Removal of contaminants from industrial wastewater through various non-conventional technologies: a review

It is difficult to separate industrial growth from environmental pollution but it can be minimised through cost-effective approaches of pollution abatement. To reach the full objectives of zero pollution, adoption of alternative technologies which suit the situation of low capital availability, minimum man-power and limited energy consumption are necessary. Adsorption through agricultural products such as rice husk, sugarcane bagasse, soybean hulls, saw dust, coconut shell, groundnut shell, apple-waste, fly-ash etc., has been demonstrated to be a useful alternative to the conventional treatment systems for the removal of toxic metals such as dyes/ colour, chromium (Cr), mercury (Hg), copper (Cu), nickel (Ni), etc., from aqueous solution., It could be considered as an eco-friendly device to the existing relatively more expensive treatment technologies. Various biological species such as algae, fungi and bacteria were found to be in extensive use for the removal of contaminants. In this review, an extensive list of sorbents literature has been compiled to provide a summary of available information on a wide range of potentially low-cost non-conventional sorbents and their effectiveness.