Experimental study on combination of microbial flocculants with PAC in in-situ remediation of black odorous water and sediment

Abstract

This study, the sediment of black and odorous water body in Xinyang main flood drainage channel of Xiamen City was taken as the research object, and the effect of in-situ remediation of black and odorous water body sediment by microbial flocculant (MBF) and polyaluminium chloride (PAC) in different proportions was studied through laboratory static simulation test. The experimental results show that: (a) The MBF dosage of 20 mg/L has a good effect on the remediation of the sediment in the black-odor river. The removal rates of TP and COD in the overlying water are 86.5% and 87.37% after 15 days of experiments, respectively. The removal efficiency of acid volatile sulfur in sediment (AVS) is not very good, the removal rate is only 27.1%. 100 mg/L PAC is added to remedy the black-odor river sediment, and the overlying water under the same experimental conditions. The removal rate of TP was 51%. (b) The combination of MBF and PAC has a good effect on the remediation of the sediment and overlying water of the black and odorous river in the city. The optimum dosage scheme is PAC with 20 mg/L and microbial flocculant with 10 mg/L. Under this scheme, the removal rates of NH4+-N, TP and COD in overlying water were 92.37%, 70.82% and 64.52% respectively after 15 days of restoration experiment. AVS in sediment was reduced by 52.21%, which basically eliminated the black odor in overlying water.