铬对人工湿地净化生活污水的影响及铬积累规律  

Effects of Chromium on Purification of Domestic Wastewater and Its Accumulation in Constructed Wetlands

作　　者：李志刚[1] 黄海连[1] 李素丽[1] 蒲琦[1] 陈伟刚[2] 王振丰[3] 崔新晓[1] 陈永[1] 

机构地区：[1]广西大学农学院,南宁530005 [2]南宁市环境保护局,南宁530022 [3]广西建设职业技术学院,南宁530005

出　　处：《农业环境科学学报》2010年第7期1362-1368,共7页Journal of Agro-Environment Science

基　　金：重点流域水污染的绿色生态修复技术研究与应用示范(桂科攻0719005-2-2B);小城镇简易高效低耗污水处理共性关键技术研究与应用示范(桂科攻0816002-4);环境修复与生态健康教育部重点实验室开放基金项目(050102)

摘　　要：采用沙培法,研究了不同浓度Cr6+(0、10、20、40 mg.L-1)对风车草湿地和薏米湿地净化生活污水的影响及铬积累规律。结果表明:(1)COD的去除率在苗期随铬浓度增大而逐渐升高,其余时期在20、40 mg.L-1处理下受到显著抑制(除了花期风车草湿地外);随铬处理浓度的增大,风车草湿地对TN的去除率变化不明显,薏米湿地对TN的去除率则受到抑制作用(除了花期10 mg.L-1外);这两种湿地对生活污水中铬的净化效果较好,仅在40 mg.L-1处理的风车草湿地出水中检测出铬。(2)10 mg.L-1铬促进风车草和薏米的生物量增大,较高浓度铬(20、40 mg.L-1)则抑制。(3)基质细沙及植物根系对污水中铬具有较好的吸附及积累作用,铬含量在细沙及植物中均随铬浓度增大而显著升高,其中两种植物对铬的积累量都表现为地下部显著大于地上部,表明风车草和薏米的根部中铬较难转移到其地上部。Sand culture experiments were conducted in order to study the effect of different concentrations of chromium（0,10,20,40 mg.L-1） on domestic wastewater purification of Cyperus alternifolius and Coix aquatica Roxb wetlands and chromium accumulation rules.The results were as follow：（1）At the seedling stage,the COD removal rates gradually increased along with the enhancement of chromium concentration,but they were significantly inhibitted under the treatments of 20,40 mg.L-1 in the other stages（except the flowering stage of Cyperus alterni-folius）;TN removal rate of Cyperus alternifolius wetland wasn′t significantly affected along with the increase of Cr6＋ concentrations,but it was inhibitted as far as Coix aquatica Roxb wetland was concerned（except treatment with Cr6＋ 10 mg.L-1 at flowering stage）;These two wetlands had good purification effects on domestic wastewater which contained chromium.Chromium was only detected in water that flowed out from the constructed Cyperus alternifolius wetland under 40 mg.L-1 treatment（.2）Treatment with Cr6＋ 10 mg.L-1 induced the enhancement of Cyperus alternifolius and Coix aquatica Roxb biomass,but higher concentrations（20 mg.L-1 and 40 mg.L-1）showed inhibition effects on the biomass（.3）Fine sand and plant roots had great capabilities of adsorption and accumulation of Cr6＋ in wastewaster.Chromium contents in fine sand and plants significantly increased along with Cr6＋ concentration enhancement.The accumulations of chromium in roots of the two plants were significantly higher than those in shoots,proving that roots chromium of the two plants were hardly transfered to the shoots.

关 键 词：人工湿地 Cr6+ 净化 生活污水 积累 

分 类 号：X701.3[环境科学与工程—环境工程]