| 纳米沸石对土壤Cd形态及大白菜Cd吸收的影响 |
| 摘要点击 2961 全文点击 1446 投稿时间：2015-05-30 修订日期：2015-07-22 |
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| 中文关键词 土壤镉污染 纳米沸石 土壤Cd形态 Cd吸收 大白菜 |
| 英文关键词 soil Cd contamination nano zeolite soil Cd fraction Cd uptake cabbage |
| 作者 | 单位 | E-mail | | 熊仕娟 | 西南大学资源环境学院, 重庆 400715 | xiongshijuan5@163.com | | 徐卫红 | 西南大学资源环境学院, 重庆 400715 | xuwei_hong@163.com | | 谢文文 | 西南大学资源环境学院, 重庆 400715 | | | 陈蓉 | 西南大学资源环境学院, 重庆 400715 | | | 陈永勤 | 西南大学资源环境学院, 重庆 400715 | | | 迟荪琳 | 西南大学资源环境学院, 重庆 400715 | | | 陈序根 | 西南大学资源环境学院, 重庆 400715 | | | 张进忠 | 西南大学资源环境学院, 重庆 400715 | | | 熊治庭 | 武汉大学资源与环境科学学院, 武汉 430079 | | | 王正银 | 西南大学资源环境学院, 重庆 400715 | | | 谢德体 | 西南大学资源环境学院, 重庆 400715 | |
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| 中文摘要 |
| 通过室内培养试验研究了不同镉污染水平(1、5、10和15 mg ·kg-1 Cd)下,不同施用量(0、5、10和20g ·kg-1)的纳米沸石(NZ)和普通沸石(OZ)对土壤镉形态分配比例(FDC)随时间的变化情况,并通过盆栽试验进一步研究纳米沸石和普通沸石对土壤镉形态和大白菜Cd吸收的影响. 室内培养试验表明,施用纳米沸石和普通沸石有效降低了土壤可交换态镉FDC,增加了铁锰氧化态镉FDC,在0~28 d的培养过程中,可交换态镉FDC呈先降后增后趋于平缓最后增加的趋势. 培养结束时,沸石处理使可交换态镉FDC从0 d时的72.0%~88.0%降至30.0%~66.4%,各处理土壤镉主要以可交换态存在. 盆栽试验表明,施用纳米沸石和普通沸石均显著降低了土壤可交换态镉含量和FDC,增加了碳酸盐结合态、铁锰氧化态、有机态和残渣态镉含量和FDC,以高量纳米沸石处理(20 g ·kg-1)对可交换态镉的降低效果最好. 土壤可交换态镉FDC与土壤pH呈显著负相关(P<0.05),与大白菜地上部和根部镉含量呈极显著正相关(P<0.01). 施用沸石使1和5 mg ·kg-1 Cd水平土壤pH分别提高了1.8%~45.5%和6.1%~54.3%,土壤可交换态镉FDC分别降低了16.3%~47.7%和16.2%~46.7%,大白菜各部位镉含量分别降低了1.0%~75.0%和3.8%~53.2%,纳米沸石对土壤和植株镉的降低效果优于普通沸石. 中低量(≤10 g ·kg-1)的沸石对大白菜生长有明显的促进作用,而高量沸石(20 g ·kg-1)则抑制了大白菜的生长. 与普通沸石相比,纳米沸石显著提高大白菜生物量的同时,也显著降低了土壤可交换态镉含量和大白菜镉含量及镉积累量. |
| 英文摘要 |
| Incubation experiments were carried out to investigate the influence of different nano zeolite(NZ) and ordinary zeolite(OZ) levels(0, 5, 10 and 20 g ·kg-1) on the change trends in fraction distribution coefficient (FDC) of Cd when exposed to different Cadmium(Cd)levels(1, 5, 10 and 15 mg ·kg-1), and pot experiments were carried out to investigate their influence on soil Cd fraction and Cd uptake by cabbage. The results in incubation experiments showed that the application of nano zeolite as well as ordinary zeolite effectively decreased the FDC of exchangeable Cd and increased the FDC of Fe-Mn oxide fraction. The FDC of soil Cd from 0 d to 28 d was deceased at first, then increased and tended to be stable, and finally increased. At the end of incubation, the FDC of soil exchangeable Cd decreased from 72.0%-88.0% to 30.0%-66.4%. Exchangeable fraction Cd was the most dominant Cd fraction in soil during the whole incubation. The results in pot experiment indicated that the application of nano zeolite and ordinary zeolite decreased the concentration and FDC of soil exchangeable Cd, and concurrently the concentration and FDC of Cd in carbonate, Fe-Mn oxide, organic matter and residual fraction were increased. The lowest EX-Cd was observed in the treatment with high dose of nano zeolite(20 g ·kg-1). The FDC of exchangeable Cd showed significant negative relationship with the soil pH(P<0.05), and was concurrently extremely positively correlated with Cd concentration in shoot and root of cabbage(P<0.01). Soil pH increased by 1.8%-45.5% and 6.1%-54.3% in the presence of zeolite when exposed to 5 mg ·kg-1 1 and Cd, respectively; FDC of exchangeable Cd decreased by 16.3%-47.7% and 16.2%-46.7%; Cd concentration in each tissues of cabbage decreased by 1.0%-75.0% and 3.8%-53.2%, respectively. Moreover, the reduction effect of nano zeolite on soil and plant Cd was better than that of ordinary zeolite. The growth of cabbage was stimulated by low and medium zeolite doses (≤10 g ·kg-1), while inhibited by high zeolite doses (20 g ·kg-1). Compared to ordinary zeolite, the biomass of Chinese cabbage was significantly increased by Nano zeolite, while the exchangeable Cd in soil as well as Cd concentration and Cd accumulation of cabbage were significantly reduced. |
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