碱性Cd污染农田原位稳定化修复研究  

Stabilization of cadmium in alkaline soil

作　　者：张庆泉[1] 尹颖[1] 杜文超[1] 郭红岩[1] 

机构地区：[1]南京大学环境学院污染控制与资源化国家重点实验室,南京210023

出　　处：《南京大学学报（自然科学版）》2016年第4期601-608,共8页Journal of Nanjing University（Natural Science）

摘　　要：围绕碱性农田重金属Cd污染原位稳定化修复技术,通过实验室小试筛选出以椰壳生物炭为核心材料的稳定剂应用于修复重金属Cd污染的碱性土壤,并进一步探究了施加稳定剂对于小麦生长的影响.研究结果表明,随着稳定剂施加量的增加重金属Cd钝化效果显著增加,在施加量为2%时,椰壳生物炭对土壤有效态Cd钝化率达到99.08%,远高于木质生物炭、硅肥以及钙镁磷肥.稳定化修复后,土壤中Cd由生物可利用性较高的形态向稳定的结合态转化,降低土壤环境风险.此外椰壳生物炭的施加还可以促进小麦生长,降低小麦体内Cd含量,稳定剂施加量为1.5%时,与对照组相比小麦根中Cd含量降低64.31%,地上部Cd含量降低69.60%.本研究筛选的椰壳生物炭作为稳定剂不仅能够实现Cd污染碱性农田的持效性修复,还能够显著改善土壤结构并提高土壤肥力,促进小麦生长,为以后该技术在我国北方大面积重金属污染碱性农田的修复及规模化应用提供支持.Heavy metal contamination in soil is seriously threating the grain production and food safety,constraining the sustainable development of the economy and society.There have been a lot of studies about remediation of heavy metals in acidic soil,but little is known about the in-situ stabilized remediation of cadmium（Cd）in alkaline soil.In this study,we chose eight different stabilizers（fused calcium-magnesium phosphate,silicon fertilizer,lime,coconut shell bio-char,rice straw bio-char,wood bio-char,peach pit bio-char and bamboo bio-char）,applied them to the remediation of the alkaline soil contaminated with Cd,screened out the more effective stabilizers,and checked their ecological risk using wheat.Results show that all the stabilizers applied could induce dose-dependent passivation effect on Cd in soil,but coconut shell bio-char is more effective than other seven stabilizers.2.0% coconut shell bio-char in soil stabilized up to 99.08% of available Cd,and could remain the bio-available Cd at a relative low level for more than 250 days.In addition,the application of coconut shell bio-char also promoted the wheat growth and decreased Cd concentrations in wheat.1.5%coconut shell bio-char in soil decreased the Cd concentrations in root and shoot by 64.31% and 69.60% respectively when compared with the control group.By speciation analysis,coconut shell bio-charshowed its ability in transforming Cd from the bio-available form to the stable form in soil.It decreased the proportion of water-soluble and exchangeable forms of Cd and increased that of organic-bound and residual forms.Results prove that coconut shell bio-char could not only remediate the Cd contaminated alkaline soil in long-term,but also significantly improve the soil conditions and promote the plant growth.

关 键 词：稳定化修复 椰壳生物炭 碱性农田 CD污染土壤 

分 类 号：TP181[自动化与计算机技术—控制理论与控制工程]