水平潜流人工湿地对邻苯二甲酸酯类的去除效率分析

Phthalate acid ester removal efficiency in horizontal subsurface flow constructed wetland

邻苯二甲酸酯(Phthalate acid esters,PAEs)是一类生产量大、应用广泛的人工合成有机化合物,在环境中普遍存在;同时,PAEs作为一类环境内分泌干扰物,对人类及生态环境都具有潜在威胁.人工湿地系统作为一种污水处理技术,已被用于处理各种类型的污水,但其对PAEs的去除效率的研究尚不多见.本文通过对天津一个实际运行中的水平潜流人工湿地系统中进出水及单元内部水样的采集,探讨处理单元水中常见的4种PAEs,即邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DEHP)的去除效果,结果显示,在进出水及湿地单元内部均检测到4种目标PAEs,进水及出水中PAEs平均总质量浓度分别为2.53、0.98μg·L-1,在湿地单元内部存在PAEs质量浓度随着水流方向降低的趋势,其中,DMP的质量浓度始终都低于另外3种PAEs的质量浓度.该人工湿地对DMP、DEP及DBP的去除效果较好,而对DEHP的去除效果则较差.

Phthalate acid esters （PAEs） are a group of synthetic organic compounds widely used and ubiq- uitously present in the environment As a class of environmental endocrine disruptors, phthalate acid esters pose a potential threat to human and environment health Constructed wetlands as wastewater treatment systems have been used to treat wastewater. However, very few studies have been conducted on removal of PAEs in constructed wetlands. In the present work, the removal of four common PAEs （dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-（2-ethylhexyl） phthalate） in horizontal subsurface flow constructed wetland and their distribution in the wetland system were investigated. All PAE were detected in the water samples （influent, effluent of the wetland and the water from wetland chamber）. The mean concentrations of PAE in the influent and effluent of the wetland were 2.53 and 0.98 μg·L-1 respectively. PAEs concentrations decreased along the flow in the wetland chamber. The concentration of dimethyl phthalate was always lower than other PAEs. The mean removal efficiencies of dimethyl phthalate, diethyl phthalate and dibutyl phthalate were 31.1 %, 41.1 % and 37.6%respectively while removal of di-（2-ethylhexyl） phthalate was not achieved.