生物炭影响下土壤中铜镉锌复合污染物的淋溶迁移  

Leaching behavior of Cu,Cd,and Zn in combined pollution soil as affected by biochar

作　　者：邹佳慧 林青 邵明艳 徐绍辉 ZOU Jiahui;LIN Qing;SHAO Mingyan;XU Shaohui(College of Environmental Science and Engineering,Qingdao University,Qingdao 266071;Qingdao Geo-Engineering Surveying Institute(Qingdao Geological Exploration and Development Bureau),Qingdao 266101)

机构地区：[1]青岛大学环境科学与工程学院,青岛266071 [2]青岛地质工程勘察院(青岛地质勘查开发局),青岛266101

出　　处：《环境科学学报》2023年第9期333-345,共13页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41807010);江西省红壤丘陵区农业环境污染防控重点实验室开放基金(No.JXKL2021007)。

摘　　要：生物炭是一种具有较强吸附能力和稳定性的土壤改良剂,在治理土壤重金属污染方面有巨大发展前景.采用玉米秸秆生物炭和木材木屑生物炭探究在不同条件下生物炭添加到复合污染土壤中对重金属Cu(Ⅱ)、Cd(Ⅱ)、Zn(Ⅱ)淋溶迁移的影响,并结合扫描电镜(SEM)、能谱(EDS)和FTIR图谱进行分析.结果表明,生物炭具有较多的孔隙结构、丰富的官能团组成和较低的Zeta电位,这些都为其提供了大量的吸附位点;随着生物炭添加量的增加吸附位点增多,添加2%生物炭与未添加生物炭的土壤淋出液相比,Cu(Ⅱ)、Cd(Ⅱ)、Zn(Ⅱ)浓度分别降低78.25%、31.60%、24.90%;同时在pH为3~6时,pH值越高生物炭和土壤对重金属的吸附能力越强,且生物炭的添加增大了土壤的pH,使土壤的表面活性位点增多;不同生物炭添加方式下,生物炭与土壤完全混合时可充分发挥吸附能力同时改变土壤的理化性质,使得Cu(Ⅱ)、Cd(Ⅱ)、Zn(Ⅱ)迁移能力最弱;玉米秸秆生物炭相比于木材木屑生物炭拥有更多的孔隙结构且显著降低了土壤的表面电位,对重金属的固定能力更强.Biochar,a soil conditioner,has strong adsorption capacity and stability which has great prospects in controlling heavy metal pollution in soil.Combined with scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),and FTIR,biochar derived from corn straw and wood sawdust were used to investigate their effects on the leaching behavior of Cu(II),Cd(II),and Zn(II)under different conditions.The results showed that biochar has a pore structure,abundant functional groups,and low zeta potential,which contributed to the large adsorption capacity for heavy metals.With the increase in biochar amount,the adsorption sites increased.Compared with no biochar addition,the leachate concentration of Cu(II),Cd(II),and Zn(II)in soil with 2%biochar addition decreased by78.25%,31.60%,and 24.90%,respectively.At a pH of 3~6,the higher the pH,the greater the adsorption capacity of biochar and soil for heavy metals.Meanwhile,biochar addition increased the soil pH,resulting in an increased number of surface-active sites on soil particles.Under different biochar application methods,when biochar was completely mixed with soil,it can fully exert its adsorption capacity as well as change the physical and chemical properties of the soil,which led to the lowest transport ability of Cu(II),Cd(II)and Zn(II).Compared with wood sawdust biochar,corn straw biochar has more pores and significantly reduced the surface potential of soil,resulting in enhanced retention of heavy metals in soil.

关 键 词：生物炭 土壤 重金属 吸附 迁移 

分 类 号：X131.3[环境科学与工程—环境科学]