Utility of bentonite composite for wastewater treatment

One of the major sources, which wastes the environment is the wastewater produced from the human activity due to enhanced discharge of toxic and persistent organic pollutants into the fresh water sources like rivers etc. Ground and surface waters contain, generally, impurities including organic pollutants such as pesticides, polychlorinated biphenyls (PCBs), halogenated organic solvents and polycyclic aromatic hydrocarbons (PAHs), discharged from industrial and wastewater treatment plants affect their appearance and may have adverse effects for consumers. Presence of large colloidal particle leads to clogging of filtering devices which increases cost of water purification. Bentonite is a kind of low-cost and easily obtained clay mineral. Dominant clay minerals in bentonites are smectites such as montmorillonite, beidellite, saponite, nontronite and hectronite. Natural Bentonite is effective adsorbent for cations but it shows lower affinity towards negative groups, like phosphate, due to the absence of reactive adsorption sites for anions in water. Bentonite clay can treat oil, sulfate, phosphate and is extremely effective at removing certain cationic components from wastewater and has a remarkable affinity for metals, particularly heavy metals in solution.