We apply a new natural high efficiency of unchanged chitosan(VCG)to retreatment of city sewage,which was used after traditional activity sludge treatment.

• 采用一种新型高效的天然高分子混凝剂一改性壳聚糖VCG对城市污水用于传统活性污泥法处理后的再处理,可有效地除掉余下的污染物质。