铬在水平潜流和垂直流人工湿地中的形态转化和迁移  

Morphological transformation and migration of chromium in horizontal subsurface flow and vertical flow constructed wetlands

作　　者：伍振华 李良香 李素丽[1] 程夕冉[1] 王学礼[1] 李正文[1] 李志刚[1] WU Zhenhua;LI Liangxiang;LI Suli;CHENG Xiran;WANG Xueli;LI Zhengwen;LI Zhigang(College of Agriculture,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学农学院,南宁530004

出　　处：《农业环境科学学报》2023年第8期1803-1815,共13页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(21167002,41867023);广西自然科学基金项目(2018GXNSFAA281214)。

摘　　要：本研究以薏苡为湿地植物,构建了小型垂直流人工湿地(VC)和水平潜流人工湿地(HC),研究了不同水分管理对处理Cr^(6+)废水时铬的迁移转化的影响。结果表明:Cr^(6+)处理下,两种湿地的薏苡生长均受到了抑制,水平潜流人工湿地薏苡生长受抑制程度低于垂直流人工湿地。水平潜流人工湿地铬含量较高,而垂直流人工湿地易吸收的可交换态和碳酸盐提取态铬含量较高。基质的pH和Eh均随Cr^(6+)浓度的增加而呈现减小趋势。垂直流人工湿地pH及Eh值均大于水平潜流人工湿地。与潜流人工湿地相关的酶活性相比,垂直流人工湿地可以增加基质中蔗糖酶活性,但Cr^(6+)处理下脲酶活性却低于水平潜流人工湿地。高通量分析表明,不同处理下的两种人工湿地基质微生物群落存在显著差异,水平潜流人工湿地微生物更有利于将铬转化为难以利用的铬形态。水平潜流人工湿地对废水中的Cr^(6+)有更好的去除能力。研究表明,水平潜流人工湿地有利于促进Cr^(6+)转化为难以利用的铬形态,提高了人工湿地对污水中Cr^(6+)的去除能力。In this study,a small vertical flow-constructed wetland(VC)and a horizontal subsurface flow-constructed wetland(HC)were constructed with Coix lacryma-jobi L.as a wetland plant.The effects of different water management techniques on the migration and transformation of chromium in Cr^(6+)wastewater were investigated.The results revealed that:Under Cr^(6+)treatment,the growth of Coix lacryma-jobi L.in the two wetlands was inhibited,and the growth of Coix lacryma-jobi L.in horizontal subsurface flow-constructed wetland was less inhibited than that in vertical flow-constructed wetland.The content of chromium in the horizontal subsurface flowconstructed wetland was higher,whereas the content of exchangeable and carbonate-extractable chromium in the vertical flow-constructed wetland was higher.The pH value and Eh of the substrate decreased as Cr^(6+)concentration increased.The pH and Eh values of vertical flowconstructed wetlands were higher than those of horizontal subsurface flow-constructed wetlands.Compared with the enzyme activities related to the subsurface flow-constructed wetland,vertical flow-constructed wetland could increase the sucrase activity in the substrate;however,the urease activity under Cr^(6+)treatment was lower than that in the horizontal subsurface flow-constructed wetland.Highthroughput analysis demonstrated significant differences in microbial communities between the two constructed wetlands under different treatments.Horizontal subsurface flow-constructed wetland microorganisms were more conducive to converting chromium into difficult-touse chromium forms.Horizontal subsurface flow-constructed wetland is more effective at removing Cr^(6+)from wastewater.The results demonstrated that the horizontal subsurface flow-constructed wetland was beneficial in promoting Cr^(6+)transformation into chromium form,which was challenging to use,and improved the removal ability of Cr^(6+)in wastewater.

关 键 词：人工湿地 薏苡 铬 铬形态 土壤酶 可溶性有机物 

分 类 号：X703[环境科学与工程—环境工程]