复合改性生物炭的吸附特性及其对轻中度镉污染农田土壤的钝化效应  

Adsorption characteristics of composite modified biochar and its passivation effect on farmland soil with light to moderate cadmium pollution

作　　者：潘国俊 卢信[2] 杨振泉[1] 陈丙法 耿淑芳 樊广萍 高岩[2] 尹小乐[2] PAN Guo-jun;LU Xin;YANG Zhen-quan;CHEN Bing-fa;GENG Shu-fang;FAN Guang-ping;GAO Yan;YIN Xiao-le(College of Food Science and Engineering,Yangzhou University,Yangzhou 225009,China;Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences/Key Laboratory of Agricultural Environment in the Lower Yangtze River Plain of the Ministry of Agriculture and Rural Affairs,Nanjing 210014,China)

机构地区：[1]扬州大学食品科学与工程学院,江苏扬州225009 [2]江苏省农业科学院农业资源与环境研究所/农业农村部长江下游平原农业环境重点实验室,江苏南京210014

出　　处：《江苏农业学报》2024年第3期457-468,共12页Jiangsu Journal of Agricultural Sciences

基　　金：江苏省农业科技自主创新基金项目[CX(20)1010]。

摘　　要：农田土壤中的镉污染会导致作物中的镉过量累积,而作物中的镉会通过食物链传递给人,从而严重威胁人体健康,因此迫切需要采取合理的应对措施。本研究旨在将不同材料[氢氧化钾(K)、凹凸棒土(A)、钙镁磷肥(M)和聚丙烯酰胺(P)]与生物炭混合后进行球磨改性(Q)处理,通过吸附平衡试验、盆栽试验研究改性生物炭对镉的吸附特性及其对镉污染土壤的钝化效果。结果表明,与未改性生物炭(YC)相比,改性生物炭具有更丰富的官能团和矿物元素,对镉的吸附动力学曲线符合准二级动力学方程,吸附方式主要表现为单分子层吸附。pH值、温度的升高可以提高生物炭对镉离子的吸附能力。在土壤中添加生物炭可以显著提高土壤的pH值和养分含量,并且降低土壤有效镉含量,其中添加氢氧化钾+凹凸棒土+钙镁磷肥+聚丙烯酰胺球磨改性的生物炭(QKAMP)和添加氢氧化钾+凹凸棒土+聚丙烯酰胺球磨改性的生物炭(QKAM)分别可使土壤有效镉含量较对照(CK)显著降低25.5%、23.4%(P<0.05)。与添加未改性生物炭(YC)的处理相比,添加QKAMP、QKAM处理的土壤中有效镉含量分别显著降低了16.84%、14.57%(P<0.05)。此外,与对照相比,添加QKAMP、QKAM分别可使小青菜地上部的镉含量显著降低36.1%、33.6%;与未添加改性生物炭处理(YC)相比,添加QKAMP、QKAM处理小青菜地上部的镉含量分别显著降低了21.6%、18.6%。由此可见,QKAMP作为一种重金属钝化材料,可以更好地降低中性(pH值7.07)、轻中度镉污染(≤1.75 mg/kg)土壤中镉的生物有效性,确保农产品安全生产。Cadmium(Cd)pollution in farmland soil leads to excessive Cd in crops,which can be transferred to humans through the food chain,posing a significant threat to human health.Therefore,it is urgent to take reasonable countermeasures.The purpose was to mix different materials(potassium hydroxide:K,attapulgite:A,calcium magnesium phosphate fertilizer:M,polyacrylamide:P)with biochar for ball milling modified(Q)treatment.The Cd adsorption performance of the modified biochar and its passivation effect on Cd-contaminated agricultural soils were investigated through adsorption equilibrium and pot experiments.The results showed that the modified biochar had richer functional groups and mineral elements than the unmodified biochar(YC).The adsorption kinetics curve of Cd adsorption was in accordance with the proposed second-order kinetic equation.The adsorption mode of Cd was mainly monolayer adsorption.The increase of pH value and temperature could improve the adsorption capacity of cadmium ions by biochar.The addition of biochar to the soil significantly increased the soil pH value and nutrient content,and reduced the bioavailable cadmium content in the soil.Among them,the application of biochar+potassium hydroxide+attapulgite+calcium-magnesium-phosphorus fertilizer+polyacrylamide ball-milled modified biochar(QKAMP)and biochar+potassium hydroxide+attapulgite+polyacrylamide ball-milled modified biochar(QKAM)significantly reduced the bioavailable Cd content by 25.5%and 23.4%(P<0.05),respectively,compared with the control(CK),and significantly reduced the bioavailable Cd content by 16.84%and 14.57%(P<0.05),respectively,compared with unmodified biochar(YC)treatment.Meanwhile,the addition of QKAMP and QKAM significantly reduced the cadmium content in Brassica rapa var.chinensis(Linnaeus)Kitamura aerial part by 36.1%and 33.6%,respectively,compared with the control(CK),and by 21.6%and 18.6%,respectively,compared with the unmodified biochar treatment.It can be seen that,as a heavy metal passivation material,QKAMP is more effective i

关 键 词：改性生物炭 镉 重金属 吸附性能 钝化 

分 类 号：S151.93[农业科学—土壤学]