石灰、羟基磷灰石、秸秆生物炭对烟草吸收镉的影响  

Effects of Lime,Hydroxyapatite and Straw Biochar on Cadmium Accumulation in Tobacco

作　　者：李晓锋 吴锋颖 剧永望 丁豪杰 张慧娟[1,2] 刘雪 Li Xiaofeng;Wu Fengying;Ju Yongwang;Ding Haojie;Zhang Huijuan;Liu Xue(Institute of Ecology and Environment,Southwest Forestry University,Kunming 650224,China;Institute of Environment Remediation and Health,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学生态与环境学院,昆明650224 [2]西南林业大学环境修复与健康研究院,昆明650224

出　　处：《生态毒理学报》2022年第1期381-394,共14页Asian Journal of Ecotoxicology

基　　金：国家重点研发计划项目(2018YFC1800504);国家自然科学基金资助项目(41867066,41907129);云南省自然科学基金资助项目(2019FB032);云南省高端外国专家项目(YNQR-GDWG-2018-017);大学生创新创业训练计划项目。

摘　　要：烟草是我国重要经济作物且极易吸收镉(Cd),如何降低烟草Cd含量已引起广泛关注。通过盆栽实验,在Cd(0.83 mg·kg^(-1)和12 mg·kg^(-1))污染土壤中添加2 g·kg^(-1)或16 g·kg^(-1)石灰(Ca(OH)_(2))、羟基磷灰石(HAP)或秸秆生物炭,分析3种钝化材料对土壤Cd的钝化效率及烟草Cd吸收的降低效率。结果表明:(1)种植60 d后,施用16 g·kg^(-1)石灰或HAP均显著(P<0.05)提高土壤pH值,轻微(0.83 mg·kg^(-1) Cd)、中度(12 mg·kg^(-1) Cd)Cd污染土壤pH值分别提高1.98~2.84和1.99~3.06;(2)3种钝化材料均使土壤Cd有效态含量降低,其中,16 g·kg^(-1)石灰使土壤Cd有效态含量降低69.7%~71.5%;(3)生物炭(2 g·kg^(-1)和16 g·kg^(-1))显著(P<0.05)提高烟草生物量且降低烟草Cd含量,轻微、中度Cd污染土壤烟草生物量分别提高5.07倍~18.5倍和5.00倍~29.7倍,烟草根、茎、叶Cd含量分别降低68.7%~74.6%、32.1%~50.7%、70.2%~82.5%(轻微)和68.7%~74.6%、51.4%~59.3%、33.2%~46.5%(中度),根、茎、叶Cd富集系数亦显著降低,根(Cd_(0.83):122降至31~38.1,Cd_(12):24.7降至12.2~16.8),茎(Cd_(0.83):203降至35.6~60.6,Cd_(12):41.7降至17.6~23.1),叶(Cd_(0.83):247降至100~120,Cd_(12):48.6降至26.0~32.5);(4)溶液吸附实验发现,HAP和生物炭均通过表面吸附Cd^(2+),且该吸附过程符合准二级动力学模型,表明在钝化过程中这2种钝化剂与Cd^(2+)发生键能结合的化学吸附。研究表明,3种钝化剂在同等剂量水平下,生物炭提高烟草生物量且降低Cd吸收最显著,可优先选作降低烟草Cd吸收的钝化剂。Tobacco is a cash crop which is readily to uptake and accumulate cadmium(Cd).Methods on decreasing Cd uptake and accumulation in tobacco have attracted increased attention.Effect of lime(Ca(OH)_(2)),hydroxyapatite(HAP)and straw biochar(2 g·kg^(-1) or 16 g·kg^(-1))on soil Cd passivation and uptake and accumulation in tobacco was determined in slight and moderate Cd(0.83 mg·kg^(-1) and 12 mg·kg^(-1))contaminated soils in pot experiments.The results showed that:(1)16 g·kg^(-1) lime or HAP significantly(P<0.05)increased soil pH values after 60 d,which were increased by 1.98~2.84 and 1.99~3.06 units in slight and moderate Cd soils,respectively;(2)the three passivators can reduce soil available Cd concentrations,and specifically,16 g·kg^(-1) lime reached a reduction efficiency to 69.7%~71.5%;(3)2 g·kg^(-1) or 16 g·kg^(-1) biochar significantly(P<0.05)increased tobacco biomass and decreased Cd content,with the biomass being increased by 5.07~18.5 and 5.00~29.7 times and the Cd concentration in roots,stems and leaves being decreased by 68.7%~74.6%,32.1%~50.7%,70.2%~82.5%(0.83 mg·kg^(-1))and 68.7%~74.6%,51.4%~59.3%,33.2%~46.5%(12 mg·kg^(-1))in slight and moderate Cd soils.The Cd bioconcentration factors were also decreased in root(Cd_(0.83):122 to 31~38.1,Cd_(12):24.7 to 12.2~16.8),stem(Cd_(0.83):203 to 35.6~60.6,Cd_(12):41.7 to 17.6~23.1),and leaf(Cd_(0.83):247 to 100~120,Cd_(12):48.6 to 26.0~32.5);(4)Cd^(2+) was shown to adsorb onto HAP and biochar surface following the pseudo-second-order kinetics,indicating these two passivators chemically bind Cd^(2+) with bond energy during the passivation process.The results showed that biochar was the best in improving plant biomass and reducing Cd accumulation in tobacco among the three passivators at the same application level,which can be a potential candidate in soil Cd passivation to reduce Cd accumulation in plants.

关 键 词：镉 烟草 石灰 羟基磷灰石 生物炭 生物量 

分 类 号：X171.5[环境科学与工程—环境科学]