石灰用量和培养时间对红壤镉形态转化的影响  

Effects of Lime Dosage and Cultivation Time on Forms Transformation of Cadmium in Red Soil

作　　者：林小兵 陈燕[1] 周利军[1] 黄欠如[1] 武琳[1] LIN Xiao-bing;CHEN Yan;ZHOU Li-jun;HUANG Qian-ru;WU Lin(Jiangxi Institute of Red Soil, Nanchang 331717, China)

机构地区：[1]江西省红壤研究所,南昌331717

出　　处：《科学技术与工程》2022年第5期2130-2139,共10页Science Technology and Engineering

基　　金：江西省重大科技研发专项(20194ABC28010);江西省重点研发计划(20171ACG70022);国家红壤改良工程技术研究中心开放基金(2020NETRCRSI-10)。

摘　　要：石灰是酸性镉(Cd)污染土壤修复的主要钝化材料。通过室内培养试验,研究了石灰不同用量对镉污染红壤土壤pH、阳离子交换量和Cd赋存形态的影响,并探讨Cd形态间与土壤pH和阳离子交换量的关系。结果表明,与对照比,施用石灰显著提高了土壤的pH和阳离子交换量,且随施入量的增加而效果明显。培养期间土壤Cd形态主要以可交换态为主,其次是碳酸盐结合态和铁锰氧化物态,而有机结合态和残渣态含量最少;随培养时间土壤可交换态Cd所占比例呈降低趋势,其他4种形态Cd均呈增加趋势。随着石灰用量的增加,土壤交换态Cd降低比例逐渐增大,培养120 d后,在0.5 mg/kg Cd污染条件的土壤可交换态Cd同对照比依次减少了29.74%、43.99%和47.61%;而在1 mg/kg Cd污染条件的土壤可交换态Cd同对照比依次减少了37.47%、38.09%和54.28%;两个Cd溶度下其他4种形态Cd均增加。相关性表明,土壤pH、阳离子交换量与碳酸盐结合态Cd和残渣态Cd呈显著正相关,而与可交换态Cd呈显著负相关;可交换态Cd与其他4种形态Cd呈显著负相关。总之,石灰通过影响土壤中的pH、阳离子交换量等,使Cd从可交换态向其他4种形态转化,从而降低土壤中Cd的有效性。Lime is the main passivation material for remediation of acid cadmium(Cd)contaminated soil.Through indoor laboratory experiments,the effects of different application of lime on the pH,cation exchange capacity and Cd forms in Cd contaminated soil were studied,and the relationship between Cd forms,pH and cation exchange capacity was investigated.The results show that compared with the control,the application of lime significantly increases the soil pH and cation exchange capacity,and the effect is obvious with the increase of the application amount.During the culture period,the forms of Cd in soil are mainly exchangeable,following by carbonate bound and iron manganese oxide,while the contents of organic bound and residue are the least.The proportion of exchangeable Cd in soil decreases with the culture time,and the other four forms of Cd increase.With the increase of lime dosage,the decrease proportion of soil exchangeable Cd gradually increase.After 120 days of culture,the soil exchangeable Cd under the condition of 0.5 mg/kg Cd pollution decreases by 29.74%,43.99%and 47.61%compared with the control.Compared with the control,exchangeable Cd in soil polluted with 1 mg/kg Cd decreases by 37.47%,38.09%and 54.28%respectively.The other four forms of Cd increase under two Cd solubility.The correlation show that soil pH and cation exchange capacity are significantly positively correlated with carbonate bound Cd and residual Cd,but negatively correlated with exchangeable Cd.Exchangeable Cd is significantly negatively correlated with the other four forms of Cd.In short,lime can change Cd from exchangeable state to other four forms by affecting pH and cation exchange capacity in soil,so as to reduce the availability of Cd in soil.

关 键 词：石灰 红壤 CD形态 可交换态 培养时间 

分 类 号：X53[环境科学与工程—环境工程]