to become a popular raw material in textiles.

Acetate method: Paul Schutzenberger discovered that cellulose can be reacted with acetic anhydride to form cellulose acetate. The triacetate is only [citation needed] soluble in chloroform making the method expensive. The discovery that hydrolyzed cellulose acetate is soluble in less polar solvents, like acetone, made production of cellulose acetate fibers cheap and efficient.

Cuprammonium Method:The German chemist Eduard Scheweizer discovered that tetraaminecopper dihydroxide could dissolve cellulose. Max Fremery & Johann Urban developed a method to produce carbon fibers for use in light bulbs in 1897. Production of Rayon for textiles started in 1899 in the Vereinigte Galanzstofffariken AG in Oberbrunch. Improvement by J. P. Bamberg AG in 2004 made the artificial silk a product comparable to real silk.

VISCOSE METHOD

Finally, in 1894, English chemist Charles Frederic Cross, and his collaborators Edward John Bevan, & Clayton Beadle patented their artificial silk, which they named “VISCOSE”, because the reaction product of carbon disulphide and cellulose in basic conditions gave a highly viscous solution of Xanthate. The first commercial viscose rayon was produced by the UK Company Courtaulds Fibers in 1905. Avtex Fibers Incorporated began selling their formulation in the United States in 1910. The name “RAYON” was adopted in 1924, with “VISCOSE” being used for the viscous organic liquid used to make both rayon and cellophane. In Europe, though, the fabric itself became known as “Viscose”, which has been ruled an acceptable alternative term for rayon by the U.S. Federal TradeCommission. The method is able to use wood (Cellulose & Lignin) as a source of cellulose while the other methods need lignin-free cellulose as starting material. This makes it cheaper and therefore it was used on a larger scale than the other methods.Contamination of the waste water by carbon disulfide, lignin and the xanthates made this process detrimental to the environment. Rayon was only produced as a filament fiber until the 1930’s when it was discovered that broken waste rayon could be used in staple fiber.The physical properties of rayon were unchanged until the development of high-tenacity rayon in the 1940’s. Further research & development led to the creation of high-wet-modulus rayon (HWM Rayon) in the 1950’

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RAYONMAJOR FIBER PROPERTIES:-Rayon is a very versatile fiber and has the same comfort properties as natural fibers. It can imitate the feel and texture of silk, wool, cotton and linen. The fibers are easily dyed in a wide range of colors. Rayon fabrics are soft, smooth, cool, comfortable, and highly absorbent, but they do not insulate body heat, making them ideal for use in hot and humid climates.The durability and appearance retention of regular rayon are low, especially when wet; also, rayon has the lowest elastic recovery of any fiber. However, HWM rayon is much stronger and exhibits higher durability and appearance retention. Recommended care for regular is dry-cleaning only. HWM rayon can be machine washed.

BASIC PRINCIPLESOF RAYON FIBER PRODUCTION:-In the production of Rayon, purified cellulose is chemically converted in to a soluble compound. A solution of this compound is passed through the spinneret to form soft filaments that are then converted or “Regenerated” into almost pure cellulose. Because of the reconversions of the soluble compound to cellulose, Rayon is referred to as a regenerated cellulose fiber.There are several types of Rayon fibers in commercial use today, named according to the process by which the cellulose is converted to the soluble form and then regenerated. Rayon fibers are wet spun, which means that the filaments emerging from the spinneret pass directly into chemical baths for sodifying of regeneration.Viscose rayon is made by converting purified cellulose to Xanthate, dissolving the Xanthate in dilute caustic soda and then regenerating the cellulose from the product as it emerges from the spinneret. Most rayon is made by the viscose process.

PRODUCTION OF VISCOSE

Viscose Process:Most commercial rayon manufacturing today utilizes the viscose process. This process dated to the early 1900’s, with most of the growth in production occurring between 1925 & 1955. In the early period, production was mainly textile filament, although the first staple was produced in 1916. High performance rayons, such as tire cord, did not appear until the late 1930’s with the advent of hot-stretching and addition of larger amounts of zinc to the spin bath. Invention of modifiers in 1947 brought on super tire cords and marked the beginning of the high-performance rayon fibers.All of the early viscose production involved batch processing. In more recent times, processes have been modified to allow some semi-continuous production. For easier understanding, the viscose process is a batch operation.

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RAYON

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RAYONCellulose:Purified cellulose for rayon production usually comes from specially processed wood pulp. It is sometimes referred to as “Dissolving Cellulose” or “Dissolving Pulp” to distinguish it from lower grade pulps used for papermaking and other purposes. Dissolving cellulose is characterized by high α-cellulose content. I.e. it is composed of long-chain molecules, relatively free from lignin and hemicelluloses, or other short-chain carbohydrates.

Steeping:The cellulose sheets are saturated with a solution of caustic soda (or sodium hydroxide) and allowed to steep for enough time for the caustic solution to penetrate the cellulose and convert some of it into “Soda cellulose” the sodium salt of cellulose. This is necessary to facilitate controlled oxidation of the cellulose chains and the ensuing reaction to form cellulose Xanthate.

Pressing:The soda cellulose is squeezed mechanically to remove excess caustic soda solution.

Shredding:The soda cellulose is mechanically shredded to increase surface area and make the cellulose easier to process. This shredded cellulose is often referred to as ‘White crumb”.

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RAYONAgeing:The white crumb is allowed to stand in contact with the oxygen of the ambient air. Because of the high alkalinity of white crumb, the cellulose is partially oxidized and degraded to lower molecular weights. This degradation must be carefully controlled to produce chain lengths and short enough to give manageable viscosities in the spinning solution, but still long enough to impart good physical properties to the fiber product.

Xanthation:The properly aged white crumb is placed into a churn, or other mixing vessels, and treated with gaseous carbon disulfide. The soda cellulose reacts with carbon disulfide to form Xanthate ester groups. The carbon disulfide also reacts with the alkaline medium to form inorganic impurities which give the cellulose mixture a characteristic yellow color and this material is referred to as “Yellow crumb”. Because accessibility to the carbon disulfide is greatly restricted in the crystalline regions of the soda cellulose, the yellow crumb is essentially a block co-polymer of cellulose and cellulose Xanthate.

Dissolving:The yellow crumb is dissolved in aqueous caustic solution. The large Xanthate substituents on the cellulose force the chains apart, reducing the inter chain hydrogen bonds and allowing water molecules to solvate and separate the chains, leading to solution of the otherwise in soluble cellulose. Because of the blocks of unxanthated cellulose in the crystalline regions, the yellow crumb is not completely soluble at this stage. Because the cellulose Xanthate solution (or more accurately, suspension) has a very high viscosity, it has been termed “Viscose”.

Ripening:The viscose is allowed to stand for a period of time to “Ripen”. Two important processes occur during ripening: Redistribution and loss of Xanthate groups. The reversible Xanthation reaction allows some of the Xanthate groups to revert to cellulosic hydroxyls and free carbon disulfide CS 2 . This free CS2 can then escape or react with other hydroxyn on other portions of the cellulose chain. In this way, the ordered, or crystalline, regions are gradually broken down and more complete solution is achieved. The CS2 i.e. lost reduces the solubility of the cellulose and facilitates regeneration of the cellulose after form in to a filament.

Filtering:The viscose is filtered to remove undissolved materials that might disrupt the spinning process or cause defects in the rayon filament.

Degassing:Bubbles of air entrapped in the viscose must be removed prior to extrusion or they would cause voids, or weak spots, in the fine rayon filaments.

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RAYON

Spinning:The viscose is forced through a spinneret, a device resembling a shower head with many small holes. Each hole produces a fine filament of viscose. As the viscose exits the spinneret, it comes in contact with a solution of sulfuric acid, sodium sulfate and, usually, Zn++ ions. Several processes occur at this point which cause the cellulose to be regenerated and precipitate from solution. Water diffuses out from the extruded viscose to increase the concentration in the filament beyond the limit of solubility. The Xanthate groups form complexes with the Zn++ which draw the cellulose chains together. The acidic spin bath converts the Xanthate functions into unstable Xantheic acid groups, which spontaneously lose CS2 and regenerate the free hydroxyls of cellulose. This is similar to the well-known reaction of carbonate salts with acid to form unstable carbonic acid, which loses CO2. This results in the formation of fine filaments of cellulose, or rayon.

(JET USED IN SPINNING)

Drawing:The rayon filaments are stretched while the cellulose chains are still relatively mobile. This causes the chains to stretch out and orient along the fiber axis. As the chains become more parallel, inter chain hydrogen bonds form, giving the filaments the properties necessary for use as textile fibers.

Washing:The freshly regenerated rayon contains many salts and other water soluble impurities which need to be removed. Several different washing techniques may be used. In cake conditioning room, cakes are kept in 65% humid atmosphere to retain moisture and become soft and conditioned.

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RAYON

Cutting:If the rayon is to be used as staple (i.e. discreet lengths of fiber), the group of filaments (termed “TOW”) is passed though a rotary cutters to provide a fiber which can be processed in much the same way as cotton.

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YARNYarn is a long continuous length of interlocked fibers, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and rope making.Thread is type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to with stand the stresses involved in sewing. Embroidery threads are yarns specifically designed for hand or machine embroidery.

YARN SPOOLS OF THREAD

Structure:Spun yarn is made by twisting or otherwise bonding staple fibers together to make a cohesive thread. Twisting fibers in to yarn in the process called spinning can be dated back to the upper Paleolithic, and yarn spinning was one of the very first processes to be industrialized. Spun yarns may contain a single type of fiber, or be blend of various types. Combining synthetic fibers (which have high strength, artificial luster, and fire retardant qualities) with natural fibers (which have good water absorbance and skin comforting qualities) is very common. The most widely used blends are cotton-polyester and wool-acrylic fiber blends. Blends of different natural fibers are common too, especially with more expensive fibers such as Angora and Cashmere.Yarns are made up of a number of plies, each ply being a single spun yarn. These single plies of yarn are twisted in the opposite direction (plied) together to make a thicker yarn. Depending on the direction of this final twist, the yarn will be known as S – TWIST or Z – TWIST. For a single ply, the direction of the final twist is the same as its original twist.

Filament yarn consists of filament fibers twisted together. Thicker monofilaments are typically used for industrial purposes rather than fabric production or decoration. Silk is a natural filament, and synthetic filament yarns are used to produce silk-like effects.

Texturized yarns are made by a process of air texturizing (sometimes referred to as taslanizing), which combines multiple filaments yarns into a yarn with some of the characteristics of spun yarns.

A SPINNING JENNY, SPINNING MACHINE WHICH INITIATED THE INDUSTRIAL REVOLUTION & Z AND S TWIST.

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YARNVISCOSE PROCESS OF RAYON YARN PRODUCTION

1. PULPER:-

Pulp is cellulose and mostly obtained from Eucalyptus plant. In pulper, pulp + caustic are mixed properly to form alkali cellulose slurry.

2. HOMOGENISER TANK:-

It receives alkali cellulose slurry from pulper through pump. The homogenizer tank is surrounded by jacket through which hot water is circulated to

maintain temperature of slurry at 470C

3. GRASIM DRUM PRESS:-

As the name suggests it is made up of 2 drums which rotates in opposite direction so that the solid particles (alkaline cellulose slurry) can be grabbed by drums to form mat.

The liquid caustic and dissolved impurities removed from the Grasim drum press can be reused.

4. SHREDDER:-

Alkali cellulose mat gets cut here into pieces to form filthy crumbs.

5. AGEING DRUM:-

Long chain polymers are converted into short chain polymers by air oxidation. Time for one rotation is 3 min. The alkali cellulose is oxidized for 8 hrs.

6 .HOPPER:-

It weights up to 2000 kg of alkali cellulose and then dumps it into simplex. Hopper balance is calibrated periodically to avoid any error in batch weight.

7 .XANTHATOR:-

After dumping alkali cellulose in Xanthator, vacuum is created in simplex to avoid inflammation during addition of CS2 (highly inflammable and toxic).

Here, alkali cellulose is converted into sodium cellulose Xanthate which is in the form of sticky balls.

To dissolve the Xanthate balls chilled NaOH ( 8OC-24GPL) is added to 5500 liters.

8. DISSOLVER:-

Xanthate slurry from simplex form raw viscose for further purposes. The impurities present the slurry mainly contains air bubbles, particles and maturity.

9 .BLENDER:-

Viscose is constantly agitated in blender.

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YARN

10 .GRASIM CONTINOUS FILTER (GCF):-

This is Іst stage filter. Different size particles are separated in this filter.

11. RECEIVING TANK (REACTION TANK):-

This is Пnd stage filter. Waste impurities are allowed to settle down.

12. B – TANK:-

It is a type of storage tank and has same purpose as reaction tank.

13 .FLASH DEAERATOR:-

Viscose is passed by feed pump to flash deaerator where air bubbles are removed to avoid breaking of filament.

14. F.D.BLENDER:-

This is Шrd stage filter. Here fine particles are filtered away.

15. SPINNING VISCOSE TANKS:-

The viscose is metered by a viscose metering pump for each spinning position. The metering pump action ensures constant and regular delivery of viscose to the candle filter

and spinning jet. Any change in the speed of pump drive will change the deiner of the yarn. (Denier is wt. in

Gms of 9000m length of a yarn.)

16. SPINNING DEPARTMENT:-

Viscose is passed in spinning department through pumps. In this, spinnerets are submerged in the acid spin bath. The acid spin bath contains 3 main acids , H2SO4 , ZnSO4 & Na2SO4 respectively H2SO4 (138 gpl) helps neutralize caustic in viscose. ZnSO4 (16 gpl) helps to give strength. Na2SO4(238 gpl ) helps solidification and regeneration . Spinneretes (jets) are made up of an alloy of noble metals like gold, platinum and rhodium. It

has 24 holes having diameter of 250 microns. As the viscose sol. Passes through spinnerets into the acid bath it solidifies into filaments. Cake formation takes place due to Bakelite spinning pot which rotates at about 7800 rpm.

17 .WASHING:-

Washing of cake is done by soft water and by using various chemicals like EDTA, FSS etc. Bleaching is also done in order to remove yellowness.

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YARN18 .HYDRO EXTRACTOR:-

It is used to remove water.

19. DRYING:-

After washing the yarn contains 200 % moisture. In drying process the moisture% is brought down to 0% by maintaing 900c for 68-72 hrs.

20. CAKE CONDITIONING ROOM (C.C.ROOM):-

In C.C.Room cakes are kept in 65% humid atmosphere to retain moisture and become soft and conditioned.

21. CONNING :-

Conning is done to form a uniform bundle of yarn. 3 cakes may give 1 cone.

22. INSPECTION :- The yarn is thoroughly inspected to check its quality before final packaging. Quality and cost of yarn is affected by hairy or broken filament, shade variation, oil stain,

cross ends etc.

23. PACKAGING:- This is the final task. One carton box contains 50 kg yarn cones.

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EFFLUENT TREATMENT

The viscose fiber industry requires huge amount of water of which only a small fraction is incorporated in the product the remainder fined the ways into the water ways as effluent water. Principally two types of wastes originate in the viscose Rayon plant-acidic and alkaline.

The acid water also discharged from the industry contains chiefly sulfuric acid, sodium, and sulphate and zinc sulphate. The alkali wastes contain sodium hydroxide soluble hemi cellulose of row pulp, residual viscose, sodium polysulphides and sodium thiosulphate.

Effluent flow of 27000m3/day is being neutralized by addition of lime solution on the way of equalization tank. Hydraulic system has been provided into the tank for equalizing effluent quality and to keep the solids in suspension.

EXISTING EFFLUENT TREATMENT SYSTEM

There is automatic addition of lime near CS2 plant as the effluent coming is highly acidic. There is pH meter present to detect the pH of the effluent. There is another automatic lime addition sensor near ETP inlet were the automatic lime addition is done in order to increase the pH. This effluent further goes to neutralizer equalization tank 1. NEUTRALISER EQUALISATION TANK (NET) FOR NORMAL EFFLUENT.

Total effluent from acid plant, boiler house rayon plant and tyre cord plant gets collected in neutralization tank. This effluent contains soda, ash, charcoal, and ash-dust. The normal effluent flow in equalization tank 22000m3/day.

In order to prevent settlement of (soda, ash, charcoal, ash-dust) the circulatory motion of water is maintained by used of hydraulic pump. 3 hydraulic pumps are present out of which 2 are 24 hr in working position and 1 pump is in spare. The effluent water from neutralizer equalization tank (NET) is pumped to flash mixer were coagulant is added for removal of small particles and colloids and also for reducing BOD and COD to some extent. From flash mixer the effluent water is pumped to clariflocculator with the help of NEP pump. (Neutralizer equalization pump).

Incoming effluent in (NET) is almost neutralized by inlet auto control value by addition of lime. In certain times the concentration of effluent is highly acidic which is not neutralized by outlet inlet control valves. In such condition two additional auto control valves with lime are given in NET namely New equalization tank stage - 1 and New equalization tank stage - 2 due to use of these two auto control valves lime almost all effluent is neutralized. There is no treatment present in the plant to treat alkali effluent.

2. CLARIFLOCULATION FOR NORMAL EFFLUENT

The treated effluent from NET is pumped with help of NEP pump in clarifloculator. In clarifloculator two chambers are provided. In inner chamber there is sludge present along with effluent water. The sludge settles down and is transferred to Thickener. The effluent water which is now sludge free is carried out to outer chamber from the opening present at the bottom of the inner tank, then it goes to Aeration tank.

3. ZINC REDUCTION PLANT

Zinc rich waste from rayon plant is separated from the rest of the industrial effluent. Then lime slurry is added to adjust pH of the zinc waste in pH adjustment tank. Lime addition is controlled by pH controller which is automatic. The overflow from pH adjustments tank is sent to flash mixing unit where floculant is added to coagulate zinc or zinc hydroxide. From flash mixture the effluent passes to clarifloculator where large blocks of zinc hydroxide is formed and settled in the outer zone of the clarifloculator. From clarifloculator which is rich in zinc hydroxide is pumped

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to thickener. From thickener sludge is subjected to centrifuge where water and moist sludge are separated. Sludge goes to Thickener tank and effluent water is transferred to Aerator.

4. REMOVAL OF SLUDGE PRESENT IN CLARIFLOCULATOR

The sludge (solid) acquired from clarifloculators of normal effluent treatment plant and zinc recovery plant are transferred to gravity thickener where concentration of sludge with supernant takes place. It’s later pumped to centrifuge for dewatering of solid. The sludge cake having 30% - 40% solid separated. the liquid or effluent water separated from the sludge is transferred to Aeration tank.

5. AERATION TANK

Four aerators are provided in the aeration tank. They are immersed in water two of the aerators are in working condition for 24 hr and 2 are in real condition. The aerators are used to increase the DO (Dissolved O2) before the final discharge.

SUMMARY

The effluent water from equalization tank is pumped by neutralized effluent pump to flash mixer.

Pumping of effluent water in flash mixer is followed by addition of poly-electrolytes and then to clariflocculator where flocculation and sending process occur. The clarified water is over flowed to aeration tank for increasing the dissolved oxygen before final disposal of effluent.

Part of Rayon after treatment and tyrecord spin bath rich in zinc is taken separately in clariflocculator tank where pH is maintained at pH 9 supernatant liquid is taken back to inlet of equalization tank.

The settled sludge of both clarifiers are taken into thickener for concentrating the sludge and then pumped to centrifuge for separation of solid and liquid. Solid sludge is collected in trolley, and is disposed in an 1100m3 pit made for hazardous water disposal in front of century chemicals. The liquid or effluent water is Aerated and treated well before the final disposal.

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Zink Rich Effluent 5000m3/Day

+Lime Slurry

Neutralizer Equalization Tank for Zinc Recovery

Neutralizer Equalization Tank for Normal Effluent

Normal Effluent 22000m3/Day

+Lime Slurry

FLASH MIXERFLASH MIXER

CLARIFOCLULATOR

FOR ZINC RECOVERY

FOR NORMAL EFFLUENT

SLUDGE EFFLUENT WATER FROM RAYON

PLANT

EFFLUENT WATER FORM ZINK

RECOVERY TANK

COAGULATE ZINK OR

ZINK HYDROXIDE

GRAVITY THICKENER

CENTRIFUGE

AERATOR

FINAL EFFLUENT OUT

SLUDGE DISPOSSED OFF IN PIT

EFFLUENT WATER

EFFLUENT TREATMENT PLANT27000 m3 PER DAY

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USE OF EFFLUENT WATER

This treated effluent water is used in various purposes.1. Lime solution preparation for ETP.2. Sulphuric acid coolers.3. Gardening is entire factory area.4. Treated effluent water is used for ash quenching in boiler house.5. Plan is under study to use treated effluent for floor watering.6. Gardening in ETP and inCS2 plant. 7. Dimensions of each unitEQUALISATION DIMENSION [m] CAPACIYY [m3]

Tank for normal effluent 43.75 x 11.12 x 2.43 1200

Clarifier for normal effluent 32 x 3.2 swd 2800

Equalisation Thickener 32 x 3 swd 400

Aerator 30.1 x 7.5 x 2.5 600

Equalisation tank for zinc recovery 12.8 x 12.8 x 2.25 370

Clarifier for zinc recovery 18 x 2.8 swd 730

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TOTAL QUALITY MANAGEMENT (TQM)

Among its guiding principles, the company has adopted Total Quality Management (TQM) concepts as core policy to bring about cultural changes in the organization, where customer’s delight is Prime Motto.To achieve appreciation of our products from domestic and international customers, we shall able to provide products and services of desired quality at competitive cost. In this chemical laboratory following things are analyzed:

Pollution analysisWater analysisStandardization and preparation of chemicals

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POLLUTION ANALSIS

METHOD OF ANALYSIS:

Wastewater characterization studies are conducted to determine the best means of reducing pollutants concentration.The analysis used to characterize water ranges from precise quantitative chemical determination. The result of analysis is are most commonly expressed in physical units such as mg/l it is important to note that for dilute System such as industrial waste water. The unit of mg/l are interchangeable with parts per million (ppm) which is mass to mass ratio. The following characteristic of the wastewater determined in rayon plant:

1. PHYSICAL PARAMETER:

A) TEMPERATURE:-

The temperature of water or effluent is basically important for its effect on the chemical and biological reaction of organisms in water. An increase in temperature it speeds up the rate of chemical reaction in water reduce the solubility of gases and amplifier the taste and odors. At higher temperature the metabolic activity of organisms increases. They require more oxygen while at same time the solubility of oxygen is reduced.In the present study the temperature of effluent before treatment is found to be 390C and effluent after treatment is found to be 380C.

The standard prescribed by MPCB is 400C for inland surface water disposal purpose, the temperature of waste water from century rayon under permissible limit of MPCB.

B) pH:-The ion concentration is an important quality parameter as the suitable range for existing of most biological life is quite narrow and critical. If the is not altered before discharge it may effect the concentration. H in the surface water body loading to change in the aquatic system it can be conveniently measured using pH meter. We have a digital pH meter for accuracy.Conclusion:- The pH is defined as the logarithm of hydrogen ion with negative sign the pH is a measure of relative acidity or alkalinity of water. It does not measure the total acidity; alkalinity depends upon express H+ or OH- ions over the other and measures in normality or gram equivalent of acid or alkali. pH is generally measured on log scale and equal to negative log10 of hydrogen ion concentration. pH = -log10 (H+)pH of waste water ranges from 6.37 to 7.33 is combined effluent of century rayon plant.The MPCB limit for pH is 5.5 to 9.0 for disposal into river. The waste water from century plant is under permissible limit of MPCB.

C) TOTAL SUSPENDED SOLID (TSS):-

These are classified as suspended or filterable solids and can be measured by passing a known volume of liquid through a suitable filter.Experimental procedure:-

100ml of sample is filtered through a weighed G4 sintered glass crucible which is previously weighed using a vacuum pump for suction.

The residue is washed with distilled water and the crucible heated in an oven at 150 0C for 2-3hrs.

The crucible is cooled in desiccators and weighed.

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Formula:-Suppose the difference is ‘X’100 = X106 =? TSS =10 6 x ‘X’ 100 =104 x ‘X’ ppm

Conclusion:-The total suspended solid is non-filterable residue; they may contain organic or inorganic substances.Suspended solids are contained in effluents which are not in solution suspended solids are contained in effluence which are insoluble. Suspended solids comprise settle able floating are not settle able component.The total suspended solid contained in century rayon effluent is 27.75 to 70.5 mg/l.The tolerance limit of industrial effluent discharge into stream allowed by state pollution control board for TSS is 100mg/l. The TSS in the effluent of century rayon plant is below permissible limit.

D) TOTAL DISSOLVE SOLID (TDS):-

These are solid which is present in dissolved form and can be measured bykeeping a known volume of liquid in evaporating dish.It contain both suspended and dissolved solid i.e. (TDS + TSS) Experimental procedure:-

Take 100ml of sample in aluminum dish which is previously weighed. Evaporate on the hot plate. Weighed again after cooling.

Formula:-Suppose the difference is ‘X’100 = ‘X’ 106 =?TDS = 10 6 x ‘X’ 100 =104 x ‘X’ ppm

[NOTE: - TDS = (TDS + TSS) – TSS And TDS + TSS = TS (TOTAL SOLID)]

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2. CHEMICAL PARAMETER

A) CHLORIDE TEST (NaCl):

Procedure: Take 100ml of sample in a beaker. Add 1 spoon of CaCO3. Add 2ml of 2N HNO3. Add 2ml of 5% of K2Cr2O4 (which itself act as a indicator). Titrate it against 0.1 N AgNO3 solutions. End point will be yellow to brick red.

Formula:-Suppose the value is ‘Y’

Then, 1000ml of 1N AgNO3 [solution in burette] = 58.5gms (equivalent wt. of NaCl) [solution in flask]. 1ml of 1N AgNO3 = 58.5 1000 1ml of 0.1 N AgNO3 = 58.5 x 0.1 x ‘Y’ x 106

1000 x volume of sample = 58.5 x ‘Y’ ppm.

B) SULPHATE:- Procedure:

Take 300ml of sample in beaker. Add 2 drops of conc. HCL [To settle the dust particle]. Keep it in a hot plate till its volume reduces to half. Add 20ml of 10% BaCl2 when it is warm [white ppt out of BaSO4 forms. Filter it through a G4 crucible which is previously weighed. Dry it inside oven for 6 hours. Again wt. and take the difference.

Formula:-Suppose the value is 1.4269Then, 1.4269 = BaSO4

In 300ml the reading is 1.4269 Then, in 100? So, 100 x 1.4269 = 0.2853 (the amount BaSo4 present in sample) 500Now, molecular wt. of BaSO4 = 137 + 32 + 64 = 233.For SO4 = 32 + 64 = 96 i.e. 233 96 0.2853?So, 0.2853 x 96 = 0.1175 %( amount of SO4 present in BaSO4) 233In 100 0.1175Then, in 106 =?So, 0.1175 x 10 6 = 1175 ppm. (Amount of SO4 present in per million). 100

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C) LIME:-

Procedure: Take some amount of lime in a crucible and keep in oven for 6 hours to remove

moisture. Weighed approximately 1gm of lime in a beaker. Add 25ml of conc.HCl in it and keep for 11/2 hour to liberate CO2. Make the dilution in 500ml of standard conical flask. Pipette out 25ml in a conical flask. Add 2ml of buffer pH in it. Titrate it against EDTA. End point will be purple to blue.

Formula:-Suppose the value is ‘Y’

Now, 1) Percentage of CaO: Wt. of lime = 1gm 1000ml of 1N EDTA = 56gm of CaO 1ml of 0.00619N EDTA = 56 x 0.00619 x ‘Y’ x 100 x 20 1000 x 1 = Z%2) Percentage of Ca(OH)2:- 1000ml of 1N EDTA = 74 gm of Ca(OH)2

1ml of 0.00619N EDTA = 74 x 0.00619 x ‘Y’ x 20 x 100 1000 x 1

D) OIL:

Procedure:- Take 100ml of sample in a separating funnel. Add 10ml of 4N H2SO4. Add 50ml of Diethyl ether. Mix it well. Remove water from the lower side of separating funnel and then Diethyl ether is taken in a

round bottom flask which is previously weighed. Distilled out all the Diethyl ether from round bottom flask. Keep the flask in the oven for 2 hours. Weigh it again. Difference will give you amount of oil.

Formula:-OIL = Difference x 10 6

100

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E) CHEMICAL OXYGEN DEMAND (COD):-

Principle (open reflux method):-Most types of organic matter are oxidized by a boiling mixture of chromic and sulfuric acids. A sample is refluxed in strongly acid solution with known excess of potassium dichromate (K2Cr2O7). After digestion, the remaining unreduced K2Cr2O7 is titrated with ferrous ammonium sulfate to determine the amount of K2Cr2O7 consumed and the oxidizable matter is calculated in terms of oxygen equivalent.

The COD test is used to measure the total organic matter content of waste water the oxygen equivalent to organic mater that can be oxidized is measured by using a strong chemical oxidizing agent in acidic medium potassium dichromate has been found to be best for the general chemical reaction can be represented by the following unbalanced reaction:

Organic matter (CHO) + K2Cr2O7 + H+ Cr3+ + CO2 + H2O.

In the process of oxidizing the organic substances found in the water sample, potassium dichromate is reduced (since in all redox reaction, one reagent is oxidized and the other is reduced), forming Cr3+. The amount of Cr3+ is determined after oxidization is complete, and is used as an indirect measure of the organic contents of the water sample.The determination of chemical oxygen demand (COD) widely used in municipal and industrial laboratories. In practice, it is usually expressed in milligram O2 per litre. Oxygen demand is determined by measuring the amount of oxidant consumed using titrimetric methods. The test is not adversely affected by toxic substances, and test data is available in 1-1/2 to 3 hours, providing faster quality assessment and process control. A COD test is measures all organic carbon with the exception of certain aromatics (benzene, toluene, phenol, etc.) which are not completely oxidized in the reaction. COD is a chemically chellated/thermal oxidation reaction, and therefore, other reduced substances such as sulphide, sulfites, and ferrous iron will also be oxidized and reported as COD.The COD of waste is generally higher than the BOD as more compounds can be chemically oxidized then biological. COD and BOD can be correlated for many types of waste COD measurement can be used for treatment plant control and operation.

Importance of COD:- Many organic substances which are difficult to oxidize biologically can be oxidized

chemically. COD test is faster than BOD. COD is usually measured and the test is simple and easy to

perform with right equipment and can be done in 2 hours. BOD usually takes 5 days. Since BOD cannot be determined accurately when toxins are present and conditions are

unfavorable for growth of microbes, COD is used. This test is used extensively in the analysis of industrial waste. It is particularly valuable in surveys designated to determine and control losses of sewer

system. Experimental procedure:-

Take 25ml of 0.25 N K2Cr2O7 solutions in conical flask and glass bids are added to avoid bumping action.

Pinch of HgSO4 and 5cc conc. H2SO4. Add 20ml of sample. Add slowly 35cc of conc. H2SO4 thoroughly. For the blank test the same procedure is used except that distilled water is used instead of

sample. Connect the flask to condenser. Mix the content thoroughly before heating. Improper

mixing result in bumping and the sample may be blown out.

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Reflux for a minimum period of 2 hours. Cool and wash down the condenser with distilled water.

Titrate against excess potassium dichromate with 0.1 N ferrous ammonium sulphate Fe(NH4)SO4 (FAS) using ferrion indicator.

Sharp colour change from blue green to wine red indicates the end point. Formula:- COD mg/l = (blank reading-sample) x 8000 x 0.1 Volume of sample

Where 8000 = milliequivalent weight of oxygen x 1000 ml/l

Conclusion:- The COD test is very important parameter in management and design of the treatment plant. COD values are than BOD values for sample of most of the industrial wastes. COD contained in the century rayon effluent ranges from 60.8 to 135.4 mg/lThe tolerance limit for COD given by MPCB is 250mg/l. Thus the COD in the effluent of century rayon plant is below permissible limit.

F) BIOLOGICAL OXYGEN DEMAND (BOD):-Biochemical oxygen demand (BOD) is the amount of oxygen, expressed in mg/l or parts per million (ppm), that bacteria take from water when they oxidized organic matter or Biochemical oxygen demand, measures the amount of oxygen consumed by microorganisms in decomposing organic matter. A test is used to measure the amount of oxygen consumed by these organisms during a specified period of time. (Usually 5 days at 20oC ). The rate of oxygen consumption in a stream is affected by number of variables:temperature, pH, the presence of certain kind of microorganisms, and the type of organic and inorganic material in water. The carbohydrates (cellulose, starch, sugars), proteins, petroleum hydrocarbons and other materials that comprise organic matter get into water from natural sources and from pollution. They may be dissolved, like sugar, or suspended as particulate matter, like solids in sewage. Because organic matter always contains carbon and hydrogen, oxidation produces carbon dioxide and water. Bacteria in water live and multiply when organic matter is available for food and oxygen is available for oxidation. About 1/3rd of the food bacteria consumed becomes the solid organic cell material of the organisms. The other 2/3rd is oxidized to carbon dioxide and water by the biochemical action of the bacteria on the oxygen dissolved in the water.

Importance of BOD:- Measurement of BOD has long been the basic means for determining the degree of water

pollution. BOD test is used to determine size of waste treatment facilities. The BOD test is used to measure waste load to treatment plant, determine plant efficiency (in

terms of BOD removal), and control plant processes. BOD directly affects the amount of dissolved oxygen in river and streams. The greater the

BOD, the more rapidly oxygen is depleted in the stream.Major disadvantage:-The BOD test is the amount of time (5 days) required to obtain the results.

Experimental procedure:-For estimating BOD of sample 2 special stoppered bottles (approximately 300ml each) are required.For each sample and an addition pair of the blank test carried out with distilled water.

Each bottle is filled exactly to 1/10th of its volume of dilution water.Dilution water is prepared by making a 2% by volume solution of filtered domestic sewage with distilled water and adjusting its pH to 7.

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Prepare seeding water separately. Seeding water is distilled water in which nutrient CaCL2, MgSO4, FeCl3 and phosphate buffer is added. 2ml of each nutrient is added for 1liter of distilled water.

Seeding is done in dilution water ml 6.6ml of sample is added to one liter of distilled water. Clean the bottles. Keep two bottles for blank and three sample dilution bottles in incubator for 3 days, at 20OC. After 3 days, at 200C, add 2ml of MnSO4 and 2ml of alkali iodide azide to each bottle, put

stopper and shake the bottle well. Allow the ppt to settle. White ppt indicates absence of dissolved oxygen.

{When MnSO4 and alkali iodide azide (NaOH + KI + NaN3) is added to sample in which no dissolved oxygen (DO) is present, white ppt of Mn(OH)2 is formed. If dissolved oxygen is present, it oxidizes some of Mn2+ ions to Mn4+, forming MnO2 as follows:

Mn2+ + 2OH- Mn(OH) (under zero condition)

Mn2+ + 2OH- + 1/2O2 MnO2 + H2O (in the presence of DO sample)}

Add 2ml of conc. H2SO4 and mix well so that ppt will dissolve completely and yellow colour is obtained in each bottle.

Transfer 200ml of sample from each bottle to titrate it against 0.1N sodium thiosulphate solution using starch indicator.

Titration is continued till colour changes from blue to colourless. Find BOD for each sample.

Formula:-

BOD = [Reading of blank – Reading of sample] x 100 Dilution factor

Conclusion:-The BOD test is widely used to determine the pollution length of sewage and industrial waste in terms of oxygen that would be required if these waste are discharged into natural water in which aerobic condition exist.BOD contained in century rayon effluent ranges from 19.1 to 40.8mg/l The tolerance limit for BOD is given by MPCB is 100mg/l. Thus the BOD in the effluent of century rayon plant is below permissible limit. MPCB limit for discharge of industrial effluent:-

Sr. No. Parameter Concentration1. Temperature 402. pH 5.5 to 93. COD 2504. BOD 1005. TSS 1006. OIL & GREASE 107. ZINC 5

All values in mg/l except pH.

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SUMMARY AND CONCLUSION

Now-a-days pollution is a serious problem on national and international level. As the industrialization grows the pollution also grows due to that life particularly is threatened so from these point present study is attempted. It’s broad summary and conclusion is as follows:- The analysis of treated effluent shows temperature: 370C, pH:6, 45.5, COD:135, BOD: 39.84, Oil and Grease:6.2, Zinc:4.5mg/l. These values are below limit, prescribed by Maharashtra pollution control board (MPCB). This clearly indicates that the ETP was working efficiently and the water would be used for gardening or any other purpose.As the study period was restricted to 2 weeks. It is difficult to draw a right conclusion on the basis of the study carried out for a short period of time.From the present study it appears that environment development conflict can be minimized if not avoided, though the century rayon is giving adequate treatment. Sometimes lacked of trained personal or some drawbacks in the existing ETP system creates serious problems thus industry should take all possible measurements to control pollution.

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WATER ANALYSIS

Century Rayon is one of the largest companies in Asia producing Rayon fiber. It is independent & produces its raw materials & required chemical by itself. It does’ not import any of its raw materials & have a successfully established & set up plants for required chemical demand. Going one step ahead it even have set up effluent or waste water treatment plants by itself. The effluent water is well treated and thoroughly examined before letting out in environment. Thus environmental care is taken & aquatic life is conserved.

In Century Rayon water from Boilers, Rivers, filter, waste water etc. is analyzed. A through checking of pH, Alkalinity, Acidity, turbidity, presence of O2 & silica is attempted in laboratory; even COD & BOD is checked. Hence we found out that Century Rayon have established laboratory which take care of checking water samples from respective areas.

In the following report represents the water analysis experiments carried out to check the various parameter before letting out in the aquatic environment.

Waste water characterization studies are conducted to determine the best means of reducing pollutants concentration. The analysis used to characterize water ranges from precise quantitative chemical determination. The result of analysis are most commonly expressed a physical units such as mg/l. it is important to note that for dilute system such as industrial waste water. The unit of mg/l or g/m3 are interchangeable with parts per million (ppm) which is mass to mass ratio.

1. pH 2. Turbidity3. Alkalinity4. Acidity 5. Sulphite6. Phosphates 7. Total hardness of water 8. Silica 9. Dissolved O2

10. Dialyser & waste caustic11. Chloride 12. Total dissolved solid (TDS)

1. pH

The pH is defined as the negative logarithm of hydrogen ion concentration. The pH is a measure of relative acidity or alkalinity of water. pH of waste water range from 6.37 to 7.33 in combined effluent of century Rayon plant. The MPCB limit for pH is 5.5 to 9.0 for disposal into river. The hydrogen concentration is an important quality parameter, as the suitable range for

existence of most biological life is quite narrow & critical. If the pH is not altered before the discharge, it many effect the concentration of the water. This parameter is measured with the help of a digital pH meter. pH can be determined also by taking 50 cc sample & adding universal indicator to it. The

color change can be compared by standard pH paper. In Century Rayon, pH of boiler sample River, Filter, Condensate & Deager samples, 45 ton,

Anion, Cation etc are determined.

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2. TURBIDITY

Turbidity is a measure of the amount of light scattered and absorbed by water because of the suspended matter in the water.

In simple words, turbidity is the lack of clarity or brilliance in water which may be due to clouding of substance like clay, rock flour, silt, silica, manganese, sulfur or other organic & industrial wastes.

In Century Rayon water from River & filter water sample are checked for their turbidity through Nephlo- Turbidity meter whose unit is NTU (Nephlo Turbidity unit).

Therefore the potability of water sample can be easily verified & determined whether it is safe for consumption.

3. ALKALINITY

Alkalinity refers to the capability of water to neutralize acid. Water with a value greater than 7 indicates alkalinity & tends to affect the taste of the water. Since hard water contains metal carbonates (mostly CaCO3) it is high in alkalinity. In Century Rayon alkalinity of feed water, Boiler, Anion, Condensate is determined. The required chemicals are- Phenolphthalein indicator Methyl orange indicator 1N H2SO4 solution

PROCEDURE

100cc sample of the given water sample is taken in a conical flask & few drops of Phenolphthalein indicator is added to it & titrated against 1N H2SO4 unit end point reaches to pink to colorless.E.g. Suppose the reading is 1.0 then 1.0 x 100 = 100 (where 100= standard factor)

To this same colorless solution, few drops of methyl orange indicator is added & continued titrating against 1N H2SO4 till the end point reaches to yellow to orange. E.g. suppose the reading is 2.1 then 2.1 x 100 = 210 (where 100 = standard factor)

By performing the above experiment Alkalinity can be easily determined.

4. ACIDITY

Water with a pH value less than 7 indicates acidity & tends to be corrosive. Also low mineral content in water are common causes of corrosiveness.

For the above reasons Cation & degraser water samples acidity is regularly checked in Century Rayon.

The reagents required for the experiment are Methyl red indicator. 0.01N NaOH.

PROCEDURE

100cc 0f given water sample is taken in a conical flask & few of methyl red indicator are added to it.

The solution is then titrated against 0.01N NaOH till end point reaches from yellow to brick red.

E.g. suppose the reading is 6 then 6x4.9 = 29.4 where 4.9 is a factor.

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5. SULPHITE IN BOILER WATER

Sulfate is a substance that occurs naturally in drinking water but large amount of sulfate could be hazardous.

This experiment is attempted in order to find the amount of sulfate in the given water sample to keep the sulfate level in check.

The reagents required for the experiment are : 1:1 HCL Starch indicator Standard potassium iodate- iodide sol. (0.71gm of KIO3+7gm of KI + 0.5gm NaHCo3 per liter of the solution).

PROCEDURE

100cc of given water sample is taken in conical flask & 2cc of 1:1 HCL is added using 1cc of starch indicator.

This solution is titrated is against standard KIO3 till a trace of blue color is obtained throughout the solution. The end point being colorless to blue.

E.g. Suppose the reading is 3.8 then 3.8x12.5=475 Formula:-

Sulfide as Na2SO3 ppm = Reading of KIO3 x12 (1cc of KIO3 solution = 0.00125gm of Na2So3)

6. PHOSPHATE IN BOILER WATER

Phosphorous allows plants & animal to grow & function. It is a component of ATP which is the very basic source of energy for all cellular work.

Most of the time phosphates added to the soil during forming or other related activities leaches out to rivers and ocean excess leaching may cause diversions phosphorous cycle & aquatic environment. Hence it is very important to keep the phosphate level in check through regular analyzing the water sample.

In Century Rayon boiler water sample are checked for there phosphate levels before discharging it in near rivers.

The reagents required to carry out the test are – molybdic acid Hydroquinone solution. (Na2Co3+Na2So3) solution.

PROCEDURE

5ml of given water sample is taken in conical flask & 2cc of molybdic acid, 2cc hydroquinone solution and 2cc of (Na2CO3+Na2SO3) solution is added.

During & after each addition the sample is swirled & mixed thoroughly. The blue color developed in the solution is compared with the help of lens bond comparator The blue color is molybdenum blue & is said to have a composition. (MoO2.4MoO3)2. H3PO4.

Formula: - PO4 ppm = vol. of std. phosphate solution X 20 E.g suppose the reading is 20 then 20 X 20=400.

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7. TOTAL HARDNESS OF WATER In Century Rayon Rivers, filter, water sample are checked for their hardness. The hardness of this sample is due to presence of CaCO3 & MgCO3.

PROCEDURE

Taking 100 cc samples in conical flask, 10cc buffer solution is added along with few drops of mixed indicator.

The above solution is then titrated against standard EDTA solution. The end point being wine red to green.

Formula: - total hardness = reading of std. EDTA x 6.195 solution. E.g. suppose the reading is 2 then 2 x 6.195 = 12.39.

8. SILICA

The following experiment is carried out to trace the presence of silica or amount of sand particles present in feed, boiler, 4ST, Anion, Cation & condensate water sample in Century Rayon.

TRACER SILICA

Chemicals required to carryout the experiment are 1. 1:1 HCL.2. 5%Ammonium molybdate. 3. 10% oxalic acid. 4. Sulphonic acid.

PROCEDURE

50cc sample is taken in conical flask & 1ml of 1:1 HCL is added along with 2ml of 5%Ammonium molybdate, 2cc of 10% oxalic acid & 2ml of Sulphonic acid. It is then compared with the standards.

1cc in 50ml silica free water = 0.1 ppm. FOR HIGH PPM SILICA

Reagent required are 1. 1:1 HCL.2. 5%Ammonium molybdate.3. Oxalic acid.

PROCEDURE

50cc sample is taken in conical flask & 1ml of 1:1 HCL is added along with 2ml of 5%Ammonium molybdate, 2ml of 10% oxalic acid & 2ml of Sulphonic acid. It is then compared with the standards.1cc in 50cc silica free water = 2 ppm.

9 .DISSOLVED OXYGEN

Oxygen is the main element required for life. Water contains oxygen is dissolved form which is used by aquatic life for their respiratory processes.

Variations in oxygen level in aquatic environment can disrupt the aquatic life hence it is very essential to maintain the optimum oxygen level.

The following experiment is attempted to check the amount of dissolved oxygen in the given water sample.

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Precautions are taken during sampling such that the bottle does not contain water bubble as air contain oxygen and it could get mixed and dissolved with the water sample and there may be error while finding the result.

The following are the reagents required to carry out the experiment-

1. The manganese sulphate solution (48gms/100ml of D.W).2. Iodide solution (360gms NaOH and 100gms KI dissolved in 1litre of D.W).3. Hydrochloric acid 1:1 or H2SO4 (specific gravity 1:4).4. 0.01N sodium thiosulphate solution.5. Starch indicator.

PROCEDURE

In the water sample contend in the bubble free bottle by means of a pipette 2ml of manganese sulphate solution and iodide solution is added. The bottle is restoped and shaken thoroughly.

After the precipitate has settled 2ml of conc. H2SO4 is added and shaked till the precipitate dissolves completely.

100cc of this solution is taken in conical flask and titrated against sodium thiosulphate solution using starch indicator.

Formula and ReactionO2 ml/liter= reading of thiosulphate x 0.56MnSo4+2NaoH → Mn (OH)2+Na2So4.2Mn (OH)2+O2 → 2MnO(OH)2

MnO (OH)2+2KI+2H2SO4= MnSO4+K2SO4+I2+3H2O+I2+Na2S2O3=Na2S4O6+2NaI. Calculation based on- 1ml of 1N sodium thiosulphate 0.008gm of O2

(32gms of O2 will occupy 22.4litres)

10. WASTE CAUSTIC SAMPLE (NaOH)

The waste caustic contains maximum proportion of NaOH. The following experiment is attempted in order to check the caustic level. The required reagents are-

1. 1.0N H2So4

2. Methyl red indicator.

PROCEDURE

5ml of sample is pipetted out in conical flask and few drops of methyl red indicator is added to it this solution is then titrated against 1.0NH2So4.

The end point being yellow to light red.Formula: - NaOH (gpl) =R x 8. (1ml of 1N H2SO2=0.04gm of NaOH).

11. CHLORIDE

Through following experiments chlorides in water sample as NaCl is analyzed. The chemicals required are as follows.1. Nitric acid (2N)2. Phenolphthalein indicator. 3. Potassium chromate indicator (5%)

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4. 0.1N silver nitrate solution 5. Solid calcium carbonate

PROCEDURE 50cc sample is taken in conical flask and neutralized with 2N HNO3 to the same solution

pinch of CaCO3 is added using Potassium chromate indicator. This solution is then titrated against 0.1Nsilver nitrate till end point yellow to reddish

brown is attended.Formula:-Chloride as NaCl (ppm) =B.R.of 0.1N AgNo3 x 2 x 58.5(1ml of 1N AgNo3=0.0585gm of NaCl)

12. TOTAL DISSOLVED SOLID (TDS)

TDS is an expression for the combined content of all inorganic and organic substances combined in a liquid which are present in a molecular, ionized or micro-granular suspended form.

In century rayon TDS of water sample from boilers is obtained to check the amount of suspended solid particles present in the sample.

PROCEDURE

50cc sample is taken in weighed steel dish and kept on water bath till all the water evaporates.

The weighed steel dish is then cooled, desiccated and weighed again to obtain the weigh of the residue.

Formula:-TDS (ppm = weigh of the residue x 20,000)E.g. Suppose 29.893 is the weight of steel plate and 29.899 is the weight of steel plate with residue then 0.006 is the amount of residue present then 0.006 x 20,000=120 TDS (ppm)

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PREPARATION AND STANDARIZATION OF 1N NaOH

REAGENTS:

1N H2SO4 SOLUTION NaOH PELLATE METHYLERED INDICATOR

PROCEDURE:

Equivalent wt of NaOH = 40gmTherefore, 40gm in 1 Liter = 1N NaOHI.e. 40g of NaOH pellet weighted and added in 1Liter of distilled water will give us 1N NaOH and shake well.

To check and standardized the prepared solution of 1N NaOH for normality we titrated it against 1N H2SO4 using methylered indicator.This is an acid base titration and End points is yellow to bricked.

Calculation:N1V1 = N2V2

Where, N1 = 1N H2SO4 ……knownV1 = Burette reading…...knownN2 = Normality of NaOH to be found.V2 = 25.0ml of NaOH

If burette reading = 25mlTherefore, N1V1 = N2V2

N2 = 1.0 x 25/25= 1.0N

If N2 = 1N we get correct 1.0N NaOHCase I:

If burette reading = 25.5mlThen, N1V1 = N2V2

N2 = 1.0 X 25.5/25= 1.02N

Here, 1.02 > 1.0NThe prepared solution is concentrated.To dilute it we take N1 = 1.02 and V1 = 1000mlV2 is the total volume of distilled water which is substrated from V1 (the actual 1000ml) and the difference is the amount to be added and N2 = 1N NaOH

N1V1 = N2V2

V2 = 1.02 x 1000/1.0= 1020 ml

Therefore, V2 - V1 = 1020 – 1000= 20ml

Therefore, if we add 20ml in the prepared concentrated solution we will get perfect 1N NaOH solution and even the burette reading when titrated against 1N H2SO4 will be 25.Take one more reading for conformation.

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Case II: If the burette reading = 24.8mlThen, N1V1 = N2V2

N2 = 1.0 x 24.8/25= 0.992N

Here, 0.992 < 1.0The prepared solution is diluted so, we use the formula

GPL = Equivalent wt x normality= 40 x 0.992= 39.68GPL

39.68gpl is to be substrated from 40 (the standard GPL for 1N NaOH)40 – 39.68 = 0.32 gm

0.32 gm is the amount of NaOH pellate to be added in the prepared diluted solution to get perfect 1N solution. Titrated against 1N H2SO4 and the burette will be 25ml

N1V1 = N2V2

N2 = 1.0 x 25.0/25.0N2 = 1N

For conformation take one more reading.Therefore we will get perfect 1N standardized NaOH solution.

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PREPARATION & STANDARIZATION OF 1N H2SO4

Reagents: 1N NaOH Cone H2SO4

Methyl red indicator

Procedure:

Equivalent wt of H2SO4 = 49gTherefore 49g in 1000ml = 1N H2SO4

I.e. 49g of H2SO4 weighted and added in 1000ml of distilled water in a standard flask, shake well and this will give us 1N H2SO4.If we take it by volume then 27.7ml of H2SO4 in 1000ml of distilled water we will get 1N H2SO4

To check and standardize the prepared solution of 1N H2SO4 for normality we titrate it against 1N NaOH using methyl red indicator.

This is an acid base titration and the end point is pink to Brick red.

Calculation:N1V1 = N2V2

Where, N1 = NaOH…KnownV1 = Burette reading …knownN2 = Normality of H2SO4 to be foundV2 = 25ml of H2SO4

If burette reading = 25.2ml Then, N1V1 = N2V2

N2 =1.0 x 25/25= 1.0N

If N2 = 1 we get correct 1N H2SO4

Case I:If burette reading = 25ml

N1V1 = N2V2

N2 = 1.0 x 25.2/25= 1.008N

Here, 1.008 > 1.0Therefore, the prepared solution is concentrated.To dilute it we take N1 = 1.008 and V1 = 1000mlV2 is the total volume of distilled water which is subtracted from V1 (the actual 1000ml) and the difference is the amount to be added.

N2 = 1N H2SO4

Therefore, N1V1 = N2V2V2 = 1.008 x 1000/1.0

= 1008ml

Dilution:Therefore, V2 – V1 = 1008 – 1000

= 8mlIf we add 8ml in the prepared concentrated solution we will get perfect 1N H2SO4 and even the burette reading when titrated against 1N NaOH will be 25ml

N1V1 = N2V2

N2 = 1.0 X 25/25.0 = 1.0N

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Take one more reading for conformation.

Case II:If the burette reading = 24.8ml

Then, N1V1 = N2V2

N2 = 1 x 24.8/25= 0.992N

Here, 0.992 < 1Therefore, the prepared solution is dilutedSo, we use the formula

GPL = Equivalent wt x Normality= 49 x 0.992= 48.608 g

48.608 gpl is to be subtracted from 49(the standard gpl for 1N H2SO4)Then, difference in gpl is taken

GPL = 49.0 – 48.608 = 0.392 gm

0.392 gm is the amount of H2SO4 to be added in the prepared diluted solution to get perfect 1N H2SO4 and even the burette reading when titrated against 1N NaOH will be 25ml.

N1V1 = N2V2

N2 = 1 X 25/25N2 = 1.0N

For conformation take one more reading.Note:As the acid is in liquid form we can take it’s normality by weight as well as by volume also.If we take it in volume then, we use formula

Volume = Mass/ densityFor e.g.

Volume = 0.392/ 1.84Volume = 0.312 ml

Where, 1.84 is the density of H2SO4

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PREPARATION AND STANDARDISATION OF 0.1N H2SO4

Reagents:

0.1N NAOH CONE H2SO4

METHYL RED INDICATOR

Procedure:Equivalent wt of H2SO4 = 49g

I.e. 49g in 1000ml = 1N H2SO4

So, for 0.1N H2SO4 we will take 4.9 gm in 1000ml of distilled water to make 0.1N H2SO4

4.9 gm in 1000ml = 0.1N H2SO4

I.e. 4.9g of H2SO4 weighted and added in 1000ml of distilled water in a standard flask, shake well and this will give us 0.1N H2SO4.To check and standardize the prepared solution of 0.1N H2SO4 for normality we titrate it against 0.1N NaOH using methyl red indicator.This is an acid base titration and the end point is pink to brick red.

Calculation:N1V1 = N2V2

Where, N0.1 NaOH…KnownV1 = Burette reading …knownN2 = Normality of H2SO4 to be foundV2 = 25ml of H2SO4

If burette reading = 25.2ml Then, N1V1 = N2V2

N2 =0.1 x 25/25= 0.1N

If N2 = 0.1 we get correct 0.1N H2SO4 solution.

Case I:If burette reading = 25.5ml

N1V1 = N2V2

N2 = 0.1 x 25.5/25= 0.102N

Here, 0.102 > 0.1NTherefore, the prepared solution is concentrated.To dilute it we take N1 = 0.102 and V1 = 1000mlV2 is the total volume of distilled water which is subtracted from V1 (the actual 1000ml) and the difference is the amount to be added.

N2 = 0.1N H2SO4

Therefore, N1V1 = N2V2

V2 = 0.102 x 1000/0.1 = 1020ml

Dilution:Therefore, V2 – V1 = 1020 – 1000

= 20mlIf we add 20ml in the prepared concentrated solution we will get perfect 0.1N H2SO4 and even the burette reading when titrated against 0.1N NaOH will be 25ml

N1V1 = N2V2

N2 = 0.1 X 25/25.0 = 0.1N

Take one more reading for conformation.

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Case II:If the burette reading = 24.8mlThen, N1V1 = N2V2

N2 = 0.1 x 24.8/25= 0.0992N

Here, 0.0992 < 0.1Therefore, the prepared solution is dilutedSo, we use the formula

GPL = Equivalent wt x normality= 49 x 0.0992= 3.968 g

3.968 gpl is to be subtracted from 4.9(the standard gpl for 0.1N H2SO4)Then, difference in gpl is taken

GPL = 4.9 – 3.968 = 0.932 gm

0.932 gm is the amount of H2SO4 to be added in the prepared diluted solution to get perfect 0.1N H2SO4 and even the burette reading when titrated against 0.1N NaOH will be 25ml.

N1V1 = N2V2

N2 = 0.1 X 25/25N2 = 0.1N

For conformation take one more reading.

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PREPARATION AND STANDARDATISATION OF 0.1 NaOH

REAGENTS:

0.1N H2SO4 SOLUTION NaOH PELLATE METHYLERED INDICATOR

PROCEDURE:

Equivalent wt of NaOH = 40gmTherefore, 40gm in 1 Liter = 1N NaOHSo for 0.1N NaOH we will take 4.0gm in 1000ml of distilled water to make 0.1N NaOH.

4.0gm in 1000ml = 0.1N NaOHI.e. 4.0gm of NaOH pellet weighted and added in 1Liter of distilled water will give us 0.1N NaOH and shake well.To check and standardized the prepared solution of 0.1N NaOH for normality we titrated it against 0.1N H2SO4 using methylered indicator.This is an acid base titration and End point is yellow to bricked.

Calculation:N1V1 = N2V2

Where, N1 = 0.1N H2SO4 ……knownV1 = Burette reading…...knownN2 = Normality of NaOH to be found.V2 = 25.0ml of NaOH

If burette reading = 25mlTherefore N1V1 = N2V2

N2 = 0.1 x 25/25= 0.1N

If N2 = 0.1N we get correct 0.1N NaOH

Case I:If burette reading = 25.5mlThen, N1V1 = N2V2

N2 = 0.1 X 25.5/25 = 0.102N

Here, 0.102 > 0.1NThe prepared solution is concentrated.To dilute it we take N1 = 0.102 and V1 = 1000mlV2 is the total volume of distilled water which is substrated from V1 (the actual 1000ml) and the difference is the amount to be added and N2 = 0.1N NaOH

N1V1 = N2V2

V2 = 0.102 x 1000/0.1 = 1020 ml

Therefore, V2-V1 = 1020 – 1000 = 20ml

Therefore, if we add 20ml in the prepared concentrated solution we will get perfect 0.1N NaOH solution and even the burette reading when titrated against 0.1N H2SO4 will be 25.Take one more reading for conformation.

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Dilution:V2 – V1 = 1020 – 1000

= 20mlTherefore, if we add 20ml in the prepared concentrated solution we will get perfect 0.1N NaOH and even the burette reading when titrated against 0.1N H2SO4, the burette reading will be 25ml.

N1V1 = N2V2

N2 = 0.1 X 25/25= 0.1N NaOH

Take one more reading for conformation.

Case II: If the burette reading = 24.8mlThen, N1V1 =N2V2

N2 = 0.1 x 24.8/25= 0.0992N

Here, 0.0992 < 0.1The prepared solution is diluted so, we use the formula

GPL = Equivalent wt x normality= 40 x 0.0992= 3.968gpl

3.968gpl is to be substrated from 4.0 (the standard gpl for 0.1N NaOH)GPL = 4.0 – 3.968

= 0.032 gm

0.032 gm is the amount of NaOH pellate to be added in the prepared diluted solution to get perfect 0.1N solution. Titrated against 0.1N H2SO4 and the burette will be 25ml

N1V1 = N2V2

N2 = 0.1 x 25.0/25.0N2 = 0.1N

For conformation take one more reading.Therefore we will get perfect 0.1N standardized NaOH solution.

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PREPARATION AND STANDARDISATION OF 0.1N SODIUM THIOSULPHATE (Na2S2O3.5H2O)

Reagents: 0.1N Potassium iodate solution (KIO3) Solid Potassium iodide (KI) 2N acetic acid Starch indicator Sodium carbonate (Na2CO3) and chloroform (CHCl3) as preservative

Procedure:

Equivalent weight of Na2S2O3.5H2O = 248gmI.e. 248gm in 1000ml = 1N Na2S2O3

So, for 0.1N Na2S2O3 we will take 24.8gm in 1000ml of soft water to make 0.1N Na2S2O3

24.8gm in 1000ml = 0.1N Na2S2O3

I.e. 24.8gm Na2S2O3 of weighted and added in 1000ml of soft water in a standard flask, shake well. This will give us 0.1N Na2S2O3. Allow the solution to stand for 5-6 days.To check and prepare standard solution we titrated 0.1N KIO3 against prepared solution.Take 25ml 0.1KIO3 in a flask and add 2gm of KI and add 10ml of 2N acetic acid to it.The colorless solution turns brown as iodine is librated in the solution.Titrate the librated iodine against the prepared solution and add starch indicator when the solution turns pale yellow.End point shows the color change from Blue to colorless

Calculation:N1V1 = N2V2

Where, N1 = 0.1N KIO3 ……knownV1 = 25ml of KIO3…...knownN2 = Normality of Na2s2O3 to be found.V2 = Burette reading

If burette reading = 25mlTherefore N1V1 = N2V2

N2 = 0.1 x 25/25= 0.1N

If N2 = 0.1N we get correct 0.1N Na2S2O3 solution.

Case I:If burette reading = 24.9ml

Then, N1V1 = N2V2

N2 = 0.1 X 25/24.9 = 0.1004N

Here, 0.1004 > 0.1NThe prepared solution is concentrated.To dilute it we take N1 = 0.1004 and V1 = 1000mlV2 is the total volume of distilled water which is substrated from V1 (the actual 1000ml) and the difference is the amount to be added and N2 = 0.1N Na2S2OH3

N1V1 = N2V2

V2 = 0.1004 x 1000/0.1 = 1004 ml

Therefore, V2-V1 = 1004 – 1000

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= 4mlTherefore, if we add 4ml in the prepared concentrated solution we will get perfect 0.1N Na2S2O3

solution and even the burette reading when titrated against 0.1N KIO3 will be 25ml.Take one more reading for conformation.

Dilution:V2 – V1 = 1004 – 1000

= 4mlTherefore, if we add 4ml in the prepared concentrated solution we will get perfect 0.1N Na2S2O3 and even the burette reading when titrated against 0.1N KIO3, the burette reading will be 25ml.

N1V1 = N2V2

N2 = 0.1 X 25/25 = 0.1N Na2S2O3

Take one more reading for conformation.

Case II: If the burette reading = 25.1ml

Then, N1V1 = N2V2

N2 = 0.1 x 25/25.1 = 0.0996NHere, 0.0996 < 0.1

The prepared solution is diluted so, we use the formulaGPL = Equivalent wt x normality

= 248 x 0.0996= 24.7011 gpl

24.7011gpl is to be substrated from 24.8 (the standard gpl for 0.1N Na2S2O3)GPL = 24.8 –24.7011 = 0.1 gm

0.1 gm is the amount of Na2S2O3 to be added in the prepared diluted solution to get perfect 0.1N Na2S2O3 and even the burette reading when Titrated against 0.1N KIO3 will be 25ml

N1V1 = N2V2

N2 = 0.1 x 25.0/25.0N2 = 0.1N

For conformation take one more reading.Therefore we will get perfect 0.1N standardized Na2S2O3 solution.

Note:As the prepared solution is degradable so we add preservative to keep constant normality. 0.1gm of sodium carbonate (Na2CO3) and 0.2ml chloroform (CHCl3) is added in the prepared solution.

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PREPARATION OF INDICATORS

Preparation of Methyl red indicator

1gm of methyl red powder is dissolved in 1000ml of alcohol or acetone this will give us 1GPL solution of methyl red indicator. Keep it for stirring till all the particles of methyl red powder gets dissolved in alcohol or acetone. In acid it will give Pink color and in base it will give yellow color and in neutral medium it will give Brick red color.

Preparation of Phenolphthalein indicator

1gm of Phenolphthalein powder is dissolved in 1000ml of alcohol. This will give 1GPL solution of indicator. Stir it and we will get Phenolphthalein indicator. In acidic and neutral medium it is colorless and in base it is pink color.

Preparation of Methyl orange indicator

1gm of methyl orange powder in 1000ml of distilled water will give us 1GPL of methyl orange indicator. In acid it will give red color and in base it will give yellow orange color.

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GENERALVISCOSITY (BALL & FALL)

RELATIVE VISCOSITY OF VISCOSE :-

PROCEDURE

1. FILL a viscosity tube with air free viscose. Place it in a constant temperature bath at 200 C + 0.20 C.

2. Drop a polished steel ball (1/8” diameter) in the centre and record the time of fall between the two marks, which are 20cm apart, with a stopwatch. The time in seconds is of an expression of relative viscosity of the viscose.

COAL GCV, MOISTURE, AND ASH

INTRODUCTION

Bomb calorimeterIt’s used to find the calorific value of steam coal.Unit = cal/gram Calorie:Amount of heat required to raise the temperature of 1gm of water to 10CFactors affecting calorific value are moisture and ash. Humidifier:It’s used to absorb inherent moisture for coal sample. Moisture in charcoal:

PROCEDURE:

After obtaining a representative sample, crush about 50gms of charcoal in the form of fine powder.Weight 8-10gms of powder sample in a flat weighting bottle.Heat in an oven for about 8hrs at 105-1100C to constant weight.

Percentage (%) moisture = loss in weight x 100/ weight of the sample Or

By halogen moisture weight 2-2.5gm at 1050C

VOLATILE MATTER IN CHARCOAL :

PROCEDURE:

1. Weight 1.5-2 Gms of the powdered sample in a silica crucible.2. Cover the crucible with the lid. Keeping a very small opening and heat over the oxidizing

flame of burner for exactly 7mins. (for the first 2mins heat over the low flame & next 5min over the strong flame)

3. At the end of 7mins remove the flame and cover the crucible completely with the lid.4. Cool in a dessicator and weight. Percentage (%) volatile matter + moisture = loss in weight X 100/ weight of sample.

Deduct percentage (%) moisture to get only percentage (%) volatile matter.

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PERCENTAGE (%) ASH AND FIXED CABON IN CHARCOAL:

1. After determining the volatile matter, heat the same sample over the strong flame of a burner (may increase in the temperature gradually to avoid mechanical loss)

2. For about 2hrs to constant weight heating should be done without the lid of the crucible.3. Cool in a dessicator and weight the ash.

percentage(%) ash = weight of the ash X 100/ weight of the sample% fixed carbon = 100 – (% moisture + volatile matter + ash)

FOR CALORIFIC VALUE:

WE use a bomb calorimeter. For that we are taking 0.9960 – 0.9990 dry sample.FORMULA:(T2 – T1) X 2457 – 45 / weight of sample=_____________ cal/gmWhere, T2 = final temperatureT1 = initial temperature2457 = factor calculated using Benzoic acid sampleHeat equivalent of bomb calorimeter for 10C = 2457 cv 45 = calorific value of nichrome wire + thread

Coal is divided in to two parts:

1. Wooden charcoalExampleWeight of sample Volatile matter moisture %ash16.3662 16.3662 15.2867- 15.2618 - 16.2204 -15.26181.1044__ 0.1458__ 0.0249__

% moisture = 6.2%% volatile matter = 7.0%% ash = 2.3%% free carbon = 84.5%

2. Steam coalExampleWeight of sample % ash18.628 17.135 - 16.693 - 16.693 1.935 0.442 % moisture = 9.2% (halogen moisture)% ash = 22.8%Gross Calorific Value (GCV) = 5248 cal/gm

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SPECIFIC GRAVITY OF SPINBATH BY HYDROMETER

SULPHURIC ACID IN SPINBATH:

Reagents:1. 1.0N sodium hydroxide solution2. Methyl red indicator

PROCEDURE:1. Pipette 10ml of spin bath at 400C in a conical flask.2. Add 15-20ml of distilled water and 2-3 drops of methyl red indicator.3. Titrate against 1.0N NaOH.4. The N point being color change from Red to Light Yellow.

H2SO4 gm/ltr = Reading in ml of 1.0N NaOH x 4.9therefore, 1ml of 1.0N NaOH = 0.049gm of H2SO4

2NaOH + H2SO4 → Na2SO4 + 2H2O

AIR ANALYSIS

INTRODUCTION:This section mainly deals with the various sources of AIR Pollution in the company and

estimation their concentration. This section also deals with the hazard analysis related to the rupture of chlorine or carbon disulphide tank. Dispersion modeling by Pasquil Giffords models is done to estimate the effects of such hazard and predict on how to the gases are going to spread when they leak.

1. CARBON DISULPHIDE A solution containing 21ml of rectified spirit, 2.0ml of diethyl amine and 2.0ml of 1gm per liter of copper acetate was prepared.Air was passed for specific period of time.The volume of 25ml was made up with rectified spiritTransmittance was found at 435nm.

2. HYDROGEN SULPHIDE 15ml of cadmium sulphate was taken and passed through the required amount of air.A volume of 15ml was made distilled water 1.0ml of 1.1 Sulphonic acid, 0.05ml (1drop) of ferric sulphate (saturated), and 0.6ml of Diphenyl diamine sulphate was added and the volume 22.0ml was made up using distilled waterTransmittance at 670nm was found.

3. SULPHUR DIOXIDE A solution 23ml of sodium tetrachloromerculate and 1.0ml of 0.2% HCHO (formaldehyde) was prepared and air was passed.1.0ml of parasosatitine indicator was added.Transmittance was found at 560nm.

4. NITROGEN DIOXIDE A solution of 10ml absorbing solution (4gm/ltr NaOH) was taken and air was passed.Then 1.0ml of H2O2, 10ml of Sulponil amide and 1.5ml NEDA solution was addedTransmittance was found at 540nm.

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SAFETY IN LABORATORY

Every person working in a laboratory must be aware of many kinds of hazards. Many of them occur because of ignorance and carelessness of the worker.

Following are listed few precautions to be taken while working in a laboratory.

1. Wearing an Apron in laboratory is must.2. One should always wear safety glasses in laboratory for protection of eyes. If any chemical

flashes in ones eye, eyes should be washed with plenty of water and medical help should be called.

3. Chemicals like concentrated H2SO4 and concentrated HCL are very dangerous as they are highly dehydrating agents. If they fall on skin they absorb moisture from skin and burn skin to give a permanent scar.

4. One must use dropper and test tube holder.5. One must not smell deeply basic chemicals.6. One must be familiar with the procedure for operating fire extinguisher in laboratory.7. Work in such a way that you and your neighbor both are safe.8. Never use open flame near inflammable liquids.9. never heat graduated glass apparatus over flame10. One must wear half sleeves and comfortable clothes to avoid accidents.

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