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The Use of Biosorbents in Water Treatment: History
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Contributor: Mothusi Molebatsi

Biological materials used to adsorb pollutants from water.

  • biosorption
  • adsorption
  • materials
  • heavy metals
  • organic pollutants
  • water purification
  • mechanisms

1. Introduction

The introduction Water is essential to our lives; it plays a pivotal role in maintaining public health, promoting social well-being, and is a critical driver of economic growth [1][2][3]. In Botswana, mining activities, industries, and agricultural processes add problems to the already scarce freshwater resources due to the country’s semi-arid climate. Studies show that wastewater from Gaborone treatment plants is not well treated before discharge, leading to contamination of surface and groundwater sources [4].

Within the Southern African Development Community (SADC) region, industrialization, poor sanitation, and climate change have also caused water scarcity and pollution. A review by the United Nations stated that many African countries struggle with access to clean water, and that the treated wastewater in Africa is mostly discharged untreated due to a lack of sustainable water treatment technologies. Lack of clean water systems is a global problem and creates risks to human health and the environment [5][6]. Addressing the water challenges requires innovative, low-cost, and sustainable solutions such as the use of biosorbents, which is closely aligned with the United Nations Sustainable Development Goals, SDG 6, that focuses on ensuring access to clean water and sanitation for all [7].

Access to clean and safe drinking water is crucial for preventing waterborne diseases (aligns with SDG 3 which aims to promote good health and well-being for people everywhere), reducing child mortality, and ensuring overall community health [8][7]. Water is beneficial to the body as it flushes waste out of the body through perspiration and urination. It transports minerals and oxygen throughout the body and regulates body temperature [9]. Access to clean water is essential for maintaining overall health as it prevents medical conditions by lubricating the joints and regulating the body temperature. It also improves strength and endurance, especially during physical activities [10].

Industries and businesses also require a reliable water supply for their operations. Access to safe water supports agricultural activities, enabling farmers to irrigate their crops and ensure food security. Furthermore, it fosters entrepreneurship by providing a foundation for small-scale businesses, encouraging economic growth at the local level [11].

Therefore, to maintain water safety, the World Health Organization (WHO), the Environmental Protection Agency (EPA), and Bureau of Standards from different countries are statutory bodies that safeguard human life and the environment by removing pollutants from water resources.

2. Types of Pollutants

Pollutants compromise the water quality, making it necessary to purify water to make it safe. They come from various sources like industries, domestic waste, and agriculture (pesticides, fertilizers, and animal waste), effluent discharges, mining activities, pharmaceuticals, tanks, and pipeline leakages [12]. Polluted water may contain organic, radioactive, inorganic substances, emerging, and microbial pollutants [13][14].

Examples of organic pollutants are dyes (for example, methyl red, methyl orange, methylene blue, etc), phenolic compounds, petroleum products, surfactants, pesticides, and pharmaceuticals [15][16]. Inorganics include cations of heavy metals e. g., lead (Pb), mercury (Hg), copper (Cu), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), and anions (chlorides (Cl-), fluorides (F-), nitrates (NO3-), phosphates (PO4-), nitrites (NO-), sulfates (SO42-) [14][17][18][19]. The physicochemical parameters, including biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, total suspended solids (TSS), dissolved oxygen (DO), electrical conductivity (EC), and total dissolved solids (TDS) [20] are critical indicators of water quality.

In many parts of Africa, domestic waste is mostly from faecal waste, which contaminates underground water sources that supply drinking water through wells and boreholes, especially in undeveloped communities. These communities rely on the use of pit latrines where there are no maintained sewage lines, and urban road runoff [21]. Countries such as Uganda, Nigeria, Malawi, Kenya, Ethiopia, Ghana, South Africa, and Zimbabwe face challenges as pit latrines are located close to boreholes, and this leads to elevated concentrations of microbial contaminants, and anions amongst other pollutants, posing a risk of cholera [22][23].

Research was done in South Africa, where the use of pit latrines was not advised in areas where groundwater was used for drinking. This was because the levels of nitrates were above the acceptable limit of 10 ppm, and Escherichia coli (E. coli) counts above 10,000 colony-forming units (E. coli/100 mL) [24]. In Botswana, groundwater pollution was linked to pit latrine usage, especially in villages surrounding the capital city, Gaborone. Villages like Ramotswa and Mochudi wellfields experienced nitrate and bacterial contamination linked to pit latrine seepage. High levels of nitrates were reported in Ramotswa to the point where the Ramotswa wellfield had to be shut down as a source of potable water. Other areas like Molepolole, Serowe, Palapye, Pallaroad, and in the northeast were also affected in a similar way [25].

Polluted water sources can contribute to diseases such as cholera, dysentery, and diarrhea, particularly affecting vulnerable populations, including children, the elderly, and those with compromised immune systems. Table 1 illustrates how various pollutants impact human health and the environment.

Table 1. Effects of pollutants on human health.

Pollutant class

Pollutant

Effects

Organics

Volatile organic compounds, for example, toluene, benzene, vinyl chloride, etc

Exposure can be through ingestion or inhalation and causes chronic illnesses like cancer and reproductive disorders, and affects the central nervous system. Inhalation brings lung problems, and a mild problem associated with ingestion is ulcers [26][27]

Persistent organic pollutants (POPs): Polychlorinated Biphenyls (PCBs), DDT (Dichloro diphenyl trichloroethane),

These can cause stroke, hypertension leading to heart failure, metabolic disease, reduced fetal growth, endocrine disruption (when hormones are interfered with), and cancerous [8]

Pesticides e.g. benzamide found in Fluopyram

They cause skin irritation and allergic reactions [28]
 

Pharmaceuticals like amoxicillin, ciprofloxacin, ibuprofen, diclofenac

Prolonged or even low-level exposure may lead to various organ dysfunctions. May also lead to hormonal imbalances to decreased fertility, as some of them are contraceptives, developmental abnormalities, and even congenital conditions in future generations [29]

Dyes: methylene blue, turmeric, congo red, crystal violet

Dye pollution in water brings allergies, cancer, dermatitis, and skin irritation [30]

Inorganics

Nickel (Ni)

It has harmful effects on human health. These include gastrointestinal complications, headache, anemia, dizziness, allergies, lung, and kidney failure [31]

Total dissolved solids (TDS)

Fluoride, F

Prolonged exposure to high amounts of dissolved salts leads to kidney stones. Fluoride consumption causes dental problems like teeth discoloration and weakening [32]

Arsenic, As

Besides causing cancer, elevated levels of Arsenic are associated with discoloration of the skin, stomach pain, nausea, diarrhea, and vomiting.

Mercury, Hg

Causes neurological disorders and may lead to abortion in expectant women. Methylmercury causes cardiovascular diseases and dementia in elderly people [33].

 

Copper, Cu

Chromium, Cr

Nausea, diarrhea, liver, and kidney damage [34][18]

Cadmium, Cd

Lead, Pb

Excessive amounts of damage to the nervous system and destroy the blood circulation. Irritation of the respiratory system [35][36][37]

Biological pollutants

Viruses, protozoa, and bacteria

These produce harmful toxins and are cholera-causing organisms. Exposure causes liver damage and skin problems [32]. Mild problems are diarrhea, nausea, vomiting, headaches, and dehydration

To address water pollution challenges, a wide range of water treatment methods has been developed, such as adsorption, flocculation, photocatalysis, sedimentation, neutralization, and membrane technologies [38][39][40][41]. These methods are simple, fast, and target various pollutants, but often come with high operational costs, limited removal of dissolved pollutants, and environmental impacts [30]. In recent years, biosorption has emerged as an eco-friendly and cost-effective alternative, yielding high pollutant removal efficiencies [42][26]. Biosorption is a process that involves using materials of a biological nature known as biosorbents to remove contaminants from water, making it an attractive option for water treatment in areas with limited access to advanced filtration technologies [41]. Biosorbents, including microbial, agricultural, and modified materials, are extensively used in the removal of heavy metals from industrial effluents, ensuring compliance with environmental regulations [43]. Furthermore, biosorbents are useful in decentralized water purification systems, especially in remote or disaster-stricken areas, providing cost-effective and sustainable water management practices through biosorption [44].

References

  1. "Types of Agricultural Water Use. M. Agrifood, . Retrieved 2025-7-10
  2. Why Industries have to be water efficient in coming future?. Beltecno. Retrieved 2025-7-10
  3. Fun without limitations. Goodnet. Retrieved 2025-7-10
  4. Setlhare, L, "Assessment of Wastewater Management in Gaborone, Botswana," Department of Environmental Affairs, Gaborone, 2021.
  5. UNEP, "Wastewater Management in Africa: A Review of the Current Status and Future Prospects.," United Nations Environment Programme (UNEP), Nairobi, 2021.
  6. World Health Organization. Water Pollution and Health. Geneva: WHO. World Health Organization. Retrieved 2025-7-10
  7. United Nations: Department of Economic and Social Affairs. UnitedNations. Retrieved 2025-7-10
  8. Prüss-Ustün, A., Wolf, J., Bartram, J., Clasen, T., Cumming, O., Freeman, M. C., ... & Johnston, R. "Burden of disease from inadequate water, sanitation and hygiene for selected adverse health outcomes: an updated analysis with a focus on low-and middle income countries," International journal of hygiene and environmental health, pp. 765-777, 2019 https://doi.org/10.1016/j.ijheh.2019.05.004.
  9. Why Is Water Important? 16 Reasons to Drink Up. Healthline. Retrieved 2025-7-10
  10. WorldBank, "High and dry: climate change, water and the economy," World Bank, 2016 High and Dry: Climate Change, Water, and the Economy.
  11. Water for Sustainable Food and Agriculture: A Report Produced for the G20 Presidency of Germany. Rome: FAO. Food and Agriculture Organization of the United Nations. Retrieved 2025-7-10
  12. A. Redha; Removal of heavy metals from aqueous media by biosorption. Journal of basic and applied sciences 2020, 1, 183-193, .
  13. Lu, F., Astruc, D., "Nanocatalysts and other nanomaterials for water remediation from organic pollutants," Coordination chemistry reviews, 2020
  14. Guo, Z., Chen, X., Hang, J., Li, Z., Zhong, C., Sun, A., Li, J., Xu, S., "Oxidative magnetization of biochar at relatively low pyrolysis temperature for efficient removal of different types of pollutants," Bioresource technology, 2023
  15. Rathi, B. S., Kumar, P. S., Dai-Viet, N. V., "Critical review on hazardous pollutants in water environment: Occurrence, monitoring, fate, removal technologies and risk assessment," Science of the total environment, 2021
  16. Xu, R., Su, M., Liu, Y., Chen, Z., Ji, C., Yang, M., Chang, X., Chen, D., "Comparative study on the removal of different-type organic pollutants on hierarchical tetragonal bismutite microspheres: Adsorption, degradation and mechanism," Journal of cleaner production, 2020
  17. Yefremova, S., Kablanbekov, A., Satbaev, B., Zharmenov, A., "Rice Husk-Based Adsorbents for Removal of Metals from Aqueous Solutions," Materials, pp. 16, 7353, 2023 Aqueous Solutions," Materials, pp. 16, 7353, 2023
  18. Tokay, B., & Akpınar, I., "A comparative study of heavy metals removal using agricultural waste biosorbents," Bioresource technology report, 2021
  19. Madela, M., & Skuza, M., "Towards a Circular Economy: Analysis of the Use of Biowaste as Biosorbent for the Removal of Heavy Metals," Energies, 2021
  20. Addisie, M., "Evaluating Drinking Water Quality Using Water Quality Parameters and Esthetic Attributes.," Air, Soil and Water Research, 2022.
  21. Lapworth, D. J., Nkhuwa, D. C. W., Okotto-Okotto, J., Pedley, S., Stuart, M. E., Tijani, M. N., & Wright, J. J. H. J., "Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health.," Hydrogeology, 2017
  22. Howard, G., Pedley, S., Barette, M., Nalubega, M., Johal, K., "Risk factors contributing to microbiological contamination of shallow groundwater in Kampala, Uganda," Water Research, pp. 3421-3429, 2003
  23. Kanyerere, T., Levy, J., Xu, Y., Saka, J., "Assessment of Microbial Contamination of Groundwater in Upper Limphasa River Catchment, Located in a Rural Area of Northern Malawi," Water SA, p. 581–596, 2012
  24. Still, D. A., Nash, S. R., "Groundwater contamination due to pit latrines located in a sandy aquifer: A case from Maputaland," 19-23 MAy 2002.
  25. Alemaw, B. F., Shemang, E. M., Chaoka, T. R., "Assessment of groundwater pollution vulnerability and modelling of the Kanye Wellfield in SE Botswana—a GIS approach," Physics and Chemistry of the earth, pp. 1125-1128, 2004
  26. Yaashikaa, P.R., Kumar, P. S., Saravanan, A., Dai-Viet, N. V., "Advances in biosorbents for removal of environmental pollutants: A review on pretreatment, removal mechanism and future outlook," Journal of hazardous materials, 2021
  27. Makoś-Chełstowska, P., Słupek, E., Gębicki, J., "Agri-food waste biosorbents for volatile organic compounds removal from air and industrial gases – A review," Science of the total environment, 2024
  28. Martín-García, B., Longo, E., Ceci, A. T., Pii, Y., Romero-Gozalez, R., Frenich, A. G., Boselli, E., "Pesticides and winemaking: A comprehensive review of conventional and emerging approaches," Reviews in food science and food safety, 2024
  29. Gao, P., Chen, D., Chen, W., Sun, J., Wang, G., Zhou, L., "Facile synthesis of amine-crosslinked starch as an efficient biosorbent for adsorptive removal of anionic organic pollutants from water," International Journal of Biological Macromolecules, pp. 1240-1248, 2021
  30. Bhatnagar, A., Vilar, V. J., Botelho, C. M., & Boaventura, R. A. , " Coconut-based biosorbents for water treatment—a review of the recent literature.," Advances in colloid and interface science, pp. 1-15, 2010
  31. Aranda-García, E., Chávez-Camarillo, G. M., & Cristiani-Urbina, E., " Effect of Ionic Strength and Coexisting Ions on the Biosorption of Divalent Nickel by the Acorn Shell of the Oak Quercus crassipes Humb. & Bonpl.," Processes, 2020
  32. Sharma, S., & Bhattacharya, A. J. A. W. S, "Drinking water contamination and treatment techniques.," Applied water science, pp. 1043-1067, 2017
  33. Landrigan, P., Stegeman, J. J., Fleming, L. E., "Human health and ocean pollution.," National central for biotechnology information, 2020
  34. Richards, M., Dawson, J., Stutter, M, "The potential use of natural vs commercial biosorbent material to remediate stream waters by removing heavy metal contaminants.," Environmental management, pp. 275-281, 2019
  35. Bulgariu, L. & Bulgariu, D., " Potential use of alkaline treated algae waste biomass as sustainable biosorbent for clean recovery of cadmium (II) from aqueous media: batch and column studies.," Journal of Cleaner Production, pp. 4525-4533, 2016
  36. Hossain, M. S., Hossain, M. M., Khatun, M. K., & Hossain, K. R., "Hydrogel-based superadsorbents for efficient removal of heavy metals in industrial wastewater treatment and environmental conservation.," Environmental Functional Materials, 2024
  37. Wu, J., Wang, T., Wang, J., Zhang, Y., Pan, W., "A novel modified method for the efficient removal of Pb and Cd from wastewater by biochar: Enhanced the ion exchange and precipitation capacity," Science of the total environment, 2021
  38. Mushtaq, F., Zahid, M., Bhatti, A. A., Nasir, S., Hussain, T., "Possible applications of coal flu ash in wastewater treatment," Environmental Management, pp. 27-46, 2019
  39. Nasrollahzadeh, M., Sajjadi, M., Iravani, S., Varma, R. S., "Carbon-based sustainable nanomaterials for water treatment: State-of-art and future perspectives," Chemosphere, p. 128005, 2021
  40. Lu, F., Astruc, D., "Nanocatalysts and other nanomaterials for water remediation from organic pollution," Coordination chemistry, p. 213180, 2020
  41. Tee, G. T., Gok, X. Y., Yong, W. F., "Adsorption of pollutants in wastewater via biosorbents, nanoparticles and magnetic biosorbents: A review," Environmental Research, p. 113248, 2022
  42. C. Zamora-Ledezma, "Heavy metal water pollution: a fresh look about hazards, novel and conventional remediation methods," Environmental technology, p. 101504, 2021
  43. S. M. M. Chowdhury, "Recent trends and emerging strategies of biosorbent-based heavy metals removal from wastewater: A review," 2021
  44. Gupta, V. K., Pathania, D., " Biosorbents for water purification: a review," 2021
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