In Palestine, there are five major wastewater treatment plants built to treat not more than 100million m3 per year of domestic wastewater which is equivalent to 20% of total produced wastewater. Nablus West Wastewater treatment plant, NWWTP, is the most recent plant commissioned in 2013 with 70% of its full capacity of 15000m3/day.
The 12ton/d produced semi sludge forms a severe ecological problem as it is still not fully accepted to be disposed in the sanitary landfill. Therefore, the current practice of improper disposal of the sludge is a threat to the groundwater as well as the agricultural lands due to the pathogenic and toxic content of the sludge. However, according to the Palestinian legislations on the sludge disposal, numerous biological and physicochemical parameters are fully analyzed in this study for further use of sludge.
Potential use of the sludge as a biomass, fertilizer and a biodiesel production feed stock was studied. A “TGA” analysis of dried sludge shows that the organics content is around 40wt%. The yield of lipids extracted from sludge was25wt% oil/dry sludge thus a 1.4 ton of biodiesel can be produced daily. The calorific value of residual sludge is 12.7MJ/kg. Mixing it with saw dust can raise the heating value up to 15MJ/kg. Heat integration concept shows that direct burning of sludge produced can generate 1.52 times the electricity consumption at NWWTP. Finally, the produced sludge can be used as a fertilizer that equivalent to 11% of total fertilizers used in Palestine.