改性酒糟生物炭对紫色土壤镉形态及水稻吸收镉的影响  

Effects of Modified Distillers'Grains Biochar on Cadmium Forms in Purple Soil and Cadmium Uptake by Rice

作　　者：肖乃川 王子芳[1] 杨文娜 谢永红 代文才[1] 高明[1] XIAO Nai-chuan;WANG Zi-fang;YANG Wen-na;XIE Yong-hong;DAI Wen-cai;GAO Ming(College of Resources and Environment,Southwest University,Chongqing 400715,China;Fruit Research Institute,Chongqing Academy of Agricultural Sciences,Chongqing 401329,China)

机构地区：[1]西南大学资源环境学院,重庆400715 [2]重庆农业科学院果树研究所,重庆401329

出　　处：《环境科学》2024年第5期3027-3036,共10页Environmental Science

基　　金：重庆市技术创新与应用发展专项重点项目(cstc2019jscxtjsbX0001);国家自然科学基金项目(42177019)。

摘　　要：生物炭及改性生物炭已被广泛应用于重金属污染农田土壤修复领域.为探寻经济有效的镉(Cd)污染酸性紫色土壤修复改良材料,将酒糟制成酒糟生物炭(DGBC),并用纳米二氧化钛(Nano-TiO_(2))对其改性,制得两种改性酒糟生物炭TiO_(2)/DGBC和Fe-TiO_(2)/DGBC,采用水稻盆栽试验研究不同生物炭和不同施用量(1%、3%、5%)处理对土壤理化性质、养分含量、Cd赋存形态与生物有效性、水稻生长与Cd富集的影响.结果表明:①施用DGBC显著提高了酸性紫色土pH、CEC和养分含量,且TiO_(2)/DGBC和Fe-TiO_(2)/DGBC效果更好.②DGBC和改性DGBC使土壤Cd形态由可溶态向难溶态转变,残渣态Cd相较对照增加了1.22%~18.46%.土壤Cd生物有效性显著降低,DGBC、TiO_(2)/DGBC和Fe-TiO_(2)/DGBC分别使有效态Cd降低11.81%~23.67%、7.64%~43.85%和19.75%~55.82%.③施用DGBC和改性DGBC提高了水稻产量,DGBC、TiO_(2)/DGBC和Fe-TiO_(2)/DGBC在3%添加量时水稻产量最高,分别为30.60、37.85和39.10 g·pot^(−1),是对照的1.13、1.40和1.44倍.水稻各部位Cd含量显著降低,施用3种生物炭时水稻籽粒ω(Cd)分别为0.24~0.30、0.16~0.26和0.14~0.24 mg·kg^(−1),TiO_(2)/DGBC在5%、Fe-TiO_(2)/DGBC在3%和5%添加量时,水稻籽粒ω(Cd)低于0.2 mg·kg^(−1),符合国家食品中污染物限量标准(GB 2762-2022).总体来看,Nano-TiO_(2)改性DGBC通过自身的吸附作用和影响土壤Cd形态分布有效降低了土壤Cd生物有效性,从而降低了水稻对Cd的吸收,同时促进了水稻生长,提高水稻产量.是一种具有潜在应用前景的Cd污染土壤修复改良材料.研究结果可以为Cd污染酸性紫色土农田修复和农业安全生产提供科学依据.Biochar and modified biochar have been widely used as remediation materials in heavy metal-contaminated agricultural soils.In order to explore economical and effective materials for the remediation of cadmium(Cd)-contaminated acidic purple soil,distillers'grains were converted into distillers'grains biochar(DGBC)and modified using nanotitanium dioxide(Nano-TiO_(2))to produce two types of modified DGBCs:TiO_(2)/DGBC and Fe-TiO_(2)/DGBC.A rice pot experiment was used to investigate the effects of different biochar types and application rates(1%,3%,and 5%)on soil properties,nutrient content,Cd bioavailability,Cd forms,rice growth,and Cd accumulation.The results showed that:①DGBC application significantly increased soil pH,cation exchange capacity(CEC),and nutrient content,with TiO_(2)/DGBC and Fe-TiO_(2)/DGBC exhibiting better effects.②DGBC and modified DGBCs transformed Cd from soluble to insoluble forms,increasing residual Cd by 1.22%to 18.46%compared to that in the control.Cd bioavailability in soil decreased significantly,with available cadmium being reduced by 11.81%to 23.67%for DGBC,7.64%to 43.85%for TiO_(2)/DGBC,and 19.75%to 55.82%for Fe-TiO_(2)/DGBC.③DGBC and modified DGBCs increased rice grain yield,with the highest yields observed at a 3%application rate:30.60 g·pot^(−1) for DGBC,37.85 g·pot^(−1) for TiO_(2)/DGBC,and 39.10 g·pot^(−1) for Fe-TiO_(2)/DGBC,representing 1.13,1.40,and 1.44 times the control yield,respectively.Cd content in rice was significantly reduced,with grain Cd content ranging from 0.24 to 0.30 mg·kg^(−1) for DGBC,0.16 to 0.26 mg·kg^(−1) for TiO_(2)/DGBC,and 0.14 to 0.24 mg·kg^(−1) for Fe-TiO_(2)/DGBC.Notably,Cd content in rice grains fell below the food safety limit of 0.2 mg·kg^(−1)(GB2762-2022)at 5%for TiO_(2)/DGBC and 3%and 5%for Fe-TiO_(2)/DGBC.In conclusion,Nano-TiO_(2) modified DGBC effectively reduced the bioavailability of soil Cd through its own adsorption and influence on soil Cd forms distribution,thus reducing the absorption of Cd by rice and simult

关 键 词：镉(Cd)污染 紫色土 改性酒糟生物炭 土壤-水稻系统 镉积累 

分 类 号：X171.5[环境科学与工程—环境科学]