碱联合微波预处理污泥及交联聚合回收上清液中有机质和氮磷

Crosslinking polymerization to recover organic matter and nitrogen/phosphorus from the supernatant of sludge combined alkalimicrowave pretreated sludge

从污泥中回收有机组分是实现污泥的妥善处理和资源再利用的理想途径.本研究系统考察了碱联合微波处理下污泥中有机质及氮磷的释放特征,同时使用甲基三乙酰氧基硅烷(methyltriacetoxysilane,MTAC)以絮凝聚合物的形式回收污泥上清液中的营养物质,并探究其内在机制.结果表明,碱联合微波处理能有效加速污泥的溶解和胞内物质释放,最佳处理条件为NaOH剂量1.12 g·L^(−1)污泥、碱处理时间40 min,微波辐射功率640 W、微波辐射时间120 s.碱联合微波处理比单独碱处理SCOD溶出浓度提高了97.6%,TN和TP分别增加了51.35%和25.13%.MTAC与上清液中营养物质通过交联、絮凝和团聚作用,有效地分离回收了营养物质,其中蛋白质、多糖、TN和TP回收率分别高达44.72%、58.49%、76.90%和48.71%.本研究证实了碱联合微波处理污泥,以MTAC为交联剂进行化学聚合,是一种污泥高效处置和资源回收的简单的替代策略.

Recovery of high-value products is an ideal option to achieve proper treatment and resource recycling of sludge.In this study,the release behaviors of organic matter and nitrogen/phosphorus during sludge pretreatment by the combined alkali-microwave process were systematically investigated,and methyltriacetoxysilane(MTAC)was used to recover nutrients from sludge supernatant by crosslinking polymerization method.The results showed that combined alkalimicrowave could effectively accelerate sludge dissolution and intracellular substance release,and the optimal treatment conditions were observed to be 1.12 g·L^(−1) NaOH-sludge for 40 min and microwave radiation power 640 W for 120 s.Under the optimal conditions,SCOD concentration in supernatant increased by 97.6%,and TN and TP increased by 51.35%and 25.13%,compared with the alkali treatment alone.MTAC effectively separated and recovered nutrients from the supernatant through chemical cross-linking,flocculation,and agglomeration.The recovery efficiencies of protein,polysaccharide,TN,and TP reached 44.72%,58.49%,76.90%,and 48.71%.Our current study demonstrated that combined alkali-microwave pretreatment,followed by chemical polymerization with MTAC as the crosslinking agent,can be a simple and alternative strategy for highly efficient disposal and resource recovery from sewage sludge.