水生植物滤床的植物组合及定期收割对植物铅蓄积的影响

Effects of plants arrangement and periodical reaping in aquatic plant filter bed on Pb in plants

通过水生植物滤床中试以及温室模拟试验,发现水生植物滤床(APFB)在2.5m3/(m2·d)的水力负荷下对水中Pb的去除率为25%～37%.采用合理的植物组合和定期收割,可分别使APFB中水生经济植物可食部位的Pb蓄积量减少20%和50%左右,经济水生植物的食用安全性显著提高.不同种类经济水生植物对水中Pb的吸收能力不同,茎叶/根质量比值大的植物对Pb的去除速度快,通常在12～24h内出现除Pb能力高峰.

A pilot scale aquatic plant filter bed (APFB) and static experiments in the greenhouse were carried out. At the hydraulic loading rate of 2.5 m3/(m2&middotd), the average removal efficiency of Pb was 25%-37%. Through reasonable plants arrangement and periodical reaping the accumulation of Pb in edible parts of economic aquatic plants could be cut down by 20% and 50% respectively and the edible safety of wetland plants can be enhanced evidently. The capacity of dealing with Pb is different for different kinds of economic aquatic plants. The plants that have higher ratio of (stem + leat)/root show higher rate of absorption of Pb and the absorption capacity peaks usually appear within 12-24 h.