一种负载功能型微生物的营养缓释填料的制备及性能评价

根据乳化交联和吸附固定化原理,制备了一种负载功能型微生物的营养缓释填料(SC填料),并以乙酸丁酯作为模拟废气,考察了其在生物反应器中的使用效果.填料理化特性分析结果表明,该填料孔隙率为92.6%,堆积密度为40.75kg·m~(-3),比表面积为2.45 m2·g~(-1),真密度为551.52 kg·m~(-3);表面存在大量的O—H、C=O等亲水基团,同时填料内分布氮(N)、磷(P)等营养元素,N和P的释放速率分别为22.35 mg·(L·d)-1和8.36 mg·(L·d)-1;微生物负载量(蛋白/填料)为14.61 mg·g~(-1),储藏7 d和30 d后填料内微生物对乙酸丁酯的去除率 96%,表明其储藏稳定性较好.应用SC填料的生物滴滤塔经过8 d完成挂膜过程,在外界不供给营养、不调节循环液pH的情况下,应用SC填料的反应器运行性能稳定,去除率始终保持在94%以上,而采用聚氨酯海绵填料(PU填料)的生物滴滤塔挂膜期稍长、运行不稳定.高通量测序表明,填料制备过程中固定的特定降解菌在整个运行阶段均处于优势地位,且菌群结构较为稳定,从而能保证反应器的稳定运行.

Preparation of a Nutritional Slow-release Packing Material with Function Microorganisms and Its Characteristics Evaluation

A nutritional slow-release packing material with function microorganisms (SC) was prepared using emulsification and the cross-linked method. Its potential as packing material in biotrickling filters (BTF) for butyl acetate removal was evaluated. The physicochemical properties show that the packing has a porosity of 92.6%, bulk density of 40.75 kg·m^-3, surface area of 2.45 m²·g^-1, and real density of 551.52 kg·m^-3. The packing material contains hydrophilic groups (O-H, C O) on its surface and nutrient elements (N, P), which are distributed uniformly, with release rates of 22.35 and 8.36 mg·(L·d)^-1, respectively. The biomass concentration of the packing (protein/packing) is 14.61 mg·g^-1. After storage for 7 and 30 d, the microorganisms fixed on the packing material could still remove more than 96% of butyl acetate. The BTF using SC as packings reach stable performance within a short time (8 d) and the removal efficiency is maintained at 94% unless there nutrition is supplied or the pH is adjusted. The BTF with polyurethane as packing material need a longer time to start up and the removal efficiency decreases to 80% under the same operating conditions. High-throughput sequencing analysis shows that the fixed degrading stains are dominant during the whole operation and the microbial structure is more stable, which could sustain the stable removal of butyl acetate in BTF using SC.