1. H. Li, X. Dong, E.B. da Silva, L.M. de Oliveira, Y. Chen, L.Q. Ma, Mechanisms of metal sorption by biochars: biochar characteristics and modifications, Chemosphere, 178 (2017) 466–478.
  2. A. Shakya, T. Agarwal, Removal of Cr(VI) from water using pineapple peel derived biochars: adsorption potential and re-usability assessment, J. Mol. Liq., 293 (2019) 111497.
  3. R. Pechancová, T. Pluháček, D. Milde, Recent advances in chromium speciation in biological samples, Spectrochim. Acta, Part B, 152 (2019) 109–122.
  4. Q. Chen, Y. Yao, X. Li, J. Lu, J. Zhou, Z. Huang, Comparison of heavy metal removals from aqueous solutions by chemical precipitation and characteristics of precipitates, J. Water Process Eng., 26 (2018) 289–300.
  5. I.A. Aguayo-Villarreal, A. Bonilla-Petriciolet, R. Muñiz-Valencia, Synthesis of activated carbons from pecan nutshell and their application in the antagonistic adsorption of heavy metal ions, J. Mol. Liq., 230 (2017) 686–695.
  6. T. Wang, H. Sun, X. Ren, B. Li, H. Mao, Adsorption of heavy metals from aqueous solution by UV-mutant Bacillus subtilis loaded on biochars derived from different stock materials, Ecotoxicol. Environ. Saf., 148 (2018) 285–292.
  7. D. Pradhan, L.B. Sukla, B.B. Mishra, N. Devi, Biosorption for removal of hexavalent chromium using microalgae Scenedesmus sp., J. Cleaner Prod., 209 (2019) 617–629.
  8. X.F. Tan, S.B. Liu, Y.G. Liu, Y.L. Gu, G.M. Zeng, X.J. Hu, X. Wang, S.H. Liu, L.H. Jiang, Biochar as potential sustainable precursors for activated carbon production: multiple applications in environmental protection and energy storage, Bioresour. Technol., 227 (2017) 359–372.
  9. F.R. Oliveira, A.K. Patel, D.P. Jaisi, S. Adhikari, H. Lu, S.K. Khanal, Environmental application of biochar: current status and perspectives, Bioresour. Technol., 246 (2017) 110–122.
  10. L. Lonappan, T. Rouissi, S.K. Brar, M. Verma, R.Y. Surampalli, Adsorption of diclofenac onto different biochar microparticles: dataset - characterization and dosage of biochar, Data Brief, 16 (2018) 460–465.
  11. Y. Deng, S. Huang, D.A. Laird, X. Wang, Z. Meng, Adsorption behaviour and mechanisms of cadmium and nickel on rice straw biochars in single- and binary-metal systems, Chemosphere, 218 (2019) 308–318.
  12. T. Li, X. Bai, Y.-X. Qi, N. Lun, Y.-J. Bai, Fe3O4 nanoparticles decorated on the biochar derived from pomelo pericarp as excellent anode materials for Li-ion batteries, Electrochim. Acta, 222 (2016) 1562–1568.
  13. J. Li, B. Li, H. Huang, N. Zhao, M. Zhang, L. Cao, Investigation into lanthanum-coated biochar obtained from urban dewatered sewage sludge for enhanced phosphate adsorption, Sci. Total Environ., 714 (2020) 136839.
  14. J. Li, B. Li, H. Huang, X. Lv, N. Zhao, G. Guo, D. Zhang, Removal of phosphate from aqueous solution by dolomite-modified biochar derived from urban dewatered sewage sludge, Sci. Total Environ., 687 (2019) 460–469.
  15. K.-m. Jiang, C.-g. Cheng, M. Ran, Y.-g. Lu, Q.-l. Wu, Preparation of a biochar with a high calorific value from chestnut shells, New Carbon Mater., 33 (2018) 183–187.
  16. Y. Wang, R. Liu, H2O2 treatment enhanced the heavy metals removal by manure biochar in aqueous solutions, Sci. Total Environ., 628–629 (2018) 1139–1148.
  17. K.M. Poo, E.B. Son, J.S. Chang, X. Ren, Y.J. Choi, K.J. Chae, Biochars derived from wasted marine macro-algae (Saccharina japonica and Sargassum fusiforme) and their potential for heavy metal removal in aqueous solution, J. Environ. Manage., 206 (2018) 364–372.
  18. H.P. Lu, Z.A. Li, G. Gasco, A. Mendez, Y. Shen, J. Paz-Ferreiro, Use of magnetic biochars for the immobilization of heavy metals in a multi-contaminated soil, Sci. Total Environ., 622–623 (2018) 892–899.
  19. M. Li, H. Liu, T. Chen, C. Dong, Y. Sun, Synthesis of magnetic biochar composites for enhanced uranium(VI) adsorption, Sci. Total Environ., 651 (2019) 1020–1028.
  20. D. Harikishore Kumar Reddy, S.-M. Lee, Magnetic biochar composite: facile synthesis, characterization, and application for heavy metal removal, Colloids Surf., A, 454 (2014) 96–103.
  21. D. Yuan, C. Zhang, S. Tang, X. Li, J. Tang, Y. Rao, Z. Wang, Q. Zhang, Enhancing CaO2 Fenton-like process by Fe(II)-oxalic acid complexation for organic wastewater treatment, Water Res., 163 (2019) 114861.
  22. T. Wang, J. Wu, Y. Zhang, J. Liu, Z. Sui, H. Zhang, W.-Y. Chen, P. Norris, W.-P. Pan, Increasing the chlorine active sites in the micropores of biochar for improved mercury adsorption, Fuel, 229 (2018) 60–67.
  23. Y. Li, Q. Du, X. Wang, P. Zhang, D. Wang, Z. Wang, Y. Xia, Removal of lead from aqueous solution by activated carbon prepared from Enteromorpha prolifera by zinc chloride activation, J. Hazard. Mater., 183 (2010) 583–589.
  24. H. Zhao, Y. Lang, Adsorption behaviors and mechanisms of florfenicol by magnetic functionalized biochar and reed biochar, J. Taiwan Inst. Chem. Eng., 88 (2018) 152–160.
  25. G.M. Al-Senani, F.F. Al-Fawzan, Adsorption study of heavy metal ions from aqueous solution by nanoparticle of wild herbs, Egypt. J. Aquat. Res., 44 (2018) 187–194.
  26. M.A. Al-Anber, Removal of high-level Fe3+ from aqueous solution using natural inorganic materials: bentonite (NB) and quartz (NQ), Desalination, 250 (2010) 885–891.
  27. Y. Huang, X. Lee, M. Grattieri, M. Yuan, R. Cai, F.C. Macazo, S.D. Minteer, Modified biochar for phosphate adsorption in environmentally relevant conditions, Chem. Eng. J., 380 (2020) 122375.
  28. Q. An, Y.Q. Jiang, H.Y. Nan, Y. Yu, J.N. Jiang, Unraveling sorption of nickel from aqueous solution by KMnO4 and KOH-modified peanut shell biochar: implicit mechanism, Chemosphere, 214 (2019) 846–854.
  29. L. Lu, Y. Lin, Q. Chai, S. He, C. Yang, Removal of acenaphthene by biochar and raw biomass with coexisting heavy metal and phenanthrene, Colloids Surf., A, 558 (2018) 103–109.
  30. Y. Chen, B. Wang, J. Xin, P. Sun, D. Wu, Adsorption behavior and mechanism of Cr(VI) by modified biochar derived from Enteromorpha prolifera, Ecotoxicol. Environ. Saf., 164 (2018) 440–447.
  31. C. Jiang, X. Wang, G. Wang, C. Hao, X. Li, T. Li, Adsorption performance of a polysaccharide composite hydrogel based on crosslinked glucan/chitosan for heavy metal ions, Composites Part B, 169 (2019) 45–54.
  32. J. Pan, J. Jiang, R. Xu, Adsorption of Cr(III) from acidic solutions by crop straw derived biochars, J. Environ. Sci., 25 (2013) 1957–1965.
  33. H. Li, J. Xiong, G. Zhang, A. Liang, J. Long, T. Xiao, Y. Chen, P. Zhang, D. Liao, L. Lin, H. Zhang, Enhanced thallium(I) removal from wastewater using hypochlorite oxidation coupled with magnetite-based biochar adsorption, Sci. Total Environ., 698 (2019) 134166.
  34. S. Norouzi, M. Heidari, V. Alipour, O. Rahmanian, M. Fazlzadeh, F. Mohammadi-Moghadam, H. Nourmoradi, B. Goudarzi, K. Dindarloo, Preparation, characterization and Cr(VI) adsorption evaluation of NaOH-activated carbon produced from Date Press Cake; an agro-industrial waste, Bioresour. Technol., 258 (2018) 48–56.
  35. X. Liu, Z.Q. Chen, B. Han, C.L. Su, Q. Han, W.Z. Chen, Biosorption of copper ions from aqueous solution using rape straw powders: optimization, equilibrium and kinetic studies, Ecotoxicol. Environ. Saf., 150 (2018) 251–259.
  36. X. Zhou, J. Zhou, Y. Liu, J. Guo, J. Ren, F. Zhou, Preparation of iminodiacetic acid-modified magnetic biochar by carbonization, magnetization and functional modification for Cd(II) removal in water, Fuel, 233 (2018) 469–479.
  37. F. Xiao, J. Cheng, W. Cao, C. Yang, J. Chen, Z. Luo, Removal of heavy metals from aqueous solution using chitosan-combined magnetic biochars, J. Colloid Interface Sci., 540 (2019) 579–584.
  38. T. Chen, Z. Zhou, R. Han, R. Meng, H. Wang, W. Lu, Adsorption of cadmium by biochar derived from municipal sewage sludge: impact factors and adsorption mechanism, Chemosphere, 134 (2015) 286–293.
  39. L.Y. Gao, J.H. Deng, G.F. Huang, K. Li, K.Z. Cai, Y. Liu, F. Huang, Relative distribution of Cd2+ adsorption mechanisms on biochars derived from rice straw and sewage sludge, Bioresour. Technol., 272 (2019) 114–122.
  40. M. Gutiérrez-Valtierra, C. Salazar-Hernández, J.M. Mendoza-Miranda, E. Elorza-Rodríguez, M.J. Puy-Alquiza, M. Caudillo-González, M.M. Salazar-Hernández, Cr(III) removal from tannery effluents using silica obtained from rice husk and modified silica, Desal. Wat. Treat., 158 (2019) 152–163.
  41. Y. Wu, S. Zhang, X. Guo, H. Huang, Adsorption of chromium(III) on lignin, Bioresour. Technol., 99 (2008) 7709–7715.
  42. H. Zhao, X. Liu, Z. Cao, Y. Zhan, X. Shi, Y. Yang, J. Zhou, J. Xu, Adsorption behavior and mechanism of chloramphenicols, sulfonamides, and non-antibiotic pharmaceuticals on multiwalled carbon nanotubes, J. Hazard. Mater., 310 (2016) 235–245.
  43. Z.-b. Zhang, X.-h. Cao, P. Liang, Y.-h. Liu, Adsorption of uranium from aqueous solution using biochar produced by hydrothermal carbonization, J. Radioanal. Nucl. Chem., 295 (2012) 1201–1208.
  44. V.K. Garg, R. Gupta, A. Bala Yadav, R. Kumar, Dye removal from aqueous solution by adsorption on treated sawdust, Bioresour. Technol., 89 (2003) 121–124.