一种新型水溶性共聚物生物降解性评价

Evaluation on biodegradability of a novel water-soluble copolymer

将聚天冬氨酸与脱乙酰基壳聚糖(chitosan)进行共聚反应生成新的水溶性共聚物-一种新型阻垢剂.运用生物方法研究聚天冬氨酸壳聚糖共聚物的可降解性.将共聚物用活性污泥滤液降解处理后,测得其28 d的TOC降解率达到52.95%.其生物降解性能弱于PASP,属于可生物降解物质.研究还表明,水溶液中存在Ca2+,Mg2+,Fe3+,Zn2+等金属离子时不会对共聚物的降解性产生明显影响.然而Cu2+以及Hg2+等重金属离子则使共聚物的降解率明显下降.此外,降解残余物的红外分析表明在1654.27 cm-1处的峰形(酰胺中的C=O伸展振动峰和Schiff碱C=N伸展振动峰的叠加峰)明显变窄,推测聚天冬氨酸共聚物在发生生物降解时,首先在Schiff碱C=N键处断裂.研究结果说明聚天冬氨酸壳聚糖共聚物是可以被生物降解的.

The test aimed to carry out research on biodegradability of the polyaspartic acid-chitosan copolymer——a new water treating chemical. After the copolymer was treated by the active sludge for several days, TOC test was done for total organic carbon of the solution. And the copolymer＇s maximum degradation rate only arrived to 52.95% for 28 days, its biodegradability being poorer than that of PASP. Accordingly, it was concluded that the copolymer was a degradable reagent. Furthermore, the tested result also said that the degradation rate of the copolymer wasn＇t dropped by Ca^2＋ , Mg^2＋ , Fe^3＋ , Zn^2＋ , while was markedly decreased by Cu^2＋ and Hg^2 ＋ in aqueous medium. In addition, Infrared analysis for the degraded remains of the copolymer showed that the peak shape at 1 654.27 cm^ - 1 （ an overlap of the C = O stretch of amide with the C = N stretch of Schiff base） turned narrow apparently, then it could be inferred that, during the course of biodegradation of the copolymer, the C = N bond of Schiff base was broken firstly. Different analytical methods and corresponding results explained the copolymer could be biodegraded comparatively.