Abstract: This study used a modified natural product，cationic guar gum (CGG)，combined with polyacrylamide(PAM) to investigate sludge settling and dewatering. Two kinds of treatment reagents were added in different dosage and order，capillary suction time (CST)，settling velocity(SV)，water content of centrifugal sludge and supernatant centrifugal transmittance were investigated. The results showed that CGG improved the dewatering performance and settlement performance. The combination of CGG and PAM had better performances. The optimal operational condition was at 900 mg/L CGG followed by 150 mg/L PAM. SV decreased 17.2% than the original sludge，CST decreased from 470 s to 14 s and the supernatant centrifugal transmittance was up to 96.1%.

Key words: sludge, cationic guar gum(CGG), polyacrylamide(PAM), settlement performance, dewatering performance

摘要： 采用改性天然产物阳离子瓜尔胶（CGG）和聚丙烯酰胺（PAM）调理污泥，研究它们对城市生活污泥的沉降和脱水效果，分析两种药剂以不同投加量和不同投加顺序对污泥毛细吸水时间（CST）、30 min污泥沉降比（SV）、离心后污泥含水率及离心后污泥上清液透光率的影响。结果表明：CGG能够提高污泥的脱水性和沉降性，与PAM复合使用时，效果更显著。试验得出CGG和PAM用量分别为900 mg/L和150 mg/L，投加方式为先加阳离子瓜尔胶，搅拌后加PAM，污泥脱水和沉降效果较好，SV比原污泥下降了17.2%，CST由470 s下降到14 s，上清液透光率达到96.1%。

关键词: 污泥, 阳离子瓜尔胶, 聚丙烯酰胺, 沉降性, 脱水性