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MASSA Spin-off – Riduzione dei rischi ambientali
MASSA Spin-off – Riduzione dei rischi ambientali
Atualmente é uma das maiores organizaçoes de pesquisa e formaçao superior na Itália, com 2.300 docentes e pesquisadores, mais de 1.400 doutorandos de pesquisa e 60.000 estudantes.
Universidade de FlorençaUniversidade de Florença
MASSA Spin-off – Riduzione dei rischi ambientali
Conselho Nacional de Pesquisas Conselho Nacional de Pesquisas CNRCNR
Ente público nacional responsável pela produçao, promoçao, difusao, transferência e valorizaçao das atividades de pesquisa e respectivas aplicaçoes para o desenvolvimento do país.
11 Departamentos
Mais de 100 Institutos
MASSA Spin-off – Riduzione dei rischi ambientali
M.A.S.S.A. Spin-offM.A.S.S.A. Spin-offMetodologias e Aplicações Científicas para a Metodologias e Aplicações Científicas para a
Salvaguarda AmbientalSalvaguarda Ambiental Oferecer soluçoes para mitigaçao dos impactos ambientais.
MONITORAMENTO DE RISCOS
MASSA Spin-off – Riduzione dei rischi ambientali
European directiveEuropean directiveMember States shall take appropriate measures to encourage: (a) firstly, the prevention or reduction of waste production and its harmfulness, (b) secondly: - the recovery of waste by means of recycling, reuse or reclamation or any other process with a view to extracting secondary raw materials, or - the use of waste as a source of energy.
MASSA Spin-off – Riduzione dei rischi ambientali
Waste hierarchyWaste hierarchy
MASSA Spin-off – Riduzione dei rischi ambientali
LandfillsLandfills
The European Union has laid down strict requirements for landfills to prevent and reduce as far as possible the negative effects on the environment, specifically on surface water, groundwater, soil, air and human health.
Stringent operational and technical requirements on the waste and landfills
Stringent operational and technical requirements on the waste and landfills
MASSA Spin-off – Riduzione dei rischi ambientali
Municipal waste productionMunicipal waste production
MASSA Spin-off – Riduzione dei rischi ambientali
Municipal waste recycledMunicipal waste recycled
MASSA Spin-off – Riduzione dei rischi ambientali
Municipal waste incineratedMunicipal waste incinerated
MASSA Spin-off – Riduzione dei rischi ambientali
Landfills are still presentLandfills are still present
MASSA Spin-off – Riduzione dei rischi ambientali
Municipal waste landfilledMunicipal waste landfilled
MASSA Spin-off – Riduzione dei rischi ambientali
Even if people don’t like them…Even if people don’t like them…
MASSA Spin-off – Riduzione dei rischi ambientali
……Sanitary landfills are much better then uncontrolled Sanitary landfills are much better then uncontrolled disposaldisposal
MASSA Spin-off – Riduzione dei rischi ambientali
CONTROL AND MONITORING PROCEDURES IN CONTROL AND MONITORING PROCEDURES IN OPERATION AND AFTER-CARE PHASESOPERATION AND AFTER-CARE PHASES
To be carried out in order to verify:
that the waste accepted to disposal meets the criterias established for the landfill category,
that the processes undertaken within the landfill are correct,
that the environmental protection systems function fully as intended,
that the permit conditions for the landfill are fulfilled.
MASSA Spin-off – Riduzione dei rischi ambientali
How is a landfill made…How is a landfill made…
MASSA Spin-off – Riduzione dei rischi ambientali
Technical features3 type of landfills
(a) excavated trench (b) area (c) canyon/depression
(b) (c)
MASSA Spin-off – Riduzione dei rischi ambientali
Municipal waste degradation produce leachate and biogas, main landifill vectors of environmental pollution. Municipal waste degradation produce leachate and biogas, main landifill vectors of environmental pollution.
Leachate
Liquid mixture caused mainly by water percolating through waste deposited in a landfill. Once in contact with decomposing solid waste, the percolating water becomes contaminated.
Leachate
Liquid mixture caused mainly by water percolating through waste deposited in a landfill. Once in contact with decomposing solid waste, the percolating water becomes contaminated.
Biogas
Gas produced by the biological breakdown of organic matter. Biogas comprises primarily methane (CH4) and carbon dioxide (CO2).
Biogas
Gas produced by the biological breakdown of organic matter. Biogas comprises primarily methane (CH4) and carbon dioxide (CO2).
Chemical, Physical and Biological processes Chemical, Physical and Biological processes inside municipal landfillinside municipal landfill
MASSA Spin-off – Riduzione dei rischi ambientali
Existing site drainage must be modified to route any runoff away from the area. Existing site drainage must be modified to route any runoff away from the area.
Preparation of the site for landfillingPreparation of the site for landfilling
Excavation and preparation of the landfill bottom and subsurface sides. Geomembrane liners are installed.Excavation and preparation of the landfill bottom and subsurface sides. Geomembrane liners are installed.
MASSA Spin-off – Riduzione dei rischi ambientali
Leacheate collection and extraction facilities are placed within or on the top of the liner.Leacheate collection and extraction facilities are placed within or on the top of the liner.
Preparation of the site for landfillingPreparation of the site for landfilling
Horizontal gas recovers trenches may be installed at the bottom of the landfill.Horizontal gas recovers trenches may be installed at the bottom of the landfill.
Before the fill operation begins, a soil berm in constructed at the downwind side of the planned fill area. The berm serves as a windbreak to control blowing materials and as a face against which the waste can be compacted
Before the fill operation begins, a soil berm in constructed at the downwind side of the planned fill area. The berm serves as a windbreak to control blowing materials and as a face against which the waste can be compacted
MASSA Spin-off – Riduzione dei rischi ambientali
Preparation of the site for landfillingPreparation of the site for landfilling
MASSA Spin-off – Riduzione dei rischi ambientali
MASSA Spin-off – Riduzione dei rischi ambientali
Phase I. Initial adjustment phase Phase I. Initial adjustment phase
The organic biodegradable components in MSW undergo microbial decomposition as they are placed in a landfill and soon after.
Biological composition occurs under aerobic conditions, because a certain amount of air is trapped within the landfill.
The principal source of microrganisms is the soil material used as a daily and final cover.
Digested wastewater sludges and recycled leachate are other sources of organisms.
MASSA Spin-off – Riduzione dei rischi ambientali
Phase II – Transition phase Phase II – Transition phase
• Oxygen is deplated and anaerobic conditions begin to develop.
• Nitrate and sulphate are often reduced to nitrogen gas and hydrogen sulphide.
• The onset of anaerobic conditions can be monitored by measuring the oxidation/reduction potential of waste.
• The pH of leachate starts to drop due to the presence of organic acids and the effect of high CO2 concentrations within the landfill.
MASSA Spin-off – Riduzione dei rischi ambientali
Phase III: Acid phase Phase III: Acid phase • First step: Enzyme mediated transformation (hydrolis) of
higher molecular mass compunds (lipids, polysaccharides, proteins and nucleic acids) into compounds suitable for use by microrganisms as a source of energy and cell carbon;
• Second step: Microbial conversion of the compounds resulting from the first step into lower molecular mass intermediate compounds (typified by acetic acid: CH3COOH). Carbon dioxide is the principal gas generated.
• The pH of the leachate will often drop to a value of 5 and lower. The BOD and COD and the conductivity of the leachate will encrease significantly. If leachate is not recycled , the essential nutrients will be lost from the system.
MASSA Spin-off – Riduzione dei rischi ambientali
Phase IV: methane fermentation phase Phase IV: methane fermentation phase A second group of microrganisms which converts the
acetic acid and hydrogen gas to CH4 and CO2, becomes predominant. They are identified as methanogens or methane formers.
The pH will rise to more neutral values in the range of 6.8 to 8. The COD and conductivity value of the leachate will be reduced. With higher pH values, fewer inorganic constituents can remain in solution.
MASSA Spin-off – Riduzione dei rischi ambientali
Phase V: Maturation phase Phase V: Maturation phase
The maturation phase occurs after the readily available biodegradable organic material has been converted to CH4 and CO2. The rate of landfill gas generation diminishes significantly. The substrates that remain in the landfill are slowly biodegradable. During maturation phase, the leachate will often contain humic and fulvic acids, which are difficult to process further biologically.
MASSA Spin-off – Riduzione dei rischi ambientali
MASSA Spin-off – Riduzione dei rischi ambientali
Quality and quantity of biogas and leachate result from numerous elements
Environmental characteristics
RainfallAir temperatureAir UmidityWind
Environmental characteristics
RainfallAir temperatureAir UmidityWind
Waste characteristics
DensityPre-treatmentsWaste UmidityWaste product analysisWaste granulometry
Waste characteristics
DensityPre-treatmentsWaste UmidityWaste product analysisWaste granulometry
Landfill
Type and geometryCoverage materialsBiogas and leachate drainage techniques
Landfill
Type and geometryCoverage materialsBiogas and leachate drainage techniques
MASSA Spin-off – Riduzione dei rischi ambientali
Typical constituents found in MSW Typical constituents found in MSW landfill gas landfill gas
Component Percent (dry volume)
Methane 45-60
Carbon dioxide 40-60
Nitrogen 2-5
Oxygen 0.1-1.0
Sulfides, Disulfides, Mercaptans, etc. 0-1.0
Ammonia 0.1-1.0
Hydrogen 0-0.2
Carbon monoxide 0-0.2
Trace constituents 0.01-0.6
MASSA Spin-off – Riduzione dei rischi ambientali
Typical data (mg/l) on the composition of leachate Typical data (mg/l) on the composition of leachate
Constituent New landfill (<2 years)
Mature landfill (> 10 years)
BOD5 10.000 150
COD 18.000 300
TSS 500 250
Organic Nitrogen 200 100
Nitrate 25 10
Total phoshorous 30 10
Alkalinity as CaCO3 3.000 600
pH 6 7
Chloride 500 250
The presence of trace compounds (some of which may pose high health risks) will depend on the concentration of these in the gas phase within the landfill
MASSA Spin-off – Riduzione dei rischi ambientali
Biogas and Leachate controlBiogas and Leachate control
Biogas – It is necessary to monitor diffusion from the capping system in order to identify the more critical areas.
Leachate – It is necessary to verify the risk of groundwater pollution due to leakages.
Biogas – It is necessary to monitor diffusion from the capping system in order to identify the more critical areas.
Leachate – It is necessary to verify the risk of groundwater pollution due to leakages.
MASSA Spin-off – Riduzione dei rischi ambientali
Leachate monitoringLeachate monitoring
MASSA Spin-off – Riduzione dei rischi ambientali
Chemical parameters to be controlled Chemical parameters to be controlled
Italian Law requires:
pH, Temperature, Conductivity, Oxidability (Kubel), BOD5, TOC, COD, Ca, Na, K, Chlorides, Sulphates, Fluorides, IPA, Metals, Cyanides, Nitrogen compounds, Organoalogen compounds, Pesticides, Phenols, Solvents.
Italian Law requires:
pH, Temperature, Conductivity, Oxidability (Kubel), BOD5, TOC, COD, Ca, Na, K, Chlorides, Sulphates, Fluorides, IPA, Metals, Cyanides, Nitrogen compounds, Organoalogen compounds, Pesticides, Phenols, Solvents.
Often what Regulations ask is not sufficient to identify a possible dangerous mixing between natural water and leachate.
Often what Regulations ask is not sufficient to identify a possible dangerous mixing between natural water and leachate.
MASSA Spin-off – Riduzione dei rischi ambientali
Isotopes Isotopes Isotopes are variants of atoms of a particular chemical element, which have
differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation of the atom as a particular element. The number of nucleons (protons and neutrons) in the nucleus, known as the mass number, is not the same for two isotopes of any element. For example, hydrogen-1, hydrogen-2 (Deuterium) and hydrogen-3 (Tritium) are three isotopes of the element hydrogen with mass numbers 1, 2 and 3 respectively. The atomic number of nitrogen is 1 (every hydrogen atom has 1 proton); therefore the neutron numbers in these isotopes are 0, 1 and 2 respectively.
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation of the atom as a particular element. The number of nucleons (protons and neutrons) in the nucleus, known as the mass number, is not the same for two isotopes of any element. For example, hydrogen-1, hydrogen-2 (Deuterium) and hydrogen-3 (Tritium) are three isotopes of the element hydrogen with mass numbers 1, 2 and 3 respectively. The atomic number of nitrogen is 1 (every hydrogen atom has 1 proton); therefore the neutron numbers in these isotopes are 0, 1 and 2 respectively.
MASSA Spin-off – Riduzione dei rischi ambientali
Leachate isotopic monitoring Leachate isotopic monitoring
Leachate and Natural water have different isotopic characteristics, which can led to different concentrantions of some species by more than 2 orders of magnitude.
Leachate and Natural water have different isotopic characteristics, which can led to different concentrantions of some species by more than 2 orders of magnitude.
In a landfill monitoring system, isotopes can be used a tracer of water pollution due to leachate mixing.
In a landfill monitoring system, isotopes can be used a tracer of water pollution due to leachate mixing.
MASSA Spin-off – Riduzione dei rischi ambientali
Isotopic ratio as regards a standard in term of ‰ (per mil)
‰ = [ (Rcp/Rst) –1 ]*1000
Rcp and Rst are isotopic ratios (18O/16O, 2H/1H). Rcp refers to the sample while Rst
refers to the standard V-SMOW (Vienna Standard Mean Ocean Water).
18O/16O
2H/1H
Isotopic contents of hydrogen radioactived (3H). It is expressed in term of absolute
concentrantion U.T. (Tritium Unitiy; 1 U.T. is equivalent to one atom of 3H for every
1018 atoms of H, equivalent to a radioactiviy of 0,12 Bq/l).
3H/H
13C/12C Isotopic ratio of dissolved inorganic carbon (DIC). It is expressed in term of ‰ as to
the standard PDB (Pee Dee Belemnitella, South Carolina/USA carbonatic rock)
Principal isotopic parameters Principal isotopic parameters
MASSA Spin-off – Riduzione dei rischi ambientali
Craig, 1961 – con modifiche
WORLD RAINFALL LINEAR REGRESSION
MASSA Spin-off – Riduzione dei rischi ambientali
2H and 18O
COMPARISON BETWEEN
RAINFALL WATER AND
LEACHATE
LEACHATES COMING FROM ANAEROBIC DEGRADATED ORGANIC WASTE
WORLD RAINFALL LINE
WORLD RAINFALL LINE
MEDITERRANEAN RAINFALL LINE
MEDITERRANEAN RAINFALL LINE
MASSA Spin-off – Riduzione dei rischi ambientali
1
10
100
1000
1950 1960 1970 1980 1990 2000 Anno
U.T
.
U.T. Piogge Genova proiettate al 2006
U.T. Piogge Pisa proiettate al 2006
ESPLOSI ONI TERMONUCLEARI I N ATMOSFERA
Concentration of TRITIUM (3H) in Italian rainfall water
MASSA Spin-off – Riduzione dei rischi ambientali
1
10
100
1000
1950 1960 1970 1980 1990 2000 Anno
U.T
.
U.T. Piogge Genova proiettate al 2006
U.T. Piogge Pisa proiettate al 2006
ESPLOSI ONI TERMONUCLEARI I N ATMOSFERA LANDFILL LEACHATE 3H
CONCENTRATION FREQUENTLY
RANGES FROM 200 AND 1500 U.T.
SOMETIMES IT CAN ACHIEVE MORE
THAN 3000 U.T.
Concentration of TRITIUM (3H) in Italian rainfall water
MASSA Spin-off – Riduzione dei rischi ambientali
1
10
100
1000
1950 1960 1970 1980 1990 2000 Anno
U.T
.
U.T. Piogge Genova proiettate al 2006
U.T. Piogge Pisa proiettate al 2006
ESPLOSI ONI TERMONUCLEARI I N ATMOSFERA
THIS CLEAR DIFFERENCE ALLOW TO FIND OUT LOW WATER
CONTAMINATION FROM LEACHATE
(EVEN LESS (EVEN LESS 1% OF LEACHATE)1% OF LEACHATE)
LANDFILL LEACHATE 3H
CONCENTRATION FREQUENTLY RANGE
FROM 200 AND 1500 U.T. SOMETIMES IT
CAN ACHIEVE MORE THAN 3000 U.T.
Concentration of TRITIUM (3H) in Italian rainfall water
MASSA Spin-off – Riduzione dei rischi ambientali
TRITIUM versus CHLORIDES
1
10
100
1,000
1 10 100 1,000 10,000
triz
io (U
.T.)
cloruri (mg/l)
TRIZIO VS. CLORURI
1
10
100
1,000
1 10 100 1,000 10,000
trizi
o (U
.T.)
cloruri (mg/l)
TRIZIO VS CLORURI
percolato
punti d'acqua
Curve che delimitano il campo di potenziale mescolamento
1
10
100
1,000
1 10 100 1,000 10,000
triz
io (U
.T.)
cloruri (mg/l)
TRIZIO VS CLORURI
percolato
punti d'acqua
Curve che delimitano il campo di potenziale mescolamento
1
10
100
1,000
1 10 100 1,000 10,000
triz
io (U
.T.)
cloruri (mg/l)
TRIZIO VS CLORURI
percolato
punti d'acqua
Curve che delimitano il campo di potenziale mescolamento
1
10
100
1,000
1 10 100 1,000 10,000
triz
io (U
.T.)
cloruri (mg/l)
TRIZIO VS CLORURI
percolato
punti d'acqua
Curve che delimitano il campo di potenziale mescolamento
1
10
100
1000
10000
10 100 1000 10000
triz
io (
U.T
.)
cloruri (mg/l)
TRIZIO VS. CLORURI
LEACHATE GROUNWATER SAMPLE
POTENTIAL MIXING CURVES
MASSA Spin-off – Riduzione dei rischi ambientali
13C‰ 13C‰
LEACHATE
Range from +15 and +30
LEACHATE
Range from +15 and +30
GROUNDWATER
Range from - 25 and 0
GROUNDWATER
Range from - 25 and 0
CARBON ISOTOPE
MASSA Spin-off – Riduzione dei rischi ambientali
OTHER ISOTOPES PARAMETERS
34S‰
of dissolved
sulphate
LEACHATE
Frequently around +8
GROUNDWATER
Range from - 21 and - 8
18O‰
of dissolved
sulphateLEACHATE
Frequently around +27
GROUNDWATER
Range from - 0,20 and +11,40
MASSA Spin-off – Riduzione dei rischi ambientali
Biogas monitoringBiogas monitoring
MASSA Spin-off – Riduzione dei rischi ambientali
It is really important to identify and quantify the biogas sources inside a landfill:
• Diffuse sources from the coverage
• Gas extraction wells
• Biogas flares
• Biofilters
Air pollution control
A relevant part of the biogas could be diffused into the atmosphere.A relevant part of the biogas could be diffused into the atmosphere.
MASSA Spin-off – Riduzione dei rischi ambientali
The CNR worked out a system to monitor gas flux from landfill coverage on the basis of the experience used to monitor gas emission from volcanic and geothermal areas.
Monitoring biogas diffusion from coverage
MASSA Spin-off – Riduzione dei rischi ambientali
The gas transport phenomenon through the soil are mainly ruled by two different mechanisms: diffusion and advection. In the geological literature these two factors are referred to the Fick (diffusion) and to the Darcy (advection) laws.
Diffusion phenomenon are due to concentration gradients. In a porous media, the diffusion process in a direction is described by Fick’s first law:
Fd = -K d (dc/dx)Fd is the diffusion velocity in a surface unit (moli/cm2sec), K is the porosity coefficient, d is the diffusion coefficient (cm2/sec) and dc/dx is the concentration gradient in x direction.
Advective motions are due to pressure gradients and are described by the Darcy law: Fc = - (K/µ) (dp/dx)
Fc is the specific flow (cm/sec), K is the permeability coefficient expressed as Darcy units [1Darcy=1cm2/(sec atm)], µ is the gas viscosity in centipoise and dp/dx the concentration gradient in x direction.
Physical laws: diffusion and advectionPhysical laws: diffusion and advection
MASSA Spin-off – Riduzione dei rischi ambientali
The estimation of the total amount of gas discharged at the soil-air interface can be obtained by well distributed punctual flux measurements carried out on all the investigated area.
Anyway there are a lot of problems concerning the single measurement depending on the reliability of the measuring system, the influence of the meteorological parameters (atmospheric pressure, temperature, relative humidity), on the characteristics of the monitored soil (moist content, presence of fracture).
Finally the choice of the right data treatment can make the difference between reliable results and quite pure fantasy.
How to estimate the total emissionHow to estimate the total emission
MASSA Spin-off – Riduzione dei rischi ambientali
There are various different systems to get soil gas flux measurements. The principal developed techniques can be divided in three main categories:
i.Measurements of the gas concentration gradientii.Micro-meteorological techniques (e.g. eddy correlation)iii.Enclosure based techniques (static and dynamic accumulation chamber)
The accumulation chamber method is commonly considered superior to other techniques such as those based on the dynamic concentration, in situ gas concentration measurements at different depths, tracer gas, and eddy correlation. Furthermore, Trégourès et al. (1999) demonstrated that the accumulation chamber method is less dependent on meteorological conditions compared to the other methodologies.
Measurement techniquesMeasurement techniques
MASSA Spin-off – Riduzione dei rischi ambientali
The accumulation chamber methodThe accumulation chamber methodThe device developed by CNR, consists of an accumulation chamber, two IR spectrophotometers to measure CO2 and CH4 concentrations, a PID (Photoionization detectors) sensor for VOC and a electro- chemical sensor for H2S. The system is completed by an analogical-digital converter, a palmtop computer, and a Global Positioning System (GPS).The gas flux is proportional to the slope of the straight line fitting the concentration versus time curve.
Soil Surface
MASSA Spin-off – Riduzione dei rischi ambientali
The measurements made on site, are referred to the slope of the straight line fitting the concentration versus time curve. This data, expressed in ppm/sec (or ppb/sec) units, are correlated to the specific flux (e.g. mol/m2 day) of every analyzed gas, by mean of calibration curves. Laboratory tests have to be performed before each survey in order to get these calibration curves.
Accumulation chamber: calibrationAccumulation chamber: calibration
MASSA Spin-off – Riduzione dei rischi ambientali
Although the accumulation chamber method is less dependent on meteorological conditions, compared to the other methodologies, some parameters may have an influence on the gas emission at soil-air interface.
To avoid or minimize these effects, it’s important to carry out the investigations in steady dry weather period and completing each flux survey in few working days.
Moreover it’s important to keep under control the atmospheric pressure and the influence of its variations with additional measurements repeated on the same site during all the survey period.
Accumulation chamber: field Accumulation chamber: field measurementsmeasurements
MASSA Spin-off – Riduzione dei rischi ambientali
The right sampling gridThe right sampling gridTo choose the proper sampling grid it’s important to have information about the spatial characteristic of the studied phenomenon. In some case auxiliary analysis can give a help to get the right dimensioning of sampling array.For example in landfill biogas emission monitoring, a preliminary infrared thermographic survey can be useful to understand the areal extension of anomalous degassing zones.
Typically, in environmental applications, the sampling mesh varies from 10 to 30 m (1 measure every 100 m2 to 1 every 900 m2). The total number of measurements is usually greater than 100-150 (up to 1000)
MASSA Spin-off – Riduzione dei rischi ambientali
The sampling gridThe sampling grid
100 m500
1
2
3
4
5
6
7
89
10
11
12
13
14
1516
17
18
19
20
2122
23
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31
32
3334
35
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4849
50
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52 53
55 5657
5859
60
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70 71
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107108
109110
111
112113
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118119120
121
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124125
126127
128
129
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132133
134
135136
137
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140141
142
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149150
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160161
162
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173174
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179180
258259
260261262
263264265
266
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273274
275
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278279
280
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289290 291
292293
294295 296 297
298299
301
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318319
320321
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331332
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183 184185
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213214
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252 253254 255 256
257
100 m500
MASSA Spin-off – Riduzione dei rischi ambientali
We have already seen that to get reliable estimations of global gas emission, large datasets are needed. The bigger is the number of measurements, the more trustworthy the evaluations are. Some tests have been done to assess the sampling density influence on results and to find the right balance between cost and effectiveness.
The right sampling gridThe right sampling grid
D is ta n c e ( c m )
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
C o lo rs
> = 4 .5
3 .7 2 7 8 1
3 .5 0 3
3 .3 5 3 5 5
3 .1 8 8 5 8
2 .9 9 5 1 5
2 .7 7 1 5 6
2 .5 0 0 7 6
2 .3 9 7 3 2
2 .2 8 1 7 9
2 .1 4 6 2 6
1 .9 5 3 4
1 .7 2 2 8 1
< 0 .5
Tes t
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
0 .
0 .
1 00 .
1 00 .
2 00 .
2 00 .
3 00 .
3 00 .
4 00 .
4 00 .
5 00 .
5 00 .
6 00 .
6 00 .
7 00 .
7 00 .
8 00 .
8 00 .
9 00 .
9 00 .
0 . 0 .
1 00 . 1 00 .
2 00 . 2 00 .
3 00 . 3 00 .
4 00 . 4 00 .
5 00 . 5 00 .
6 00 . 6 00 .
0 .
0 .
1 00 .
1 00 .
2 00 .
2 00 .
3 00 .
3 00 .
4 00 .
4 00 .
5 00 .
5 00 .
6 00 .
6 00 .
7 00 .
7 00 .
8 00 .
8 00 .
9 00 .
9 00 .
0 . 0 .
1 00 . 1 00 .
2 00 . 2 00 .
3 00 . 3 00 .
4 00 . 4 00 .
5 00 . 5 00 .
6 00 . 6 00 .
0 .
0 .
1 0 0 .
1 0 0 .
2 0 0 .
2 0 0 .
3 0 0 .
3 0 0 .
4 0 0 .
4 0 0 .
5 0 0 .
5 0 0 .
6 0 0 .
6 0 0 .
7 0 0 .
7 0 0 .
8 0 0 .
8 0 0 .
9 0 0 .
9 0 0 .
0 . 0 .
1 0 0 . 1 0 0 .
2 0 0 . 2 0 0 .
3 0 0 . 3 0 0 .
4 0 0 . 4 0 0 .
5 0 0 . 5 0 0 .
6 0 0 . 6 0 0 .
Grid dimension=chamber diameter Extraction
0
10
20
30
40
50
60
70
80
90
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
number of samples
mo
l/da
y
"true" value
Sinclair procedure on 900 samples
min value
max value
Starting from 900 sampling sites, the total emission estimation seems to be reliable up to a total of 50 measurements points. The most important effect is on flux maps that show drastic change from the real situation
MASSA Spin-off – Riduzione dei rischi ambientali
A critical revision of the data set is the first step of any kind of elaboration. This preliminary analysis have to be focused to:
i. Evaluation of the influence of non detects values;ii. Detection of outlier valuesiii. Determination of the correct weight for the outlier values when there is a
clear origin (e.g. fractures)
The presence of outliers can be tested by means of both Box-Whisker plots and other analytical process based on the Central Limit Theorem (Sigh A., 1993; Sigh et al., 1997), depending on the statistical distribution of the data set. Values lower than the instrumental detection limits are usually treated as zero values.
How to get global gas emission How to get global gas emission estimation from punctual estimation from punctual
measurements ? measurements ?
MASSA Spin-off – Riduzione dei rischi ambientali
Isoflux mapsIsoflux maps
Isoflux maps are a fundamental tool to identify anomalous degassing areas and to estimate the flux values where there are not measurements.
The question is: how to get reliable maps ?
There are a lot of deterministic interpolation methods:
i.Nearest neighbor method;
ii.Moving average within a neighborhood
iii.Inverse distances (IDW)
iv.Inverse of distances or squared distances
v.Spline
vi.………
MASSA Spin-off – Riduzione dei rischi ambientali
Isoflux map
10
10
10
10
10
20
80.0060.0040.0035.0030.0025.0020.0015.0010.00 5.00 4.00 3.00 2.00 1.50 1.00 0.50 0.00
Flusso m o l/m * d a y2
7 9
8 0
8 1
8 2
8 3
8 4
8 5
8 6
8 7
8 8
8 9
9 0
9 1
9 2
9 3
9 4 9 5
9 6
9 7
9 8
9 9
1 0 0
1 0 1
1 0 2
1 0 3
1 0 4
1 0 5
1 0 6
1 0 7
1 0 8
1 0 9
1 1 0 1 1 1
1 1 2
1 1 2 .5
1 1 3
1 1 4
1 1 5
1 1 6
1 1 7
1 1 8
1 1 9
1 2 0
1 2 1
1 2 2
1 2 3
1 2 41 2 5
1 2 6
1 2 7
1 2 8
1 2 9
1 3 0
1 3 1
1 3 2
1 3 3
1 3 4
1 3 5
1 3 6
1 3 7
1 3 8
1 3 9
1 4 0
1 4 1
1 4 21 4 3
1 4 4
1 4 5
1 4 6
1 4 7
1 4 8
1 4 9
1 5 0
1 5 1
1 5 2
1 5 3
1 5 4
1 5 5
1 5 6
1 5 7
1 5 8
1 5 9
1 6 0
1 6 1
1 6 2
1 6 3
1 6 4
1 6 5 1 6 6
1 6 7
1 6 8
1 6 9
1 7 0
1 7 1
1 7 2
1 7 3
1 7 4
1 7 5
1 7 6
1 7 7
1 7 8
1 7 9
1 8 0
1 8 1
1 8 2
1 8 3
1 8 4
1 8 51 8 6
1 8 71 8 81 8 9
1 9 0
1 9 1
1 9 2
1 9 3
1 9 4
1 9 5
1 9 6
1 9 7
1 9 8
1 9 9
2 0 0
2 0 1
2 0 2
2 0 3
2 0 4 2 0 5
2 0 6
2 0 7
2 0 8
2 0 9
2 1 0
2 1 1
2 1 2
2 1 3
2 1 4
2 1 5
2 1 6 2 1 72 1 8
2 1 92 2 0
2 2 1
2 2 2
2 2 3
2 2 4
2 2 5
2 2 6
2 2 7
2 2 8
2 2 9
2 3 0
2 3 1
2 3 2
2 3 3
2 3 4
2 3 5
2 3 6
2 3 7 2 3 8
2 3 9
2 4 0
2 4 1
2 4 2
2 4 3
2 4 4
2 4 5
2 4 6
2 5 0
2 4 9
2 4 7
2 4 8
2 5 1
2 5 2
2 5 3
2 5 4
2 5 5
2 5 9
2 5 8
2 5 7
2 5 6
2 6 0
2 6 1
2 6 22 6 3
2 6 4
2 6 5
2 6 6
2 6 7
2 6 8
2 6 9
2 7 0
2 7 1
2 7 2
2 7 3
2 7 4
2 7 5
2 7 6
2 7 7
2 7 8
2 7 9
2 8 0
2 8 1
2 8 2
2 8 3
2 8 4
2 8 5
2 8 6
2 8 7
2 8 8
2 8 9
2 9 0
2 9 1
2 9 2
2 9 3 2 9 4
2 9 5
2 9 6
1
0 50 100 m
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 9
2 0
2 1
2 2
2 3
2 4
2 5
2 6
2 7 2 8
2 9
3 0
3 1
3 2
3 3
3 4
3 5
3 6
3 7
3 8
3 9
4 0
4 1
4 2
4 3 4 4
4 5
4 6
4 7
4 8
4 9
5 0
5 1
5 2
5 3
5 4
5 5
5 6
5 7
5 8
5 9
6 0 6 1
6 2
6 3
6 4
6 5
6 6
6 7
6 8
6 9
7 0
7 1
7 2
7 3
7 4
7 5
7 6
7 7 7 8
MASSA Spin-off – Riduzione dei rischi ambientali
Standard deviation map
MASSA Spin-off – Riduzione dei rischi ambientali
Isoflux maps: how to choose?Isoflux maps: how to choose?
340 350 360 370 380 390 400 410 420 430 440
X (km)
5275
5300
5325
5350
5375
5400
5425
Y (km)
NO2
50
45
40
35
30
25
20
15
10
5
0
Inverse distances
340 350 360 370 380 390 400 410 420 430 440
X (km)
5275
5300
5325
5350
5375
5400
5425
Y (km)
NO2
50
45
40
35
30
25
20
15
10
5
0
Inverse of squared distances
Deterministic approach The calculation of the
weights is only based on the geometric location of the measured data
For a given data configuration, whatever the phenomenon looks like (from regular to erratic), we get the same prediction map
Making a choice needs to add subjective criteria as, « does the map look realistic or not ? »
MASSA Spin-off – Riduzione dei rischi ambientali
Geostatistics is based on the definition of a regionalized variable, a variable with geographic data location, continuous in the space, with deterministic and random correlation in each point. To investigate these correlations mean to understand the spatial structure of the observed phenomenon. The tool used to get information about spatial correlation and structure is the (semi)variogram.
Interpolation data processing with geostatistics methods mean to follow 5 main steps: •Data analysis and computation of variogram and variogram cloud;•Selecting of the right mathematical model to fit the experimental variogram;•Choosing of the proper neighborhood •Cross validation•Kriging
Kriging method (Krige 1951; Matheron, 1962; 1965; 1969; 1970; Clark, 1979; David, 1977; Davis, 1986) allow to extrapolate values where the measures had not been taken.
Isoflux maps: geostatistics methodsIsoflux maps: geostatistics methods
MASSA Spin-off – Riduzione dei rischi ambientali
Variogram cloudData base map Experimental Variogram
Kriging e costruzione del semivariogramma Kriging e costruzione del semivariogramma
Variogram model
MASSA Spin-off – Riduzione dei rischi ambientali
Come si fa la valutazione globale dei flussi di gas
• The total flux can be determined with the integral
( , )A
Q F x y dxdy
Specific Flux
MASSA Spin-off – Riduzione dei rischi ambientali
Isotopic gas monitoringIsotopic gas monitoring
Two reasons
Identification of biological processesIdentification of biological processesSource identificationSource identification
1E-006 1E-005 0.0001 0.001 0.01
1/CO2 (ppm-1)
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
13C
CO
2 (‰
)
1E-006 1E-005 0.0001 0.001 0.01
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
Riscaldamento
Veicoli
Biogas Toscana
Emissioni naturali
Biogas Emilia
Aria area urbana
Aria Campus Jussieu
Aria area suburbana
Respiration Coal
Diesel
Combusted Natural gas
Leaded
Unleaded
Domestic fuel oil
UnpolluttedAir end-member
Classroom air
Parking lot
MASSA Spin-off – Riduzione dei rischi ambientali
Area: 10Kmx10Km
Grid: 250 m
Nx=40 Ny=40
Data input
Diffuse pollution from landfill
Landfill surface 83 000 m2
Modeled compound: CH4
AIR POLLUTION MODELING : CALPUFF
MASSA Spin-off – Riduzione dei rischi ambientali
hourly concentrations
MASSA Spin-off – Riduzione dei rischi ambientali
Thank you for your attention…Thank you for your attention…
OBRIGADO!OBRIGADO!