摘要
以板蓝根药渣为原料,选择300℃和500℃厌氧裂解制备2种生物炭(BC300和BC500)、BC500载Fe改性炭(FeBC500)、天然麦饭石(MFS)、BC500与MFS等质量组合[BC500∶MFS(1∶1)]、Fe-BC500与MFS等质量组合[Fe-BC500∶MFS(1∶1)]材料为钝化剂,采用室内盆栽实验和等温吸附实验,研究了其对土壤-黑麦草体系的调控效果,并通过比表面孔分布测定(BET)、扫描电镜分析(SEM)、X射线衍射(XRD)和傅里叶变换红外光谱(FTIR)探讨了其机制.结果表明,在添加量为2%(土)时,BC300、BC500、Fe-BC500、MFS、BC500∶MFS(1∶1)和Fe-BC500∶MFS(1∶1)均可显著降低(P <0. 05)黑麦草体内Cu和Cd含量以及显著增加黑麦草的生物量,且黑麦草的叶绿素含量和根系活力均可指示这一效果. BC300处理抑制黑麦草吸收Cu和Cd,增加黑麦草的生物量的效果要优于其他处理,可使黑麦草地下部分Cu和Cd含量分别减少44. 78%和63. 89%,地上部分分别减少76. 34%和53. 40%;地下部分生物量增加327. 22%,地上部分生物量增加504. 11%. Langmuir方程更好地拟合BC300、BC500和Fe-BC500的吸附效果,且对Cu的最大吸附量分别为8. 02、9. 20和8. 82 mg·g-1;对Cd的最大吸附量分别为7. 97、8. 51和7. 70 mg·g-1. Freundlich方程能更好地拟合MFS的吸附效果,对Cu和Cd的最大吸附量分别为7. 03 mg·g-1和6. 10 mg·g-1. BC300和BC500主要通过其表面羟基、羧基、羰基和酯基,Fe-BC500主要通过其表面羟基和铁羟基,MFS主要通过其中Na Al Si3O8和Al2Si2O5(OH)4表面的硅羟基、羟基和羧基分别与Cu和Cd发生配合反应,进而达到钝化修复Cu和Cd污染土壤的效果.因此,药渣生物炭、铁改性药渣生物炭和麦饭石及其组合材料均可被用于Cu和Cd复合污染土壤修复,但修复机制不同.
An indoor pot experiment and isothermal adsorption experiment were used to examine the regulation of soil-ryegrass system treatments.For the treatments,Banlangen dregs were selected as a raw material alongside two kinds of biochar(BC300,BC500)prepared by pyrolysis at 300℃and 500℃under anoxic conditions.Fe was modified by BC500(Fe-BC500),which was then combined with maifanite(MFS)as a passivating agent(BC500∶MFS(1∶1)and Fe-BC500∶MFS(1∶1))Surface pore distribution(BET),scanning electron microscopy(SEM),X-ray diffraction(XRD),and Fourier-transform infrared spectroscopy(FTIR)were used in the analyses.The results showed that treatment with BC300,BC500,Fe-BC500,MFS,BC500∶MFS(1∶1),and Fe-BC500∶MFS(1∶1)significantly reduced the Cu and Cd content(2%content in soil)of ryegrass(P<0.05)and significantly increased the biomass of ryegrass.This effect could have resulted from the enhanced chlorophyll content and root activity of the ryegrass.The effect of BC300 was better than the other treatments,which reduced the content of Cu and Cd in the roots of ryegrass by 44.78%and 63.89%,respectively,and in the aboveground biomass by 76.34%and 53.40%,respectively.The biomass of roots was also increased by327.22%,and the aboveground biomass increased by 504.11%.The Langmuir equation produced the best fit for adsorption effects of BC300,BC500,and Fe-BC500,for which the maximum adsorption capacity for Cu was 8.02,9.20,and 8.82 mg·g-1,respectively.The maximum adsorption capacity for Cd was 7.97,8.51,and 7.70 mg·g-1,respectively.The Freundlich equation gave a better fit for the adsorption of MFS.In this case,the maximum adsorption capacity for Cu and Cd was 7.03 mg·g-1 and 6.10 mg·g-1,respectively.BC300 and BC500 mainly passes through their surface hydroxyl,carboxyl,carbonyl,and ester groups;Fe-BC500 mainly passes through its surface hydroxyl group and iron hydroxyl group;MFS mainly passes through its silicon hydroxyl group,hydroxyl group,and carboxyl group on the surface of Na Al Si3 O8 and Al2 Si2 O5(OH)4 and then
作者
肖亮亮
丁园
XIAO Liang-liang;DING Yuan(College of Environment and Chemical Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2019年第10期4668-4677,共10页
Environmental Science
基金
江西省科技厅自然科学基金项目(20171BAB203033,2015BBF60003)
关键词
中药渣生物炭
麦饭石
土壤
黑麦草
铜
镉
修复机制
traditional Chinese medicine slag biochar
maifanite
soil
ryegrass
copper
cadmium
repair mechanism
