Evaluation Of Vertical Subsurface Flow Constructed Wetland System For Polluted River Wastewater Treatment A Case Study On Akaki River Source Of Urban Agriculture In Addis Ababa
Water Supply And Environmental Engineering Project Topics
Urban Agriculture (UA) in Addis Ababa has a number of challenges and opportunities sincernUrban farmers on the riverbank mainly dependent on irrigated water from Akaki River. Arnnumber of studies have been conducted focused on characterization of Akaki River waterrnquality, challenges faced by farmers in UA , health risks associated with irrigated vegetables byrnthe river and economic losses resulted due to the river pollution. However a realistic solution tornthe urgent situation of UA was not given yet. This study aims at performance evaluation ofrnVertical subsurface flow constructed wetland (VSSFCW) as cheap and efficient onsiternwastewater treatment solution functioned by farmers. No odors or insects were detected duringrnthe six month operation of VFCW, beside a beautiful landscape view. The efficiency ofrnVSSFCW was studied on pilot plant. An evaluation of the efficiency in the purification of thernmain polluting agents were done. The average removal efficiencies of chemical oxygen demandrn(COD), biological oxygen demand (BOD), total suspended solids (TSS), Turbidity, Facialrncoliform(FC), Sulfide( ), Total ammonia( ), nitrate( ), Nitrite( ), total nitrogen(TN),rntotalrnphosphorous(T-P),werern76rn%,rn87rn%,rn93rn%,rn100%,rn94rn%,rn80rn%,rn16.7rn%,rn97.7rn%,rn43rn%,rnrn46rn%rnrespectively.rnThernphysiochemicalrncharactersrnofrntreatedrnwastewaterrnwererncomplyingrnwithrnrnthernrnWHO standard for wastewater reuse in Irrigation of crops likely to be eaten uncooked.rnHowever biological parameters were slightly above the guidelines.