Mn^(2+)对两种人工湿地植物冬季净化生活污水效果的影响

Effects of Mn^(2+) on sewage purification efficiency of two constructed wetland plants in winter

以风车草和蜘蛛兰为材料,采用水培的方法,研究冬季Mn2+胁迫对人工湿地植物净化生活污水效果的影响,为应用人工湿地修复重金属污染污水奠定基础。结果表明,在0～50mg/LMn2+胁迫条件下,两种植物对生活污水中CODcr的去除率较高,而在较高浓度(250mg/L)下,风车草对CODcr的净化效果大幅降低,蜘蛛兰甚至出现负值;两种植物均是在前期对污水中TP处理效果较好,且不同处理间较稳定,后期处理效果比前期降幅较大;两种植物在两个采样期均是在Mn2+中浓度(50mg/L)以下时对污水中的NH3-N的去除效果较好,高浓度(250mg/L)时对污水中NH3-N的去除率则急剧下降,风车草前期是负值,蜘蛛兰两个时期都是负值。说明风车草和蜘蛛兰比较适合处理浓度为50mg/L以下的含Mn2+污水。

Hydroponic experiment was conducted by using Cyperus altemifolius and Hymenocallis americana plants in order to study the effects of Mn^2＋ stress on sewage purification efficiency of constructed wetland plants in winter for providing the basis on the remediation of sewage polluted by heavy metals. The results indicated that at low Mn^2＋ concentration （0-50 mg/L）, the removal rate of CODer in sewage by both kinds of plants was higher, while under high concentration （250mg/L）, the purification efficiency of Cyperus ahernifolius on CODer decreased significanthy, and showed negative value of CODer. The purification efficiency of two kinds of plants on TP in sewage were good and stable when treated at early stage, while the purification efficiency decreased significanthy when treated during late stage. At Mn^2＋ concentration of 50mg/L, the purification efficiency on NH3-N in sewage by the two plants was good at both stages, while the removal rate of NHa-N in sewage decreased suddenly at Mn^2＋ concentration of 250mg/L, and that of Cyperus altemifolius showed negative value at early stage and Hymenocallis americana showed negative value at both stages. Therefore, Cyperus altemifolius and Hymenoeallis Americana were suitable for treating the sewage with lower than 50mg/L Mn^2＋ concentration.