Qin Yu-Li, Xiong Shi-Juan, Xu Wei-Hong, Zhao Wan-Yi, Wang Wei-Zhong, Chen Yong-Qin, Chi Sun-Lin, Chen Xu-Gen, Zhang Jin-Zhong, Xiong Zhi-Ting, Wang Zheng-Yin, Xie De-Ti
College of Resources and Environment, Southwest University, Chongqing 400715, China.
College of Resources and Environmental Sciences, Wuhan University, Wuhan 430079, China.
Huan Jing Ke Xue. 2016 Oct 8;37(10):4030-4043. doi: 10.13227/j.hjkx.2016.10.047.
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) on the fraction distribution coefficient (FDC) of Cd and soil CEC at different soil pH (4, 5, 6, 7 and 8) when exposed to different cadmium(Cd) levels(1, 5, 10 and 15 mg·kg), and pot experiment were carried out to investigate the effects of nano zeolite(NZ) and ordinary zeolite(OZ) on the growth, Cd concentration and Cd accumulation of Chinese cabbage. The results showed that nano zeolite and ordinary zeolite decreased the concentration and FDC of exchangeable Cd (EX-F), and increased the concentration and FDC of carbonate(CAB-F), Fe-Mn oxide(FMO-F), organic matter (OM-F) and residual fraction(RES-F) in incubation experiments. At the end of incubation, the FDC of soil exchangeable Cd decreased from 72.0%-88.0% to 2.4%-10.7%. The decreasing effect of zeolite on the concentration and FDC of exchangeable Cd (EX-F) increased with the increase of zeolite, and the decreasing effect of nano zeolite (NZ) was better than that of ordinary zeolite (OZ). During the culture of 28 d, the concentration of different Cd fractions in soil was in order of EX-F>RES-F>FMO-F>CAB-F>OM-F under different pH conditions. Exchangeable fraction Cd was the dominant fraction of Cd in soil during the whole incubation. Soil CEC had significant negative correlation with soil exchangeable Cd (EX-F) (<0.01), and significant positive correlation with the concentrations of Fe-Mn oxide(FMO-F) and organic matter (OM-F) in soil(<0.01). Nano zeolite and ordinary zeolite effectively increased soil CEC, and soil CEC increased with the increase of the pH value of soil in the zeolite treatments. Significant negative correlation was found in soil pH with soil exchangeable Cd (EX-F)(<0.01). The dry weight of plant tissues in Chinese cabbage increased by 14.3%-131.4% in the presence of nano zeolite(NZ) and ordinary zeolite(OZ), and Cd concentration of shoot and root decreased by 1.0%-75.0% and 3.8%-53.2%, respectively. Higher concentration and accumulation of Cd were observed in XJC3 variety than those in SD 4 variety. Compared with ordinary zeolite (OZ), nano zeolite (NZ) was better in increasing the biomass of Chinese cabbage as well as decreasing accumulation of Cd in Chinese cabbage.
进行了培养实验，以研究不同纳米沸石（NZ）和普通沸石（OZ）水平（0、5、10和20 g·kg）在不同土壤pH值（4、5、6、7和8）下，暴露于不同镉（Cd）水平（1、5、10和15 mg·kg）时对镉的分配系数（FDC）和土壤阳离子交换量（CEC）的影响；并进行了盆栽实验，以研究纳米沸石（NZ）和普通沸石（OZ）对大白菜生长、镉浓度和镉积累的影响。结果表明，在培养实验中，纳米沸石和普通沸石降低了可交换态镉（EX-F）的浓度和FDC，增加了碳酸盐结合态（CAB-F）、铁锰氧化物结合态（FMO-F）、有机质结合态（OM-F）和残渣态（RES-F）的浓度和FDC。培养结束时，土壤可交换态镉的FDC从72.0%-88.0%降至2.4%-10.7%。沸石对可交换态镉（EX-F）浓度和FDC的降低作用随沸石用量的增加而增强，且纳米沸石（NZ）的降低效果优于普通沸石（OZ）。在28天的培养期间，不同pH条件下土壤中不同镉形态的浓度顺序为EX-F>RES-F>FMO-F>CAB-F>OM-F。在整个培养过程中，可交换态镉是土壤中镉的主要形态。土壤CEC与土壤可交换态镉（EX-F）呈显著负相关（<0.01），与土壤中铁锰氧化物（FMO-F）和有机质（OM-F）的浓度呈显著正相关（<0.01）。纳米沸石和普通沸石有效提高了土壤CEC，且在沸石处理中，土壤CEC随土壤pH值的升高而增加。土壤pH值与土壤可交换态镉（EX-F）呈显著负相关（<0.01）。在有纳米沸石（NZ）和普通沸石（OZ）存在的情况下，大白菜植株组织的干重增加了14.3%-131.4%，地上部和根部的镉浓度分别降低了1.0%-75.0%和3.8%-53.2%。XJC3品种中镉的浓度和积累量高于SD 4品种。与普通沸石（OZ）相比，纳米沸石（NZ）在增加大白菜生物量以及降低大白菜中镉积累方面效果更好。
