采用生物亲和聚氨酯处理污水的原理与应用

作为生物膜法的核心，生物载体在污水处理中起着关键作用. 然而，传统的商用生物载体存在生物亲和性差、挂膜困难等固有缺陷，因此，开发新型载体用以提高废水处理效率对生物膜反应器的应用与发展具有重要意义. 通过物理涂覆方法制备得到BPU(生物亲和性聚氨酯)，对载体的表观特性和化学组分进行表征，并将其作为移动床生物膜反应器的填料处理模拟生活污水，初步评价BPU的生物亲和性和污水处理效果，之后通过比较生物膜生长情况差异和微生物群落结构变化对其增效机理进行分析. 结果表明:①改性增加了载体表面的粗糙度和比表面积，载体表面Zeta电位由(?31.70±1.93) mV变为(2.14±0.14) mV，接触角由44.50°±0.14°降至24.88°±1.46°. ②投入生物膜反应器使用后，BPU表面附着的生物量和胞外聚合物(EPS)分泌量增加，生物膜组成结构得到改善，TN和NH₄+-N的去除率分别增加了6.27%±0.30%和13.74%±0.68%. ③微生物分析表明，BPU丰富了微生物群落多样性，脱氮功能菌数量增加，从而促进了污染物的去除. 研究显示，BPU具有良好的生物亲和性，能够有效提高生物膜反应器的性能. 

Mechanism and Application of Bioaffinity Polyurethane in Wastewater Treatment

Biocarriers play a critical role in the biofilm process, so they are essential in wastewater treatment. Commercial biocarriers have inherent defects such as poor bioaffinity and inefficient biofilm formation. It is thus important to develop new carriers to improve wastewater treatment efficiency to benefit the application and development of biofilm reactors. The polyurethane with bioaffinity (BPU) was prepared by physical coating method, and the apparent characteristics and chemical composition of the carrier before and after modification were analyzed and compared. Then, the new carrier was applied in a moving bed biofilm reactor as a filler to treat simulated domestic wastewater. Its bioaffinity and wastewater treatment efficiency were evaluated. In addition, the synergistic mechanism was analyzed by comparing the biofilm growth and the changes in microbial community structure. The results showed that: (1) The modification increased the surface roughness and specific surface area of the carrier. The zeta potential of the carrier surface changed from (?31.70±1.93) mV to (2.14±0.14) mV. The contact angle decreased from 44.50°±0.14° to 24.88°±1.46°. (2) After being applied to the biofilm reactor, the biomass attached to the surface of the BPU and the secretion of extracellular polymer substances (EPS) increased, the composition of biofilms was improved, and the removal rate of TN and NH₄+-N increased by 6.27%±0.30% and 13.74%±0.68%, respectively. (3) Microbial analysis showed that the BPU enriched the diversity of the microbial communities, increased the abundance of denitrification functional bacteria, and promoted the removal of contaminants. Therefore, the BPU has a good bioaffinity for improving the performance of biofilm reactor.