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

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 alkali-microwave 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.