The purposes of wastewater treatment plant are to protect the environment, to save water resources and to use the treated water in agricultural application and others.
This report gives a detailed design for complete mix activated sludge wastewater treatment plant for Nablus city (Palestine), which will treat domestic wastewater, for the western part of the city and its western villages .The maximum influent flow rate to the plant is 17000 m3/d which was estimated based on wastewater projected amounts for the year 2030, with quality of total suspended solids of 784 mg/L, and biological oxygen demand of 656 mg/L. The plant is designed to give effluent quality of 20/30 (Biological oxygen demand per total suspended solids). The effluent flow rates are 16264, 38, and 4899 m3/d, of treated water, sludge and biogas respectively.
The mass balance was done on the main plant units. These are screen, grit chamber, equalization, primary clarifier, aeration tank with recycle, secondary clarifier, disinfection and sludge treatment unit. The later includes thickener, blending tank, digester and dewatering facility. The area of the plant is 32560 m2 which will be located at Wadi Zeimar near Dayr Sharaf. The contour of the chosen location will help the flow to occur by gravity within plant facilities.
The total capital cost of the plant is estimated to be $90.3 million, and the annual operating cost is estimated $7.5 million. The cost of treating one cubic meter of wastewater is $1.8 which includes annual operating cost and capital cost recovery in 25 year. It’s proposed that Nablus Municipality charges $1.5/m3 of consumed fresh water, assuming 85% of consumed fresh water will end up as wastewater.