综合生态净化系统对凡纳滨对虾养殖尾水的净化效果OA

Aquaculture has rapidly expanded to meet the growing global demand for animal protein,but the discharge of nutri-ent-rich effluent poses significant environmental challenges.Therefore,this study explores an efficient and sustainable ecolo-gical treatment technology,the integrated ecological purification system,to improve aquaculture effluent quality and support the industry's long-term ecological balance.In order to understand the purification effect of the integrated ecological purifica-tion system on the aquaculture tail water of Litopenaeus vannamei continuous freshwater pond,the water quality index of each unit in the system was monitored for two consecutive years.High-throughput sequencing technology and bioinformatics ana-lysis were employed to analyze the microbial community structures in each unit.Correlation analysis and random forest regres-sion model were utilized to assess the relationship between dominant microorganisms and water quality factors.The results indicated that,according to the requirements of Shanghai Municipal Aquaculture Tail Water Standard(DB31/1 405-2023),the main pollutants exceeding the standard in the aquaculture effluent were TSS and TN,with exceedance rates of 36.84%and 5.26%,respectively.After treatment in each unit of the system,significant reductions(P<0.05)were observed in the concentra-tions of TSS,TN,TP,CODMn,and TAN,resulting in effluent water quality meeting the standards.The microbial richness increased along the treatment units(P>0.05),with Proteobacteria,Actinobacteriota,and Cyanobacteria being the dominant phyla.The top five dominant bacteria genera explained 51.50%,23.42%and 18.44%of the variation in NO3-N,TN and TAN concentrations,respectively.The hgcI_clade was the most dominant bacterium,whose abundance gradually increased along the unit,and exhibited a significant negative correlation with TN and NOx(P<0.05).Overall,the comprehensive ecological purific-ation system significantly improved the water quality of aquaculture effluent.Different treatment units exhibited varying effects on improving different water quality indicators in the effluent.Microbial communities capable of promoting nutrient metabol-ism gradually became dominant along the treatment units,significantly influencing the removal of nitrogen pollutants from the effluent.This study provides valuable insights for the practical application and further optimization of multi-level aquaculture effluent treatment systems.