In-situ stabilization of multiple heavy metals (Pb, Zn, As) by ferrous sulfate—From batch experiments to pilot study

Highlights

	● Bioavailable Pb, Zn and As contents decreased by 61%, 28%, and 69% in batch tests.
	● In situ stabilization effect of heavy metals was 27%–65% lower than batch tests.
	● Injected FeSO4 had limited radius of influence at 1.0–2.0 m for stabilization.
	● Stabilization efficiency was negatively correlated with the initial BHM contents.
	● The low pH induced by FeSO4 addition increased Zn concentration in groundwater.

Abstract

Chemical stabilization has been widely applied to stabilize various heavy metals in soil, but there have been few systematic investigations of in situ stabilization at practical contaminated sites. In this study, batch experiments were conducted to investigate the stabilization effect of heavy metals in soil from an iron-smelting site using multiple materials. The results showed that FeSO₄ simultaneously reduced the bioavailable heavy metal (BHM) concentrations of Pb, Zn, and As by 61.1%, 28.1%, and 68.6%, respectively. Therefore, FeSO₄ was further applied at the practical contaminated site. Experimental results indicated that the heterogeneous distribution of stabilization efficiency deviated from that of batch experiments, which were influenced by multiple factors. Compared to the control group, the bioavailable Pb, Zn, and As concentrations decreased by 23.1, 13.6, and 4.73 mg/kg, respectively, when the injected FeSO₄ concentration was 0.27 mol/L in the saturated zone. The decreased concentrations of bioavailable Pb, Zn, and As decreased with the distance from the injection well, showing a limited radius of influence at 1.0–2.0 m, larger than the theoretical value (0.92 m). Correlation analysis revealed a significant negative relationship between the change in BHM content and the fraction of BHM content before stabilization (FB), indicating that FB significantly controlled the stabilization efficiency. While excess injected FeSO₄ had only a slight influence on the stabilization efficiency of heavy metals, it negatively impacted groundwater. This study provides new perspectives for in situ stabilization and highlights the importance of pilot-scale experiments over batch experiments for guiding engineering activities.

Graphical abstract

Keywords

Ferrous sulfate / Bioavailable heavy metal / Batch experiments / In situ stabilization / Groundwater

References

[1] Ahmad A, Van Der Wal A, Bhattacharya P, Van Genuchten C M. (2019). Characteristics of Fe and Mn bearing precipitates generated by Fe(II) and Mn(II) co-oxidation with O₂, MnO₄ and HOCl in the presence of groundwater ions. Water Research, 161: 505–516

[2] Aihemaiti A, Chen J J, Hua Y H, Dong C L, Wei X K, Yan F, Zhang Z T. (2022). Effect of ferrous sulfate modified sludge biochar on the mobility, speciation, fractionation and bioaccumulation of vanadium in contaminated soil from a mining area. Journal of Hazardous Materials, 437(5): 129405

[3] Buzatu T, Ghica V, Buzatu M, Iacob G. (2015). Solubilisation kinetics of the lead hydroxide in acetic acid. Revista de Chimie -Bucharest- Original Edition, 66: 285–289

[4] Cao P, Qiu K, Zou X, Lian M, Liu P, Niu L, Yu L, Li X, Zhang Z. (2020). Mercapto propyltrimethoxysilane- and ferrous sulfate-modified nano-silica for immobilization of lead and cadmium as well as arsenic in heavy metal-contaminated soil. Environmental Pollution, 266: 115152

[5] Chien S W C, Wang H H, Chen Y M, Wang M K, Liu C C. (2021). Removal of heavy metals from contaminated paddy soils using chemical reductants coupled with dissolved organic carbon solutions. Journal of Hazardous Materials, 403: 123549

[6] Cutler W G, El-Kadi A, Hue N V, Peard J, Scheckel K, Ray C. (2014). Iron amendments to reduce bioaccessible arsenic. Journal of Hazardous Materials, 279: 554–561

[7] Giordano T H. (1989). Anglesite (PbSO₄) solubility in acetate solutions: The determination of stability constants for lead acetate complexes to 85°C. Geochimica et Cosmochimica Acta, 53(2): 359–366

[8] Guo F, Ding C, Zhou Z, Huang G, Wang X. (2018). Stability of immobilization remediation of several amendments on cadmium contaminated soils as affected by simulated soil acidification. Ecotoxicology and Environmental Safety, 161: 164–172

[9] He Y, Fang T, Wang J, Liu X, Yan Z, Lin H, Li F, Guo G. (2022). Insight into the stabilization mechanism and long-term effect on As, Cd, and Pb in soil using zeolite-supported nanoscale zero-valent iron. Journal of Cleaner Production, 355: 131634

[10] Horst J, Divine C, Schnobrich M, Oesterreich R, Munholland J. (2019). Groundwater remediation in low-permeability settings: The evolving spectrum of proven and potential. Ground Water Monitoring and Remediation, 39(1): 11–19

[11] Hu Y M, Zhang P, Yang M, Liu Y Q, Zhang X, Feng S S, Guo D W, Dang X L. (2020). Biochar is an effective amendment to remediate Cd-contaminated soils: a meta-analysis. Journal of Soils and Sediments, 20(11): 3884–3895

[12] HuangB (2016). Studies on the adsorption, accumulation, transportation and immobilization of heavy metals in paddy soil. Dissertation for the Doctoral Degree. Changsha: Hunan University (in Chinese)

[13] HuangR QWang GTangR YLiaoS QChenY H (2005). Extraction method for available arsenic in acid soils. Journal of AGRO-Environment Science, 24(3): 610–615 (in Chinese)

[14] Jin Z, Ci M, Yang W, Shen D, Hu L, Fang C, Long Y. (2020). Sulfate reduction behavior in the leachate saturated zone of landfill sites. Science of the Total Environment, 730: 138946

[15] Jolly Y N, Rakib M R J, Sakib M S, Shahadat M A, Rahman A, Akter S, Kabir J, Rahman M S, Begum B A, Rahman R. . (2022). Impact of industrially affected soil on humans: a soil-human and soil-plant-human exposure assessment. Toxics, 10(7): 347

[16] Jurgens B C, Parkhurst D L, Belitz K. (2019). Assessing the lead solubility potential of untreated groundwater of the United States. Environmental Science & Technology, 53(6): 3095–3103

[17] Ke W, Zeng J, Zhu F, Luo X, Feng J, He J, Xue S. (2022). Geochemical partitioning and spatial distribution of heavy metals in soils contaminated by lead smelting. Environmental Pollution, 307: 119486

[18] Kramer C, Gleixner G. (2008). Soil organic matter in soil depth profiles: distinct carbon preferences of microbial groups during carbon transformation. Soil Biology & Biochemistry, 40(2): 425–433

[19] Krok B, Mohammadian S, Noll H M, Surau C, Markwort S, Fritzsche A, Nachev M, Sures B, Meckenstock R U. (2022). Remediation of zinc-contaminated groundwater by iron oxide in situ adsorption barriers: from lab to the field. Science of the Total Environment, 807: 151066

[20] Li J, Yang D, Zou W, Feng X, Wang R, Zheng R, Luo S, Chu Z, Chen H. (2024). Mechanistic insights into the synergetic remediation and amendment effects of zeolite/biochar composite on heavy metal-polluted red soil. Frontiers of Environmental Science & Engineering, 18(9): 114

[21] Luo X, Jiang X, Xue S, Tang X, Zhou C, Wu C, Qian Z, Wu K. (2021). Arsenic biomineralization by iron oxidizing strain (Ochrobactrum sp.) isolated from a paddy soil in Hunan, China. Land Degradation & Development, 32(6): 2082–2093

[22] Miao Z, Brusseau M L, Carroll K C, Carreón-Diazconti C, Johnson B. (2012). Sulfate reduction in groundwater: characterization and applications for remediation. Environmental Geochemistry and Health, 34(4): 539–550

[23] MukhopadhyaySMastoR ETripathiR C SrivastavaN K (2019). Application of soil quality indicators for the phytorestoration of mine spoil dumps. In: Pandey V C, Bauddh K, eds. Phytomanagement of Polluted Sites. Dhanbad: Elsevier

[24] Mun E A, Hannell C, Rogers S E, Hole P, Williams A C, Khutoryanskiy V V. (2014). On the role of specific interactions in the diffusion of nanoparticles in aqueous polymer solutions. Langmuir, 30(1): 308–317

[25] Qi S, Ji H, Shen D, Mao Y, Shentu J. (2023). Optimization strategies for Cd and Pb immobilization in soil using meta-analysis combined with numerical modeling. Pedosphere, 33(1): 61–73

[26] Schroth M H, Kleikemper J, Bolliger C, Bernasconi S M, Zeyer J. (2001). In situ assessment of microbial sulfate reduction in a petroleum-contaminated aquifer using push–pull tests and stable sulfur isotope analyses. Journal of Contaminant Hydrology, 51(3−4): 179–195

[27] SEPA(2007). Solid Waste-Extraction Procedure for Leaching Toxicity-Acetic Acid Buffer Solution Method. Beijing: State Environmental Protection Administration of China

[28] Shan D N, Shi Y, Zhou B, Liu Z L, Yang L, Zhu X T, Luo Q S, Li G H. (2021). Simultaneous and continuous stabilization of As and Cd in contaminated soil by a half wrapping-structured amendment. Journal of Environmental Chemical Engineering, 9(4): 105416

[29] Shentu J, Li X, Han R, Chen Q, Shen D, Qi S. (2022). Effect of site hydrological conditions and soil aggregate sizes on the stabilization of heavy metals (Cu, Ni, Pb, Zn) by biochar. Science of the Total Environment, 802: 149949

[30] StateEnvironmental Protection Administration China (1987). Water Quality-Determination of Copper, Zinc, Lead and Cadmium-Atomic Absorption Spectrometry (GB 7475–87). Beijing: State Environmental Protection Administration of China

[31] Strebel O, Böttcher J, Fritz P. (1990). Use of isotope fractionation of sulfate-sulfur and sulfate-oxygen to assess bacterial desulfurication in a sandy aquifer. Journal of Hydrology, 121(1−4): 155–172

[32] USEPA(2023). Recent Remedy Selection (FY 2018-2020). In: Office of Land and Emergency Management, ed. Superfund Remedy Report, 17th Edition. Washington, DC: USEPA

[33] Van Groeningen N, Thomasarrigo L K, Byrne J M, Kappler A, Christl I, Kretzschmar R. (2020). Interactions of ferrous iron with clay mineral surfaces during sorption and subsequent oxidation. Environmental Science. Processes & Impacts, 22(6): 1355–1367

[34] Voegelin A, Jacquat O, Pfister S, Barmettler K, Scheinost A C, Kretzschmar R. (2011). Time-dependent changes of zinc speciation in four soils contaminated with zincite or sphalerite. Environmental Science & Technology, 45(1): 255–261

[35] Wang F, Xu J, Yin H, Zhang Y, Pan H, Wang L. (2021a). Sustainable stabilization/solidification of the Pb, Zn, and Cd contaminated soil by red mud-derived binders. Environmental Pollution, 284: 117178

[36] Wang J L, Zeng G C, Deng H, Liu X M, Zhao D Y. (2022). Microwave-enhanced simultaneous immobilization of lead and arsenic in a field soil using ferrous sulfate. Chemosphere, 308: 136388

[37] Wang L W, Rinklebe J, Tack F M G, Hou D Y. (2021b). A review of green remediation strategies for heavy metal contaminated soil. Soil Use and Management, 37(4): 936–963

[38] Weaver A R, Kissel D E, Chen F, West L T, Adkins W, Rickman D, Luvall J C. (2004). Mapping soil pH buffering capacity of selected fields in the coastal plain. Soil Science Society of America Journal, 68(2): 662–668

[39] Wu Y, Li X, Yu L, Wang T, Wang J, Liu T. (2022). Review of soil heavy metal pollution in China: spatial distribution, primary sources, and remediation alternatives. Resources, Conservation and Recycling, 181: 106261

[40] YangY (2020). Study on pretreatment for determination of total arsenic and mercury in soil. Shanxi Science & Technology of Communications, 4: 143–145 (in Chinese)

[41] Yu C, Zhang Y, Lu Y, Qian A, Zhang P, Cui Y, Yuan S. (2021). Mechanistic insight into humic acid-enhanced hydroxyl radical production from Fe(II)-bearing clay mineral oxygenation. Environmental Science & Technology, 55(19): 13366–13375

[42] Zafar A M, Javed M A, Hassan A A, Mohamed M M. (2021). Groundwater remediation using zero-valent iron nanoparticles (nZVI). Groundwater for Sustainable Development, 15: 100694

[43] Zhang Y, Wang J, Feng Y. (2021). The effects of biochar addition on soil physicochemical properties: a review. Catena, 202: 105284

[44] ZhaoHYang CZhangXZhangYQiuG (2021). Microorganisms used in chalcopyrite bioleaching. In: Zhao H, Yang C, Zhang X, Zhang Y, Qiu G, eds. Biohydrometallurgy of Chalcopyrite. Changsha: Elsevier

Acknowledgements

This study was supported by the National Key R&D Program of China (No. 2018YFC1800506), the Zhejiang Gongshang University “Digital+” Disciplinary Construction Management Project (China) (No. SZJ2022B010), the National Natural Science Foundation of China (Nos. 42377070 and 42107261), and the Zhejiang Provincial Natural Science Foundation of China (No. LQ22D030002).

Conflict of Interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11783-025-1956-0 and is accessible for authorized users.

RIGHTS & PERMISSIONS

2025 Higher Education Press 2025