摘要
通过在所构建的3组垂直流人工湿地(CW1、CW2、CW3)中添加不同ρ(DOC)(0、14、28 mg/L,DOC为溶解性有机碳)的美人蕉根系浸出液来模拟根系分泌物浓度变化,考察其对2种SEs(steroidal estrogens,类固醇雌激素)去除效果的影响.结果表明:1虽然根系浸出液和根系分泌物中的ρ(DOC)存在差异,但二者成分比例类似,均含有多种小分子化合物(如氨基酸、多糖、有机酸、脂肪酸、醇、烷等),并且甘油含量均为最高.2各组湿地对SEs的去除率表现为CW2>CW3≈CW1,CW2对E1(Estrone,雌酮)、EE2(17α-Ethinylestradiol,17α-乙炔基雌二醇)的去除率最高可分别达到86.9%、72.7%.3各组湿地全细菌和AOB(ammonia oxidizing bacteria,氨氧化细菌)平均密度大小表现为CW3>CW2>CW1,NOB(nitrite oxidation bacteria,亚硝酸氧化细菌)平均密度大小表现为CW2>CW3>CW1,DNB(denitrifying bacteria,反硝化细菌)平均密度大小表现为CW3>CW1≈CW2,各组湿地基质上生物膜的脱氢酶活性表现为CW2>CW1>CW3.研究显示,适量添加根系浸出液有利于SEs的去除,但根系浸出液中ρ(DOC)过高,可能会对植物根系和特定根系微生物(如NOB)的生长造成毒害作用,并抑制微生物活性,从而影响SEs的去除效果.
Steroidal estrogens （SEs） have been found to pose a threat to humans and animals even at an extremely low level. However, little research has investigated the removal of SEs from wastewater in constructed wetlands. The removal of estrone （E1） and 17α-ethinylestradiol （EE2） in constructed wetlands （CW1, CW2, CW3） was studied when different concentrations of root extracts from Canna （ρ（DOC）=0,4, 28 mg/L） were applied to simulate the change of root exudates. The influences of root exudates on the micro-environment of the root zone and the SEs removal were determined. The results showed that：1） The root exudates and root extracts from Canna were similar in composition, both of which included amino acid, polysaccharose, organic acid, fatty acid and other low molecular weight organic matters, and the concentration of glycerin was the highest among them. 2） The removal rates of E1 and EE2 in CW2 were the highest, reaching 86.9% and 72.7%, respectively. 3） The average densities of total bacteria and ammonia oxidizing bacteria followed the sequence CW3〉CW2〉CW1 and CW2〉CW3〉CW1 for nitrite oxidation bacteria, and CW3〉CW1≈CW2 for denitrifying bacteria. The dehydrogenase activity of CW2 was the highest, followed by CW1 and CW3.In conclusion, the addition of root exudates posed great influence on SEs removal in constructed wetlands and the dehydrogenase activities of microorganisms.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2016年第1期59-66,共8页
Research of Environmental Sciences
基金
国家自然科学基金项目(41571476)
江苏省自然科学基金项目(BK20141117)
