Physiological Responses of Pistia stratiotes and Its Fluoride Removal Efficiency

大薸对水中氟化物的去除及生理响应

Phytoremediation technology using aquatic plants is being used increasingly in constructed wetlands to purify wastewater. The physiological responses of water lettuce(Pistia stratiotes) and its effectiveness in removing fluoride(F~–) from water are described in this article. The results indicate that Pistia stratiotes has the ability to accumulate F~–. The removal efficiency ranged from 27.79% to 56.32% for the various initial F~– concentrations tested, and was highest(56.32%) in the highest initial concentration group 60 mg/L. The F~– concentrations in control groups(without Pistia stratiotes) changed very little, from –1.135% to –0.007% of the initial concentrations. At the highest removal rate, the bioconcentration factor was 7.84. The rate of purification conformed to the Michaelis-Menten equation, and the correlation coefficients(R^2) were all greater than 0.97. The Specific Growth Rates(SGR) of the treatment groups were –8.03% to –1.22%, and the SGR of plants under F~– stress decreased during the experimental period. The partial correlation analysis showed that concentrations of F~– in water were strongly linearly correlated with peroxidase.

采用水生植物构建的人工湿地生态修复技术在用于净化废水方面正逐渐兴起。试验采用大薸为实验材料,采用室内培养方法,研究该湿地植物对水中氟化物水体的去污效果及其植物生理响应。实验结果表明大薸可富集水中氟化物,对于所试验的水中氟化物初始浓度,去除率在27.79%到56.32%之间,最高的去除效率出现在氟化物最高初始浓度60 mg L-1时。对照组中氟化物的浓度波动很小,最终浓度为其对应初始浓度的-1.135%--0.007%,处理组净化速率符合Michaelis-Menten方程,其相关系数均高于0.97。在试验周期内,大薸在氟化物的胁迫下比生长速率(SGR)呈降低趋势,处理组植物的SGR在-8.03%与-1.22%之间。对照组植物的SGR呈增长趋势,为4.18%。偏相关分析表明水中氟化物浓度与POD呈高度线性相关。