| The training of river silt is the whole of the most difficult part of the river regulation. The problems of low efficiency of sludge dewatering, long drying time, large area occupied have become the most urgent task. The moisture content of the silt generally remain above 95%, so how to quickly reduce the moisture content has been the premise of the rivers treatment.Tooking the silt from Xunsi River in Wuhan as the research object. It aimed to compound a high efficiency agent of sludge dehydration by the method of chemical coagulation, then to improve the sludge dewatering performance. The paper firstly studied the influence of single dehydrant（M g（ O H）2、AlCl3、MgO、Ca（OH）2、FeCl3、CaO、KOH、PAM） on the sludge dewatering performance, by the sedimentation rate of the clear mixture interface, the settling volume and the turbidity of the supernatant. The results show that the dehydration performance has improved. Between them, C a（ O H）2, CaO and PAM had the optimum effects. Next it has researched the particle settling process of the silt under the influence of C a（ O H）2,CaO and PAM with the SV30, the concentration ratio and solid content of the silt. The results shows that when the sludge concentration was 10%, the silt dehydration had the optimum effect with the dose ratio of Ca（OH）2 10g/L. While, in the best situation, the SV30 was 36.5%,the concentration ratio can reach 3.73,and the silt had a solid content of 16% when the setting finished,while the optimum dose of Ca O was 8g/L, the SV30 was 35.4%, the concentration ratio can reach 3.81,and the silt had a solid content of 16.7% when the setting finished,And the optimum dose of PAM was 0.04g/L,the SV30 was about 26.3%. Besides it had discussed the changes of the COD, it turned out that the supernatant treated by CaO had a decline of 49%.At the end, we ompound CaO and PAM with flyash the waste from some power plants. Eventually,we found the optimum proportions with CaO 1g/L,flyash 8g/L,PAM 0.09g/L,It means CaO:flyash:PAM=1:8:0.09。... |
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