聚丙烯酰胺胶状杂质的形成原因

Formation reason of gel-like impurities of polyacrylamide

在聚丙烯酰胺(PAM)配制现场发现过滤器滤袋内存在大量黑色和黄色且有刺鼻腐臭气味的胶状条形物;这类杂质造成过滤装置严重堵塞和设备腐蚀.鉴于此,从细菌和无机离子含量两方面着手分析了聚丙烯酰胺胶状条形杂质的形成原因.结果表明:由于细菌和金属离子Fe3+含量的增加,PAM的侧酰胺基降解成羧基;而含大量金属离子的PAM溶液经缠结交联形成条形物.与此同时,PAM经生物降解产生NH3,硫酸盐还原菌(SRB)利用细胞膜内产生的氢将硫酸盐还原为H2S,从而产生腐臭气味.

With a view to the emerge of a great deal of black and yellow strip substances with pungent putrid odor in the filter-bag of percolator at the site where polyacrylamide（PAM） was prepared as well as severe blockage of the percolator and corrosion of equipments caused by the impurities,analyses were made in relation to bacteria and inorganic ions so as to search the reasons leading to the impurities.It was found that,due to the increase of amount of bacteria,the content of Fe3＋ increased,and the side amide chain of PAM was degraded to form carboxyl.This,in association with tangling and cross-linking of PAM solution containing increased content of metal ions,resulted in the strip substances.At the same time,PAM was biodegraded to generate NH3,and sulfate reducing bacteria（SRB） reduced sulfate to form H2S by making use of H2 produced inside cell membrane,resulting in putrid odor.