Anaerobic Biodegradability and Treatment of Egyptian Domestic Sewage

Abstract The anaerobic biodegradability of domestic sewage for four Egyptian villages and four Egyptian cities was determined in batch experiments. The results showed that the biodegradability of the Egyptian-villages sewage (73%) was higher than that of the cities (66%). The higher biodegradability of the soluble COD of village sewage (69%) as compared to that of the cities (46%) was the reason for the higher biodegradability of the total COD of the villages sewage. The biodegradability of suspended COD was similar for the sewage of both villages and cities (73–74%). The results of a mathematical-model, developed based on anaerobic digestion model number 1, indicate that at applying a UASB reactor for the treatment of Egyptian villages and cities sewage, an optimum HRT of, respectively, 16 and 8 h is required. At these HRTs, a total COD removal and a conversion to methane of, respectively, 62–70% and 59–64% can be achieved for the sewage of cities and, respectively, 71–77% and 67–69% for the villages sewage. The model results also show that in the treatment of villages sewage in a two-step (anaerobic filter + UASB reactor) system a higher total COD removal can be obtained (77–81%) at a short HRT of 10 h (4 + 6 h). However, the excess sludge from the first-step of the two-step system will be less stabilized.

[1]  Grietje Zeeman,et al.  Treatment of domestic sewage in a two-step anaerobic filter/anaerobic hybrid system at low temperature. , 2002, Water research.

[2]  Grietje Zeeman,et al.  Advanced anaerobic wastewater treatment in the near future , 1997 .

[3]  S. Pavlostathis,et al.  Kinetics of Anaerobic Treatment , 1991 .

[4]  Grietje Zeeman,et al.  Low temperature treatment of domestic sewage in upflow anaerobic sludge blanket and anaerobic hybrid reactors , 1999 .

[5]  G. Zeeman,et al.  Low temperature pre-treatment of domestic sewage in an anaerobic hybrid or an anaerobic filter reactor. , 2002, Bioresource technology.

[6]  G Lettinga,et al.  Anaerobic treatment of domestic sewage at low temperature. , 2001, Water science and technology : a journal of the International Association on Water Pollution Research.

[7]  Kaijun Wang,et al.  Integrated anaerobic and aerobic treatment of sewage , 1994 .

[8]  Awwa,et al.  Standard Methods for the examination of water and wastewater , 1999 .

[9]  Grietje Zeeman,et al.  The role of anaerobic digestion of domestic sewage in closing the water and nutrient cycle at community level , 1999 .

[10]  G. Zeeman,et al.  Biodegradability and change of physical characteristics of particles during anaerobic digestion of domestic sewage. , 2001, Water research.

[11]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[12]  Gatze Lettinga,et al.  Anaerobic treatment of domestic sewage under moderate climatic (Dutch) conditions using upflow reactors at increased superficial velocities. , 1992 .

[13]  G Lettinga,et al.  Treatment of domestic sewage at low temperature in a two-anaerobic step system followed by a trickling filter. , 2004, Water science and technology : a journal of the International Association on Water Pollution Research.

[14]  Grietje Zeeman,et al.  The role of filter media in removing suspended and colloidal particles in an anaerobic reactor treating domestic sewage , 2000 .

[15]  Nidal Mahmoud,et al.  Anaerobic pre-treatment of sewage under low temperature (15 [degrees] C) conditions in an integrated UASB-digester system , 2002 .