芦苇和香蒲对重金属钼的吸收特性研究

Absorption Characteristics of Molybdenum by Reed and Cattail

研究了水生植物芦苇和香蒲对重金属钼的吸收特性.通过短期室内水培实验,对比考察了2种植物对重金属钼的耐毒性、动态去除率、吸收过程及富集情况,并对在不同浓度营养液中植物对重金属钼吸收的影响进行了分析.结果表明,2种植物钼中毒导致其茎叶发黄、蒸腾能力下降,在钼浓度为2～20 mg.L-1时,香蒲对重金属钼的耐毒性较芦苇强.香蒲对重金属钼的去除率高于芦苇,在钼浓度为2 mg.L-1时,香蒲和芦苇去除率分别为87%和62%.2种植物对重金属钼的吸收是一个动态平衡过程,且以被动吸收为主.香蒲对钼的富集量较芦苇高,且植物地上部重金属积累量大于根部,符合超积累植物特征之一.营养液浓度的增加不会提高植物对重金属钼的吸收量,反而会因离子竞争等因素使去除率有所下降.芦苇和香蒲对溶液中钼的吸收均具有显著效果,香蒲吸收效果较芦苇好.

The adsorption characteristics of reed and cattail to molybdenum were studied.The toxicity,removal rate,adsorption process and accumulation of Mo were investigated in the short-term indoor-culture experiment.The effects of Mo adsorbed by two plants in nutrition solution with different concentrations were also studied.Due to the Mo toxicity,the color of stems and leaves of two plants had become scorch and the transpiration was declined.The cattail illustrated higher tolerance to Mo than reed when Mo concentration was in the range of 2-20 mg·L-1.The removal rate of Mo by cattail was 87%,which was higher than reed（62%） with Mo concentration of 2 mg·L-1.The absorption process of Mo by two plants was homeostasis,and the passivity absorption was the main absorption mechanism.Mo enrichment amount in cattail was higher than that in reed,and Mo concentration in shoot were higher than that in roots.The results displayed that cattail was Mo hyper accumulator.The absorption of Mo was not enhanced with the increase of nutrition solution concentration,due to the competition of other ions.The study suggested that the absorption capacity of Mo was significant by the two plants,and cattail was better for Mo removal than reed.