Fenton-like试剂联合PFS对污泥脱水性能影响的过程研究

摘要

Fenton-like reagent and PFS were investigated for sludge dewatering with combined conitioning,and the moisture content and SRF were the major parameters to evaluate the sludge dewatering performance.Then the response surface methodology optimized the sludge dewatering conditions.Several other parameters were used to analyze the conditioning mechanism,such as soluble COD,extracellular polymeric substance,protein and polysaccharide contents in the filtrate,and the sludge partical size and Zeta potential.The results showed that combined conditioning using Fenton-like reagent and PFS could improve the sludge dewatering performance.When the initial pH was 2.98,and the dosage of Co2+,H2O2 and PFS were 10.44,59.45,48.63 mg/g(dry solids),respectively,the slduge dewateralibity was best.Under the conditions,the moisture content and the SRF decreased from raw sludge's 79.77％,1.17 × 1013 m/kg to (63.12 ± 0.5)％ and (5.32 ± 0.29) × 1012 m/kg,respectively.After the Fenton-like reagent's treatment,the partical size became the smallest,and the sludge flocs stucture were damaged,so that more bound water and intracellular water was released,and the sludge dewatering performance was improved.Then after the PFS treatment,the crushed sludge flocs flocculated again forming new dense folocs and the performance of sludge dewatering was improved greatly.Meanwhile,the partical size and Zeta potential incresed at the same time,which meant that the mechanism of re-flocculation process was dominant in charge neutralization.%以泥饼含水率和污泥比阻为主要评价指标探究Fenton-like试剂(Co2+/H2O2)联合聚合硫酸铁(PFS)改善污泥脱水性能的可行性,并采用响应面法优化污泥脱水的条件;通过滤液中的SCOD、EPS、多糖和蛋白质以及Zeta电位、粒径等指标初步探讨其调理机制.结果表明:Fenton-like试剂联合PFS可以改善污泥的脱水性能,当pH为2.98,Co2、H2O2和PFS的投加量分别为10.44,59.45,48.63 mg/g时污泥的脱水性能最佳,此条件下泥饼含水率从原污泥的79.77％降至(63.12±0.5)％,污泥比阻从原污泥的1.17×1013 m/kg降至(5.32±0.29)×1012 m/kg.Fenton-like试剂处理后,污泥粒径达到最小,破坏污泥絮体结构释放了束缚水和细胞内部水.投加PFS后已破碎的污泥絮体重新再絮凝,形成更加密实的新絮体,提高了污泥的脱水性能;污泥粒径和Zeta电位同时增大,说明再絮凝过程是以电中和的机理为主导的.