响应面法优化光聚合CMCTS-g-CPAM及其污泥脱水性能

以羧甲基壳聚糖(CMCTS)为主链模板、丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为共聚单体,通过紫外光引发聚合法制备新型阳离子絮凝剂CMCTS-g-CPAM。采用响应曲面法(RSM)得到CMCTS-g-CPAM的最佳制备条件:光照时间为2h、光引发剂质量分数为0.04%、pH值为8。接枝共聚物CMCTS-g-CPAM的红外光谱(FT-IR)和核磁共振(~1H-NMR)表征表明AM、DMC和CMCTS已成功聚合。污泥脱水实验验证其具有良好的污泥脱水性能:在絮凝剂投加量和pH值分别为30mg/L和10时,污泥比阻(SRF)由9.10×10~(13) m/kg降至1.96×10~(13) m/kg,滤饼含水率(FCMC)从90.15%降至79.28%,其污泥脱水效果和经济效益均优于市售CPAM。同时,此研究在污泥脱水中的应用为污泥脱水领域的絮凝处理和改性壳聚糖提供了一定参考。

Optimization of photopolymerization CMCTS-g-CPAM by response surface methodology and evaluation of sludge dewatering performance

The novel cationic flocculant of CMCTS-g-CPAM was synthesized by polymerizing carboxymethyl chitosan (CMCTS), acrylamide (AM) and methacryloyloxyethyl trimethyl ammonium chloride (DMC) under ultraviolet (UV) radiation. The response surface method was adopted to obtain the optimum preparation conditions:illumination time 2 h, initiator mass fraction 0.04%, pH=8. FT-IR and ¹H-NMR of the graft copolymer indicated that AM, DMC and CMCTS have been successfully aggregated. Additionally, it can be verified by sludge dewatering test that it has good sludge dewatering performance:SRF decreased from 9.10×10¹³ m/kg to 1.96×10¹³ m/kg, and FCMC decreased from 90.15% to 79.28%,at the flocculant dosage and pH of 30 mg/L and 10, respectively. Sludge dewatering effect and economic benefits of CMCTS-g-CPAM are significantly precede to commercially available CPAM. Simultaneously, the research provides a reference for the flocculation treatment in the field of sludge dewatering and the application of chitosan modification in sludge dewatering.