摘要
【目的】重金属对环境危害的大小主要取决于其形态分布,尤其是生物有效态镉(Cd)的含量和存在比例。添加生物炭可以降低Cd超标土壤中生物有效态Cd的含量,本文研究了施用生物炭后红壤和褐土中Cd形态的变化及其与生物炭施用量的关系,以加深对生物炭修复Cd污染土壤机理的认识。【方法】选择红壤(pH5.21)和褐土(pH 7.75)两类土壤进行了室内培养试验。将两个过2 mm筛的自然风干土壤各40 kg,分别装于20L塑料盒中,加Cd(NO3)2溶液使土壤外源Cd含量达到5 mg/kg,保持70%田间最大持水量,于25℃条件下平衡两周;之后,在每1000 g土内,分别添加生物炭0、5、10、20 g,均匀混合后,室温培养50 d;在培养1、4、7、14、21、35、49 d时分别取样,测定土壤pH和有机碳含量,利用Tessier分级法测定土壤Cd形态。【结果】红壤pH随生物炭施用量的增加显著升高,培养14天后,生物炭施加量为2%时,土壤由酸性变为弱碱性,生物炭对褐土pH的提高作用不显著。红壤和褐土有机碳含量均随生物炭施用量的增加而升高。培养49天后,红壤可交换态Cd含量的降幅较大,降幅为0.31～0.82 mg/kg,且处理2%的可交换态Cd含量最低,为1.24 mg/kg,生物炭施用量2%的红壤碳酸盐结合态Cd含量最高,为1.06 mg/kg,施用生物炭的红壤碳酸盐结合态Cd和Fe、Mn氧化物结合态Cd所占比例增加了3.14%～14.21%、8.20%～23.96%,施用生物炭的褐土碳酸盐结合态Cd和Fe、Mn氧化物结合态Cd升高了0.94%～2.61%、0.80%～7.90%。褐土的土壤有机碳含量和生物炭施用量与土壤可交换态Cd呈极显著负相关关系,与土壤碳酸盐结合态Cd,土壤Fe、Mn氧化物结合态Cd和土壤有机结合态Cd呈极显著正相关关系;红壤pH、有机碳含量和生物炭施用量均与土壤可交换态Cd呈极显著负相关关系,与土壤其他四种形态Cd呈极显著正相关关系。但在红壤中土壤有机碳和生物炭施用量与各形态Cd的�
【Objectives】The environmental damage of heavy metals mainly depends on their speciation,especially the content and proportion of bioavailable ones.Biochar had been attempted as artificial measures for reducing the content of bioavailable Cd in Cd contaminated soils.The paper examined the transformation of Cd forms in red soils and cinnamon soils when a certain amount of biochar were added,which would deepen the understanding of the remediation mechanism of biochar to Cd pollution.【Methods】Natural air-dried red soil(pH 5.21)and cinnamon soil(pH 7.75)of less than two 2 mm in size were selected as tested soils for a incubation experiment.40 kg of the tested soil were loaded into a 20 L-plastic box,Cd(NO3)2 solution was added to make the exogenous Cd content of the soil to 5 mg/kg,and kept stood for two weeks at(25±2)℃,keeping the maximum soil water content of 70%of filed capacity.Then,biochar were evenly mixed with the soil in ratio of 0,5,10 and 20 g/kg soil,and cultured at room temperature for 50 days.Soil samples were collected at 1,4,7,14,21,35,and 49 days of culture.The soil pH and organic carbon content were determined,and the soil Cd was divided into five forms by Tessier classification method,and the contents were analyzed.【Results】The red soil pH was significantly increased with the increase of biochar addition,and after 14 days of cultivation at the biochar addition rate of 20 g/kg,the soil pH changed from acidic to weak alkaline.While the pH of cinnamon soil did not significantly changed with biochar addition.The organic carbon content increased with the increasing amount of biochar in both red soil and drab soil.In red soil after 49 days of cultivation,the content of exchangeable Cd decreased by 0.31 to 0.82 mg/kg.At the biochar addition rate of 2%,the exchangeable Cd content was the lowest(1.24 mg/kg),the carbonate bound Cd was the highest(1.06 mg/kg).The proportion of carbon-bound Cd were increased by 3.14%-14.21%,and that of Fe and Mn oxide-bound Cd increased by 8.20%-23.96%.In cinnamon
作者
周涵君
韩秋静
马静
秦燚鹤
张晓远
吴福如
卢剑
叶协锋
ZHOU Han-jun;HAN Qiu-jing;MA Jing;QIN Yi-he;ZHANG Xiao-yuan;WU Fu-ru;LU Jian;YE Xie-feng(College of Tobacco Science,Henan Agricultural University/National Tobacco Cultivation and Physiology and BiochemistryResearch Centre/Key Laboratory for Tobacco Cultivation of Tobacco Industry,Zhengzhou 450002,China;Yunnan LincangMunicipal Tobacco Company,Lincang,Yunnan 677000,China;Sichuan Tobacco Company Liangshan Prefecture Company,Xichang,Sichuan 615000,China;Sichuan Tobacco Company Xichang City Company,Xichang,Sichuan 615000,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2019年第3期433-442,共10页
Journal of Plant Nutrition and Fertilizers
基金
烟草行业烟草栽培重点实验室项目"植烟土壤肥力培育及提高肥料利用率技术研究"
河南省烟草公司项目(HYKJ201301)
重庆市烟草公司项目(NY20140401070010)资助
关键词
生物炭
红壤
褐土
CD形态
biochar
red soil
cinnamon soil
Cd form
