3种水生植物对锰污染水体修复作用的研究

通过静态水培试验,研究了3种水生植物水葫芦（Eichhornia crassipes（Mart.）Solms）、水浮莲（Pistia stratiotes L.）、水花生（Atlernanthera philoxeroides）在55、155mg L-1锰（Mn）质量浓度下的生物量、Mn质量分数、富集系数、转运系数,以及对2种Mn质量浓度水体的修复作用。结果表明,水浮莲的鲜质量、干质量、相对生长率、Mn质量分数、富集系数随着取样时间的延长而显著增加（P〈0.05）。2种Mn质量浓度下,水葫芦与水浮莲的鲜质量与相对生长率显著高于水花生。植物茎叶的Mn质量分数依次为水浮莲〉水葫芦〉水花生（P〈0.05）,其中155mg L-1Mn处理水浮莲与水葫芦茎叶Mn质量分数均高于10000mg kg-1,分别为12431.05mg kg-1、11238.28mg kg-1。3种植物茎叶、根的富集指数均显著大于1,且茎叶的富集系数依次为水浮莲〉水葫芦〉水花生（P〈0.05）,根富集指数依次为水浮莲≈水葫芦〉水花生（P〈0.05）。在10,21d这2个取样时期,水浮莲的转运系数要高于其它植物,其中在155mg L-1处理下,水浮莲的转运系数要高于1,分别为1.04、1.01。种植3种水生植物后,2种Mn处理水体的Mn质量浓度随着取样时间的延长而降低。水葫芦、水浮莲、水花生收获时,55mg L-1Mn处理的水体Mn质量浓度分别降低了31.84%、31.44%、18.47%;155mg L-1Mn处理则降低了12.02%、18.53%、7.57%。可见,水浮莲符合超积累植物对Mn质量分数、富集系数、转运系数的要求,其在Mn污染水体修复方面有很好的应用前景。

Phytoremediation of manganese-contaminated water by three aquatic macrophytes

The biomass,manganese（Mn） content,enrichment factor and translocation factor of water hyacinth（Eichhornia crassipes（Mart.） Solms）,water lettuce（Pistia stratiotes L.）,and slligator alternenthera（Atlernanthera philoxeroides）,and the Mn content in water were investigated with two Mn levels：55,155 mg L-1.The fresh weight,dry weight,relative growth rate,Mn content and enrichment factor of water lettuce were significantly（P 0.05） increased with the sampling date.At 55 and 155 mg L-1 Mn levels,the fresh weight and relative growth rate of water hyacinth and water lettuce were markedly greater（P 0.05） than that of slligator alternenthera.For shoots Mn content,it decreased（P 0.05） as follows：water lettuce water hyacinth slligator alternenthera.At 155 mg L-1 Mn level,the shoots Mn contents of water lettuce and water hyacinth were 12 431.05 and 11 238.28 mg kg-1,respectively,which were much greater than 10 000 mg kg-1,a characteristic of good phytoremediators.The shoots and roots enrichment factor were remarkably greater than 1,and the decreasing order of shoots enrichment factor was：water lettuce water hyacinth slligator alternenthera（P 0.05）,and of roots enrichment factor was：water lettuce ≈ water hyacinth slligator alternenthera（P 0.05）.At 10 d and 21 d,the translocation factor of water lettuce was higher than other aquatic macrophytes,which were 1.04 and 1.01,respectively at 155 mg L-1 Mn level.The water Mn contents were decreased with the sampling date in this experiment,which were 31.84%,31.44% and 18.47% reduction for water hyacinth,water lettuce and slligator alternenthera,respectively at 55 mg L-1 Mn level,and 12.02%,18.53% and 7.57% reduction,respectively at 155 mg L-1 Mn level at the harvest time.In short,water lettuce meets the general characteristics of good phytoremediation plants,and has standout potentials as a phytoremediation plant for Mn-contaminated waters.