热处理凹凸棒土对小白菜根际土壤中镉毒性缓解效应及其吸附机理  

Alleviating Effect of Heat Treated Attapulgite on Soil Cadmium Toxicity Around Rhizosphere Soil of Pakchoi and Its Adsorption Mechanism

作　　者：谢伟芳[1] 程婷[1] 王文华[2] 柳玲玲[2] 周瑞荣[2] 张邦喜 XIE Wei-fang;CHENG Ting;WANG Wen-hua;LIU Ling-ling;ZHOU Rui-rong;ZHANG Bang-xi(College of Environmental Ecology,Jiangsu Open University,Jiangsu Nanjing 210017,China;Institute of Agricultural Resources and Environment,Guizhou Academy of Agricultural Sciences,Guizhou Guiyang 550006,China)

机构地区：[1]江苏开放大学环境生态学院,江苏南京210017 [2]贵州省农业科学院农业资源与环境研究所,贵州贵阳550006

出　　处：《西南农业学报》2021年第3期633-640,共8页Southwest China Journal of Agricultural Sciences

基　　金：江苏省高等学校自然科学研究面上项目(17KJB610002);贵州省环保厅“土壤加密”调查项目。

摘　　要：【目的】为探讨凹凸棒土(ATP)经不同温度煅烧后对土壤中镉毒害缓解的影响机理。【方法】以小白菜为实验对象进行盆栽试验,设置未添加凹凸棒土(CK),25℃处理凹凸棒土(25℃ATP)、200℃煅烧凹凸棒土(200℃ATP)、300℃煅烧凹凸棒土(300℃ATP)、400℃煅烧凹凸棒土(400℃ATP)和500℃煅烧凹凸棒土(500℃ATP)6个处理对小白菜进行土培种植,并采用SEM、FI-IR、XRD、XPS、氮气吸附及热重分析对其热处理材料变化及吸附机理进行探究。【结果】在镉污染土壤中施用凹凸棒土能有效地增加小白菜的生物量,显著促进小白菜的生长发育,提高土壤的pH值,随着煅烧温度升高,土壤中速效磷被吸附导致含量降低;此外,施用凹凸棒土能显著增加土壤中全镉的含量,降低土壤中有效态镉含量,从而抑制小白菜对镉的吸收,大大降低了镉对小白菜可食用部分的毒害作用。与其它5个处理组相比,400℃ATP煅烧处理对小白菜的生长发育及镉的钝化效果最好,小白菜镉含量显著降低55.81%,土壤中有效态镉含量显著减少43.90%。在400℃处理下的凹凸棒土与土壤结合吸附镉后,其(110)晶面仍存在,吸附后未破坏凹凸棒土结构,凹凸棒土表面存在大量孔隙及棒晶,使得凹凸棒土表面硅羟基与镉通过静电引力进行表面络合,减少了植物对镉的吸收。【结论】凹凸棒土经适当温度煅烧改性,加入土壤后,可以明显改善土壤性质,降低土壤中镉有效态含量,促进植株的生长发育。【Objective】The present paper aimed to investigate the effect of calcined Attapulgite(ATP)on the mitigation of cadmium(Cd)toxicity in soil and its mechanism.【Method】Taking pakchoi as the material.,indoor planting pakchoi in pots was carried out in this experiment,which set no Attapulgite(CK),processing attapulgite at 25℃(25℃ATP),calcining attapulgite at 200℃ATP(200℃ATP),calcining attapulgite at 300℃ATP(300℃ATP),calcining attapulgite at 400℃ATP(400℃ATP)and calcining attapulgite at 500℃ATP(500℃ATP).SEM,FI-IR,XRD,XPS,N2-adsorption and TGA were used to investigate the change of heat treatment materials and its adsorption mechanism.【Result】The application of attapulgite in Cd contaminated soil could effectively increase the biomass of pakchoi,significantly promote the growth and development of pakchoi,and increase the pH of soil.However,the content of available phosphorus in soil decreased because of adsorption with the increase of calcination temperature.In addition,application of attapulgite could significantly increase the total Cd content and reduce the available Cd content in soil,thus,inhibiting the absorption of cadmium in pakchoi and greatly reducing the toxic effect of Cd on edible parts of pakchoi.Compared with CK,400℃ATP treatment had the best effect on the growth of pakchoi and the passivation effect of heavy metal of Cd.And the Cd content of pakchoi reduced by 55.81%significantly and the content of effective Cd in soil decreased by 43.90%.After Cd was adsorbed by Attapulgite at 400℃combined with soil,its crystal plane(110)still existed,and the structure of attapulgite was not destroyed after adsorption.There were a lot of pore and rod crystals on the surface of attapulgite,which enabled the surface of silicon hydroxyl group of attapulgite to interact with Cd by electrostatic attraction,thus reducing the absorption of Cd by plants.【Conclusion】Therefore,after calcining of the attapulgite and adding soil,the soil properties can be improved obviously,the content of effec

关 键 词：凹凸棒土 镉毒害 小白菜 有效态Cd含量 吸附机理 

分 类 号：X53[环境科学与工程—环境工程]