聚己内酯与聚羟基丁酸戊酸酯的脱氮性能对比

以可生物降解聚合物聚己内酯(PCL)和聚羟基丁酸戊酸酯(PHBV)作为反硝化缓释碳源和微生物载体,利用清水释碳和批式反硝化试验选出适用于再生水反硝化深度脱氮生物滤池的可生物降解碳源滤料,通过比较与分析碳源滤料的表面形态及物质特性和附着微生物的群落特征揭示其性能优越的原因.结果表明,PHBV反硝化启动时间短,反硝化速率高,剩余有机物浓度低,相比PCL具有更稳定持续的反硝化效果.原因是其表面粗糙,且含有大量C—O和CO等亲水性基团,易于微生物附着和降解利用;其表面附着的微生物种类多样,其中发硫菌属(Thiothrix)、假单胞属(Pseudomonas)、菌胶团属(Zoogloea)、黄杆菌属(Flavobacterium)和脱氯菌属(Dechloromonas)等优势菌属均具有异养反硝化功能.因此,PHBV更适合作为再生水反硝化深度脱氮生物滤池的碳源滤料.

Comparison of Polycaprolactone and Poly-3-hydroxybutyrate-co-3-hydroxyvalerate for Nitrogen Removal

Two types of biodegradable polymers, polycaprolactone (PCL) and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), were used as a denitrification slow-release carbon source and a microbial carrier. By comprehensively comparing their performances in denitrification, carbon release, surface morphology, and material composition as well as their microbial community characteristics, the PHBV was determined as the better performer. It had a shorter denitrification start time, a higher denitrification rate, a lower residual organic matter concentration, and a more stable and sustained denitrification performance than PCL. This is because its surface was rough and contained large amounts of hydrophilic groups such as C-O and C=O, which is easily attached and degraded by microorganisms. As a result, the microorganisms on its surface were diverse. The dominant ones were identified with heterotrophic denitrification potentials, such as Thiothrix, Pseudomonas, Zoogloea, Flavobacterium, and Dechloromonas. Therefore, PHBV is suitable as a carbon source medium for tertiary nitrogen removal.