不同钝化剂及其组合对玉米（Zea mays）生长和吸收Pb Cd As Zn影响研究

选取硅藻土、生物炭、沸石粉、石灰及其组合开展田间试验,研究它们对玉米(Zea mays)生长、玉米籽粒吸收Pb、Cd、As、Zn与土壤有效态Pb、Cd、As、Zn的影响。结果表明,除石灰粉外,施用其他3种钝化剂及其组合均能促进玉米生长,增加玉米株高、叶面积和生物量,显著提高玉米产量。4种钝化剂及其组合可升高土壤的p H值和降低土壤中的有效态Pb、Cd、As、Zn含量,与CK处理相比,施用不同改良剂导致土壤有效态Pb降低6.82%~20.46%,有效态Cd降低12.76%~28.28%,有效态As降低26.89%~48.74%,和有效态Zn降低13.88%~28.95%,其中BZD(生物炭+沸石粉+硅藻土)处理降低效果最明显,BLD(生物炭+石灰粉+硅藻土)处理次之;4种钝化剂及其组合都能降低玉米籽粒对Pb、Cd、As、Zn的吸收,其中BZD处理能明显降低玉米籽粒中Pb、Cd、As、Zn含量,较对照分别降低47.71%、95.00%、90.90%、31.41%。在原位钝化修复镉-砷-锌复合污染农田土壤时,BDZ组合的施用效果最佳。

Effects of different amendments on growth and Pb, Cd, As, Zn uptake by Zea mays

Field experiments were conducted to investigate the effects of diatomite, biochar, zeolite and lime and their additive proportion on maize growth and lead(Pb), cadmium(Cd), arsenic(As) and zinc(Zn) uptake by maize kernels and the available Pb, Cd, As and Zn in soil. The results showed that except lime,three amendments could improve maize growth and increase plant height, leaf area as well as biomass. The yield of maize was also significantly increased. All four amendments could increase soil pH values and reduce the concentration of available Pb, Cd, As and Zn in soil. Compared to the control treatment, applying different amendments led to a decrease of available Pb content in soil by 6.82%~20.46%, available Cd by 12.76%~28.28%, available As by 26.89%~48.74%, and available Zn by 13.88%~28.95%. Additions of BZD(biochar+zeolite +diatomite) was the most available treatments to decrease the available content of heavy met als in soil, and BLD(biochar+lime+diatomite) was ranked to be the second. At the same time, All four amendments could all reduce Pb, Cd, As and Zn uptake by maize kernels. Compared to the control treatment, the application of BDZ reduced the concentration of Pb, Cd,As and Zn in maize kernels by 47.71%, 95.00%, 90.90% and 31.41% respectively. Our results in this study demonstrated that applying BDZ additive proportion amendments was the best functional amendments for the remediation of heavy metal contaminated soil of Cd-As-Zn.