混凝好氧颗粒污泥的絮凝剂选择

Selection of flocculants for coagulation of aerobic granular sludge

为选择出适应于混凝好氧颗粒污泥培养的絮凝剂,通过絮凝剂添加量、污泥浓度、搅拌速度、搅拌时间等因子进行L9(3)4正交实验,以COD、浊度去除效果及絮凝颗粒结构为考察因子,研究聚合氯化铝(PAC)、聚丙烯酰胺(PAM)及壳聚糖的絮凝效果。结果表明,在不同絮凝剂的最佳混凝条件下,PAM的效果最好,壳聚糖次之,PAC最差,但壳聚糖COD随其添加浓度的增加而增加;絮凝颗粒结构中,以PAM的絮凝颗粒效果最好,其结构紧溱而颗粒中间的空隙相对较大,有利于吸附污染物和微生物的生长,适宜作为颗粒污泥培养的絮凝剂。

The aim of this study is to select a suitable flocculant for cultivation of coagulation aerobic granular sludge. L9( 34) orthogonal test was performed with four factors: flocculant dosage,sludge concentration,stirring speed and stirring time. COD,turbidity removal effects and flocculant particle structure were used to investigate the flocculating effect of the polymerization aluminum chloride( PAC),polyacrylamide( PAM),and chitosan.The results show that PAM has the best flocculating effect in different flocculants of best coagulation conditions,chitosan followed and PAC is the worst. However,the COD value of chitosan increases with its increased concentration. Furthermore,PAM is best with flocculant particle structure as it is compact and has relatively large space among the particles,which helps the adsorption of pollutants and the growth of microorganisms. In conclusion,PAM is a suitable flocculant for the cultivation of granular sludge.