Study on Biodegradation Characteristics of Simulated In-Situ Remediation in Taihu Lake by Four Fillers

Biodegradation characteristics are investigated by biofilm process with 4 types of fillers for high dissolved oxygen (DO7.5∼8.5 mg/L) in Taihu Lake, under the conditions of the water temperature of 30 °C, 20 °C, 10 °C,and the filling rate of 70%,50%.30%, respectively. The results show that Optimal treatment conditions are temperature of 30 °C and filling rate of 70% for micro-polluted water in Taihu Lake, filler A achieves the best result on the conditions of 30 °C and filler rate of 70%, CODMn concentrations are reduced from 6.01∼6.24 mg.L-1 to 3.79∼3.96 mg.L-1, CODMn removal rate reaches 39.74%, TKN concentrations are reduced from 1.33∼3.96 mg.L-1 to 0.92∼1.67 mg.L-1, the TKN removal rate reaches 72.86%.CODMn concentrations for other 3 kinds of fillers are reduced from 4.07∼6.24 mg.L-1 to 3.84∼3.99 mg.L-1,TKN concentrations are reduced from 1.33∼3.96 mg.L-1 to 0.67∼1.75 mg.L-1. filler C gets worst result with the CODMn removal rate of 35.02%, TKN removal rate of only 7.89%, and the relationship of CODMn and BOD5 is provided for the actual restoration project with a theoretical basis.