水平潜流人工湿地处理邻二氯苯废水研究

采用水平潜流人工湿地(SFCW)处理邻二氯苯(o-DCB)废水，构建了基质分别为壤土、 细沙和粗砂的3套芦苇湿地中试系统W-L、 W-F、 W-C和无植物的壤土湿地对照组W-Z.结果表明，最佳水力停留时间为5 d，最适表面负荷率为150 mg·(m²·d)^-1，湿地组W-L、 W-F、 W-C和W-Z对o-DCB的去除率分别为81.2%、 71.1%、 72.4%和65.2%；8月中旬湿地运行效果最好，进入10月后性能有所下降，各个湿地系统对o-DCB废水处理效果顺序为W-L>W-C>W-Z>W-F，壤土和粗砂基质具有各自的优势；o-DCB浓度和溶解氧(DO)在湿地W-L和W-Z空间分布状况表明DO有利于o-DCB降解；o-DCB残留量在各层土壤中沿水流方向递减，随深度加深而增加；在芦苇组织中呈阶梯状分布，根、 茎、 叶中平均残留值分别为30.28、 14.85和 6.18 μg·g^-1.

Treatment of 1, 2-dichlorobenzene in Wastewater by Using Horizontal Subsurface Flow Constructed Wetlands

Pilot-scale horizontal subsurface flow constructed wetlands (SFCW) planted with Phragmites australis were constructed to treat in 1,2-dichlorobenzene (o-DCB) wastewater. Different soil substrates of loam (W-L), fine sand (W-F) and coarse sand (W-C) were used in the three SFCW and a loam wetland with no reeds W-Z was taken as control. Results showed that the optimal hydraulic retention time (HRT) and pollutants surface loading rate(ALR)were 5 d and 150 mg x (m2 x d)(-1). Removal efficiencies for o-DCB of W-L, W-F, W-C and W-Z were 81.2%, 71.1%, 72.4% and 65.2%, respectively. The performance of systems achieved in mid-August and declined from October, with order of W-L > W-C > W-Z > W-F. Spatial concentration dynamics of o-DCB and dissolved oxygen (DO) were also investigated in W-L and W-Z, which indicated that DO was an important role to removal of o-DCB. The residual quantity of o-DCB in wetland substrate decreased along the flow direction and increased with the depth of substrate layers, the mean residual in the root, stem and leaf of reeds were 30.28, 14.85 and 6.18 microg x g(-1).