Treatability studies and determination of kinetic parameters for a high-strength opium production wastewater

Physicochemical and biological treatment studies of Opium plant wastewater were carried out in lab-scale systems. Ferrous sulphate, ferric chloride and alum were used in chemical coagulation studies at varying pH and doses. Best removal efficiency, 11% removal in TOC, was found by using alum. In lab-scale batch biological experiments, oxygen utilization coefficients a' and b' was obtained to be 0.82 mgO(2) mgBOD(5)(-1) and 0.18 mgO(2) mgVSS(-1) d(-1) respectively. Biomass yield and decay rate coefficients, Y and b were 0.24 mgVSS mgBOD(5)(-1) and 0.04 d(-1) respectively. Lab-scale continuous experiments showed that the system could be able to treat the wastewater down to 36 mg l(-1) as BOD5 and 1120 mg l(-1) as COD without major changes under recommended conditions. By process modifications, the treatment system efficiencies have been increased by 69% and 30% in terms of BOD, and COD removals respectively.