Indian Journal of Chemical Technology, Vol.23, No.6, 491-496, 2016
Treatment of rice grain based biodigester distillery effluent (BDE) using inorganic coagulants
The removal of COD and colour from biodigester effluent (BDE) of rice grain based alcohol distillery plant has been studied using inorganic coagulant such as CaCO3, CuNO3 and Na2SiO3. CuNO3 is found to be more effective, among all coagulant. COD reduction of 78, 83 and 51% and colour reduction of 75, 78 and 41% is obtained using 60 mM CaCO3, 40 mM CuNO3 and 40 mM Na2SiO3 respectively, at their optimum initial pHi. The pH of effluent-coagulant mixture play a major role in removal of pollutant from the BDE. CuNO3 gives 83% COD reduction and 78% colour reduction along with good settling property. 82% settling occurred with alum in 25 min. The properties of filtrate and residues have also been analyzed.
Keywords:Rice grain based biodigester effluent;Chemical oxygen demand;Settling;Coagulation;Copper nitrate