中文摘要：

壳聚糖作为一种天然高分子絮凝剂,在污水处理中应用较多,特别是作为絮凝剂的运用,具有絮凝效果好、无毒无害、不会造成二次污染等优点。本文以活性污泥为研究对象,考察了不同浓度的壳聚糖对活性污泥异养菌产率系数（YH）和自养菌产率系数（YA）的影响。结果表明,一定浓度的壳聚糖能降低YH和YA,对微生物具有一定的抑制作用。

英文摘要：

Chitosan, as a natural polymeric flocculant, is widely used in sewage treatment processes. It possesses advantages of good flocculation, harmless and no secondary pollution. This article studied the impact of chitosan in different concentrations on activated sludge heterotrophic yield coefficient （Yn） and activated sludge yield coefficient of autotrophic bacteria （YA） .The experiment results showed that chitosan in certain concentrations can reduce YH and YA, and can produce inhibitory action to microorganisms.