絮凝剂和溶菌酶联用促进污泥脱水性能

Effect of Flocculant and Lysozyme Treatment on Sludge Dewaterability

通过小试试验考察了絮凝剂(聚丙烯酰胺)和溶菌酶联合使用对污水厂二沉池回流污泥的脱水性能、沉降性能及絮体特性的影响,并与2种药剂单独作用时进行了对比研究.结果表明,絮凝剂和溶菌酶分别单独作用于污泥脱水时,均可改善污泥的脱水性能;但2种药剂共同作用时,能同时提高污泥沉降性能和脱水速度,且脱水程度较2种药剂单独处理时进一步提升.2种药剂联用时的最佳投加量为20 mL/L絮凝剂+0.05 g/g溶菌酶,且最优添加顺序为先絮凝剂再溶菌酶.此时污泥抽滤泥饼含水率和比阻分别为65.7%和0.8×1012 m/kg,与原泥相比下降25.3%和75.8%.通过污泥胞外聚合物(EPS)含量与污泥絮体形态分析可知,溶菌酶可以有效破坏污泥絮体结构,改变污泥EPS的分布;高分子絮凝剂的吸附架桥作用则加快了污泥过滤脱水速度.而两者联合使用增大了污泥絮体二维分形维数,可使污泥絮体结构更加细密紧实,并提高污泥可脱除水分的比例,从而提高了污泥脱水性能.研究结果表明,絮凝剂和溶菌酶联用调理污泥脱水具有较好的应用前景.

Batch experiments were employed to investigate the effect of flocculant and lysozyme treatment on the sludge dewaterability,settling performance and floc characteristics.The results showed that the sludge settling performance was improved in the presence of flocculant and lysozyme alone.When the flocculant and lysozyme worked together,both the sludge settling performance and dewatered speed were further enhanced.The optimum flocculant and lysozyme dosage in the combined system was2mL and0.15g/g,respectively.And the moisture content of the sludge cake and specific resistance were determined to be65.7%and0.08×10^12m,respectively,which were decreased by25.3%and75.8%compared with the original mud.The results of extracellular polymeric substance(EPS)and floc shape suggested that lysozyme could change the EPS distribution and crack the floc structure.The absorption and bridge effect of the flocculant improved the sludge dewatering speed.The combination of flocculants and lysozyme increased the number of the two-dimensional fractal dimension of floc,made the floc structure closer and tighter,and improved the moisture ratio that could be dewatered in the sludge.This resulted in the enhanced sludge dewatering performance.This study demonstrated that the combination of flocculant and lysozyme on sludge dewaterbility treatment has a promising application potential.