Study on the Feasibility of Enhancing the Biodegradation of Aniline Wastewater by Polyvinyl Alcohol-Sodium Alginate Gel Pellets Embedded Activated Sludge

Embedded pellets obtained by means of embedding activated sludge in polyvinyl alcohol—sodium alginate were successfully adapted in aniline wastewater degradation system. The results of shake flask experiment showed that the combination of sludge and embedded pellets had the best performance in degrading aniline, compared with sludge system and pellet system. Moreover, the application of embedded pellets promoted the toxicity tolerance and operation performance of the reactor. The enhanced reactor could completely degrade aniline and ammonia nitrogen in 150 and 240 min, and the total nitrogen removal rate increased by 26.83%. Meanwhile, high-throughput sequencing results illustrated that the addition of embedded pellets can effectively protect the diversity of functional microbial community. The average relative abundances of main functional genera such as Hydrogenophaga (aromatic amine compounds degradation and heterotrophic nitrification-aerobic denitrification), Norank_f__ Microscillaceae (nitrification), Brevundimonas (heterotrophic nitrification-aerobic denitrification), and Flavobacterium (denitrification) increased by 50.63%, 73.45%, 99.71%, 89.6%, 72.01%, and 95.70%, respectively.