Fe(Ⅱ)协同过硫酸钾改善河道底泥的脱水性能

The moisture of river sediment significantly influenced its dehydration and the disposal cost. Response surface method (RSM) and central composite design (CCD) were applied to optimize the effectiveness of combined oxidation conditioning process using Fe (Ⅱ) and potassium persulfate (K₂S₂O₈). The results indicated that the optimum values for K₂S₂O₈, Fe(Ⅱ), and initial pH were found to be 22.26 mg•g^-1 TSS, 43.63 mg•g^-1 TSS(n(K₂S₂O₈): n(Fe(Ⅱ))=1:1.9), pH=5.95, respectively. CST reduction was decreased to 86.16% in 10 min, in agreement with the predicted value of 86.44%. R² and R_adj ² of predicted model was 0.905 8 and 0.821 1, respectively, which showed that RSM could explain the dehydration process with combined oxidation conditioning. ANOVA analysis confirmed that Fe(Ⅱ) (P<0.001) had the largest effect on CST reduction, followed by initial pH (P=0.023) and then K₂S₂O₈. Compared with polymeric ferric sulfate (PFS) and polyacrylamide (PAM), the combined oxidation conditioning has good performance in economy and dehydration property.