Bioaugmentation strategy for the treatment of fungicide wastewater by two triazole-degrading strains

In this study, bioaugmentation potential of 1H-1,2,4-triazole (TZ) degrading strain namely Shinella sp. NJUST26 and tricyclazole (TC) degrading strain namely Sphingomonas sp. NJUST37 was evaluated in a bench-scale activated sludge tank. The performance of the bioreactor demonstrated the feasibility of bioaugmentation by NJUST26 and NJUST37 in terms of almost complete TC and TZ removal, significant COD and TOC removal, as well as toxicity reduction. The effect of influent pH, hydraulic retention time (HRT) and triazole fungicide concentration was investigated in order to reach an optimal treatment performance. The bioaugmented process after the inoculation of NJUST26 and NJUST37 could maintain stable performance in terms of TZ, TC, COD and TOC removal from the wastewater. High-throughput sequencing analysis suggested that higher diversity and significant shifts in bacterial community structure were achieved after the inoculation of NJUST26 and NJUST37. However, both NJUST26 and NJUST37 lost their dominance during long-term operation, despite of the key role of the inoculation of NJUST26 and NJUST37 in the formation of effective microbial community.