三级模拟人工湿地对镉钨复合污染废水净化研究  

Purification of cadmium-tungsten composite polluted simulated wastewater by a three-stage simulated constructed wetland

作　　者：伍德 张威宇 刘玉玲 姚俊帆 张朴心 彭鸥 铁柏清[1,2,3] WU De;ZHANG Weiyu;LIU Yuling;YAO Junfan;ZHANG Puxin;PENG Ou;TIE Boqing(College of Environment and Ecology of Hunan Agricultural University,Changsha 410128,China;Hunan Engineering&Technology Research Center for Irrigation Water Purification,Changsha 410128,China;Key Laboratory of Southern Farmland Pollution Prevention and Control,Ministry of Agriculture and Rural Affairs,Changsha 410128,China)

机构地区：[1]湖南农业大学环境与生态学院,长沙410128 [2]湖南省灌溉水源水质污染净化工程技术研究中心,长沙410128 [3]农业农村部南方产地污染防控重点实验室,长沙410128

出　　处：《农业环境科学学报》2023年第6期1368-1378,共11页Journal of Agro-Environment Science

基　　金：湖南省高新技术产业科技创新引领计划项目(2020NK2001);国家重点研发计划项目(2017YFD0801505)。

摘　　要：为探究水培条件下,模拟人工湿地对镉(Cd)、钨(W)复合污染废水的净化效果及机理,本研究通过预实验筛选出的三种常见水生植物:再力花(Thalia dealbata Fraser)、旱伞草(Cyperus alternifolius L.)、铜钱草(Hydrocotyle vulgaris L.)搭建水培模式的三级模拟人工湿地,设3个处理,分别为单独种植处理(T1)、两两搭配种植处理(T2)、3种搭配种植处理(T3),对初始浓度为25μg·L^(-1)Cd、75μg·L^(-1)W的复合废水进行动态试验的研究。结果显示:T1、T2、T3三级模拟人工湿地的平均出水Cd浓度分别为3.30、3.20、2.75μg·L^(-1),平均去除率分别为87.01%、87.41%、89.18%;平均出水W浓度分别为24.02、20.14、26.75μg·L^(-1),平均去除率分别为68.24%、73.36%、64.62%,模拟人工湿地系统对Cd、W复合废水净化效果良好。T3处理共输入Cd约375 mg,系统截留333.75mg,其中植物富集截留102.66 mg,沉积物吸附截留231.09 mg;输入W约1 125 mg,系统截留723.75 mg,其中植物富集截留375.02mg,沉积物吸附截留348.73 mg。3种植物对Cd和W的富集效果良好,同种植物富集浓度沿出水方向降低,即第一级湿地>第二级湿地>第三级湿地。沉积物在系统中对两种重金属都有较大的吸附量,通过SEM电镜扫描其形态以及FTIR红外光谱图分析得知沉积物表面存在大量凹凸不平的吸附位点,存在主要吸附官能团:—OH、—COOH、C=C、C—O—C,揭示了沉积物对Cd、W吸附的部分机理。三级模拟人工湿地对废水中Cd、W净化效果良好,可以为钨矿区污染灌溉水中Cd、W的净化提供技术支撑。To explore the purification effect and mechanism of a simulated constructed wetland on simulated cadmium-tungsten composite polluted wastewater under hydroponics conditions,a pre-experiment was conducted to select three common aquatic plants:Thalia dealbata Fraser,Cyperus alternifolius L.and Hydrocotyle vulgaris L.These plants were used to build a hydroponic model of a tertiary simulated constructed wetland.Three treatments were set up:single planting treatment(T1),paired planting treatment(T2),and three types of combined planting treatment(T3).The dynamic experiment was carried out using simulated composite sewage with initial concentrations of 25μg·L^(-1) and 75μg·L^(-1) of cadmium and tungsten,respectively.The results showed that the average effluent cadmium concentrations in T1,T2,and T3 simulated constructed wetlands were 3.30,3.20,and 2.75μg·L^(-1),respectively.The average removal rates for cadmium were 87.01%,87.41%,and 89.18%,respectively.The average effluent tungsten concentrations were 24.02,20.14,and 26.75μg·L^(-1),and the average removal rates were 68.24%,73.36%,and 64.62%,respectively.The simulated constructed wetland system showed a good purification effect on the simulated wastewater.A total of 375 mg of cadmium was injected into T3 treatment,and 333.75 mg was retained by the system,of which 102.66 mg and 231.09 mg were retained by plant enrichment and sediment adsorption interception,respectively.Similarly,out of 1125 mg of input tungsten,723.75 mg was retained by the system interception,of which 375.02 mg and 348.73 mg were retained by plant enrichment and sediment adsorption interception,respectively.The enrichment effect of cadmium and tungsten in the three plants was good,and the enrichment concentration of the same plants decreased along the direction of the water outlet,namely,the first level wetland>the second level wetland>the third level wetland.The sediment had a high adsorption capacity for both heavy metals in the system.By scanning the morphology of the sediments under SEM and

关 键 词：模拟湿地 复合污染 废水净化 植物富集 沉积物 

分 类 号：X703[环境科学与工程—环境工程] X173