几种微藻的水产养殖废水净化效果

Purification effect of several microalgae on aquaculture wastewater

为筛选适应热带海水养殖环境并能高效净化养殖废水的优势藻种,分析比较五种微藻去除化学需氧量(COD)、总氮(TN)、总磷(TP)和亚硝酸盐氮(NO_(2)^(-)-N)的能力。选择海南本土筛选的藻种小球藻(Chlorella sp.)、微拟球藻(Nannochloropsis sp.)、菱形藻(Nitzschia sp.)、牟氏角毛藻(Chaetoceros sp.)和外购藻种四尾栅藻(Scenedesmus sp.),在以对虾养殖水为底液配制的富营养化养殖废水中培养6 d。结果表明,绿藻在养殖废水中生长速率快,硅藻生长速率慢,小球藻在富营养化养殖废水中生长最好,OD680值、叶绿素a含量和细胞密度均最高,并与其他藻种有显著性差异。5种藻种中COD去除效果好的藻种是菱形藻和小球藻,去除率分别为71.6%、70.4%;总氮去除效果好的藻种是菱形藻、小球藻、牟氏角毛藻和微拟球藻,去除率分别为50.36%、47.96%、46.41%、42.79%;总磷去除效果好的藻种是菱形藻,去除率为71.43%;亚硝酸盐氮去除效果好的藻种是菱形藻、四尾栅藻和牟氏角毛藻,2 d去除率分别为96.60%、95.63%和95.40%;综合所有指标,菱形藻对养殖废水综合净化效果最好。

In order to screen the dominant algae that can adapt to the tropical marine aquaculture environment and purify aquaculture wastewater efficiently,the ability of five microalgae to remove chemical oxygen demand(COD),total nitrogen(TN),total phosphorus(TP)and nitrite nitrogen(NO_(2)^(-)N)was analyzed and compared.Chlorella sp.,Nannochloropsis sp.,Nitzschia sp.,Chaetoceros sp.,which were locally screened in Hainan,and purchased species Scenedesmus sp.were selected and cultured in eutrophic aquaculture wastewater with shrimp aquaculture water as bottom solution for 6 days.The results showed that Chlorophyta grew faster and diatom grew slower in aquaculture wastewater.Chlorella sp.grew best in eutrophic aquaculture wastewater,with the highest OD 680 value,chlorophyll-a content and cell density,which were significantly different from other algae species(P<0.05).Among the five kinds of algae,the ones with good COD removal effect were Nitzschia sp.and Chlorella sp.,and the removal rates were 71.6%and 70.4%respectively.The algae species with good removal efficiency of total nitrogen were Nitzschia sp.,Chlorella sp.,C haetoceros sp.and Nannochloropsis sp.,and the removal rates were 50.36%,47.96%,46.41%and 42.79%respectively.Nitzschia sp.was the best algae to remove total phosphorus,and the removal rate was 71.43%.The algae species with good removal effect of nitrite nitrogen were Nitzschia sp.,Scenedesmus sp.and Chaetoceros sp.,The removal rates in two days were 96.60%,95.63%and 95.40%respectively.Nitzschia sp.had the best comprehensive purification effect on aquaculture wastewater.