新建组合填料垂直潜流湿地系统处理沿海垦区池塘养殖尾水的效果

Effect of a newly built vertical subsurface flow wetland system with combined filler on the treatment of tailwater from aquaculture ponds in coastal reclamation area

为探索沿海垦区池塘养殖尾水的净化技术,在条子泥垦区运行了一种以碱蓬作为净化植物,风化煤、陶瓷环和石英砂为组合填料的垂直潜流湿地系统,通过比较进、出水差异分析净化效果。70 d后,将不同填料取出进行硝化能力测试,并通过高通量测序技术比较菌群结构。结果显示:垦区尾水中的pH、总氮(TN)、总磷(TP)和高锰酸盐指数(COD_(Mn))分别为8.55~9.17、3.58~8.53 mg/L、0.47~1.16 mg/L和17.96~26.63 mg/L。经湿地净化后,出水中的pH为7.34~8.79,基本满足江苏省池塘养殖尾水排放一级标准。TN、TP和COD_(Mn)分别为2.75~6.65 mg/L、0.33~0.71 mg/L和16.32~24.16 mg/L,基本满足二级标准。pH、TP和COD_(Mn)在进、出水中的差异显著(P<0.05),平均下降8.78%、36.26%和13.52%。硝化能力测试表明,上、下层风化煤、陶瓷环和石英砂填料对总氨氮(TAN)的去除率差异显著(P<0.05),分别为97.44%、88.88%、49.30%和11.47%。细菌群落结构在不同填料上的差异显著(P<0.05),优势菌拟杆菌门(Bacteroidota)在石英砂上显著富集,norank_f__Microscillaceae在有碱蓬草根系附着的上层风化煤中显著富集(P<0.05)。本研究证实了组合填料垂直潜流人工湿地在沿海垦区池塘养殖尾水治理中的应用价值。

To explore the purification technology of the tailwater of aquaculture ponds in coastal reclamation areas,a vertical subsurface flow wetland system was designed and operated in the Tiaozini reclamation area,which was filled with Suaeda salsa as a purifying plant and weathered coal,ceramic ring,and quartz sand as combined fillers.The difference between influent and effluent was compared to analyze the purification effect.After 70 days,the different fillers were taken out for a nitrification capacity test,and high-throughput sequencing technology was used to compare the bacterial community structure.The results showed that the pH,total nitrogen(TN),total phosphorus(TP),and permanganate index(COD_(Mn))in the tailwater of the reclamation area were 8.55-9.17,3.58-8.53 mg/L,0.47-1.16 mg/L,and 17.96-26.63 mg/L,respectively.After purification,the pH of the effluent was 7.34-8.79,which basically met the second-level discharge standard of water from aquaculture ponds in Jiangsu Province.The TN,TP,and COD_(Mn) were 2.75-6.65 mg/L,0.33-0.71 mg/L,and 16.32-24.16 mg/L,basically meeting the secondary standard.The differences in pH,TP,and COD_(Mn) in influent and effluent were significant(P<0.05),with an average decrease of 8.78%,36.26%,and 13.52%.The nitrification capacity test showed that the removal rates of total ammonia nitrogen(TAN)by the upper and lower layers of weathered coal,ceramic ring,and quartz sand were significantly different(P<0.05),which were 97.44%,88.88%,49.30%,and 11.47%,respectively.The bacterial community structure on different fillers was significantly different(P<0.05).As dominant bacteria,Bacteroidota and norank_f__Microscillaceae were significantly enriched on the quartz sand and the upper layer of weathered coal with Suaeda salsa root attached,respectively(P<0.05).This study confirmed the application value of the combined filler vertical subsurface artificial wetland in the treatment of pond aquaculture tailwater in coastal reclamation areas.