Wastewater.pptx
- 1. Kinetics of biodegradation of sewage due to addition of Chlorides PRESENTED BY: Prof Prapti Shah
- 2. Contents: • Introduction • Objectives of the study • Methodology • Results • Conclusions
- 3. 17 coastal megacities covering about 25% of the world's population. INTRODUCTION
- 4. Seafood processing industry vegetable canning Pickling fishmeal manufacturing Cheese processing
- 5. Wastewater characteristics of from various fishery product and vegetable pickling industries (Dan N. P, 2001).
- 6. Leachate Highly saline wastewater is generated during the manufacture of chemicals such as pesticides, pharmaceuticals, herbicides and during oil and gas recovery processes (Henze M et al., 1995). In addition, High salt concentration found in the landfill leachates (Ellouze M et al., 2008). Leachate Domestic waste landfill Hazardous waste landfill COD mg/L 3,050 – 3,450 9,000 – 10,500 BOD 5 mg/L 1,505 – 1,710 6,950 – 7,500 TOC mg/L 905 – 965 3,040 – 3,500 SS mg/L 460 – 565 862 – 946 TDS mg/L 5,800 – 6,250 22,600 – 25,900 TKN mg/L 75 - 84 160 – 180 Oil and grease mg/L 60 – 80 pH - 4.3 – 6.0 Characteristics of leachates (Pirbazari, 1996). RO reject
- 7. Presence of salinity up to certain concentration (1-2 g/L) has been shown to improve anaerobic sludge digestion, while concentrations over 20 g/L can cause severe osmotic stress in bacteria leading to plasmolysis and/or loss of cell activity (Glenn E., 1995). High salt content in wastewater is known to significantly reduce the treatment efficiency of conventional activated sludge, nitrification and denitrification processes (Kargi F and Uygur A., 1996). Effects of high salt concentrations on biological treatment process are of great concern and present a challenge to the environmental engineers for their safe disposal.
- 8. Adverse effect of salt on activated sludge process (Dan N. P, 2001). ACTIVATED SLUDGE PROCESS :
- 9. Authors Experiment Results Baere et al. (1984) AF with surface area of 600 m2/m3 at 30 g NaCl/l - Decrease in gas production (dropped 65%) TOC removal was decreased from 98% to 70% - Decrease in pH from 6.8 to 5.4 at salt content of 60 g/L - Gas production dropped below 15% - TOC removal < 20% Feijoo et al. (1995) UASB and AF - Reducing 50% methanogenic activity at salt content > 33 g NaCl /L - Shocked at concentrations ranging from 10-21 g NaCl/L for unadapted sludge Belkin et al. (1993) Anaerobic and aerobic system at - 32 g/L (NaCl) Low COD removal for whole system (50%). COD removal (70%) could be improved at very low F/M ratio (0.02 for anaerobic and 0.04 for aerobic process Feijoo et al. (1995) Anaerobic batch digestion - Decreasing 50% of methane activity as increasing. TDS by 10-25 g NaCl/L ANAEROBIC TREATMENT :
- 10. Objectives of the study: To determine the BOD exertion rates of glucose–glutamic acid (GGA) solution mixed with sewage under controlled addition of chlorides of 0 to 20 g/L at 20°C. To develop a mathematical equation derived from experimental results in order to describe both stimulation as well as inhibitory effects by a single expression and validate it by fitting against secondary data reported in the literature.
- 11. METHODOLOGY : Grab samples of sewage were collected from STP of MNIT Jaipur. GGA solution of 150 mg/L each was prepared and 6 mL of it was mixed with sewage a controlled manner for making test samples. Samples having different chloride additions of up to 20 g/L (zero chloride sample means no additional NaCl to the GGA-sewage sample) were prepared using analytical grade NaCl. BOD test was carried out by as per APHA et al., 2010. Settled biomass from SST of STP Delawas, Jaipur (based on conventional ASP) was used as “seed” for BOD analysis.
- 12. • All experiments were conducted at a temperature of 20°C ±2°C. • For the first, two sets of samples having, 0 to 8 and 0 to 20 g/L of chlorides concentrations, BOD exertion was monitored every day for a 5- day period. However, in the third set having chloride concentrations of 0 to 12 g/L, the BOD exertion was monitored up to three-day period. In addition, in the fourth set of experiments with 10 to 20 g/L of chlorides concentrations, only BOD5 exertion was monitored. Trial version of STATISTICA 2014 software was used for data analysis. METHODOLOGY …
- 13. Calculation of Kinetic coefficient K 1) THEORETICAL CALCULATIONS OF BOD = Y=L0 (1-10-(kt/2.303)) 3) ULTIMATE BOD CALCULATIONS: • COD of sewage sample was considered as its ultimate BOD. • The theoretical COD of 373 mg/L as determined from the chemical formula of GGA solution was considered as its ultimate BOD. (373 mg/L * 6 mL) + (COD of sample mg/L* mL of Sample) (mL of GGA (6) + mL of sample taken)
- 14. Days Average BOD (mg/L) 0 g/L Chlorides 0.2 g/L Chlorides 0.4 g/L Chlorides 0.60 g/L Chlorides 0.80 g/L Chlorides 1 45 51 64 Not observed Not observed 2 55 62 72 Not observed Not observed 3 87 85 90 Not observed Not observed 4 115 117 120 Not observed Not observed 5 126 134 143 147 147 TABLE-1 BOD observations at low chloride concentrations of 0 to 0.8 mg/L RESULTS
- 15. Days Average BOD (mg/L) 0 g/L Chlorides 5 g/L Chlorides 10 g/L Chlorides 15 g/L Chlorides 20 g/L Chlorides 1 52 60 30 Not observed Not observed 2 85 93 71 Not observed Not observed 3 142 115 129 Not observed Not observed 4 167 186 137 Not observed Not observed 5 194 200 180 131 104 TABLE-2 BOD exertion at high chloride concentrations of 0-20 g/L
- 16. 189 172 147 120 102 91 87 0 20 40 60 80 100 120 140 160 180 200 5 day BOD BOD excrection mg/L DAYS 0 g/L 10 g/L 12 g/L 14 g/L 16 g/L 18 g/L 20 g/L FIGURE-1 BOD5 exertion at different chloride concentrations of 10-20 mg/L
- 17. 34 134 164 184 197 64 149 169 196 211 50 155 180 204 219 54 115 150 167 184 44 87 135 154 170 0 1 2 3 4 5 6 0 20 40 60 80 100 120 140 160 180 200 220 240 260 DAYS BOD EXERTION MG/L 0 g/L 5 g/L 6 g/L 7 g/L 8 g/L FIGURE-2 BOD exertion at 0, 5, 6, 7 and 8 g/L of chloride concentrations.
- 18. Days Reaction constant (k) per day 0 g/L of Cl 5 g/L of Cl 6 g/L of Cl 7 g/L of Cl 8 g/L of Cl 1 0.11 0.2 0.16 0.17 0.14 2 0.24 0.28 0.29 0.2 0.14 3 0.21 0.22 0.24 0.19 0.16 4 0.19 0.21 0.22 0.16 0.15 5 0.17 0.18 0.2 0.15 0.13 Days Reaction constant (k) per day 0 g/L of Cl 5 g/L of Cl 10 g/L of Cl 15 g/L of Cl 20 g/L of Cl 1 0.16 0.19 0.09 Not observed Not observed 2 0.14 0.16 0.11 Not observed Not observed 3 0.18 0.13 0.15 Not observed Not observed 4 0.16 0.19 0.12 Not observed Not observed 5 0.16 0.17 0.14 0.09 0.07 Table-4 BOD exertion rate (k) of the samples at high chloride concentrations of 0 to 20 g/L Table-3 BOD exertion rate (k) of the samples at varied chloride concentrations of 0 to 8 g/L
- 19. Chlorides (X) (g/L) Ratio (BOD5 at X g/L Chlorides / BOD5 at zero Chloride) 0 1 0.2 1.063 0.4 1.134 0.6 1.166 0.8 1.166 5 1.050 6 1.111 7 0.934 8 0.862 10 0.918 12 0.777 14 0.634 15 0.675 16 0.539 18 0.481 Table-6 Derived data of BOD exertion ratios at different chloride concentrations
- 20. Ratio (BOD5 of X g/L Chlorides / BOD5 of 0 g/L Chlorides) = 0.8801+0.1402*x-0.0212*x^2+0.0007*x^3 R² = 0.947 0 0.4 0.8 6 8 12 15 18 Chlorides g/L 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Ratio (BOD 5 of X g/L Chlorides / BOD 5 of 0 g/L Chlorides) FIGURE- 3 Curve between BOD5 exertion ratios and chloride concentrations.
- 21. Author Chlorides (x) g/L Observed value in literature Predicted value of BOD5 mg/L using our model % Error ((obs- pre)/obs) BOD5 Value at X g/L of Cl BOD5 Value of 0 g/L Cl Shivani et.al., (2012) 5 285 337 384 -34.73 10 255 337 291 -14.11 15 200 337 194 3 20 221 337 271 -22.62 Gotaas (1949) 0.55 272 236 225 17.27 1.65 240 236 250 -4.166 3.65 250 236 270 -8 6.4 243 236 258 -6.17 9.2 215 236 218 -1.39 13.75 236 236 147 37.71 18.35 242 236 151 37.60 Table-7 Observed and Predicted values of variance data under varied chloride concentrations
- 22. • Chloride concentrations of up to 0.8 g/L showed stimulation of biodegradation process • Concentrations from 0.8- 6.0 g/L showed no inhibition of biodegradation. This may perhaps be due to the fact up to this salinity, the cells exhibit a higher activity than in the freshwater medium. Microbiological studies for supporting the hypothesis are underway. • Further increase in salinity (7 to 20 g/L of chlorides) restricts the osmo-regulatory processes responsible for the breakdown of organic compounds within the cells of microorganisms. As a result, the kinetic reaction rates of decomposition reactions suffer and show continuous inhibition. • A single third order polynomial curve was able to represent both the stimulation as well as inhibition of the biological process due to the concentration of salt up to 20 g/L. • The results may help formulate strategy for environmentally safe Co-disposal of RO rejects as well as high salt containing industrial wastewaters with sewage. CONCLUSIONS
- 23. References 1. APHA, WPCF, AWWA (2010). Standard methods for the examination of water and wastewater. American Public Health Association, WPCF, AWWA. 21st Ed. NW, DC 2005. 2. Baere, D. L. A., Devocht, M., Van Assche, P., and Verstraete, W. (1984). Influence of high NaCl and NH4Cl salt levels on methanogenic associations. Water Res., 18 (5) 543-548. 3. Belkin, S., Brenner, A. and Abeliovich, A. (1993). Biological treatment of a high salinity chemical industrial wastewater. Wat. Sci. Tech., 27 (7-8), 105-112. 4. Dan, N. P. (2001). “Biological Treatment of High Salinity Wastewater Using Yeast and Bacterial Systems,” PhD Thesis, Asian Institute of Technology, Bangkok, Thailand. 5. Ellouze, M., Aloui, F. and Sayadi, S. (2008). Detoxification of Tunisian landfill leachates by selected fungi, J.Hazard. Mater, 150, 642–648. 6. Feijoo, G., Soto, M., Méndez, R. and Lema, J. M. (1995). Sodium inhibition in the anaerobic digestion process: Antagonism and adaptation phenomena. Enzyme and Microbial Technology, 17, 180-188. 7. Glenn, E., (1995). Effects of salinity on growth and evapotranspiration of Typha domingensis Pers. Aquatic Botany, 52, 75–91. 8. Gotaas, H. B. (1949) the effect of sea water on the bio-chemical oxidation of domestic wastewater. Domestic Wastewater Works Journal, 21(5). 9. Henze, M., Harremoës, P., Jansen J. and Arvin, E. (1995). Wastewater treatment Biological and Chemical Processes. Springer-Verlag, Berlin, Heidelberg, New York. 10. Kargi F. and Dincer A. R. (1996). Effect of salt content on biological treatment of saline Wastewater by fed-batch operation. Enzyme & Microbial Technology, 19, 529- 537 11. Pirbazari. (1996) Hybrid membrane filtration process for leachate treatment. Wat. Res., 30, 2691-2706. 12. Shivani, S., Dhage&Amita, A., Dalvi& Damodar, V. and Prabhu. (2012). Reaction kinetics and validity of BOD test for domestic wastewater released in marine ecosystems. Environ Monit Assess, 184, 5301–5310.