The Preparation and Application of Environment-friendly Compound Flocculant

[Objective] The research aimed to study preparation and application of the environment-friendly flocculant.[Method] Natural biological products chitosan(CTS),ferric sulfate [Fe2(SO4)3] and polymeric aluminum chloride(PAC) as the main raw materials,four kinds of environment-friendly flocculants were made to conduct flocculation treatment on the domestic wastewater of Wuhan Bioengineering Institute.COD and turbidity of the wastewater as the main indicators,influences of compound flocculant formulation,flocculant dosage and pH on flocculation effect were studied.[Result] CTS/PAC and CTS/ Fe2(SO4)3 compound flocculants had better removal rates of COD and turbidity when compared with single inorganic flocculant.The best volume ratio of CTS/PAC was 1.0∶5.0.The smallest dosage of CTS/PAC in each 500 ml of water was 4.0 ml.When pH was 7.2,removal rates of COD and turbidity were respectively 78.5% and 98.4%,which rose by 36.5% and 21.5% respectively than that singly using PAC.[Conclusion] CTS/PAC was a kind of ideal compound flocculant and had better application prospect.