Effect of KI Leaching on the Hg (Ⅱ) Removal of Loess Soil and the Physicochemical Properties of the Soil

doi:10.16258/j.cnki.1674-5906.2023.04.015

Ecology and Environment ›› 2023, Vol. 32 ›› Issue (4): 776-783.DOI: 10.16258/j.cnki.1674-5906.2023.04.015

• Research Articles • Previous Articles Next Articles

Effect of KI Leaching on the Hg (Ⅱ) Removal of Loess Soil and the Physicochemical Properties of the Soil

FENG Shuna(), LÜ Jialong, HE Hailong()

College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, P. R. China

Received:2023-02-07 Online:2023-04-18 Published:2023-07-12
Contact: HE Hailong

KI淋洗对黄绵土汞污染的去除效果及土壤理化性状的影响

冯树娜(), 吕家珑, 何海龙()

西北农林科技大学资源环境学院，陕西杨陵 712100

通讯作者: 何海龙
作者简介:冯树娜（1998年生），女，硕士研究生，主要研究方向土壤修复。E-mail: fsn2945074751@nwafu.edu.cn
基金资助:
国家自然科学基金项目(42077135)

Abstract

Abstract:

Serious threats to human health and ecological safety have been caused by soil heavy metal contamination. Chemical leaching is one of the most effective and important remediation measures for heavy metal contamination with great progress. However, few studies were conducted on chemical leaching of the Hg (Ⅱ) contaminated soil, which severely limits the mechanism analysis and applications. In this study, indoor soil column tests and HYDRUS-1D numerical simulations were used to investigate the effects of different eluents, including EDTA, citric acid (CA), Na₂S₂O₃ and KI on the removal of Hg (Ⅱ) from loess soil, and the optimal drencher types and ratios were selected. In addition, it is critical to investigate the response of physical and chemical soil properties to the migration process and leaching of heavy metals, and establish a solute transport model to better describe the migration process of Hg (Ⅱ) in soil for more efficient remediation of Hg-contaminated soil. The results showed that (1) KI was effective in removing Hg (Ⅱ) from loess soil, with a removal rate of 46.4% after the optimized ratio. The desorption of Hg (Ⅱ) from the KI solution followed the quasi-first-order kinetic model (r²=0.96), and the maximum desorption amount was 4.09 mg?kg^?1. (2) The residual mercury content in the soil column increased with the depth of the column after KI leaching, with an average mass fraction of 1.34 mg?kg^?1 and a removal rate of 82.9%. KI performed better in the removal of mercury from the soil column than the oscillation test, and the leaching process was conducive to the conversion of semi-mobile mercury to mobile mercury in the soil. (3) HYDRUS-1D could well simulate Hg (Ⅱ) penetration curve in the soil column with the fitting coefficient r²>0.95. The fitting parameters and error evaluation values were within the confidence interval. According to the fitted inversed parameters, it was predicted that 87.7 hours would be required for the mercury concentration in the leached liquid to reach the safe emission standard. (4) Soil pH and conductivity increased significantly by 0.67 and 1.15 mS?cm^?1, respectively, after KI leaching. The cation exchange capacity decreased significantly, with an average reduction of 1.64 cmol?kg^?1. Soil cation exchange capacity and pH had significant effects on Hg (Ⅱ) content and morphology. In conclusion, KI leaching could better remediate mercury-contaminated soil, and the toxicity and bioavailability of mercury in soil were significantly reduced after leaching. The remediated soil meets the efficient and cost-effective remediation objectives, which also provides a theoretical basis and technical guidance for the remediation of mercury-contaminated soil.

Key words: heavy metal pollution, chemical leaching, soil remediation, physical and chemical properties

摘要：

土壤中重金属污染严重威胁人类健康和生态环境安全，而化学淋洗是重要的重金属污染修复措施之一且取得了较大进展，但目前针对汞污染土壤修复的淋洗研究不足，严重制约其机理解析和应用。采用室内土柱试验和HYDRUS-1D数值模拟，探究不同化学淋洗剂EDTA、柠檬酸（CA）、Na₂S₂O₃和KI对黄绵土中重金属汞的去除效果，并筛选出最优的淋洗剂种类和配比。同时研究了土壤理化性状对重金属迁移过程和淋洗的响应，并建立溶质运移模型明确土壤中汞的迁移过程。结果表明：（1）KI对黄棉土中汞的去除效果较好，优化配比后土壤汞去除率达46.4%。KI溶液对土壤汞解吸过程符合准一级动力学模型（r²=0.96），最大解吸量为4.09 mg?kg^?1；（2）KI溶液淋洗后土柱中残留的汞含量随土柱深度增加而增加，平均质量分数为1.34 mg?kg^?1，去除率为82.9%；KI对土柱中重金属汞的去除效果较振荡试验好，且淋洗过程有利于土壤中半移动性汞向移动性汞的转化；（3）HYDRUS-1D对土柱中汞穿透曲线拟合较好，拟合系数r²>0.95；拟合参数和误差评价值均在置信区间范围之内，可根据拟合预测出土柱中淋出液汞质量浓度达到安全排放标准所需的时间为87.7 h；（4）淋洗后土壤pH值和电导率较淋洗前增加显著，分别增加了0.67、1.15 mS?cm^?1，而阳离子交换量则显著减少，平均减少量为1.64 cmol?kg^?1；土壤阳离子交换量和pH值对土壤汞含量和形态影响显著。综上，KI淋洗能较好的修复汞污染土壤，淋洗后显著降低了土壤中汞的毒性和生物利用度，且满足高效、经济的修复目标，为汞污染土壤的淋洗修复提供了理论依据和技术思路。

关键词: 重金属污染, 化学淋洗, 土壤修复, 理化性状

CLC Number:

FENG Shuna, LÜ Jialong, HE Hailong. Effect of KI Leaching on the Hg (Ⅱ) Removal of Loess Soil and the Physicochemical Properties of the Soil[J]. Ecology and Environment, 2023, 32(4): 776-783.

冯树娜, 吕家珑, 何海龙. KI淋洗对黄绵土汞污染的去除效果及土壤理化性状的影响[J]. 生态环境学报, 2023, 32(4): 776-783.

Figures/Tables 13

Table 1 Basic physical and chemical properties of loess soil

w_{(粒径组成)}/%			pH值	w_(有机质)/ (g∙kg⁻¹)	阳离子交换量/ (cmol∙kg⁻¹)	电导率/ (mS∙cm⁻¹)	w_(总汞)/ (mg∙kg⁻¹)	w_{(移动性汞)}/ (mg∙kg⁻¹)	w_{(半移动性汞)}/ (mg∙kg⁻¹)	w_{(不移动性汞)}/ (mg∙kg⁻¹)
砂粒	粉粒	黏粒	pH值	w_(有机质)/ (g∙kg⁻¹)	阳离子交换量/ (cmol∙kg⁻¹)	电导率/ (mS∙cm⁻¹)	w_(总汞)/ (mg∙kg⁻¹)	w_{(移动性汞)}/ (mg∙kg⁻¹)	w_{(半移动性汞)}/ (mg∙kg⁻¹)	w_{(不移动性汞)}/ (mg∙kg⁻¹)
30.10	55.11	14.79	8.16	11.33	21.17	0.25	6.89	0.18	6.47	0.24

Figure 1 Hg(Ⅱ) removal effect of different eluents

Figure 2 Influence of KI concentration on leaching effect and removal rate of Hg(Ⅱ)

Figure 3 Influence of KI leaching time on leaching effect and removal rate of Hg(Ⅱ)

Figure 4 Influence of KI liquid-soil ratio on leaching effect and removal rate of Hg(Ⅱ)

Table 2 Regression analysis of KI ratio on Hg(Ⅱ) removal rate

模型	非标准化系数		标准化系数	t	显著性	VIF
模型	B	标准误差	β	t	显著性	VIF
常量	−17.008	14.593	—	−1.137	0.270	—
浓度	243.307	60.324	0.591	4.039	0.001	1.000
浸提时间	1.0107	0.347	0.471	3.195	0.005	1.014
液土比	1.321	1.201	0.162	1.100	0.286	1.014

Table 3 Fitting parameters of kinetic model equation of Hg(Ⅱ) desorption in loess soil

模型	准一级动力学方程	准二级动力学方程	Elovich方程	颗粒内扩散方程	双常数方程
模型	q=q_e(1−e⁻^kx)	q=kq_e²x/(1+q_ekx)	q=a+blnt	q=a+t^−1/^b	lnq=a+blnt
参数q_e/a	4.093	5.134	1.307	0.003817	0.08208
参数k/b	0.1747	0.03402	$b$ =0.81	2.13	0.41
系数r²	0.9634	0.9584	0.8793	0.9149	0.9173

Table 3 Fitting parameters of kinetic model equation of Hg(Ⅱ) desorption in loess soil

模型	准一级动力学方程	准二级动力学方程	Elovich方程	颗粒内扩散方程	双常数方程
模型	q=q_e(1−e⁻^kx)	q=kq_e²x/(1+q_ekx)	q=a+blnt	q=a+t^−1/^b	lnq=a+blnt
参数q_e/a	4.093	5.134	1.307	0.003817	0.08208
参数k/b	0.1747	0.03402	$b$ =0.81	2.13	0.41
系数r²	0.9634	0.9584	0.8793	0.9149	0.9173

Figure 5 The form and mass fraction of Hg(Ⅱ) in each layer of soil column after KI leaching

Figure 6 Measured values and HYDRUS-1D simulation curve of Hg(Ⅱ) concentration in the leached solution

Figure 7 Clay content in each layer of soil column after KI leaching

Figure 8 Variation of physical and chemical properties in each layer of soil column after KI leaching

Figure 9 Redundancy analysis between soil physicochemical properties and Hg(Ⅱ) content and morphology

Table 4 Correlation between soil physicochemical properties and Hg(Ⅱ) content and morphology

指标	黏粒含量	pH值	有机质	阳离子交换量	电导率
总汞	0.479	−0.750**	−0.073	0.692*	−0.437
移动性汞	0.414	−0.832**	−0.224	0.764**	−0.461
半移动性汞	0.625*	−0.838**	−0.269	0.722**	−0.512
不移动性汞	0.175	−0.405	−0.202	0.230	0.201

References 33

[1]	ANDONI M, IOVI A, NEGRA P, et al., 2008. Mercury removing from the contamined soil using KI solution, The pH influence[J]. Revista De Chimie, 59(7): 779-781.
[2]	DERMONT G, BERGERON M, MERCIER G, et al., 2008. Soil washing for metal removal: A review of physical/chemical technologies and field applications[J]. Journal of Hazardous Materials, 152(1): 1-31. DOI PMID
[3]	DO CARMO D L, SILA C A, 2016. Electrical conductivity and corn growth in contrasting soils affected by liming application at various levels[J]. Pesquisa Agropecuaria Brasileira, 51(10): 1762-1772. DOI URL
[4]	DRISCOLL C T, MASON R P, CHAN H M, et al., 2013. Mercury as a global pollutant: sources, pathways, and effects[J]. Environmental Science Technology, 47(10): 4967-4983. DOI URL
[5]	FERNANDEZ-MARTINEZ R, LORDO J, ORDONEZ A, et al., 2005. Distribution and mobility of mercury in soils from an old mining area in Mieres, Asturias (Spain)[J]. Science of the Total Environment, 346(1-3): 200-212. DOI URL
[6]	FINZGAR N, LESTAN D, 2008. The two-phase leaching of Pb, Zn and Cd contaminated soil using EDTA and electrochemical treatment of the washing solution[J]. Chemosphere, 73(9): 1484-1491. DOI PMID
[7]	JIANG H, ZHANG L, ZHENG B H, et al., 2012. Role of organic acids in desorption of mercury from contaminated soils in eastern shandong province, China[J]. Chinese Geographical Science, 22(4): 414-421. DOI URL
[8]	KHALID S, SHAHILD M, NIAZI N K, et al., 2017. A comparison of technologies for remediation of heavy metal contaminated soils[J]. Journal of Geochemical Exploration, 182: 247-268. DOI URL
[9]	LI P, FENG X B, QIU G L, et al., 2009. Mercury pollution in Asia: A review of the contaminated sites[J]. Journal of Hazardous Materials, 168(2): 591-601. DOI URL
[10]	LI Y Y, LU C, ZHU N L, et al., 2022. Mobilization and methylation of mercury with sulfur addition in paddy soil: Implications for integrated water-sulfur management in controlling Hg accumulation in rice[J]. Journal of Hazardous Materials, 430: 128447. DOI URL
[11]	MARCHUK S, MARCHUK A, 2018. Effect of applied potassium concentration on clay dispersion, hydraulic conductivity, pore structure and mineralogy of two contrasting Australian soils[J]. Soil & Tillage Research, 182: 35-44.
[12]	OZER A, OZER D, EKIZ H I, 2004. The equilibrium and kinetic modelling of the biosorption of copper(II) ions on Cladophora crispata[J]. Adsorption-Journal of the International Adsorption Society, 10(4): 317-326. DOI URL
[13]	REDDY K R, ALA P R, 2005. Electrokinetic remediation of metal- contaminated field soil[J]. Separation Science and Technology, 40(8): 1701-1720. DOI URL
[14]	WANG J X, FENG X B, ANDERSON C W N, et al., 2012. Implications of mercury speciation in thiosulfate treated plants[J]. Environmental Science & Technology, 46(10): 5361-5368. DOI URL
[15]	WANG Y P, LIN Q T, XIAO R B, et al., 2020. Removal of Cu and Pb from contaminated agricultural soil using mixed chelators of fulvic acid potassium and citric acid[J]. Ecotoxicology and Environmental Safety, 206: 111179. DOI URL
[16]	WASAY S A, ARNFALK P, TOKUNAGA S, 1995. Remediation of a soil polluted by mercury with acidic potassiumiodide[J]. Journal of Hazardous Materials, 44(1): 93-102. DOI URL
[17]	WASAY S A, BARRINGTON S, TOKUNAGA S, 2001. Organic acids for the in situ remediation of soils polluted by heavy metals: Soil flushing in columns[J]. Water Air and Soil Pollution, 127(1-4): 301-314. DOI URL
[18]	WEI Z B, CHEN Y H, LI X Q, et al., 2022. Remediation of heavy metal contaminated farmland soil by biodegradable chelating agent GLDA[J]. Applied Sciences-Basel, 12(18): 9277.
[19]	WUANA R A, OKIEIMEN F E, IMBORVUNGU J A, 2010. Removal of heavy metals from a contaminated soil using organic chelating acids[J]. International Journal of Environmental Science & Technology, 7(3): 485-496.
[20]	XU J Y, KLEGA D B, BIESTER H, et al., 2014. Influence of particle size distribution, organic carbon, pH and chlorides on washing of mercury contaminated soil[J]. Chemosphere, 109: 99-105. DOI PMID
[21]	鲍士旦, 2000. 土壤农化分析[M]. 第3版. 北京: 中国农业出版社: 25-186.
	BAO S D, 2000. Soil agrochemical analysis[M]. The third edition. Beijng: China Agricultural Press: 25-186.
[22]	陈宗英, 张焕祯, 2012. 汞污染土壤的萃取修复技术研究[J]. 地学前缘, 19(6): 230-235.
	CHEN Z Y, ZHANG H Z, 2012. Research on extract remediation technology of mercury-contaminated soils[J]. Earth Science Frontiers, 19(6): 230-235.
[23]	董汉英, 仇荣亮, 赵芝灏, 等, 2010. 工业废弃地多金属污染土壤组合淋洗修复技术研究[J]. 土壤学报, 47(6): 1126-1133.
	DONG H Y, QIU R L, ZHAO Z H, et al., 2010. Sequential elution technique for remediation of multi-metal contaminated brownfield soils[J]. Acta Pedologica Sinica, 47(6): 1126-1133.
[24]	高震国, 钟瑞林, 杨帅, 等, 2022. HYDRUS模型在中国的最新研究与应用进展[J]. 土壤, 54(2): 219-231.
	GAO Z G, ZHONG R L, YANG S, et al., 2022. Recent progresses in research and application of HYDRUS modal in Chian[J]. Soils, 54(2): 219-231.
[25]	环境保护部, 国土资源部, 2014. 全国土壤污染状况调查公报 (2014年4月17日)[J]. 环境教育 (6): 8-10.
	Minisry of Ecology and Environment of the People’s Republic of China, Minisry of Land and Resources of the People’s Republic of China, 2014. Bulletin of the national survey on soil pollution (April 17, 2014)[J]. Environmental Education (6): 8-10.
[26]	吕晶晶, 石兰君, 窦艳艳, 等, 2022. 基于HYDRUS-1D的改良土壤渗滤处理污废水模型研究[J]. 环保科技, 28(6): 1-5, 16.
	LÜ J J, SHI L J, DOU Y Y, et al., 2022. Study on modified soil infiltration system model for wastewater treatment based on HYDRUS-1D[J]. Environmental Science and Technology, 28(6): 1-5, 16. DOI URL
[27]	邵乐, 史学峰, 李昌武, 等, 2019. 化学氧化强化化学淋洗修复汞污染土壤的试验研究[J]. 湖南有色金属, 35(6): 54-58.
	SHAO L, SHI X F, LI C W, et al., 2019. Experimental study on remediation of mercury contaminated soil by chemical oxidation enhanced chemical leaching[J]. Hunan Nonferrous Metals, 35(6): 54-58.
[28]	万朔阳, 吴勇, 唐学芳, 等, 2020. 基于HYDRUS-1D对西坝镇农田土壤重金属迁移模拟及空间解析[J]. 科学技术与工程, 20(2): 854-859.
	WAN S Y, WU Y, TANG X F, et al., 2020. Simulation and spatial analysis of heavy metal migration in xiba town soil based on HYDRUS-1D[J]. Science Technology and Engineering, 20(2): 854-859.
[29]	王娜, 2019. 汞污染土壤的修复技术概述[J]. 河南科技 (8): 156-158.
	WANG N, 2019. Overview of remediation Techniques for mercury contaminated soil[J]. Henan Science and Technology (8): 156-158.
[30]	杨文俊, 辜娇峰, 周航, 等, 2019. 农田土壤重金属淋洗剂筛选与效应分析[J]. 水土保持学报, 33(4): 321-328.
	YANG W J, GU J F, ZHOU H, et al., 2019. Screening and effect analysis of eluents rmoving heavy metals from paddy soil[J]. Journal of Soil and Water Conservation, 33(4): 321-328.
[31]	姚瑶, 张世熔, 王怡君, 等, 2018. 3种环保型淋洗剂对重金属污染土壤的淋洗效果[J]. 环境工程学报, 12(7): 2039-2046.
	YAO Y, ZHANG S R, WANG Y J, et al., 2018. Effects of different environmentally friendly washing agents on removal of soil heavy metals[J]. Chinese Journal of Environmental Engineering, 12(7): 2039-2046.
[32]	国家环境保护总局, 国家质量监督检验检疫总局, 2007. 危险废物鉴别标准——浸出毒物鉴别: GB 5085.3—2007[S]. 国家环境保护总局, 国家质量监督检验检疫总局: 5.
	State Environmental Protection Administration, State Administration of Quality Supervision, Inspection and Quarantine, 2007. Identification Standards for Hazardous Wastes: Identification for Extraction Toxiciy: GB 5085.3—2007[S]. State Administration of Quality Supervision, Inspection and Quarantine: 5.
[33]	生态环境部,国家市场监督管理总局:2018. 土壤环境质量——农用地土壤污染风险管控标准 (试行): GB 15618—2018 [S]. 生态环境部, 国家市场监督管理总局: 2.
	Ministry of Ecology and Environment, State Administration for Market Regulation, 2018. Soil Environmental Quality: Risk Control Standard for Soil Contamination of Agricultural Land: GB 15618—2018 [S]. Ministry of Ecology and Environment, State Administration for Market Regulation: 2.

Effect of KI Leaching on the Hg (Ⅱ) Removal of Loess Soil and the Physicochemical Properties of the Soil

KI淋洗对黄绵土汞污染的去除效果及土壤理化性状的影响

RichHTML

PDF

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 13

References 33

Related Articles 14

Recommended Articles

Metrics

Comments

[1]	MA Chuang, WANG Yuyang, ZHOU Tong, WU Longhua. Enrichment Characteristics and Desorption Behavior of Cadmium and Zinc in Particulate Organic Matter of Polluted Soil [J]. Ecology and Environment, 2022, 31(9): 1892-1900.
[2]	WANG Lixiao, LIU Jinxian, CHAI Baofeng. Response of Soil Bacterial Community and Nitrogen Cycle during the Natural Recovery of Abandoned Farmland in Subalpine of the North China [J]. Ecology and Environment, 2022, 31(8): 1537-1546.
[3]	FANG Xianbao, ZHANG Zhijun, LAI Yangqing, YE Mai, DIAO Zenghui. Remediation of Heavy Metals Cr and Cd in Soil by A Novel Sludge-derived Biochar [J]. Ecology and Environment, 2022, 31(8): 1647-1656.
[4]	YANG Chong, WANG Chunyan, WANG Wenying, MAO Xufeng, ZHOU Huakun, CHEN Zhe, SUONANJi , JIN Lei, MA Huaqing. Soil Nutrient Characteristics and Quality Evaluation of Alpine Grassland in the Source Area of the Yellow River on the Qinghai Tibet Plateau [J]. Ecology and Environment, 2022, 31(5): 896-908.
[5]	HAN Xin, YUAN Chunyang, LI Jihong, HONG Zongwen, LIU Xuan, DU Ting, LI Han, YOU Chenming, TAN Bo, ZHU Peng, XU Zhenfeng. Effects of Tree Species and Soil Layers on Soil Extractable Nitrogen Content [J]. Ecology and Environment, 2022, 31(11): 2143-2151.
[6]	GUO Lifang, YANG Rui, SUN Weimin. Nitrogen-Fixing Bacteria Isolation from Mine Tailings and Their Plant Growth Promoting Properties [J]. Ecology and Environment, 2022, 31(11): 2180-2188.
[7]	LIU Peiling, LIU Xiaodong, FENG Yingjie, SU Yuqiao, GAN Xianhua, ZHANG Weiqiang. Characteristics of Soil Saturated Hydraulic Conductivity of Water Conservation Forests in the Xinfengjiang Reservoir Area [J]. Ecology and Environment, 2022, 31(10): 1993-2001.
[8]	JIANG Jing, DENG Jingling, SHENG Guangyao. A Review of Biochar Aging and Its Impact on the Adsorption of Heavy Metals [J]. Ecology and Environment, 2022, 31(10): 2089-2100.
[9]	XING Shuwen, XU Jiamin, HUANG Bin, GAO Jingting, HAN Li. Effect of Heavy Metal Pollution on the Community Structure and Diversity of Soil Animals in Tea Garden Located in A Tungsten Mining Area [J]. Ecology and Environment, 2021, 30(9): 1903-1915.
[10]	CHENG Junwei, CAI Shenwen, HUANG Mingqin. Bioconcentration of Heavy Metals in Dominant Plants of Xiangjiang Manganese Mining Area in Guizhou Province [J]. Ecology and Environment, 2021, 30(8): 1742-1750.
[11]	ZHENG Zhiheng, XIONG Kangning, RONG Li, CHI Yongkuan. Effects of Biological Crusts on Soil Properties in Karst Rocky Desertification Areas of Different Levels [J]. Ecology and Environment, 2021, 30(6): 1202-1212.
[12]	NIU Xuekui, WU Xueyong, WANG Wei, AI Zhimin, WANG Shuting, HOU Juan, ZHOU Tao. Study on Enrichment Characteristics of Heavy Metals from Dominant Plants Around the Waste Slag Yard of Lead Smelting in A Typical Blast Furnace [J]. Ecology and Environment, 2021, 30(6): 1293-1298.
[13]	TONG Hui, QIAO Jiangtao, ZHOU Jimei, LEI Qinkai, CHEN Manjia, LIU Chengshuai. Coupled Transformation of Sulfur and Cadmium on Goethite Induced by Sulfate-reducing Bacterium [J]. Ecology and Environment, 2021, 30(5): 1069-1075.
[14]	RU Shuhua, ZHAO Ouya, HOU Limin, XIAO Guangmin, WANG Ce, SUN Shiyou, ZHANG Guoyin, WANG Ling, LIU Lei. Effects of Eight Kinds of Passivators on Properties and Cadmium Availability in Different Cadmium-contaminated Soil [J]. Ecology and Environment, 2021, 30(10): 2085-2092.