| Sludge dewatering is a commonly used method for sludge treatment, the purpose of which is sludge reduction. Add dewatering agent before dehydration for chemical toning can improve the dehydration properties of sludge. The effect of dehydrating agent used commonly is good, but some degradation products could cause environment pollution. So the research and preparation on modifying natural polymer are necessary.This study is based on chitin, tributyl phosphine, triphenylphosphine to produce quarternary phosphonium salt-modified chitin compounds. The synthesis conditions were optimized with phosphorus content, and it was confirmed that the salt was grafted onto chitin by FT-IR and chemical element detection.The dehydration properties of products were studied by thickener sludge dewatering experiments and comparing with PAM and PAC. Results showed:the best adding quantity of Tributyl phosphine-modified chitin was50mg/L, filter cake moisture content75.39%, sludge specific resistance3.94x1011m/Kg, capillary suction time23.1s; the results of triphenylphosphine-modified chitin was respectively60mg/L,78.52%,4.07x1011m/Kg and24.6s. Contrasted results showed:two products were better than PAM and PAC, and were close to PAC+PAM. Tributyl phosphine-modified chitin was much better compared with triphenylphosphine-modified chitin.Plate count method was used to describe the properties of products by determining sterilization ability to escherichia coli and staphylococcus aureus and being comparewith THPS. The results showed:under37℃for24hours, the minimum inhibitory concentration of tributyl phosphine-modified chitin for escherichia coli and staphylococcus aureus were respectively20and50mg/L; triphenylphosphine-modified chitin for escherichia coli was30mg/L, and the maximum sterilization rate of staphylococcus aureus was80%. Contrasted results showed:products were not as good as THPS, but improved after modification, the effect to escherichia coli was better than staphylococcus aureus. |
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