Treatment of dairy wastewater by inorganic coagulants: Parametric and disposal studies

摘要

Present study reports treatment of simulated dairy wastewater (SDW) by inorganic coag-ulants such as poly aluminum chloride (PAC), ferrous sulphate (FeSO_4) and potash alum (KA1(SO_4)_212H_2O). Batch coagulation experiments were conducted to evaluate the influ-ence of initial pH (pH;: 5-10) and coagulant dosage (m: 100-5000 mg/L) on chemical oxygen demand (COD) removal from SDW. Residual COD and system pH were observed as function of time. Optimum pH_i (pHi_(i,op)) was found to be 8.0 for all the three coagulants. Optimum m (m_(op)) was found to be 300, 800 and 500 mg/L for PAC, FeSO_4 and KAl(SO_4)_212H_2O, respec-tively, giving 69.2, 66.5 and 63.8% COD removal efficiency in 30 min. Heating values of the sludge generated by the coagulants PAC, FeSO_4 and KAl(SO_4)_212H_2O were found to be 20.7, 29.6 and 17.3 MJ/kg, respectively.