Biochar for heavy metal remediation in aquatic and terrestrial environments: Properties, influencing factors, and mechanisms

Yaoyao Cao; Jian Chen; Hui Zhang; Hongjie Sheng; Kang Lv; Jinjin Cheng; Xiaolong Chen; Dongfei Chen; Xiangyang Yu

doi:10.1016/j.gerr.2026.100167

Green Energy and Resources ›› 2026, Vol. 4 ›› Issue (1) :100167 DOI: 10.1016/j.gerr.2026.100167

Review

research-article

Biochar for heavy metal remediation in aquatic and terrestrial environments: Properties, influencing factors, and mechanisms

Yaoyao Cao ^a^,^b^,^c
, Jian Chen ^a^,^b^,^c
, Hui Zhang ^a^,^b^,^c
, Hongjie Sheng ^a^,^b^,^c
, Kang Lv ^a^,^b^,^c
, Jinjin Cheng ^a^,^b^,^c
, Xiaolong Chen ^a^,^b^,^c
, Dongfei Chen ^d
, Xiangyang Yu ^a^,^b^,^c^,^*

Author information +

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Abstract

With the rapid development of industrialization, heavy metal pollution in water and soil has become increasingly serious. Biochar has attracted extensive attention for its application in heavy metal remediation, which mainly depends on its developed porous structure, large specific surface area, abundant functional groups and minerals. This review outlines the status of heavy metal pollution and summarize the key physicochemical characteristics of biochar. Subsequently, a detailed analysis was conducted on the critical influencing factors, encompassing biochar physicochemical properties, environmental parameters, and heavy metal attributes. The core section comprehensively examines the primary remediation mechanisms, such as physical adsorption, ion exchange, precipitation, and complexation, highlighting how their relative importance shifts with biochar type and environmental context. Furthermore, remediation performance is not governed by a single mechanism but by the synergistic interplay of biochar's evolving surface chemistry, solution conditions, and metal speciation. Additionally, differences in dominant mechanisms and long-term stability are critically compared between aquatic and soil systems. Finally, we identify current knowledge gaps-particularly concerning short-term field performance, long-term aging effects, and sustainability under real-world conditions-and propose targeted future research directions to advance the practical, scalable, and safe application of biochar in heavy metal remediation.

Keywords

Heavy metal / Biochar / Physicochemical property / Influence factor / Remediation mechanism

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Yaoyao Cao, Jian Chen, Hui Zhang, Hongjie Sheng, Kang Lv, Jinjin Cheng, Xiaolong Chen, Dongfei Chen, Xiangyang Yu. Biochar for heavy metal remediation in aquatic and terrestrial environments: Properties, influencing factors, and mechanisms. Green Energy and Resources, 2026, 4 (1) : 100167 DOI:10.1016/j.gerr.2026.100167

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CRediT authorship contribution statement

Yaoyao Cao: Writing – original draft, Visualization, Funding acquisition, Data curation. Jian Chen: Writing – review & editing, Formal analysis. Hui Zhang: Validation, Methodology. Hongjie Sheng: Investigation, Conceptualization. Kang Lv: Validation, Methodology. Jinjin Cheng: Investigation, Formal analysis. Xiaolong Chen: Writing – review & editing, Formal analysis. Dongfei Chen: Writing – review & editing, Data curation. Xiangyang Yu: Writing – review & editing, Supervision, Funding acquisition, Conceptualization.

Declaration of competing interest

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.

Acknowledgements

This study was funded by the National Natural Science Foundation of China (Nos. 32302406, and 32272600).

References

Publishing order | Descend order by publishing year | Descend order by cited within

[1]	Aghababaei, A., Ncibi, M.C., Sillanpää, M., 2017. Optimized removal of oxytetracycline and cadmium from contaminated waters using chemically-activated and pyrolyzed biochars from forest and wood-processing residues. Bioresour. Technol. 239, 28-36. https://doi.org/10.1016/j.biortech.2017.04.119.

[2]	Agrafioti, E., Kalderis, D., Diamadopoulos, E., 2014. Arsenic and chromium removal from water using biochars derived from rice husk, organic solid wastes and sewage sludge. J. Environ. Manag. 133, 309-314. https://doi.org/10.1016/j.jenvman.2013.12.007.

[3]	Ahmad, M., Rajapaksha, A.U., Lim, J.E., Zhang, M., Bolan, N., Mohan, D., Vithanage, M., Lee, S.S., Ok, Y.S., 2014. Biochar as a sorbent for contaminant management in soil and water: a review. Chemosphere 99, 19-33. https://doi.org/10.1016/j.chemosphere.2013.10.071.

[4]	Ahmad, Z., Gao, B., Mosa, A., Yu, H., Yin, X., Bashir, A., Ghoveisi, H., Wang, S., 2018. Removal of Cu(II), Cd(II) and Pb(II) ions from aqueous solutions by biochars derived from potassium-rich biomass. J. Clean. Prod. 180, 437-449. https://doi.org/10.1016/j.jclepro.2018.01.133.

[5]	Ahmed, M.B., Zhou, J.L., Ngo, H.H., Guo, W., 2016. Insight into biochar properties and its cost analysis. Biomass Bioenergy 84, 76-86. https://doi.org/10.1016/j.biombioe.2015.11.002.

[6]	Akhtar, J., Amin, N.S., 2012. A review on operating parameters for optimum liquid oil yield in biomass pyrolysis. Renew. Sustain. Energy Rev. 16 (7), 5101-5109. https://doi.org/10.1016/j.rser.2012.05.033.

[7]	Awual, M.R., Yaita, T., El-Safty, S.A., Shiwaku, H., Suzuki, S., Okamoto, Y., 2013. Copper (II) ions capturing from water using ligand modified a new type mesoporous adsorbent. Chem. Eng. J. 221, 322-330. https://doi.org/10.1016/j.cej.2013.02.016.

[8]	Aziz, K.H.H., 2024. Removal of toxic heavy metals from aquatic systems using low-cost and sustainable biochar: a review. Desalination Water Treat. 320, 100757. https://doi.org/10.1016/j.dwt.2024.100757.

[9]

Bashir, S., Hussain, Q., Akmal, M., Riaz, M., Hu, H., Ijaz, S.S., Iqbal, M., Abro, S., Mehmood, S., Ahmad, M., 2018. Sugarcane bagasse-derived biochar reduces the cadmium and chromium bioavailability to mash bean and enhances the microbial activity in contaminated soil. J. Soils Sediments 18 (3), 874-886. https://doi.org/10.1007/s11368-017-1796-z.

[10]	Beesley, L., Marmiroli, M., 2011. The immobilisation and retention of soluble arsenic, cadmium and zinc by biochar. Environ. Pollut. 159 (2), 474-480. https://doi.org/10.1016/j.envpol.2010.10.016.

[11]

Bian, R., Chen, D., Liu, X., Cui, L., Li, L., Pan, G., Xie, D., Zheng, J., Zhang, X., Zheng, J., Chang, A., 2013. Biochar soil amendment as a solution to prevent Cd-tainted rice from China: results from a cross-site field experiment. Ecol. Eng. 58, 378-383. https://doi.org/10.1016/j.ecoleng.2013.07.031.

[12]

Bian, R., Joseph, S., Cui, L., Pan, G., Li, L., Liu, X., Zhang, A., Rutlidge, H., Wong, S., Chia, C., Marjo, C., Gong, B., Munroe, P., Donne, S., 2014. A three-year experiment confirms continuous immobilization of cadmium and lead in contaminated paddy field with biochar amendment. J. Hazard. Mater. 272, 121-128. https://doi.org/10.1016/j.jhazmat.2014.03.017.

[13]	Bogusz, A., Oleszczuk, P., 2018. Sequential extraction of nickel and zinc in sewage sludge- or biochar/sewage sludge-amended soil. Sci. Total Environ. 636, 927-935. https://doi.org/10.1016/j.scitotenv.2018.04.072.

[14]	Brennan, A., Jimenez, E. M.,Puschenreiter, M., Alburquerque, J.A., Switzer, C., 2014. Effects of biochar amendment on root traits and contaminant availability of maize plants in a copper and arsenic impacted soil. Plant Soil 379 (1-2), 351-360. https://doi.org/10.1007/s11104-014-2074-0.

[15]	Cao, X., Ma, L., Gao, B., Harris, W., 2009. Dairy-manure derived biochar effectively sorbs lead and atrazine. Environ. Sci. Technol. 43 (9), 3285-3291. https://doi.org/10.1021/es803092k.

[16]	Cao, Y., Xiao, W., Shen, G., Ji, G., Zhang, Y., Gao, C., Han, L., 2019. Carbonization and ball milling on the enhancement of Pb(II) adsorption by wheat straw: competitive effects of ion exchange and precipitation. Bioresour. Technol. 273, 70-76. https://doi.org/10.1016/j.biortech.2018.10.065.

[17]	Cao, Y., Xiao, W., Shen, G., Ji, G., Zhang, Y., Gao, C., Han, L.J., 2018. Mechanical fragmentation of wheat straw at different plant scales: Pb ²⁺ adsorption behavior and mechanism. Bioresources 13 (3), 6613-6630. https://doi.org/10.15376/biores.13.3.6613-6630.

[18]	Carrier, M., Joubert, J., Danje, S., Hugo, T., Görgens, J., Knoetze, J.H., 2013. Impact of the lignocellulosic material on fast pyrolysis yields and product quality. Bioresour. Technol. 150, 129-138. https://doi.org/10.1016/j.biortech.2013.09.134.

[19]	Chakma, S., Hasan, M., Hu, Y., Rakshit, S.K., Kang, K., 2025. Valorization of red mud and biomass waste via pre-pyrolysis activation for high-performance magnetic biochar in heavy metal remediation. Waste Manage 204, 114970. https://doi.org/10.1016/j.wasman.2025.114970.

[20]	Chen, C., Hu, Y., Ge, Y., Tao, J., Yan, B., Cheng, Z., Lv, X., Cui, X., Chen, G., 2025. Integrated learning framework for enhanced specific surface area, pore size, and pore volume prediction of biochar. Bioresour. Technol. 424, 132279. https://doi.org/10.1016/j.biortech.2025.132279.

[21]	Chen, D., Li, R., Bian, R., Li, L., Joseph, S., Crowley, D., Pan, G., 2017a. Contribution of soluble minerals in biochar to Pb ²⁺ adsorption in aqueous solutions. Bioresources 12 (1), 1662-1679. https://doi.org/10.15376/biores.12.1.1662-1679.

[22]	Chen, M., Wang, D., Yang, F., Xu, X., Xu, N., Cao, X ., 2017b. Transport and retention of biochar nanoparticles in a paddy soil under environmentally-relevant solution chemistry conditions. Environ. Pollut. 230, 540-549. https://doi.org/10.1016/j.envpol.2017.06.101.

[23]	Chen, T., Zhou, Z., Han, R., Meng, R., Wang, H., Lu, W., 2015a. Adsorption of cadmium by biochar derived from municipal sewage sludge: impact factors and adsorption mechanism. Chemosphere 134, 286-293. https://doi.org/10.1016/j.chemosphere.2015.04.052.

[24]	Chen, T., Zhou, Z., Xu, S., Wang, H., Lu, W., 2015b. Adsorption behavior comparison of trivalent and hexavalent chromium on biochar derived from municipal sludge. Bioresour. Technol. 190, 388-394. https://doi.org/10.1016/j.biortech.2015.04.115.

[25]	Choudhary, M., Kumar, R., Neogi, S., 2020. Activated biochar derived from Opuntia ficus-indica for the efficient adsorption of malachite green dye, Cu ⁺² and Ni ⁺² from water. J. Hazard. Mater. 392, 122441. https://doi.org/10.1016/j.jhazmat.2020.122441.

[26]	Clough, T., Condron, L., Kammann, C., Müller, C., 2013. A review of biochar and soil nitrogen dynamics. Agronomy-Basel 3 (2), 275-293. https://doi.org/10.3390/agronomy3020275.

[27]

Cui, L., Pan, G., Li, L., Bian, R., Liu, X., Yan, J., Quan, G., Ding, C., Chen, T., Liu, Y., Liu, Y., Yin, C., Wei, C., Yang, Y., Hussain, Q., 2016a. Continuous immobilization of cadmium and lead in biochar amended contaminated paddy soil: a five-year field experiment. Ecol. Eng. 93, 1-8. https://doi.org/10.1016/j.ecoleng.2016.05.007.

[28]	Cui, X., Fang, S., Yao, Y., Li, T., Ni, Q., Yang, X., He, Z., 2016b. Potential mechanisms of cadmium removal from aqueous solution by Canna indica derived biochar. Sci. Total Environ. 562, 517-525. https://doi.org/10.1016/j.scitotenv.2016.03.248.

[29]	Demirbas, A., 2008. Heavy metal adsorption onto agro-based waste materials: a review. J. Hazard. Mater. 157 (2-3), 220-229. https://doi.org/10.1016/j.jhazmat.2008.01.024.

[30]	Ding, Z., Xu, X., Phan, T., Hu, X., Nie, G., 2018. High adsorption performance for As(III) and As(V) onto novel aluminum-enriched biochar derived from abandoned tetra paks. Chemosphere 208, 800-807. https://doi.org/10.1016/j.chemosphere.2018.06.050.

[31]

Egene, C.E., Van Poucke, R., Ok, Y.S., Meers, E., Tack, F.M.G., 2018. Impact of organic amendments (biochar, compost and peat) on Cd and Zn mobility and solubility in contaminated soil of the Campine region after three years. Sci. Total Environ. 626, 195-202. https://doi.org/10.1016/j.scitotenv.2018.01.054.

[32]

Elaigwu, S.E., Rocher, V., Kyriakou, G., Greenway, G.M., 2014. Removal of Pb ²⁺ and Cd ²⁺ from aqueous solution using chars from pyrolysis and microwave-assisted hydrothermal carbonization of Prosopis africana shell. J. Ind. Eng. Chem. 20 (5), 3467-3473. https://doi.org/10.1016/j.jiec.2013.12.036.

[33]	Feng, L., He, S., Zhao, W., Ding, J., Liu, J., Zhao, Q., Wei, L., 2022. Can biochar addition improve the sustainability of intermittent aerated constructed wetlands for treating wastewater containing heavy metals? Chem. Eng. J. 444, 136636. https://doi.org/10.1016/j.cej.2022.136636.

[34]	Fu, F., Wang, Q., 2011. Removal of heavy metal ions from wastewaters: a review. J. Environ. Manag. 92 (3), 407-418. https://doi.org/10.1016/j.jenvman.2010.11.011.

[35]

Ghidotti, M., Fabbri, D., Mašek, O., Mackay, C.L., Montalti, M., Hornung, A., 2017. Source and biological response of biochar organic compounds released into water; relationships with bio-oil composition and carbonization degree. Environ. Sci. Technol. 51 (11), 6580-6589. https://doi.org/10.1021/acs.est.7b00520.

[36]	Gregory, S.J., Anderson, C.W.N., Camps Arbestain, M., McManus, M.T., 2014. Response of plant and soil microbes to biochar amendment of an arsenic-contaminated soil. Agric. Ecosyst. Environ. 191, 133-141. https://doi.org/10.1016/j.agee.2014.03.035.

[37]	Guo, P., Li, Z., Luo, J., Xu, X., Liu, H., Cao, Y., Wei, Y., Liu, Z., Qing, Y., Wu, Y., 2025. Synergistic Se/S functionalization of biochar for effective immobilization of multi-target heavy metals in water and soil. J. Hazard. Mater. 500, 140453. https://doi.org/10.1016/j.jhazmat.2025.140453.

[38]

Guo, W., Yao, X., Chen, Z., Liu, T., Wang, W., Zhang, S., Xian, J., Wang, Y., 2024. Recent advance on application of biochar in remediation of heavy metal contaminated soil: emphasis on reaction factor, immobilization mechanism and functional modification. J. Environ. Manag. 371, 123212. https://doi.org/10.1016/j.jenvman.2024.123212.

[39]	Han, L., Sun, K., Yang, Y., Xia, X., Li, F., Yang, Z., Xing, B., 2020. Biochar's stability and effect on the content, composition and turnover of soil organic carbon. Geoderma 364, 114184. https://doi.org/10.1016/j.geoderma.2020.114184.

[40]	He, L., Zhong, H., Liu, G., Dai, Z., Brookes, P.C., Xu, J., 2019. Remediation of heavy metal contaminated soils by biochar: mechanisms, potential risks and applications in China. Environ. Pollut. 252, 846-855. https://doi.org/10.1016/j.envpol.2019.05.151.

[41]

He, Y., Chen, L., Zhang, X., Deng, Q., Zhang, H., Mo, X., Huang, Y., Lv, X., Mi, B., Wu, F., 2025. Discrepancies in measurement methods for biochar's heavy metal adsorption performance caused by its dissolved organic matters. J. Hazard. Mater. 495, 139081. https://doi.org/10.1016/j.jhazmat.2025.139081.

[42]	Higashikawa, F.S., Conz, R.F., Colzato, M., Cerri, C.E.P., Alleoni, L.R.F., 2016. Effects of feedstock type and slow pyrolysis temperature in the production of biochars on the removal of cadmium and nickel from water. J. Clean. Prod. 137, 965-972. https://doi.org/10.1016/j.jclepro.2016.07.205.

[43]	Huang, X., An, D., Song, J., Gao, W., Shen, Y., 2017. Persulfate/electrochemical/FeCl₂ system for the degradation of phenol adsorbed on granular activated carbon and adsorbent regeneration. J. Clean. Prod. 165, 637-644. https://doi.org/10.1016/j.jclepro.2017.07.171.

[44]	Huijgen, W.J.J., Telysheva, G., Arshanitsa, A., Gosselink, R.J.A., de Wild, P.J., 2014. Characteristics of wheat straw lignins from ethanol-based organosolv treatment. Ind. Crop. Prod. 59, 85-95. https://doi.org/10.1016/j.indcrop.2014.05.003.

[45]	Inyang, M.I., Gao, B., Yao, Y., Xue, Y., Zimmerman, A., Mosa, A., Pullammanappallil, P., Ok, Y.S., Cao, X., 2016. A review of biochar as a low-cost adsorbent for aqueous heavy metal removal. Crit. Rev. Environ. Sci. Technol. 46 (4), 406-433. https://doi.org/10.1080/10643389.2015.1096880.

[46]

Ippolito, J.A., Cui, L., Kammann, C., Mönnig, N.W., Jose, M.E., Mendizabal, T.F., Cayuela, M.L., Sigua, G., Novak, J., Spokas, K., Borchard, N., 2020. Feedstock choice, pyrolysis temperature and type infuence biochar characteristics: a comprehensive meta-data analysis review. Biochar 2, 421-438. https://doi.org/10.1007/s42773-020-00067-x.

[47]

Jaffari, Z.H., Abbas, A., Kim, C.M., Shin, J., Kwak, J., Son, C., Lee, Y.G., Kim, S., Chon, K., Cho, K.H., 2023. Transformer-based deep learning models for adsorption capacity prediction of heavy metal ions toward biochar-based adsorbents. J. Hazard. Mater. 462, 132773. https://doi.org/10.1016/j.jhazmat.2023.132773.

[48]	Jiang, J., Xu, R., Jiang, T., Li, Z., 2012. Immobilization of Cu(II), Pb(II) and Cd(II) by the addition of rice straw derived biochar to a simulated polluted ultisol. J. Hazard. Mater. 229-230, 145-150. https://doi.org/10.1016/j.jhazmat.2012.05.086.

[49]	Jiang, J.P., Yuan, X.B., Ye, L.L., Liao, S.C., Zhang, X.H., 2013. Characteristics of straw biochar and its influence on the forms of arsenic in heavy metal polluted soil. Appl. Mech. Mater. 409-410, 133-138. https://doi.org/10.4028/www.scientific.net/AMM.409-410.133.

[50]	Kambo, H.S., Dutta, A., 2015. A comparative review of biochar and hydrochar in terms of production, physico-chemical properties and applications. Renew. Sustain. Energy Rev. 45, 359-378. https://doi.org/10.1016/j.rser.2015.01.050.

[51]	Kan, T., Strezov, V., Evans, T.J., 2016. Lignocellulosic biomass pyrolysis: a review of product properties and effects of pyrolysis parameters. Renew. Sustain. Energy Rev. 57, 1126-1140. https://doi.org/10.1016/j.rser.2015.12.185.

[52]	Karim, A.A., Kumar, M., Mohapatra, S., Panda, C.R., Singh, A., 2015. Banana peduncle biochar: characteristics and adsorption of hexavalent chromium from aqueous solution. Int. Res. J. Pure Appl. Chem. 1 (7), 1-10. https://doi.org/10.9734/irjpac/2015/16163.

[53]	Khan, A.Z.,Khan, S., Ayaz, T., Brusseau, M.L., Khan, M.A., Nawab, J., Muhammad, S., 2020. Popular wood and sugarcane bagasse biochars reduced uptake of chromium and lead by lettuce from mine-contaminated soil. Environ. Pollut. 263, 114446. https://doi.org/10.1016/j.envpol.2020.114446.

[54]

Khan, Z., Fan, X., Khan, M.N., Khan, M.A., Zhang, K., Fu, Y., Shen, H., 2022. The toxicity of heavy metals and plant signaling facilitated by biochar application: implications for stress mitigation and crop production. Chemosphere 308 (Pt 3), 136466. https://doi.org/10.1016/j.chemosphere.2022.136466.

[55]	Ko, D.C.K., Cheung, C.W., Choy, K.K.H., Porter, J.F., McKay, G., 2004. Sorption equilibria of metal ions on bone char. Chemosphere 54 (3), 273-281. https://doi.org/10.1016/j.chemosphere.2003.08.004.

[56]	Kong, L., Liu, W., Zhou, Q., 2014. Biochar: an effective amendment for remediating contaminated soil. In: Whitacre, D. (Ed.), Reviews of Environmental Contamination and Toxicology. Springer, New York, pp. 83-99. https://doi.org/10.1007/978-3-319-01619-1_4.

[57]

Kumar, A., Joseph, S., Tsechansky, L., Privat, K., Schreiter, I.J., Schüth, C., Graber, E.R., 2018. Biochar aging in contaminated soil promotes Zn immobilization due to changes in biochar surface structural and chemical properties. Sci. Total Environ. 626, 953-961. https://doi.org/10.1016/j.scitotenv.2018.01.157.

[58]	Kunkel, A.M., Seibert, J.J., Elliott, L.J., Kelley, R.L., Katz, L.E., Pope, G.A., 2006. Remediation of elemental mercury using in situ thermal desorption (ISTD). Environ. Sci. Technol. 40 (7), 2384-2389. https://doi.org/10.1021/es0503581.

[59]	Laird, D.A., Brown, R.C., Amonette, J.E., Lehmann, J., 2009. Review of the pyrolysis platform for coproducing bio-oil and biochar. Biofuel Bioprod. Biorefining 3 (5), 547-562. https://doi.org/10.1002/bbb.169.

[60]	Lee, D.H., Moon, H., 2001. Adsorption equilibrium of heavy metals on natural zeolites. Kor. J. Chem. Eng. 18 (2), 247-256. https://doi.org/10.1007/BF02698467.

[61]	Lehmann, J., 2007. A handful of carbon. Nature 447 (7141), 143-144. https://doi.org/10.1038/447143a.

[62]	Lehmann, J., Rillig, M.C., Thies, J., Masiello, C.A., Hockaday, W.C., Crowley, D., 2011. Biochar effects on soil biota - a review. Soil Biol. Biochem. 43 (9), 1812-1836. https://doi.org/10.1016/j.soilbio.2011.04.022.

[63]

Leng, L., Zheng, H., Shen, T., Wu, Z., Xiong, T., Liu, S., Cao, J., Peng, H., Zhan, H., Li, H., 2025. Engineering biochar from biomass pyrolysis for effective adsorption of heavy metal: an innovative machine learning approach. Sep. Purif. Technol. 361, 131592. https://doi.org/10.1016/j.seppur.2025.131592.

[64]	Li, B.,Li, K., 2023. Efficient removal of both heavy metal ion and dyes from wastewater using magnetic response adsorbent of block polymer brush-grafted N-doped biochar. Chemosphere 340, 139811. https://doi.org/10.1016/j.chemosphere.2023.139811.

[65]

Li, C., Li, J., Xie, S., Zhang, G., Pan, L., Wang, R., Wang, G., Pan, X., Wang, Y., Angelidaki, I., 2022. Enhancement of heavy metal immobilization in sewage sludge biochar by combining alkaline hydrothermal treatment and pyrolysis. J. Clean. Prod. 369, 133325. https://doi.org/10.1016/j.jclepro.2022.133325.

[66]	Li, H., Dong, X., Da Silva, E.B., de Oliveira, L.M., Chen, Y., Ma, L.Q., 2017. Mechanisms of metal sorption by biochars: biochar characteristics and modifications. Chemosphere 178, 466-478. https://doi.org/10.1016/j.chemosphere.2017.03.072.

[67]	Li, Q., Yin, J., Wu, L., Li, S., Chen, L., 2023a. Effects of biochar and zero valent iron on the bioavailability and potential toxicity of heavy metals in contaminated soil at the field scale. Sci. Total Environ. 897, 165386. https://doi.org/10.1016/j.scitotenv.2023.165386.

[68]	Li, S., Wen, Y., Wang, Y., Liu, M., Su, L., Peng, Z., Zhou, Z., Zhou, N., 2023b. Novel alpha-amino acid-like structure decorated biochar for heavy metal remediation in acid soil. J. Hazard. Mater. 462, 132740. https://doi.org/10.1016/j.jhazmat.2023.132740.

[69]	Lin, H., Xie, J., Dong, Y., Liu, J., Meng, K., Jin, Q., 2025. A complete review on the surface functional groups in pyrolyzed biochar and its interaction mechanism with heavy metal in water. J. Environ. Chem. Eng. 13 (3), 116681. https://doi.org/10.1016/j.jece.2025.116681.

[70]	Liu, L., Huang, Y., Zhang, S., Gong, Y., Su, Y., Cao, J., Hu, H., 2019. Adsorption characteristics and mechanism of Pb(II) by agricultural waste-derived biochars produced from a pilot-scale pyrolysis system. Waste Manage 100, 287-295. https://doi.org/10.1016/j.wasman.2019.08.021.

[71]	Long, X., Yu, Z., Liu, S., Gao, T., Qiu, R., 2024. A systematic review of biochar aging and the potential eco-environmental risk in heavy metal contaminated soil. J. Hazard. Mater. 472, 134345. https://doi.org/10.1016/j.jhazmat.2024.134345.

[72]	Lu, H., Zhang, W., Yang, Y., Huang, X., Wang, S., Qiu, R., 2012. Relative distribution of Pb ²⁺ sorption mechanisms by sludge-derived biochar. Water Res. 46 (3), 854-862. https://doi.org/10.1016/j.watres.2011.11.058.

[73]	Luo, M., Lin, H., He, Y., Li, B., Dong, Y., Wang, L., 2019. Efficient simultaneous removal of cadmium and arsenic in aqueous solution by titanium-modified ultrasonic biochar. Bioresour. Technol. 284, 333-339. https://doi.org/10.1016/j.biortech.2019.03.108.

[74]	Luo, M., Lin, H., Li, B., Dong, Y., He, Y., Wang, L., 2018. A novel modification of lignin on corncob-based biochar to enhance removal of cadmium from water. Bioresour. Technol. 259, 312-318. https://doi.org/10.1016/j.biortech.2018.03.075.

[75]	Luo, J., Cai, Y., Yu, J.,Huang, J.,Yan, J., 2025. Phosphate-modified biochar-mineral-based composites for heavy metal removal in acidic environments: development and efficiency. Appl. Clay Sci. 276, 107924. https://doi.org/10.1016/j.clay.2025.107924.

[76]	Lyu, H., Gao, B., He, F., Zimmerman, A.R., Ding, C., Huang, H., Tang, J., 2018. Effects of ball milling on the physicochemical and sorptive properties of biochar: experimental observations and governing mechanisms. Environ. Pollut. 233, 54-63. https://doi.org/10.1016/j.envpol.2017.10.037.

[77]	Ma, R., Luo, J., Duan, X., Sheng, Y., Wang, S., Zhang, D., Wang, F., Yang, S., Yi, W., 2025a. Novel laser-driven fast pyrolysis of biomass: insights into biochar characteristics and applications. Bioresour. Technol. 436, 132986. https://doi.org/10.1016/j.biortech.2025.132986.

[78]

Ma, Y., Zhang, F., Cheng, L., Zhang, D., Wu, X., Ma, Y., Liu, X., Xing, B., 2025b. Remediation potential of biochar for as and cd by modifying soil physicochemical properties: a conceptual model elucidating stabilization mechanism based on conditional probability theory. Biochar 7 (1), 63. https://doi.org/10.1007/s42773-025-00455-1.

[79]	Mandal, S., Pu, S., Adhikari, S., Ma, H., Kim, D., Bai, Y., Hou, D., 2021. Progress and future prospects in biochar composites: application and reflection in the soil environment. Crit. Rev. Environ. Sci. Technol. 51 (3), 219-271. https://doi.org/10.1080/10643389.2020.1713030.

[80]	Manyà, J.J., 2012. Pyrolysis for biochar purposes: a review to establish current knowledge gaps and research needs. Environ. Sci. Technol. 46 (15), 7939-7954. https://doi.org/10.1021/es301029g.

[81]	Meng, J., Tao, M., Wang, L., Liu, X., Xu, J., 2018. Changes in heavy metal bioavailability and speciation from a Pb-Zn mining soil amended with biochars from co-pyrolysis of rice straw and swine manure. Sci. Total Environ. 633, 300-307. https://doi.org/10.1016/j.scitotenv.2018.03.199.

[82]	Meyer, S., Glaser, B., Quicker, P., 2011. Technical, economical, and climate-related aspects of biochar production technologies: a literature review. Environ. Sci. Technol. 45 (22), 9473-9483. https://doi.org/10.1021/es201792c.

[83]	Mimmo, T., Panzacchi, P., Baratieri, M., Davies, C.A., Tonon, G., 2014. Effect of pyrolysis temperature on miscanthus (Miscanthus × giganteus) biochar physical, chemical and functional properties. Biomass Bioenergy 62, 149-157. https://doi.org/10.1016/j.biombioe.2014.01.004.

[84]

Mohan, D., Pittman, C.U., Bricka, M., Smith, F., Yancey, B., Mohammad, J., Steele, P.H., Alexandre-Franco, M.F., Gómez-Serrano, V., Gong, H., 2007. Sorption of arsenic, cadmium, and lead by chars produced from fast pyrolysis of wood and bark during bio-oil production. J. Colloid Interface Sci. 310 (1), 57-73. https://doi.org/10.1016/j.jcis.2007.01.020.

[85]	Mukherjee, A., Zimmerman, A.R., Harris, W., 2011. Surface chemistry variations among a series of laboratory-produced biochars. Geoderma 163 (3-4), 247-255. https://doi.org/10.1016/j.geoderma.2011.04.021.

[86]	Namgay, T., Singh, B., Singh, B.P., 2010. Influence of biochar application to soil on the availability of As, Cd, Cu, Pb, and Zn to maize. Aust. J. Soil Res. 48 (6-7), 638. https://doi.org/10.1071/SR10049.

[87]

Niazi, N.K., Bibi, I., Shahid, M., Ok, Y.S., Shaheen, S.M., Rinklebe, J., Wang, H., Murtaza, B., Islam, E., Farrakh Nawaz, M., Lüttge, A., 2018. Arsenic removal by japanese oak wood biochar in aqueous solutions and well water: investigating arsenic fate using integrated spectroscopic and microscopic techniques. Sci. Total Environ. 621, 1642-1651. https://doi.org/10.1016/j.scitotenv.2017.10.063.

[88]	Nie, C., Yang, X., Niazi, N.K., Xu, X., Wen, Y., Rinklebe, J., Ok, Y.S., Xu, S., Wang, H., 2018. Impact of sugarcane bagasse-derived biochar on heavy metal availability and microbial activity: a field study. Chemosphere 200, 274-282. https://doi.org/10.1016/j.chemosphere.2018.02.134.

[89]	Novotny, E.H., Maia, C.M.B.D., Carvalho, M.T.D.M., Madari, B.E., 2015. Biochar: pyrogenic carbon for agricultural use - a critical review. Rev. Bras. Cienc. Solo 39 (2), 321-344. https://doi.org/10.1590/01000683rbcs20140818.

[90]	O'Connor, D., Peng, T., Zhang, J., Tsang, D.C.W., Alessi, D.S., Shen, Z., Bolan, N.S., Hou, D., 2018. Biochar application for the remediation of heavy metal polluted land: a review of in situ field trials. Sci. Total Environ. 619-620, 815-826. https://doi.org/10.1016/j.scitotenv.2017.11.132.

[91]	Park, J., Ok, Y.S., Kim, S., Cho, J., Heo, J., Delaune, R.D., Seo, D., 2016. Competitive adsorption of heavy metals onto sesame straw biochar in aqueous solutions. Chemosphere 142, 77-83. https://doi.org/10.1016/j.chemosphere.2015.05.093.

[92]	Park, J.H., Choppala, G.K., Bolan, N.S., Chung, J.W., Chuasavathi, T., 2011. Biochar reduces the bioavailability and phytotoxicity of heavy metals. Plant Soil 348 (1-2), 439-451. https://doi.org/10.1007/s11104-011-0948-y.

[93]	Qambrani, N.A., Rahman, M.M., Won, S., Shim, S., Ra, C., 2017. Biochar properties and eco-friendly applications for climate change mitigation, waste management, and wastewater treatment: a review. Renew. Sustain. Energy Rev. 79, 255-273. https://doi.org/10.1016/j.rser.2017.05.057.

[94]	Qi, G., Pan, Z., Zhang, X., Wang, H., Chang, S., Wang, B., Gao, B., 2024. Novel pretreatment with hydrogen peroxide enhanced microwave biochar for heavy metals adsorption: characterization and adsorption performance. Chemosphere 346, 140580. https://doi.org/10.1016/j.chemosphere.2023.140580.

[95]	Qian, L., Zhang, W., Yan, J., Han, L., Gao, W., Liu, R., Chen, M., 2016. Effective removal of heavy metal by biochar colloids under different pyrolysis temperatures. Bioresour. Technol. 206, 217-224. https://doi.org/10.1016/j.biortech.2016.01.065.

[96]	Qian, T., Wu, P., Qin, Q., Huang, Y., Wang, Y., Zhou, D., 2019. Screening of wheat straw biochars for the remediation of soils polluted with Zn (II) and Cd (II). J. Hazard. Mater. 362, 311-317. https://doi.org/10.1016/j.jhazmat.2018.09.034.

[97]	Rahim, A.A., Kassim, J., 2008. Recent development of vegetal tannins in corrosion protection of iron and steel. Recent Pat. Mater. Sci. 100 (3), 223-231. https://doi.org/10.2174/1874465610801030223.

[98]

Rajapaksha, A.U., Chen, S.S., Tsang, D.C.W., Zhang, M., Vithanage, M., Mandal, S., Gao, B., Bolan, N.S., Ok, Y.S., 2016. Engineered/designer biochar for contaminant removal/immobilization from soil and water: potential and implication of biochar modification. Chemosphere 148, 276-291. https://doi.org/10.1016/j.chemosphere.2016.01.043.

[99]

Rechberger, M.V., Kloss, S., Wang, S., Lehmann, J., Rennhofer, H., Ottner, F., Wriessnig, K., Daudin, G., Lichtenegger, H., Soja, G., Zehetner, F., 2019. Enhanced Cu and Cd sorption after soil aging of woodchip-derived biochar: what were the driving factors? Chemosphere 216, 463-471. https://doi.org/10.1016/j.chemosphere.2018.10.094.

[100]

Rio, S., Faur-Brasquet, C., Le Coq, L., Le Cloirec, P., 2005. Structure characterization and adsorption properties of pyrolyzed sewage sludge. Environ. Sci. Technol. 39 (11), 4249-4257. https://doi.org/10.1021/es0497532.

[101]

Robalds, A., Naja, G.M., Klavins, M., 2016. Highlighting inconsistencies regarding metal biosorption. J. Hazard. Mater. 304, 553-556. https://doi.org/10.1016/j.jhazmat.2015.10.042.

[102]

Robinson, B., Green, S., Mills, T., Clothier, B., Velde, M.V.D., Laplane, R., Fung, L., Deurer, M., Hurst, S., Thayalakumaran, T., Dijssel, C.V.D., 2003. Phytoremediation: using plants as biopumps to improve degraded environments. Soil Res. 41 (3), 599. https://doi.org/10.1071/SR02131.

[103]

Sadegh-Zadeh, F., Samsuri, A.W., Seh-Bardan, B.J., Emadi, M., 2017. The effects of acidic functional groups and particle size of biochar on Cd adsorption from aqueous solutions. Desalination Water Treat. 66, 309-319. https://doi.org/10.5004/dwt.2017.20216.

[104]

Shahzad, A., Zahra, A., Li, H.Y., Qin, M., Wu, H., Wen, M.Q., Ali, M., Iqbal, Y., Xie, S.H., Sattar, S., Zafar, S., 2024. Modern perspectives of heavy metals alleviation from oil contaminated soil: a review. Ecotoxicol. Environ. Saf. 282, 116698. https://doi.org/10.1016/j.ecoenv.2024.116698.

[105]

Shang, Q., Chi, J., 2024. Mechanistic insight into the effects of interaction between biochar and soil with different properties on phenanthrene sorption. J. Environ. Manag. 367, 121961. https://doi.org/10.1016/j.jenvman.2024.121961.

[106]

Shen, Z., Som, A.M., Wang, F., Jin, F., McMillan, O., Al-Tabbaa, A., 2016. Long-term impact of biochar on the immobilisation of nickel (II) and zinc (II) and the revegetation of a contaminated site. Sci. Total Environ. 542, 771-776. https://doi.org/10.1016/j.scitotenv.2015.10.057.

[107]

Shen, Z., Tian, D., Zhang, X., Tang, L., Su, M., Zhang, L., Li, Z., Hu, S., Hou, D., 2018. Mechanisms of biochar assisted immobilization of Pb ²⁺ by bioapatite in aqueous solution. Chemosphere 190, 260-266. https://doi.org/10.1016/j.chemosphere.2017.09.140.

[108]

Singh, B., Singh, B.P., Cowie, A.L., 2010. Characterisation and evaluation of biochars for their application as a soil amendment. Soil Res. 48 (7), 516-525. https://doi.org/10.1071/SR10058.

[109]

Smith, C.R., Hatcher, P.G., Kumar, S., Lee, J.W., 2016. Investigation into the sources of biochar water-soluble organic compounds and their potential toxicity on aquatic microorganisms. ACS Sustain. Chem. Eng. 4 (5), 2550-2558. https://doi.org/10.1021/acssuschemeng.5b01687.

[110]

Song, Z., Lian, F., Yu, Z., Zhu, L., Xing, B., Qiu, W., 2014. Synthesis and characterization of a novel MnOx-loaded biochar and its adsorption properties for Cu ²⁺ in aqueous solution. Chem. Eng. J. 242, 36-42. https://doi.org/10.1016/j.cej.2013.12.061.

[111]

Srivastava, N.K., Majumder, C.B., 2008. Novel biofiltration methods for the treatment of heavy metals from industrial wastewater. J. Hazard. Mater. 151 (1), 1-8. https://doi.org/10.1016/j.jhazmat.2007.09.101.

[112]

Su, H., Fang, Z., Tsang, P.E., Zheng, L., Cheng, W., Fang, J., Zhao, D., 2016. Remediation of hexavalent chromium contaminated soil by biochar-supported zero-valent iron nanoparticles. J. Hazard. Mater. 318, 533-540. https://doi.org/10.1016/j.jhazmat.2016.07.039.

[113]

Suliman, W., Harsh, J.B., Abu-Lail, N.I., Fortuna, A., Dallmeyer, I., Garcia-Perez, M., 2016. Influence of feedstock source and pyrolysis temperature on biochar bulk and surface properties. Biomass Bioenergy 84, 37-48. https://doi.org/10.1016/j.biombioe.2015.11.010.

[114]

Tan, Z., Yuan, S., Hong, M., Zhang, L., Huang, Q., 2020. Mechanism of negative surface charge formation on biochar and its effect on the fixation of soil cd. J. Hazard. Mater. 384, 121370. https://doi.org/10.1016/j.jhazmat.2019.121370.

[115]

Tang, J., Zhu, W., Kookana, R., Katayama, A., 2013. Characteristics of biochar and its application in remediation of contaminated soil. J. Biosci. Bioeng. 116 (6), 653-659. https://doi.org/10.1016/j.jbiosc.2013.05.035.

[116]

Tepanosyan, G., Sahakyan, L., Belyaeva, O., Asmaryan, S., Saghatelyan, A., 2018. Continuous impact of mining activities on soil heavy metals levels and human health. Sci. Total Environ. 639, 900-909. https://doi.org/10.1016/j.scitotenv.2018.05.211.

[117]

Tognotti, L., Flytzani-Stephanopoulos, M., Sarofim, A.F., Kopsinis, H., Stoukides, M., 1991. Study of adsorption-desorption of contaminants on single soil particles using the electrodynamic thermogravimetric analyzer. Environ. Sci. Technol. 25 (1), 104-109. https://doi.org/10.1021/es00013a010.

[118]

Uchimiya, M ., 2014. Influence of pH, ionic strength, and multidentate ligand on the interaction of Cd ^II with biochars. ACS Sustain. Chem. Eng. 2 (8), 2019-2027. https://doi.org/10.1021/sc5002269.

[119]

Uchimiya, M., Chang, S., Klasson, K.T., 2011a. Screening biochars for heavy metal retention in soil: role of oxygen functional groups. J. Hazard. Mater. 190 (1-3), 432-441. https://doi.org/10.1016/j.jhazmat.2011.03.063.

[120]

Uchimiya, M., Klasson, K.T., Wartelle, L.H., Lima, I.M., 2011b. Influence of soil properties on heavy metal sequestration by biochar amendment: 1. Copper sorption isotherms and the release of cations. Chemosphere 82 (10), 1431-1437. https://doi.org/10.1016/j.chemosphere.2010.11.050.

[121]

Uchimiya, M., Wartelle, L.H., Klasson, K.T., Fortier, C.A., Lima, I.M., 2011c. Influence of pyrolysis temperature on biochar property and function as a heavy metal sorbent in soil. J. Agric. Food Chem. 59 (6), 2501-2510. https://doi.org/10.1021/jf104206c.

[122]

Uras, Ü., Carrier, M., Hardie, A.G., Knoetze, J.H., 2012. Physico-chemical characterization of biochars from vacuum pyrolysis of South African agricultural wastes for application as soil amendments. J. Anal. Appl. Pyrolysis 98, 207-213. https://doi.org/10.1016/j.jaap.2012.08.007.

[123]

Usman, A.,Sallam, A., Zhang, M.,Vithanage, M., Ahmad, M., Al-Farraj, A., Ok, Y.S., Abduljabbar, A., Al-Wabel, M., 2016. Sorption process of date palm biochar for aqueous Cd(II) removal: efficiency and mechanisms. Water Air Soil Pollut. 227 (12). https://doi.org/10.1007/s11270-016-3161-z.

[124]

Várhegyi, G., Szabó, P., Till, F., Zelei, B., Antal, M.J., Dai, X., 1998. TG, TG-MS, and FTIR characterization of high-yield biomass charcoals. Energy Fuels 12 (5), 969-974. https://doi.org/10.1021/ef9800359.

[125]

Venderbosch, R.H., Prins, W., 2010. Fast pyrolysis technology development. Biofuel Bioprod. Biorefining 4 (2), 178-208. https://doi.org/10.1002/bbb.205.

[126]

Wan Ngah, W.S., Hanafiah, M.A.K.M., 2008. Removal of heavy metal ions from wastewater by chemically modified plant wastes as adsorbents: a review. Bioresour. Technol. 99 (10), 3935-3948. https://doi.org/10.1016/j.biortech.2007.06.011.

[127]

Wang, D., Griffin, D.E., Parikh, S.J., Scow, K.M., 2016. Impact of biochar amendment on soil water soluble carbon in the context of extreme hydrological events. Chemosphere 160, 287-292. https://doi.org/10.1016/j.chemosphere.2016.06.100.

[128]

Wang, G., Li, Y., Wang, G., Cai, K., Xu, Y., 2024. Insights into the photodegradation of decamethylammonium bromide (DDAB) under UV/H₂O₂ system: photodegradation kinetic modeling, degradation mechanism and toxicity evaluation. J. Environ. Chem. Eng. 12 (5), 113344. https://doi.org/10.1016/j.jece.2024.113344.

[129]

Wang, J., Chen, C., 2009. Biosorbents for heavy metals removal and their future. Biotechnol. Adv. 27 (2), 195-226. https://doi.org/10.1016/j.biotechadv.2008.11.002.

[130]

Wang, L., Li, X., Tsang, D.C.W., Jin, F., Hou, D., 2020. Green remediation of Cd and Hg contaminated soil using humic acid modified montmorillonite: immobilization performance under accelerated ageing conditions. J. Hazard. Mater. 387, 122005. https://doi.org/10.1016/j.jhazmat.2019.122005.

[131]

Wang, M., Zhu, Y., Cheng, L., Andserson, B., Zhao, X., Wang, D., Ding, A., 2018a. Review on utilization of biochar for metal-contaminated soil and sediment remediation. J. Environ. Sci. 63, 156-173. https://doi.org/10.1016/j.jes.2017.08.004.

[132]

Wang, R., Huang, D., Liu, Y., Zhang, C., Lai, C., Zeng, G., Cheng, M., Gong, X., Wan, J., Luo, H., 2018b. Investigating the adsorption behavior and the relative distribution of Cd ²⁺ sorption mechanisms on biochars by different feedstock. Bioresour. Technol. 261, 265-271. https://doi.org/10.1016/j.biortech.2018.04.032.

[133]

Wang, Y., Liu, R., 2017. Comparison of characteristics of twenty-one types of biochar and their ability to remove multi-heavy metals and methylene blue in solution. Fuel Process. Technol. 160, 55-63. https://doi.org/10.1016/j.fuproc.2017.02.019.

[134]

Wang, Z., Liu, G., Zheng, H., Li, F., Ngo, H.H., Guo, W., Liu, C., Chen, L., Xing, B., 2015. Investigating the mechanisms of biochar's removal of lead from solution. Bioresour. Technol. 177, 308-317. https://doi.org/10.1016/j.biortech.2014.11.077.

[135]

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. Water Air Soil Pollut. 127 (1), 301-314. https://doi.org/10.1023/A:1005251915165.

[136]

Wu, J., Zhou, B., Li, Z., Liu, C., Li, Y., Wang, Y., Zhao, N., Wang, Z., Chai, Y., Scopa, A., Drosos, M., Rajput, V., Shan, S., 2025. Biochar promoted soil organic carbon accumulation and aggregate stability by increasing the content of organic complex metal oxides in paddy soil. Soil Tillage Res. 254, 106713. https://doi.org/10.1016/j.still.2025.106713.

[137]

Wu, P.,Cui, P., Fang, G., Wang, Y., Wang, S., Zhou, D., Zhang, W., Wang, Y., 2018. Biochar decreased the bioavailability of Zn to rice and wheat grains: insights from microscopic to macroscopic scales. Sci. Total Environ. 621, 160-167. https://doi.org/10.1016/j.scitotenv.2017.11.236.

[138]

Xiao, B., Jia, J., Wang, W., Zhang, B., Ming, H., Ma, S., Kang, Y., Zhao, M., 2023. A review on magnetic biochar for the removal of heavy metals from contaminated soils: preparation, application, and microbial response. J. Hazard. Mater. Adv. 10, 100254. https://doi.org/10.1016/j.hazadv.2023.100254.

[139]

Xiao, Y.,Huang, Y., Yu, M., Zhu, Z., Xu, W., Li, Z., Cheng, H., Jin, B., Fei, X., 2025. Development of silica-modified biochar for sustainable and efficient stabilization of heavy metals in municipal solid waste incineration fly ash. Waste Manage 205, 115009. https://doi.org/10.1016/j.wasman.2025.115009.

[140]

Xiao, Y., Xue, Y., Gao, F., Mosa, A., 2017. Sorption of heavy metal ions onto crayfish shell biochar: effect of pyrolysis temperature, pH and ionic strength. J. Taiwan Inst. Chem. Eng. 80, 114-121. https://doi.org/10.1016/j.jtice.2017.08.035.

[141]

Xie, T., Sadasivam, B.Y., Reddy, K.R., Wang, C., Spokas, K., 2016. Review of the effects of biochar amendment on soil properties and carbon sequestration. J. Hazard. Toxic. Radio. 20 (1), 4015011-4015013. https://doi.org/10.1061/(ASCE)HZ.2153-5515.0000293.

[142]

Xu, M., Wu, J., Luo, L., Yang, G., Zhang, X., Peng, H., Yu, X., Wang, L., 2018. The factors affecting biochar application in restoring heavy metal-polluted soil and its potential applications. Chem. Ecol. 34 (2), 177-197. https://doi.org/10.1080/02757540.2017.1404992.

[143]

Xu, R., Zhao, A., 2013. Effect of biochars on adsorption of Cu(II), Pb(II) and Cd(II) by three variable charge soils from southern China. Environ. Sci. Pollut. Res. 20 (12), 8491-8501. https://doi.org/10.1007/s11356-013-1769-8.

[144]

Xu, X., Cao, X., Zhao, L., Wang, H., Yu, H., Gao, B., 2013. Removal of Cu, Zn, and Cd from aqueous solutions by the dairy manure-derived biochar. Environ. Sci. Pollut. Res. 20, 358-368. https://doi.org/10.1007/s11356-012-0873-5.

[145]

Xu, X., Zhao, Y., Sima, J., Zhao, L., Mašek, O., Cao, X., 2017. Indispensable role of biochar-inherent mineral constituents in its environmental applications: a review. Bioresour. Technol. 241, 887-899. https://doi.org/10.1016/j.biortech.2017.06.023.

[146]

Xu, Y., Qi, F., Yan, Y., Sun, W., Bai, T., Lu, N., Luo, H., Liu, C., Yuan, B., Sheng, Z., Liu, T., 2023. The interaction of different chlorine-based additives with swine manure during pyrolysis: effects on biochar properties and heavy metal volatilization. Waste Manage 169, 52-61. https://doi.org/10.1016/j.wasman.2023.06.023.

[147]

Xu, Z., Xu, X., Tsang, D.C.W., Yang, F., Zhao, L., Qiu, H., Cao, X., 2020. Participation of soil active components in the reduction of Cr(VI) by biochar: differing effects of iron mineral alone and its combination with organic acid. J. Hazard. Mater. 384, 121455. https://doi.org/10.1016/j.jhazmat.2019.121455.

[148]

Yan, C., Li, J., Sun, Z., Wang, X., Xia, S., 2024. Mechanistic insights into removal of pollutants in adsorption and advanced oxidation processes by livestock manure derived biochar: a review. Sep. Purif. Technol. 346, 127457. https://doi.org/10.1016/j.seppur.2024.127457.

[149]

Yang, H., Yan, R., Chen, H., Lee, D.H., Zheng, C., 2007. Characteristics of hemicellulose, cellulose and lignin pyrolysis. Fuel 86 (12-13), 1781-1788. https://doi.org/10.1016/j.fuel.2006.12.013.

[150]

Yang, X., Huang, C., Sanjeewa, K.K.A., Gao, X., Mao, X., Wang, L., 2025. A comprehensive review of heavy metals in aquatic products and their removal techniques. Food Control 178, 111520. https://doi.org/10.1016/j.foodcont.2025.111520.

[151]

Yang, Y., Wei, Z., Zhang, X., Chen, X., Yue, D., Yin, Q., Xiao, L., Yang, L., 2014. Biochar from alternanthera philoxeroides could remove Pb(II) efficiently. Bioresour. Technol. 171, 227-232. https://doi.org/10.1016/j.biortech.2014.08.015.

[152]

Ye, L., Gao, G., Li, F., Sun, Y., Yang, S., Qin, Q., Wang, J., Bai, N., Xue, Y., Sun, L., 2025. A comprehensive review on biochar-based materials for the safe utilization and remediation of heavy metal-contaminated agricultural soil and associated mechanisms. J. Environ. Chem. Eng. 13 (3), 116179. https://doi.org/10.1016/j.jece.2025.116179.

[153]

Yin, D., Wang, X., Chen, C., Peng, B., Tan, C., Li, H., 2016. Varying effect of biochar Cd, Pb and as mobility in a multi-metal contaminated paddy soil. Chemosphere 152, 196-206. https://doi.org/10.1016/j.chemosphere.2016.01.044.

[154]

Yoon, K., Cho, D., Tsang, D.C.W., Bolan, N., Rinklebe, J., Song, H., 2017. Fabrication of engineered biochar from paper mill sludge and its application into removal of arsenic and cadmium in acidic water. Bioresour. Technol. 246, 69-75. https://doi.org/10.1016/j.biortech.2017.07.020.

[155]

Yuan, J., Xu, R., Zhang, H., 2011. The forms of alkalis in the biochar produced from crop residues at different temperatures. Bioresour. Technol. 102 (3), 3488-3497. https://doi.org/10.1016/j.biortech.2010.11.018.

[156]

Zhang, C., Shan, B., Tang, W., Zhu, Y., 2017a. Comparison of cadmium and lead sorption by Phyllostachys pubescens biochar produced under a low-oxygen pyrolysis atmosphere. Bioresour. Technol. 238, 352-360. https://doi.org/10.1016/j.biortech.2017.04.051.

[157]

Zhang, F., Wang, X., Yin, D., Peng, B., Tan, C., Liu, Y., Tan, X., Wu, S., 2015. Efficiency and mechanisms of Cd removal from aqueous solution by biochar derived from water hyacinth (Eichornia crassipes) . J. Environ. Manag. 153, 68-73. https://doi.org/10.1016/j.jenvman.2015.01.043.

[158]

Zhang, T., Zhu, X., Shi, L., Li, J., Li, S., Lü, J., Li, Y., 2017b. Efficient removal of lead from solution by celery-derived biochars rich in alkaline minerals. Bioresour. Technol. 235, 185-192. https://doi.org/10.1016/j.biortech.2017.03.109.

[159]

Zhang, X., Zhang, P., Yuan, X., Li, Y., Han, L., 2020. Effect of pyrolysis temperature and correlation analysis on the yield and physicochemical properties of crop residue biochar. Bioresour. Technol. 296, 122318. https://doi.org/10.1016/j.biortech.2019.122318.

[160]

Zhang, Z., Zhu, Z., Shen, B., Liu, L., 2019. Insights into biochar and hydrochar production and applications: a review. Energy 171, 581-598. https://doi.org/10.1016/j.energy.2019.01.035.

[161]

Zhao, L., Cao, X., Zheng, W., Wang, Q., Yang, F., 2015a. Endogenous minerals have influences on surface electrochemistry and ion exchange properties of biochar. Chemosphere 136, 133-139. https://doi.org/10.1016/j.chemosphere.2015.04.053.

[162]

Zhao, M., Dai, Y., Zhang, M., Feng, C., Qin, B., Zhang, W., Zhao, N., Li, Y., Ni, Z., Xu, Z., Tsang, D.C.W., Qiu, R., 2020. Mechanisms of Pb and/or Zn adsorption by different biochars: biochar characteristics, stability, and binding energies. Sci. Total Environ. 717, 136894. https://doi.org/10.1016/j.scitotenv.2020.136894.

[163]

Zhao, R., Coles, N., Kong, Z., Wu, J., 2015b. Effects of aged and fresh biochars on soil acidity under different incubation conditions. Soil and Till. Res. 146, 133-138. https://doi.org/10.1016/j.still.2014.10.014.

[164]

Zhao, S., Zhao, S., Wang, B., 2025. Combined application of biochar and PGPB on crop growth and heavy metals accumulation: a meta-analysis. Environ. Pollut. 381, 126626. https://doi.org/10.1016/j.envpol.2025.126626.

[165]

Zhu, N., Yan, T., Qiao, J., Cao, H., 2016. Adsorption of arsenic, phosphorus and chromium by bismuth impregnated biochar: adsorption mechanism and depleted adsorbent utilization. Chemosphere 164, 32-40. https://doi.org/10.1016/j.chemosphere.2016.08.036.

[166]

Zhu, X., Chen, B., Zhu, L., Xing, B., 2017. Effects and mechanisms of biochar-microbe interactions in soil improvement and pollution remediation: a review. Environ. Pollut. 227, 98-115. https://doi.org/10.1016/j.envpol.2017.04.032.