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Fondamenti di Processi eFondamenti di Processi eImpianti Biotecnologici:Impianti Biotecnologici:
LaboratorioLaboratorio
Ing. Francesco FatoneIng. Simos MalamisDott.ssa Letizia Zanetti
Nel laboratorio di ingegneria chimicadell’ambiente e dei bioprocessi:
Sistema innovativo per la rimozione dell’azoto edel fosforo: processo SCENA (Short-Cut EnhancedNutrients Abatement)
Sistema innovativo per la rimozione dell’azoto edel fosforo: processo SCENA (Short-Cut EnhancedNutrients Abatement)
Nel laboratorio di ingegneria chimicadell’ambiente e dei bioprocessi:
Digestori anaerobici inscala da laboratorio
Si studia l’effettodell’aggiunta di acidonitroso per migliorarela produzione di biogasda fanghi didepurazione
Digestori anaerobici inscala da laboratorio
Si studia l’effettodell’aggiunta di acidonitroso per migliorarela produzione di biogasda fanghi didepurazione
Nel laboratorio di ingegneria chimicadell’ambiente e dei bioprocessi:
UASB (Upflow Anaerobic Sludge Blanket) +POST TRATTAMENTO
Nel laboratorio di ingegneria chimicadell’ambiente e dei bioprocessi:
1.Testa ad innesto2. O-ring Viton con collare di spinta3. Elemento metallico interno4. Elemento Ag/AgCl per il riferimento5. Gel elettrolita6. Sensore di temperatura NTC 30K7. Diaframma in PTFE8. Elettrodo in platino o in oro
IN LABORATORIOIN LABORATORIO
Prima di andare in lab....
Attenzione!!!! (acid-basi forti)
Camice e quaderno
Chiedete se vedete qualcosa che vi interessa...
Non fate troppo caso agli odori
Fate attenzione a ciò che toccate e rispettate chi lavora per voi....
Prima di andare in lab....
Attenzione!!!! (acid-basi forti)
Camice e quaderno
Chiedete se vedete qualcosa che vi interessa...
Non fate troppo caso agli odori
Fate attenzione a ciò che toccate e rispettate chi lavora per voi....
Gruppi di Laboratorio:Gruppi di Laboratorio:Gruppo AAMBROSINI GIULIABERTONCELLO LUCABISCARO ANDREABOTTURI ALICEBRENTEGANI STEFANO
CHERUBIN ARIANNA
Gruppo BFASOLO GIANLUCACRISTOVAO BORGES LORENAFERRETTO MANUELFERRON ENRICOFRASSANITO CHIARAGAIANIGO NICOLAGHOLAMI SHABNAMCHERUBIN ARIANNA
COLUSSO VALENTINACONTRINI MARIACUCCURULLO ANNADAL COLLO GIADADELAITI BEATRICEDELLI CARRI SAMANTHA
GHOLAMI SHABNAMGROAZ ILARIAJAUPAJ LEJDIMAGNAGUAGNO ENRICO
MARCHINI *** scorso anno CARIOTAZARANTONELLO FABIOMARTINATO JESSICAMASCIA FRANCESCO
Gruppi di Laboratorio:Gruppi di Laboratorio:Gruppo C
MELIS FRANCESCA
MENINI MARTA
MICHELATTI DANIELA
MODENESE SERENA
NORTILLI SIMONE
Gruppo D
RIGON MANUEL
ROSSIGNOLI ILARIA
SANTI SOFIA
SCARTEZZINI VALERIA
STANILA LIVIU
TEDESCO STEFANONORTILLI SIMONE
PALTRINIERI STEFANIA
PELLEGRINI DANIELE
PISANI ARIANNA
PITUELLO SILVIA
POLETTI STEFANIA
QUARTUCCIA MARIO
RAMOS VALENCIA NEIL EDER
RIGHETTI EDOARDO
TEDESCO STEFANO
TIHON IGOR
VEGHINI LISA
ZAGORODNYUK MARGARYTA
ZORZI GIANLUCA
ZORZIN STEFANIA
ZULIANI LUCA
DALLA VECCHIA CLAUDIA
Calendario:Calendario:day hours groups
19/11/201313:30 - 18:30 all theory Tutor
26/11/201313:30 - 18:30 group A Yh (simos)
26/11/201313:30 - 16:00 group B mass balance (letizia)
26/11/201316:00 - 18:30 group C mass balance (letizia)
03/12/201313:30 - 18:30 group C Yh (simos)03/12/201313:30 - 18:30 group C Yh (simos)
03/12/201313:30 - 16:00 group A mass balance (letizia)
03/12/201316:00 - 18:30 group D mass balance (letizia)
10/12/201313:30 - 18:30 group B Yh (simos)
10/12/201313:30 - 16:00 group C Kla (letizia)
10/12/201316:00 - 18:30 group D Kla (letizia)
17/12/201313:30 - 18:30 group D Yh (simos)
17/12/201313:30 - 16:00 group A Kla (letizia)
17/12/201316:00 - 18:30 group B Kla (letizia)
La digestione anaerobicaLa digestione anaerobica
Descrizione del processo eBilancio di massaDescrizione del processo eBilancio di massa
La riforma della politica energetica dell’Unione Europea e le conseguenti legislazionie regolamentazioni a livello nazionale, hanno dato un forte incentivo allo sviluppo ditecnologie di produzione di energia da fonti rinnovabili sempre più competitive.
con produzione dienergia: biogas
BiogasPotere calorifico:
4500 kcal/m3
BiogasPotere calorifico:
4500 kcal/m3
Matrici utilizzabili nella digestioneMatrici utilizzabili nella digestioneanaerobicaanaerobica
- biomasse agro-industriali- reflui zootecnici- fanghi di depurazione- frazione organica dei rifiuti urbani da raccolta differenziata
La scelta di una matrice rispetto ad un’altra dipende da differenti fattori. Iprincipali:- Resa potenziale di produzione di biogas- Reperibilità della matrice rispetto alla localizzazione geografica dell’impianto-Valore economico della matrice (concorrenza con altri mercati di collocazione)- Lavorabilità e facilità di gestione della matrice (necessità di pretrattamenti, potenzialiproduzioni di composti tossici o schiume in fase di digestione, …) Segue un’analisi dellecaratteristiche generali delle matrici finalizzata ad una più consapevole analisi dei delleopportunità e problematiche relative all’uso di questebiomasse.
La scelta di una matrice rispetto ad un’altra dipende da differenti fattori. Iprincipali:- Resa potenziale di produzione di biogas- Reperibilità della matrice rispetto alla localizzazione geografica dell’impianto-Valore economico della matrice (concorrenza con altri mercati di collocazione)- Lavorabilità e facilità di gestione della matrice (necessità di pretrattamenti, potenzialiproduzioni di composti tossici o schiume in fase di digestione, …) Segue un’analisi dellecaratteristiche generali delle matrici finalizzata ad una più consapevole analisi dei delleopportunità e problematiche relative all’uso di questebiomasse.
Digestore Anaerobico
Le fasi della digestione anaerobicaLe fasi della digestione anaerobica
SintrofiaSintrofia
Tutti i microrganismi coinvolti delladigestione anaerobica cooperano tra diloro. SINTROFIA: cooperazione di
microrganismi che dipendono l’un conl’altro
Tutti i microrganismi coinvolti delladigestione anaerobica cooperano tra diloro. SINTROFIA: cooperazione di
microrganismi che dipendono l’un conl’altro
Composizione del biogasComposizione del biogas
Efficienza di rimozione del substratoEfficienza di rimozione del substrato
Esistono diversi modi di esprimere l’efficienza di rimozione del substrato nel corsodel processo di digestione anaerobica non solo legati ai diversi parametri utilizzati peresprimere la sua concentrazione (sostanza solida totale, sostanza solida volatile, CODo BOD).In generale, la più semplice relazione per la conversione del substrato in biogas, vieneespressa in termini percentuali tramite la:
dove:η, percentuale di TVS rimossi, [%];Q, portata influente ed effluente, [m3/giorno];S, concentrazione di TVS nella portata influente, [kg/m3];Se, concentrazione di TVS nella portata effluente [kg/m3]
η = (Q•S - Q•Se) / (Q•S)
Digestoreanaerobico
Qin = 145 m3/day
TVS = 5 g/lQout = 145 m3/day
TVS = 3 g/l
Biogas
Digestoreanaerobico
Qin = 145 m3/day
TVS = 5 g/lQout = 145 m3/day
TVS = 3 g/l
Calcola l’efficienza di rimozione del substrato (in questo caso TVS)
Bilancio di massa digestore anaerobicoBilancio di massa digestore anaerobicoATTENZIONE, I BILANCI DI MASSA SI FANNO SULLA MASSA [Kg/day] E NONSULLE CONCENTRAZIONI!!!
Biogas
δBIOGAS = 1,2 Kg/m3KgTS/day ?
Digestoreanaerobico
Qin =…. m3/day
δFANGO ~ 1000 Kg/m3Qout = …..m3/day
δDIGESTATO = 1000 Kg/m3
m3/day • Kg/m3 =KgIN/day
m3/day • Kg/m3 =KgOUT/day
In laboratorio misurerete il contenuto diTS e TVS
In laboratorio misurerete il contenuto diTS e TVS
KgIN/day • KgTS/Kgcampione =KgTS/day
KgOUT/day • KgTS/Kgcampione =KgTS/day
Composizione biogas: 60% CH4 e 40% CO2
PM metano =16,04 uma
PM anidride carbonica = 44,01 uma
Trova il peso molecolare medio del biogas
Bilancio di massa digestore anaerobico
Bilancio di massa digestore anaerobicoComposizione biogas: 60% CH4 e 40% CO2
PM metano =16,04 uma
PM anidride carbonica = 44,01 uma
Trova il peso molecolare medio del biogas
PM medio biogas = (16,01*0,6)+(44,01*0,4) = 9,6 + 17,6 = 27,2 uma
Massa Molare media biogas = 27,2 g/mol
Composizione biogas: 60% CH4 e 40% CO2
PM metano =16,04 uma
PM anidride carbonica = 44,01 uma
Trova il peso molecolare medio del biogas
PM medio biogas = (16,01*0,6)+(44,01*0,4) = 9,6 + 17,6 = 27,2 uma
Massa Molare media biogas = 27,2 g/mol
Bilancio sui TS e TVS – BIOGAS-Per quanto riguarda il biogas, i TS e i TVS sono calcolati secondo la relazione:
g TS Biogas /d = litri •[( PMmetano • %metano)+(PMCO2 • %CO2)]
litri occupati da 1mol gas a 25°C1 litro = 1 dm3
litri occupati da 1mol gas a 25°C:PV=nRTV = (1mol •0,082 [atm l mol-1 K-1] • 298,15 [K]) / 1 [atm]V = 24,4483 [l]
g TS Biogas/d = [l] • [(16,04 [g/mol] • 0,6)+ (44,01 [g/mol] • 0,4)]
24,45 [l]
g TS Biogas /day = g TVS Biogas /day = …….
Bilancio di massa digestore anaerobicoBilancio sui TS e TVS – BIOGAS-Per quanto riguarda il biogas, i TS e i TVS sono calcolati secondo la relazione:
g TS Biogas /d = litri •[( PMmetano • %metano)+(PMCO2 • %CO2)]
litri occupati da 1mol gas a 25°C1 litro = 1 dm3
litri occupati da 1mol gas a 25°C:PV=nRTV = (1mol •0,082 [atm l mol-1 K-1] • 298,15 [K]) / 1 [atm]V = 24,4483 [l]
g TS Biogas/d = [l] • [(16,04 [g/mol] • 0,6)+ (44,01 [g/mol] • 0,4)]
24,45 [l]
g TS Biogas /day = g TVS Biogas /day = …….
11--Bilancio di massa digestore anaerobicoBilancio di massa digestore anaerobico
Biogas
δBIOGAS = 1,2 Kg/m3KgTS/day ?
Obiettivo: applicare il bilancio di materia al processo di digestione anaerobica everificare se il bilancio dei TS e TVS si chiude
Dovete verificare se inbilancio si chiude, quindicalcolare l’errore% traIN e OUT
Digestoreanaerobico
Qin =…. m3/day
δFORSU ~ 1000 Kg/m3Qout = …..m3/day
δDIGESTATO = 1000 Kg/m3
m3/day • Kg/m3 =KgCAMPIONE/day
m3/day • Kg/m3 =KgCAMPIONE/day
In laboratorio misurerete il contenuto diTS e TVS
In laboratorio misurerete il contenuto diTS e TVS
KgCAMPIONE/day • KgTS/Kgcampione =KgTS/day
KgCAMPIONE/day • KgTS/Kgcampione =KgTS/day
SOLIDI TOTALI (TS): rappresentano la misura complessiva dei solidi presentiin un refluo; Tale misura è data dal residuo totale che si ottiene perevaporazione dalla fase liquida a 105°C.T= 105°C per 48 ore
TS = TVS + RESIDUO FISSO (Solidi inerti)
SOLIDI VOLATILI TOTALI (TVS): la misura dei TVS è data dalla differenza trail residuo totale (quello che si ottiene per evaporazione della fase liquida a T=105°C) e residuo fisso (quello che si ottiene per incenerimento a T=600°C).A 600°C la componente organica viene completamenteossidata, mentre la componente inorganica rimane sottoforma di ceneri.
http://www.isprambiente.gov.it/it/pubblicazioni/manuali-e-linee-guida/metodi-analitici-per-le-acque
TS e TVS
SOLIDI TOTALI (TS): rappresentano la misura complessiva dei solidi presentiin un refluo; Tale misura è data dal residuo totale che si ottiene perevaporazione dalla fase liquida a 105°C.T= 105°C per 48 ore
TS = TVS + RESIDUO FISSO (Solidi inerti)
SOLIDI VOLATILI TOTALI (TVS): la misura dei TVS è data dalla differenza trail residuo totale (quello che si ottiene per evaporazione della fase liquida a T=105°C) e residuo fisso (quello che si ottiene per incenerimento a T=600°C).A 600°C la componente organica viene completamenteossidata, mentre la componente inorganica rimane sottoforma di ceneri.
http://www.isprambiente.gov.it/it/pubblicazioni/manuali-e-linee-guida/metodi-analitici-per-le-acque
Mettere il crogiolo vuoto per almeno 20 minuti in stufa dopo aver scritto una sigla diriconoscimento del campione sia sul lato sia sul fondo del crogiolo;lasciar raffreddarenell’essiccatore e pesare la tara (P1)Inserire il campione nel crogiolo e pesare il lordo (P2)Il campione nel crogiolo va messo in stufa a 105°C per 48 ore; lasciar raffreddarenell’essiccatore per cerca 10 minuti e pesare (P3)Lasciare in muffola a 550-600°C per altre 24 ore; lasciar raffreddare nell’essiccatore e pesare(P4).
ACCORGIMENTO: per evitare la rottura del crogiolo eseguire, prima del raffreddamento, unpassaggio in stufa a 105°C per 30 minuti.
FORMULE:TS [g/Kg] = {(P3 - P1) / (P2 - P1)} •1000
TVS [g/Kg] = { {(P3 - P1) – (P4 - P1)} / (P2 - P1) } •1000TVS %TS = (g TVS / g TS) •100
Materiali e metodi, TS e TVS(Bilancio di materia digestore anaerobico)
Mettere il crogiolo vuoto per almeno 20 minuti in stufa dopo aver scritto una sigla diriconoscimento del campione sia sul lato sia sul fondo del crogiolo;lasciar raffreddarenell’essiccatore e pesare la tara (P1)Inserire il campione nel crogiolo e pesare il lordo (P2)Il campione nel crogiolo va messo in stufa a 105°C per 48 ore; lasciar raffreddarenell’essiccatore per cerca 10 minuti e pesare (P3)Lasciare in muffola a 550-600°C per altre 24 ore; lasciar raffreddare nell’essiccatore e pesare(P4).
ACCORGIMENTO: per evitare la rottura del crogiolo eseguire, prima del raffreddamento, unpassaggio in stufa a 105°C per 30 minuti.
FORMULE:TS [g/Kg] = {(P3 - P1) / (P2 - P1)} •1000
TVS [g/Kg] = { {(P3 - P1) – (P4 - P1)} / (P2 - P1) } •1000TVS %TS = (g TVS / g TS) •100
IN = OUT
Kg TS Fanghi/day = Kg TS biogas/day + Kg TS digestato/day
IN = OUTKg TVS Fanghi/day = Kg TVS biogas/day + Kg TVS digestato/day
IL BILANCIO SI CHIUDE? (esempio con i TVS)
SI CALCOLA LA % DI ERRORE TRA I Kg TVS/day IN INGRESSO E IN USCITA
Errore % = (Kg TVS/day INGRESSO - Kg TVS/day USCITA) * 100
Kg TVS/day INGRESSO
Bilancio di massa digestore anaerobicoTS E TVS
IN = OUT
Kg TS Fanghi/day = Kg TS biogas/day + Kg TS digestato/day
IN = OUTKg TVS Fanghi/day = Kg TVS biogas/day + Kg TVS digestato/day
IL BILANCIO SI CHIUDE? (esempio con i TVS)
SI CALCOLA LA % DI ERRORE TRA I Kg TVS/day IN INGRESSO E IN USCITA
Errore % = (Kg TVS/day INGRESSO - Kg TVS/day USCITA) * 100
Kg TVS/day INGRESSO
Se l’errore % non supera il 10%, il bilancio si chiude
La produzione specifica di biogas (SGP) del rifiuto solido urbano è 0,8 m3 biogas/Kg TVSalimentati.
All’interno di un digestore anaerobico inserisco 100 Kg di questo substrato avente 80%TS e il rapporto TVS/TS è 0,9.
Calcola i m3 di biogas derivanti da questo substrato.
Esercizio
La produzione specifica di biogas (SGP) del rifiuto solido urbano è 0,8 m3 biogas/Kg TVSalimentati.
All’interno di un digestore anaerobico inserisco 100 Kg di questo substrato avente 80%TS e il rapporto TVS/TS è 0,9.
Calcola i m3 di biogas derivanti da questo substrato.
100 kg substrato * 0,8 = 80 Kg TS
80 Kg TS * 0,9 = 72 Kg TVS
m3 biogas =72 Kg TVS *0,8 m3 biogas/Kg TVS alimentati = 57,6 m3
EsercizioLa produzione specifica di biogas (SGP) del rifiuto solido urbano è 0,8 m3 biogas/Kg TVSalimentati.
All’interno di un digestore anaerobico inserisco 100 Kg di questo substrato avente 80%TS e il rapporto TVS/TS è 0,9.
Calcola i m3 di biogas derivanti da questo substrato.
100 kg substrato * 0,8 = 80 Kg TS
80 Kg TS * 0,9 = 72 Kg TVS
m3 biogas =72 Kg TVS *0,8 m3 biogas/Kg TVS alimentati = 57,6 m3
Esperienze di laboratorio
-Bilancio di materia sul digestore anaerobico (sia TS cheTVS)
-Calcolo del coefficiente di resa cellulare eterotrofa (YH)
- Calcolo Kla
-Bilancio di materia sul digestore anaerobico (sia TS cheTVS)
-Calcolo del coefficiente di resa cellulare eterotrofa (YH)
- Calcolo Kla
Experimental exerciseDetermination of biomass yield (YΗ)
University of Verona19/11/2013
Experimental exerciseDetermination of biomass yield (YΗ)
Why do we need to treat wastewater?Why do we need to treat wastewater?Parameter Typical rangeTSS 70-250 mg/L
BODCOD
100- 300 mg/L250 – 800 mg/L
TKN 20-85 mg/L
PO4-P 3-10 mg/L
TP 5-12 mg/L
• Wastewater contains organic and inorganicsubstances that can harm the waterrecipients. Common environmentalproblems
• De-oxygenation of water recipients• Eutrophication due to nutrients
• Treated effluents needs to satisfy certainrequirements before they are dischargedTP 5-12 mg/L
• Wastewater contains organic and inorganicsubstances that can harm the waterrecipients. Common environmentalproblems
• De-oxygenation of water recipients• Eutrophication due to nutrients
• Treated effluents needs to satisfy certainrequirements before they are discharged
Parameter Concentration (mg/l)Normal recipient
Concentration (mg/l)Sensitive recipient
COD (mg/l) 125 125
BOD5 (mg/l) 25 25
TSS (mg/l) 35 (>10.000 p.e.)60 (2.000 – 10.000 p.e.) 35 (>10.000 p.e.)
N (mg/l) - 15(10.000 – 100.000 p.e.)10 (> 100.000 p.e.)
P (mg/l) - 2 (10.000 – 100.000 p.e.)1 (> 100.000 p.e.)
Directive91/271/EC
requirements
Purpose of Biological TreatmentPurpose of Biological Treatment
Oxidize constituents into an acceptable end product
Remove nutrients (N and P)◦ Nitrification and denitrification◦ Enhanced biological phosphorus removal (and or chemical removal)
Oxidize constituents into an acceptable end product
Remove nutrients (N and P)◦ Nitrification and denitrification◦ Enhanced biological phosphorus removal (and or chemical removal)
Purpose of Biological TreatmentPurpose of Biological Treatment
Treatment stages
Preliminary Treatment – Removal of grit and coarse material insuspension – Protection of equipment and facilities.
Primary Treatment – Removal of settleable solids and fats (oils andgreases). Generates stabilized sludge.
Secondary (biological) treatment Oxidation and removal of biodegradable organic matter. Generates
biological sludge to be stabilized and properly disposed off. Removal of nutrients (N, P)
Advanced Treatment – Polishing of effluent for reuse
Preliminary Treatment – Removal of grit and coarse material insuspension – Protection of equipment and facilities.
Primary Treatment – Removal of settleable solids and fats (oils andgreases). Generates stabilized sludge.
Secondary (biological) treatment Oxidation and removal of biodegradable organic matter. Generates
biological sludge to be stabilized and properly disposed off. Removal of nutrients (N, P)
Advanced Treatment – Polishing of effluent for reuse
Preliminary Treatment – Removal of grit and coarse material insuspension – Protection of equipment and facilities.
Primary Treatment – Removal of settleable solids and fats (oils andgreases). Generates stabilized sludge.
Secondary (biological) treatment Oxidation and removal of biodegradable organic matter. Generates
biological sludge to be stabilized and properly disposed off. Removal of nutrients (N, P)
Advanced Treatment – Polishing of effluent for reuse
Preliminary Treatment – Removal of grit and coarse material insuspension – Protection of equipment and facilities.
Primary Treatment – Removal of settleable solids and fats (oils andgreases). Generates stabilized sludge.
Secondary (biological) treatment Oxidation and removal of biodegradable organic matter. Generates
biological sludge to be stabilized and properly disposed off. Removal of nutrients (N, P)
Advanced Treatment – Polishing of effluent for reuse
• Bacteria perform the basic functions of:• Oxidation of substrate (i.e. food) to produce energy• Growth (formation of new biomass using the generated energy)• Endogenous respiration – decay
• Organic carbon oxidation under aerobic conditions• Heterotrophic bacteria in the presence of oxygen oxidize organic matter to
produce energy• The energy is then used to produce new biomass (i.e. growth)
Bacterial growth and decay• Bacteria perform the basic functions of:
• Oxidation of substrate (i.e. food) to produce energy• Growth (formation of new biomass using the generated energy)• Endogenous respiration – decay
• Organic carbon oxidation under aerobic conditions• Heterotrophic bacteria in the presence of oxygen oxidize organic matter to
produce energy• The energy is then used to produce new biomass (i.e. growth)
Ripartizione del substrato nellaRipartizione del substrato nellabiosintesi aerobicabiosintesi aerobica
BacterialBacterial endogenousendogenous decaydecay
Biological oxygen demand (BOD), chemical oxygen demand (COD) or volatile solids(VS) are traditionally used to characterize organic matter in wastewater.These parameters determine the quantity of the organic matter present. COD and VSare measures of the total concentration of organic matter and BOD indicates the totalamount of biodegradable organic matter. However, neither method gives detailedinformation on thecomposition of the fractions of biodegradable organic matter.
Biological oxygen demand (BOD), chemical oxygen demand (COD) or volatile solids(VS) are traditionally used to characterize organic matter in wastewater.These parameters determine the quantity of the organic matter present. COD and VSare measures of the total concentration of organic matter and BOD indicates the totalamount of biodegradable organic matter. However, neither method gives detailedinformation on thecomposition of the fractions of biodegradable organic matter.
• Endogenous decay of biomass is the loss in the mass of the cellsdue to the following reasons:• Death of cells• Predation by microorganisms higher in the food chain• Oxidation of internal products stored in the bacteria for cell
maintenance• Consequences of endogenous decay
• Less sludge production• Higher oxygen requirements• Increase in treated effluent COD (by products)
Biological oxygen demand (BOD), chemical oxygen demand (COD) or volatile solids(VS) are traditionally used to characterize organic matter in wastewater.These parameters determine the quantity of the organic matter present. COD and VSare measures of the total concentration of organic matter and BOD indicates the totalamount of biodegradable organic matter. However, neither method gives detailedinformation on thecomposition of the fractions of biodegradable organic matter.
Biological oxygen demand (BOD), chemical oxygen demand (COD) or volatile solids(VS) are traditionally used to characterize organic matter in wastewater.These parameters determine the quantity of the organic matter present. COD and VSare measures of the total concentration of organic matter and BOD indicates the totalamount of biodegradable organic matter. However, neither method gives detailedinformation on thecomposition of the fractions of biodegradable organic matter.
• Endogenous decay of biomass is the loss in the mass of the cellsdue to the following reasons:• Death of cells• Predation by microorganisms higher in the food chain• Oxidation of internal products stored in the bacteria for cell
maintenance• Consequences of endogenous decay
• Less sludge production• Higher oxygen requirements• Increase in treated effluent COD (by products)
Organic matter fractionationOrganic matter fractionation
Crude parameters like biological oxygen demand (BOD), chemical oxygendemand (COD) or volatile solids (VS) are traditionally used to characterizeorganic matter in wastewater.
These parameters determine the quantity of the organic matter present.COD and VS are measures of the total concentration of organic matter andBOD indicates the total amount of biodegradable organic matter.
Neither method gives detailed information on the composition of thefractions of biodegradable organic matter.
Crude parameters like biological oxygen demand (BOD), chemical oxygendemand (COD) or volatile solids (VS) are traditionally used to characterizeorganic matter in wastewater.
These parameters determine the quantity of the organic matter present.COD and VS are measures of the total concentration of organic matter andBOD indicates the total amount of biodegradable organic matter.
Neither method gives detailed information on the composition of thefractions of biodegradable organic matter.
A detailed characterization of the wastewater organic matter can beachieved, dividing the total COD into fractions with different microbiologicalproperties.
TOTAL COD
COD B COD NB
COD RB COD SB COD PNB COD SNB
COMPLEX VFA COLOIDAL PARTICULATE
COD: Definition and fractionation
Chemical Oxygen Demand (COD): the amount of oxygen needed to chemically oxidize theorganic constituents. The determination of COD gives the overall level of organiccontamination.
Chemical Oxygen Demand (COD): the amount of oxygen needed to chemically oxidize theorganic constituents. The determination of COD gives the overall level of organiccontamination.
TOTAL COD
COD B COD NB
COD RB COD SB COD PNB COD SNB
COMPLEX VFA COLOIDAL PARTICULATE
B – biodegradable; NB – nonbiodegradable; RB – readly biodegradable;SB – slowly biodegradable; PNB – nonbiodegradable (particulate);SNB – nonbiodegradable (soluble) VFA – Volatile Fatty Acids
The fractionation is necessary for the simulation of the operation of WWTP by usingvarious simulating models (i.e. IAWQ) and it is useful for the design of activated sludgesystems with nutrients removal.
QuantifyingQuantifying BiomassBiomass
• Bacteria Cells = Biomass– Often measured as volatile suspended solids (VSS)– Is VSS entirely biomass?– Other approaches: particulate COD, protein, DNA
• Biomass yield (YH) = g biomass produced / gsubstrate consumed– Substrate is typically the constituent in the
wastewater that is electron donor (energy source)
• Bacteria Cells = Biomass– Often measured as volatile suspended solids (VSS)– Is VSS entirely biomass?– Other approaches: particulate COD, protein, DNA
• Biomass yield (YH) = g biomass produced / gsubstrate consumed– Substrate is typically the constituent in the
wastewater that is electron donor (energy source)
In an activated sludge system oxygen consumption is mainly due to: Endogenous respiration, that gives the energy that is required for the cell
maintenance. It is measured in the absence of substrate, and it representsthe contribution of endogenous oxygen consumption;
Degradation of the substrate: the consumption of oxygen for the oxidation oforganic matter or nitrogen compounds and for the synthesis of new cells. Itrepresents the contribution of exogenous oxygen consumption.
Oxygen consumption: means the total amount of oxygen used by a biologicalsystem to perform the catabolic and anabolic processes in a certain time.
The rate of oxygen consumption represents the amount of oxygen used perunit of time from the system and is related to the speed – velocity of thebiological reaction.
Oxygen consumptionOxygen consumption
In an activated sludge system oxygen consumption is mainly due to: Endogenous respiration, that gives the energy that is required for the cell
maintenance. It is measured in the absence of substrate, and it representsthe contribution of endogenous oxygen consumption;
Degradation of the substrate: the consumption of oxygen for the oxidation oforganic matter or nitrogen compounds and for the synthesis of new cells. Itrepresents the contribution of exogenous oxygen consumption.
Oxygen consumption: means the total amount of oxygen used by a biologicalsystem to perform the catabolic and anabolic processes in a certain time.
The rate of oxygen consumption represents the amount of oxygen used perunit of time from the system and is related to the speed – velocity of thebiological reaction.
The rate of oxygen consumption for the degradation of the substrate andof cellular synthesis is much higher than that of the endogenousrespiration.
The readily biodegradable substrate in wastewater exhibits high oxygendemand in short-term; as the substrate is consumed, the rate of oxygenconsumption decreases progressively, reaching the rate of endogenousrespiration.
The rate of oxygen consumption for the degradation of the substrate andof cellular synthesis is much higher than that of the endogenousrespiration.
The readily biodegradable substrate in wastewater exhibits high oxygendemand in short-term; as the substrate is consumed, the rate of oxygenconsumption decreases progressively, reaching the rate of endogenousrespiration.
Rate of oxygen consumptionRate of oxygen consumption
The rate of oxygen consumption for the degradation of the substrate andof cellular synthesis is much higher than that of the endogenousrespiration.
The readily biodegradable substrate in wastewater exhibits high oxygendemand in short-term; as the substrate is consumed, the rate of oxygenconsumption decreases progressively, reaching the rate of endogenousrespiration.
The rate of oxygen consumption for the degradation of the substrate andof cellular synthesis is much higher than that of the endogenousrespiration.
The readily biodegradable substrate in wastewater exhibits high oxygendemand in short-term; as the substrate is consumed, the rate of oxygenconsumption decreases progressively, reaching the rate of endogenousrespiration.
Is a general term that encompasses a number of techniquesused for measuring the ‘rate of respiration of a living organism’by measuring its rate of change of oxygen and/or carbondioxide.
is an important index of enzymatic – metabolic activity of abiological system
Respirometric tests are used to obtain information onmetabolic activity and on the utilization rate of substrates
We obtain information for the:Biomass yield coefficient: YΗ
Rate of nitrification, denitrification, oxidation of carbonCOD fractionation
Is a general term that encompasses a number of techniquesused for measuring the ‘rate of respiration of a living organism’by measuring its rate of change of oxygen and/or carbondioxide.
is an important index of enzymatic – metabolic activity of abiological system
Respirometric tests are used to obtain information onmetabolic activity and on the utilization rate of substrates
We obtain information for the:Biomass yield coefficient: YΗ
Rate of nitrification, denitrification, oxidation of carbonCOD fractionation
Respirometry
Is a general term that encompasses a number of techniquesused for measuring the ‘rate of respiration of a living organism’by measuring its rate of change of oxygen and/or carbondioxide.
is an important index of enzymatic – metabolic activity of abiological system
Respirometric tests are used to obtain information onmetabolic activity and on the utilization rate of substrates
We obtain information for the:Biomass yield coefficient: YΗ
Rate of nitrification, denitrification, oxidation of carbonCOD fractionation
Is a general term that encompasses a number of techniquesused for measuring the ‘rate of respiration of a living organism’by measuring its rate of change of oxygen and/or carbondioxide.
is an important index of enzymatic – metabolic activity of abiological system
Respirometric tests are used to obtain information onmetabolic activity and on the utilization rate of substrates
We obtain information for the:Biomass yield coefficient: YΗ
Rate of nitrification, denitrification, oxidation of carbonCOD fractionation
RespirometricRespirometric test : Whichtest : Whichfractions we can estimate?fractions we can estimate?
rbCOD
+
sbCOD
CODbiodegradable
rbCOD
+
sbCOD
CODbiodegradable
The parameter YThe parameter YHH
YH is the heterotrophic yield (gCODbiomass/gCODsubstrate)
YH = CODproduced biomass / CODconsumedYH = (CODconsumed – COD oxidized) / CODconsumed
YH = 1 – ΔDOconsumed / CODadded
Nel caso di composti puri il valore di COD aggiunto può essere posto al valoreteorico di COD relativo alla massa di composto dosata nel respirometro.
YH = CODproduced biomass / CODconsumedYH = (CODconsumed – COD oxidized) / CODconsumed
YH = 1 – ΔDOconsumed / CODadded
Nel caso di composti puri il valore di COD aggiunto può essere posto al valoreteorico di COD relativo alla massa di composto dosata nel respirometro.
Value of YH in literature 0.67
TheThe experimentexperiment
Respirometer Martina
Oxygen control throughautomatic respirometerOxygen control throughautomatic respirometer
Batch reactor with: pre-aerated activated sludge probe for recording the ‘dissolved
oxygen’ (DO) temperature probe air diffusers system for data acquisition
RespirometerRespirometer
Batch reactor with: pre-aerated activated sludge probe for recording the ‘dissolved
oxygen’ (DO) temperature probe air diffusers system for data acquisition
Put in a batch reactor 0.5 L of pre-aerated activated sludge Introduce a magnetic stirrer in the reactor and the
oxygonometer (DO: ~ 7-8 mg/L); Add ~ 10 mg/L of allylthiourea (ATU) in order to inhibit
nitrification Stop aeration and start measuring the concentration of DO Stop the measurement when the DO concentration is below
1 mg/L Add different concentrations of sodium acetate substrate
◦ 2 mg/L◦ 4 mg/L◦ 6 mg/L◦ 8 mg/L
Take a sample of activated sludge from the reactor anddetermine MLSS and MLVSS
Procedure for the determination of YH
Put in a batch reactor 0.5 L of pre-aerated activated sludge Introduce a magnetic stirrer in the reactor and the
oxygonometer (DO: ~ 7-8 mg/L); Add ~ 10 mg/L of allylthiourea (ATU) in order to inhibit
nitrification Stop aeration and start measuring the concentration of DO Stop the measurement when the DO concentration is below
1 mg/L Add different concentrations of sodium acetate substrate
◦ 2 mg/L◦ 4 mg/L◦ 6 mg/L◦ 8 mg/L
Take a sample of activated sludge from the reactor anddetermine MLSS and MLVSS
8
DO
(m
g/L)
DeterminationDetermination ofofYYHH (1/2)(1/2)
Addition of substrate (S) at different concentrationsThe drop ΔDO represents the consumption of oxygen due to oxidation and
endogenous respiration for COD added = 8 mg/L
0
2
4
6
0 5 10 15 20 25
DO
(m
g/L)
Time (min)
∆DO = ΔDOendogenous + ΔDOoxidized
Endogenous decay rate
DeterminationDetermination ofofYYHH (2/(2/22))
COD added(mg/L)
Timerequired
(min)
ΔDO consumed(mg/L)
ΔDO endogenous
(mg/L)ΔDO oxidized
(mg/L)
2 1.63 0.57 0.26 0.31
4 2.73 0.99 0.44 0.55
6 4.83 1.78 0.78 1.00
8 5.43 2.08 0.88 1.218 5.43 2.08 0.88 1.21
y = 0.16xR² = 0.9796
0
0,4
0,8
1,2
1,6
0 2 4 6 8 10
ΔD
Oox
idiz
ed(m
g/L)
COD consumed (mg/L)
= 1 – slope = 0.84
Determination of COD fractions with the measurement of OxygenDetermination of COD fractions with the measurement of OxygenUptake Rate (OUR)Uptake Rate (OUR)
The method aims at the determination of the various COD fractionsthrough their correlation with the oxygen consumption rates that aremeasured in batch experiments where the wastewater is mixed with thebiomass.The fractionation is based on the correlation of the concentration ofoxygen that is consumed for each COD fraction with the concentration ofeach fraction that exists in wastewater.
The method aims at the determination of the various COD fractionsthrough their correlation with the oxygen consumption rates that aremeasured in batch experiments where the wastewater is mixed with thebiomass.The fractionation is based on the correlation of the concentration ofoxygen that is consumed for each COD fraction with the concentration ofeach fraction that exists in wastewater.
The method aims at the determination of the various COD fractionsthrough their correlation with the oxygen consumption rates that aremeasured in batch experiments where the wastewater is mixed with thebiomass.The fractionation is based on the correlation of the concentration ofoxygen that is consumed for each COD fraction with the concentration ofeach fraction that exists in wastewater.
The method aims at the determination of the various COD fractionsthrough their correlation with the oxygen consumption rates that aremeasured in batch experiments where the wastewater is mixed with thebiomass.The fractionation is based on the correlation of the concentration ofoxygen that is consumed for each COD fraction with the concentration ofeach fraction that exists in wastewater.
Organic matter fractionationOrganic matter fractionation
- By calculating the area below thecurve of the oxygen uptake rate wedetermine the oxygen that isconsumed for the metabolism of easilybiodegradable, easily hydrolysable andslowly hydrolysable COD.- By using the yield coefficient YH(coefficient for the conversion ofdissolved oxygen in COD) we candetermine the COD that correspondsin each group of organic matter. Forthe determination of YH we areperforming oxygen uptake experimentsby adding known amount of sodiumacetate.
- By calculating the area below thecurve of the oxygen uptake rate wedetermine the oxygen that isconsumed for the metabolism of easilybiodegradable, easily hydrolysable andslowly hydrolysable COD.- By using the yield coefficient YH(coefficient for the conversion ofdissolved oxygen in COD) we candetermine the COD that correspondsin each group of organic matter. Forthe determination of YH we areperforming oxygen uptake experimentsby adding known amount of sodiumacetate.
Respirometric test (OUR)Respirometric test (OUR)
The coupling between oxygen and substrate consumption canbe used to calculate the amount of substrate consumed.
When interpreting the OUR curve it is essential to know themrespiration due to the biomass itself, called the endogenousrespiration. This respiration is assumed to be caused bymaintenance of the biomass. The concept is to subtract therespiration from the measured respiration in order todetermine the true yield coefficient.
The direct registration of the oxygen consumption rate ina biological process allows us to get a first insight intothe metabolism of the micro-organisms.
When interpreting the OUR curve it is essential to know themrespiration due to the biomass itself, called the endogenousrespiration. This respiration is assumed to be caused bymaintenance of the biomass. The concept is to subtract therespiration from the measured respiration in order todetermine the true yield coefficient.
Phase I: The amount of added substrate expressed as COD, which has been oxidised, isthen equal to the white area in Fig. 1. Phase II: “slowly” readily biodegradable COD(RBCOD)
The area between the complete respirogram and theendogenous respiration identifies the total oxygen (DO) usedfor oxidation of all the biodegradable COD in the wastewater(bCOD).
The two areas can be calculated using the integral of thecurves or by the method of trapezoids. Based on this methodthe area under the curve is divided in finite elements oftrapezoidal shape delimited vertically by two consecutivevalues of OUR mutually spaced by a time interval Δt.
OUR determinationOUR determination
The area between the complete respirogram and theendogenous respiration identifies the total oxygen (DO) usedfor oxidation of all the biodegradable COD in the wastewater(bCOD).
The two areas can be calculated using the integral of thecurves or by the method of trapezoids. Based on this methodthe area under the curve is divided in finite elements oftrapezoidal shape delimited vertically by two consecutivevalues of OUR mutually spaced by a time interval Δt.
OUR graphOUR graph
Substrateaddition
Substrateaddition
Total DO consumed: calcolo dell’area sottesa mediante il metodo della sommadell’area dei trapezi
OUR acetateOUR acetate
At first the OUR measurement gives a very fast response and then after a short period, therespiration rate levels off.The first increase of the OUR curve can be explained by the adaptation of the organisms to thissudden much higher concentration of organic substrate or it could be caused by growth of thebiomass.Sudden drop: indicating that the added substrate has been removed
What data we get ?What data we get ?
01234567
0 2000 4000 6000 8000 10000 12000
mgD
O/L
Time (sec)
Endogenousconsumption
Substrate consumption
01234567
0 2000 4000 6000 8000 10000 12000
mgD
O/L
Time (sec)
normalization
sOUR= _____OURMLVSS
biomass
sOUR(20°C) = sOUR (T) /1,099^ (T-20)
temperature
Mixed liquor suspended solids (MLSS)Mixed liquor suspended solids (MLSS)
is the concentration of suspended solids, in an aeration tank during theactivated sludge process, which occurs during the treatment of waste water.consists mostly of microorganisms and non-biodegradable suspended matter.is an important part of the activated sludge process to ensure that there is asufficient quantity of active biomass available to consume the applied quantityof organic pollutant at any time.
is the concentration of suspended solids, in an aeration tank during theactivated sludge process, which occurs during the treatment of waste water.consists mostly of microorganisms and non-biodegradable suspended matter.is an important part of the activated sludge process to ensure that there is asufficient quantity of active biomass available to consume the applied quantityof organic pollutant at any time.
MLVSS is the portion of the MLSS that is actually eating the incoming food .
The volatile solids concentration in a sample of mixed liquor will consistmostly of microorganisms and organic matter.
MLVSS is the portion of the MLSS that is actually eating the incoming food .
The volatile solids concentration in a sample of mixed liquor will consistmostly of microorganisms and organic matter.
Mixed liquor volatile suspended solids (MLVSS)
MLSS and MLVSS are indicative of biomass....but MLVSS is more indicative of true biomass than MLSS since MLSS includesinorganic constituents.
MLSS and MLVSS are indicative of biomass....but MLVSS is more indicative of true biomass than MLSS since MLSS includesinorganic constituents.
SolidsSolids
Total Solids(TS)
Total suspendedsolids (TSS)
Totaldissolved
solids (TDS)Total suspended
solids (TSS)
Volatilesuspendedsolids (VSS)
Fixed (inert)suspended
solids
Totaldissolved
solids (TDS)
Volatiledissolved
solids
Fixed (inert)dissolved
solids
Distinction between suspended and solubleDistinction between suspended and soluble
Suspended solids have asize > 1 μm (10-6 m)
Dissolved solids < 1 μm We may also distinguish
a third category that liesbetween suspendedsolids and dissolvedsolids that is colloidalsolids for solids having asize of the order of 0.1-1μm
Suspended solids have asize > 1 μm (10-6 m)
Dissolved solids < 1 μm We may also distinguish
a third category that liesbetween suspendedsolids and dissolvedsolids that is colloidalsolids for solids having asize of the order of 0.1-1μm
To determine the total solids in a water/wastewater sample we needto remove all the water and then measure solids
How do we remove water? Simple by evaporation
Procedure Take a clean crucible (crogiolo) and weight it (m1= mass of clean crucible -
g)Add specific volume of water/wastewater sample to the crucible (V - mL)Put in the oven at 105oC (stufa) until all water evaporates (how do we now
that?)Remove the crucible from oven and let it reach room temperature. Then
weight it (m2 = mass of crucible and total solids - g) Total solids (mg/L) = (m2 – m1)/V * 106
To determine the total solids in a water/wastewater sample we needto remove all the water and then measure solids
How do we remove water? Simple by evaporation
Procedure Take a clean crucible (crogiolo) and weight it (m1= mass of clean crucible -
g)Add specific volume of water/wastewater sample to the crucible (V - mL)Put in the oven at 105oC (stufa) until all water evaporates (how do we now
that?)Remove the crucible from oven and let it reach room temperature. Then
weight it (m2 = mass of crucible and total solids - g) Total solids (mg/L) = (m2 – m1)/V * 106
But how do we measure total solids?
To determine the total solids in a water/wastewater sample we needto remove all the water and then measure solids
How do we remove water? Simple by evaporation
Procedure Take a clean crucible (crogiolo) and weight it (m1= mass of clean crucible -
g)Add specific volume of water/wastewater sample to the crucible (V - mL)Put in the oven at 105oC (stufa) until all water evaporates (how do we now
that?)Remove the crucible from oven and let it reach room temperature. Then
weight it (m2 = mass of crucible and total solids - g) Total solids (mg/L) = (m2 – m1)/V * 106
To determine the total solids in a water/wastewater sample we needto remove all the water and then measure solids
How do we remove water? Simple by evaporation
Procedure Take a clean crucible (crogiolo) and weight it (m1= mass of clean crucible -
g)Add specific volume of water/wastewater sample to the crucible (V - mL)Put in the oven at 105oC (stufa) until all water evaporates (how do we now
that?)Remove the crucible from oven and let it reach room temperature. Then
weight it (m2 = mass of crucible and total solids - g) Total solids (mg/L) = (m2 – m1)/V * 106
To determine the volatile solids we need to place the dried sample atvery high temperature (550oC) to volatilize the solids
ProcedurePlace the previously dried crucible that contain s the dried solids at
550oC (muffola) and maintain for at least 20 min
Remove crucible, allow to reach room temperature and weight (m3 =mass of crucible and fixed-inert (non volatile) solids
Volatile solids VS (mg/L) = (m2-m3)/V*106
To determine the volatile solids we need to place the dried sample atvery high temperature (550oC) to volatilize the solids
ProcedurePlace the previously dried crucible that contain s the dried solids at
550oC (muffola) and maintain for at least 20 min
Remove crucible, allow to reach room temperature and weight (m3 =mass of crucible and fixed-inert (non volatile) solids
Volatile solids VS (mg/L) = (m2-m3)/V*106
But how do we measure volatile solids?
To determine the volatile solids we need to place the dried sample atvery high temperature (550oC) to volatilize the solids
ProcedurePlace the previously dried crucible that contain s the dried solids at
550oC (muffola) and maintain for at least 20 min
Remove crucible, allow to reach room temperature and weight (m3 =mass of crucible and fixed-inert (non volatile) solids
Volatile solids VS (mg/L) = (m2-m3)/V*106
To determine the volatile solids we need to place the dried sample atvery high temperature (550oC) to volatilize the solids
ProcedurePlace the previously dried crucible that contain s the dried solids at
550oC (muffola) and maintain for at least 20 min
Remove crucible, allow to reach room temperature and weight (m3 =mass of crucible and fixed-inert (non volatile) solids
Volatile solids VS (mg/L) = (m2-m3)/V*106
Biomass Yield (Y = g cell/g substrate)Biomass Yield (Y = g cell/g substrate)
COD Mass Balance (Stoichiometry)◦ Assume substrate as glucose◦ Neglect nutrient other than N
What is the yield (Y) based on thisstoichiometry?
COD Mass Balance (Stoichiometry)◦ Assume substrate as glucose◦ Neglect nutrient other than N
What is the yield (Y) based on thisstoichiometry?
COD of Glucose (g O2 / g glucose)COD of Glucose (g O2 / g glucose)
Cellular Mass Balance (Stoichiometry)◦ Assume substrate as glucose◦ Neglect nutrient other than N
What is the yield (Y) based on thisstoichiometry (change in O2 over change inglucose)?
Cellular Mass Balance (Stoichiometry)◦ Assume substrate as glucose◦ Neglect nutrient other than N
What is the yield (Y) based on thisstoichiometry (change in O2 over change inglucose)?
Theoretical Yield[(g cell / g glucose) / (g COD O2 / g glucose)]
Maximum yield… actual yield will be morebecause not all substrate is converted to cellmass (synthesis) since some is needed for cellmaintenance Solve for the theoretical yield given the
following
Maximum yield… actual yield will be morebecause not all substrate is converted to cellmass (synthesis) since some is needed for cellmaintenance Solve for the theoretical yield given the
following
Theoretical Yield[(g cell / g glucose) / (g COD O2 / g glucose)]
Solve for the theoretical yield