Efficacy of Natural Coagulants in Treating Selected Industrial Wastewaters

Abstract

Natural coagulants offer an eco-friendly and biodegradable alternative to conventional inorganic coagulants. However, in spite of their proved efficiencies in several investigations, the widespread adoption of innate natural coagulants for treating water and wastewater remains relatively less. This could be due to several factors such as regulatory barriers, limited research, lack of awareness and the need for further optimization of their performance. Industrial effluents contain a range of organic and inorganic substances, biological materials, and toxic compounds, which can pose risks to public health and the environment. Traditional inorganic coagulants have been effective in treating wastewater but can alter water characteristics and complicate sludge disposal. Natural coagulants are a potential solution due to their efficient coagulation properties, lack of adverse effects on water characteristics, eco-friendliness, and biodegradability. While natural coagulants have demonstrated efficacy in research, they have yet to gain widespread acceptance in the water industry, possibly due to various barriers. Five natural coagulants were screened and four were used for further studies. A conventional Jar test apparatus was used for performing coagulation experiments. Tested coagulants have reported removal of turbidity of 97% and 30 – 40% removal of total dissolved solids and color respectively. Removal of other chemical impurities along with the aforementioned was governed by pH. Higher pH of pharmaceutical wastewaters reduced the efficiency of the coagulants. Nevertheless, the lower coagulant doses proved to be quite effective. These findings suggest a sustainable approach for the pre-treatment or treatment of industrial wastewaters