Evaluation of the Treatability and Biogas Production Potential of Chrome Line TanneryrnEffluent before and after Chrome Recovery in Anaerobic Sequential Batch ReactorrnAlemu Bejiga, 2014rnDirect discharge of tannery effluent to the surrounding water bodies affects the waterrnquality and further causes reduction and death of aquatic fauna and flora. The effect canrnbe minimized by treatment of tannery effluent prior to discharge to the environment.rnBiological treatment method is cost effective and environmentally friendly than physicochemicalrntreatment method. The objective of this study was to develop a laboratory scalernanaerobic sequence batch reactor and evaluate the treatment efficiency and biogasrnproduction potential of chrome tanning effluent at mesophilic (370CÂ±2) system. The studyrnwas conducted at five treatments (wastewater containing different concentration ofrnchrome). The treatments (T-1 to T-5) contain chrome concentrations (Cr3+) 185mg/l,rn120mg/l, 14mg/l and 6.85mg/l for T-1, T-2, T-3, T-4, and T-5 respectively. The hydraulicrnretention time of all treatments was three days and five days, the organic loading raternwas wide-ranging between 1.49 kg COD/m3/day for T-1 to 1.32 kg COD/m3/day forT-5rnthroughout the study. The removal efficiency of TS and VS of all treatments were in thernrange of 52-69% and 58-81%, respectively. The removal efficiency of COD,BOD,TN,rnNO3rn-, S-2, SO4rn-2, PO4rn3- and Cr3+ of all treatments were in the range of 42-62%,41-71%,rn31-43%, 31-49%, 40-71%, 41-64%, 48-74% and 30-61% respectively. Chrome recoveryrnwas achieved up to 96.3%. The maximum value of biogas at five days hydraulic retentionrntime for (T-1 to T-5), (0.0089, 0.0097, 0.012, 0.027 and 0.034 m3 biogas/kg VSrnrespectively) with methane content 21.1%, 22.7%, 37%, 51.3% and 54.7% was obtainedrnafter steady stable state condition. Hence, pretreated chrome tanning effluent with Crrn(III) of 6.85mg/l was a potential feedstock for ASBR.rnKey words: Anaerobic sequential batch reactor, Chrome Tanning Effluent, Biogas