1. N. Singh, G. Nagpal, S. Agrawal, Water purification by using adsorbents: a review, Environ. Technol. Innovation, 11 (2018) 187–240.
  2. WHO, Global Water Supply and Sanitation Assessment 2000 Report, World Health Organization, Geneva, Switzerland, 2000.
  3. B. Salazar-Pinto, V. Zea-Linares, J. Villanueva-Salas, E.G. Gonzales Condori, Cd(II) and Pb(II) biosorption in aqueous solutions using agricultural residues of Phaseolus vulgaris L.: optimization, kinetics, isotherms and desorption, Rev. Mex. Ing. Chim., 20 (2021) 305–322.
  4. K. Chojnacka, M. Mikulewicz, Bioaccumulation, Amsterdam, UK, 2014.
  5. M. Jaber, J. Miehé-Brendlé, L. Michelin, L. Delmotte, Heavy metal retention by organoclays: synthesis, applications, and retention mechanism, Chem. Mater., 17 (2005) 5275–5281.
  6. M. Salman, M. Athar, U. Farooq, S. Nazir, H. Nazir, Insight to rapid removal of Pb(II), Cd(II), and Cu(II) from aqueous solution using an agro-based adsorbent Sorghum bicolor L. biomass, Desal. Water Treat., 51 (2013) 4390–4401.
  7. A. Yousaf, M. Athar, M. Salman, U. Farooq, F.S. Chawla, Biosorption characteristics of Pennisetum glaucum for the removal of Pb(II), Ni(II) and Cd(II) ions from aqueous medium, Green Chem. Lett. Rev., 10 (2017) 462–470.
  8. A.A. Syukor, S. Sulaiman, M.N.I. Siddique, A. Zularisam, M. Said, Integration of phytogreen for heavy metal removal from wastewater, J. Cleaner Prod., 112 (2016) 3124–3131.
  9. D. Sud, G. Mahajan, M. Kaur, Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions–a review, Bioresour. Technol., 99 (2008) 6017–6027.
  10. M. Iqbal, Vicia faba bioassay for environmental toxicity monitoring: a review, Chemosphere, 144 (2016) 785–802.
  11. W.W. Ngah, S. Fatinathan, Adsorption characterization of Pb(II) and Cu(II) ions onto chitosan-tripolyphosphate beads: kinetic, equilibrium and thermodynamic studies, J. Environ. Manage., 91 (2010) 958–969.
  12. E.R. Bandala, M.A. Peláez, M.J. Salgado, L. Torres, Degradation of sodium dodecyl sulphate in water using solar driven Fenton-like advanced oxidation processes, J. Hazard. Mater., 151 (2008) 578–584.
  13. M. Markowitz, Lead poisoning: a disease for the next millennium, Curr. Probiotics, 30 (2000) 62–70.
  14. S. Skerfving, L. Löfmark, T. Lundh, Z. Mikoczy, U. Strömberg, Late effects of low blood lead concentrations in children on school performance and cognitive functions, Neurotoxicology, 49 (2015) 114–120.
  15. S. Gunatilake, Methods of removing heavy metals from industrial wastewater, J. Multidiscip. Eng. Sci. Stud., 1 (2015) 12–18.
  16. B. Yasemin, B.J.E.M. Zubeyde, Removal of Pb(II) from wastewater using wheat bran, J. Environ. Manage., 78 (2006) 107–113.
  17. M. Man, R. Naidu, M.H. Wong, Persistent toxic substances released from uncontrolled e-waste recycling and actions for the future, Sci. Total Environ., 463 (2013) 1133–1137.
  18. WHO, Lead in Drinking-Water: Background Document for Development of WHO Guidelines for Drinking-Water Quality, World Health Organization, Geneva, Switzerland, 2003.
  19. M.E.A. El-Sayed, Nanoadsorbents for water and wastewater remediation, Sci. Total Environ., 739 (2020) 139903, doi: 10.1016/j.scitotenv.2020.139903.
  20. A. Pagana, S. Sklari, E. Kikkinides, V. Zaspalis, Microporous ceramic membrane technology for the removal of arsenic and chromium ions from contaminated water, Microporous Mesoporous Mater., 110 (2008) 150–156.
  21. C. Jain, M. Sharma, Adsorption of cadmium on bed sediments of river Hindon: adsorption models and kinetics, Water Air Soil Pollut., 137 (2002) 1–19.
  22. H. Al Abdulgader, V. Kochkodan, N. Hilal, Hybrid ion exchange–pressure driven membrane processes in water treatment: a review, Sep. Purif. Technol., 116 (2013) 253–264.
  23. N.A. Qasem, R.H. Mohammed, D.U. Lawal, Removal of heavy metal ions from wastewater: a comprehensive and critical review, npj Clean Water, 4 (2021) 1–15.
  24. A.K. Arabi, B. Akram, S.A. Mirbagheri, Industrial wastewater treatment by combining two systems of adsorption column and reverse osmosis, J. Environ. Eng. Sci., 40 (2021) 1–8.
  25. A.S. El-Shamy, A.S. Emara, M. Mahmoud, A. Shahba, R.M. Shoeeb, A. Mohamed, Application of electrodialysis technique in removal of some heavy metal ions from discharge wastewater in paper industry, Al-Azhar Bull. Sci., 32 (2021) 1–9.
  26. X. Pei, L. Gan, Z. Tong, H. Gao, S. Meng, W. Zhang, P. Wang, Y. Chen, Robust cellulose-based composite adsorption membrane for heavy metal removal, J. Hazard. Mater., 406 (2021) 124746, doi: 10.1016/j.jhazmat.2020.124746.
  27. A.A. Khan, M. Mondal, Chapter 4 – Low-Cost Adsorbents, Removal Techniques, and Heavy Metal Removal Efficiency, M.P. Shah, S.R. Couto, V. Kumar, Eds., New Trends in Removal of Heavy Metals from Industrial Wastewater, Elsevier, Amsterdam, UK, 2021, pp. 83–103.
  28. M. Salman, M. Athar, U. Farooq, Biosorption of heavy metals from aqueous solutions using indigenous and modified lignocellulosic materials, Rev. Environ. Sci. Bio/Technol., 14 (2015) 211–228.
  29. E. Pehlivan, T. Altun, S. Cetin, M.I. Bhanger, Lead sorption by waste biomass of hazelnut and almond shell, J. Hazard. Mater., 167 (2009) 1203–1208.
  30. M. Ajmal, R.A.K. Rao, S. Anwar, J. Ahmad, R. Ahmad, Adsorption studies on rice husk: removal and recovery of Cd(II) from wastewater, Bioresour. Technol., 86 (2003) 147–149.
  31. U. Farooq, M.A. Khan, M. Athar, J.A. Kozinski, Effect of modification of environmentally friendly biosorbent wheat (Triticum aestivum) on the biosorptive removal of cadmium(II) ions from aqueous solution, Chem. Eng. J., 171 (2011) 400–410.
  32. Q. Li, J. Zhai, W. Zhang, M. Wang, J. Zhou, Kinetic studies of adsorption of Pb(II), Cr(III) and Cu(II) from aqueous solution by sawdust and modified peanut husk, J. Hazard. Mater., 141 (2007) 163–167.
  33. M. Zulkali, A. Ahmad, N. Norulakmal, Oryza sativa L. husk as heavy metal adsorbent: optimization with lead as model solution, Bioresour. Technol., 97 (2006) 21–25.
  34. A. Saeed, M. Iqbal, W.H. Höll, Kinetics, equilibrium and mechanism of Cd2+ removal from aqueous solution by mungbean husk, J. Hazard. Mater., 168 (2009) 1467–1475.
  35. K.A. Krishnan, T. Anirudhan, Removal of cadmium(II) from aqueous solutions by steam-activated sulphurised carbon prepared from sugar-cane bagasse pith: kinetics and equilibrium studies, Water SA, 29 (2003) 147–156.
  36. N. Meunier, J. Laroulandie, J. Blais, R. Tyagi, Cocoa shells for heavy metal removal from acidic solutions, Bioresour. Technol., 90 (2003) 255–263.
  37. M. Rafiq, U. Farooq, M. Athar, M. Salman, M. Aslam, H.H. Raza, Gardenia jasminoides: an ornamental plant for the biosorption of lead and cadmium ions, Desal. Water Treat., 57 (2016) 10432–10442.
  38. A. Saeed, M. Iqbal, Bioremoval of cadmium from aqueous solution by black gram husk (Cicer arietinum), Water Res., 37 (2003) 3472–3480.
  39. M.J. Rwiza, S.-Y. Oh, K.-W. Kim, S.D. Kim, Comparative sorption isotherms and removal studies for Pb(II) by physical and thermochemical modification of low-cost agro-wastes from Tanzania, Chemosphere, 195 (2018) 135–145.
  40. S. Hokkanen, A. Bhatnagar, M. Sillanpää, A review on modification methods to cellulose-based adsorbents to improve adsorption capacity, Water Res., 91 (2016) 156–173.
  41. P. Chand, A. Bafana, Y.B. Pakade, Xanthate-modified apple pomace as an adsorbent for removal of Cd(II), Ni(II) and Pb(II), and its application to real industrial wastewater, Int. Biodeterior. Biodegrad., 97 (2015) 60–66.
  42. N. Wang, Y. Qiu, K. Hu, C. Huang, J. Xiang, H. Li, J. Tang, J. Wang, T. Xiao, One-step synthesis of cake-like biosorbents from plant biomass for the effective removal and recovery heavy metals: effect of plant species and roles of xanthation, Chemosphere, 266 (2021) 129129, doi: 10.1016/j.chemosphere.2020.129129.
  43. J. Qu, X. Meng, X. Jiang, H. You, P. Wang, X. Ye, Enhanced removal of Cd(II) from water using
    sulfur-functionalized rice husk: characterization, adsorptive performance and mechanism exploration, J. Cleaner Prod., 183 (2018) 880–886.
  44. A. Yousaf, M. Athar, M. Salman, U. Farooq, N. Makshoof, Z. Zaman, M. Sohail, Biosorptive removal of cobalt from aqueous solution by using native and thiourea modified Pennisetum glaucum, Desal. Water Treat., 103 (2018) 199–207.
  45. A. de O. Jorgetto, A.C.P. da Silva, M.H.P. Wondracek, R.I.V. da Silva, E.D. Velini, M.J. Saeki, V. de A. Pedrosa, G.R. de Castro, Multilayer adsorption of Cu(II) and Cd(II) over Brazilian Orchid Tree (Pata-de-vaca) and its adsorptive properties, Appl. Surf. Sci., 345 (2015) 81–89.
  46. P.K. Pandey, S. Choubey, Y. Verma, M. Pandey, K. Chandrashekhar, Biosorptive removal of arsenic from drinking water, Bioresour. Technol., 100 (2009) 634–637.
  47. E.F. Olasehinde, A.V. Adegunloye, M.A. Adebayo, A.A. Oshodi, Sequestration of aqueous lead(II) using modified and unmodified red onion skin, Anal. Lett., 51 (2018) 2710–2732.
  48. A.F. Aiyesanmi, M.A. Adebayo, Y. Arowojobe, Biosorption of lead and cadmium from aqueous solution in single and binary systems using avocado pear exocarp: effects of competing ions, Anal. Lett., 53 (2020) 2868–2885.
  49. S. Ghasemi, R. Mafi Gholami, Lead adsorption from synthetic wastewater by Prosopis mimosaceae sawdust, Jundishapur J. Health Sci., 7 (2015) e23498, doi: 10.5812/jjhs.23498.
  50. S. Lagergren, About the theory of so-called adsorption of soluble substances, Sven. Vetenskapsakad. Handingar, 24 (1898) 1–39.
  51. Y.-S. Ho, G. McKay, Pseudo-second-order model for sorption processes, Process Biochem., 34 (1999) 451–465.
  52. M. Hj Ismail, C. Weng, Freundlich isotherm equilibrium equations in determining effectiveness a low-cost absorbent to heavy metal removal in wastewater (leachate) at Teluk Kitang Landfill, Pengkalan Chepa, Kelantan, Malaysia, J. Geogr. Earth Sci., 1 (2013) 1–8.
  53. M. Athar, U. Farooq, M. Aslam, M. Salman, Adsorption of Pb(II) ions onto biomass from Trifolium resupinatum: equilibrium and kinetic studies, Appl. Water Sci., 3 (2013) 665–672.
  54. R. Han, H. Li, Y. Li, J. Zhang, H. Xiao, J. Shi, Biosorption of copper and lead ions by waste beer yeast, J. Hazard. Mater., 137 (2006) 1569–1576.
  55. L. Zhou, Y. Liu, S. Liu, Y. Yin, G. Zeng, X. Tan, X. Hu, X. Hu, L. Jiang, Y. Ding, Investigation of the adsorption-reduction mechanisms of hexavalent chromium by ramie biochars of different pyrolytic temperatures, Bioresour. Technol., 218 (2016) 351–359.
  56. A. Murugesan, L. Ravikumar, V. SathyaSelvaBala, P. SenthilKumar, T. Vidhyadevi, S.D. Kirupha, S. Kalaivani, S. Krithiga, S. Sivanesan, Removal of Pb(II), Cu(II) and Cd(II) ions from aqueous solution using polyazomethineamides: equilibrium and kinetic approach, Desalination, 271 (2011) 199–208.
  57. M.I. Din, Z. Hussain, M.L. Mirza, A.T. Shah, M.M. Athar, Adsorption optimization of lead(II) using Saccharum bengalense as a non-conventional low cost biosorbent: isotherm and thermodynamics modeling, Int. J. Phytorem., 16 (2014) 889–908.
  58. D. Bingöl, M. Hercan, S. Elevli, E. Kılıç, Comparison of the results of response surface methodology and artificial neural network for the biosorption of lead using black cumin, Bioresour. Technol., 112 (2012) 111–115.
  59. A. Ofomaja, E. Naidoo, Biosorption of lead(II) onto pine cone powder: studies on biosorption performance and process design to minimize biosorbent mass, Carbohydr. Polym., 82 (2010) 1031–1042.
  60. D.V. Ramana, D.H.K. Reddy, J.S. Yu, K. Seshaiah, Pigeon peas hulls waste as potential adsorbent for removal of Pb(II) and Ni(II) from water, Chem. Eng. J., 197 (2012) 24–33.
  61. O.J. Akinyeye, T.B. Ibigbami, O.O. Odeja, O.M. Sosanolu, Evaluation of kinetics and equilibrium studies of biosorption potentials of bamboo stem biomass for removal of lead(II) and cadmium(II) ions from aqueous solution, Afr. J. Pure Appl. Chem., 14 (2020) 24–41.
  62. O. Lawal, A. Sanni, I. Ajayi, O. Rabiu, Equilibrium, thermodynamic and kinetic studies for the biosorption of aqueous lead(II) ions onto the seed husk of Calophyllum inophyllum, J. Hazard. Mater., 177 (2010) 829–835.
  63. T.K. Sen, M. Mohammod, S. Maitra, B.K. Dutta, Removal of cadmium from aqueous solution using castor seed hull: a kinetic and equilibrium study, CLEAN – Soil Air Water, 38 (2010) 850–858.
  64. V. Dang, H. Doan, T. Dang-Vu, A. Lohi, Equilibrium and kinetics of biosorption of cadmium(II) and copper(II) ions by wheat straw, Bioresour. Technol., 100 (2009) 211–219.
  65. P.S. Kumar, S. Ramalingam, V. Sathyaselvabala, S.D. Kirupha, A. Murugesan, S. Sivanesan, Removal of cadmium(II) from aqueous solution by agricultural waste cashew nut shell, Korean J. Chem. Eng., 29 (2012) 756–768.
  66. J. Bayuo, Decontamination of cadmium(II) from synthetic wastewater onto shea fruit shell biomass, Appl. Water Sci., 11 (2021) 1–8.
  67. T.K. Naiya, P. Chowdhury, A.K. Bhattacharya, S.K. Das, Sawdust and neem bark as low-cost natural biosorbent for adsorptive removal of Zn(II) and Cd(II) ions from aqueous solutions, Chem. Eng. J., 148 (2009) 68–79.