Preliminary Study on Treating Molasses Alcohol Wastewater with Cationic Starch with High Degree of Substitution

[Objective] The research aimed to provide basis for establishing new technology of treating molasses alcohol wastewater.[Method] The self-made cationic starch with high degree of substitution was taken as flocculant to treat molasses alcohol wastewater.The influences of the dosage of cationic starch,the initial pH value of wastewater,stirring and adsorption time on treating molasses alcohol wastewater were discussed to confirm the optimum processing conditions.[Result] The determination conditions were confirmed as follows: the wavelength was 560 nm and pH value was 8.0.The removal rate of CODcr and the decoloration rate were decreased with the increment of the dosage of cationic starch and they began to decrease when the dosage was 500 mg/L.When pH value was 6.0～9.0,the removal rate of CODcr and the decoloration rate were higher and changed a little.The adsorption time of flocculant had little effect on the removal rate of CODcr and the decoloration rate.The effects of pH value on the removal rate of CODcr and the decoloration rate was most,followed by the addition amount of cationic starch and adsorption time.[Conclusion] The processing conditions of treating molasses alcohol wastewater with cationic starch with high degree of substitution were confirmed as follows: the addition amount of cationic starch was 500 mg/L,the initial pH of wastewater was 7.0 and the adsorption time was 5 min,under which,the removal rate of CODcr reached 70.8% and the decoloration rate reached 50.3%.