Efficacy of Natural Coagulants in Treating Selected Industrial Wastewaters

Natural coagulants are eco-friendly and biodegradable alternatives to conventional inorganic coagulants. However, despite their proven efficiency in several investigations, the widespread adoption of innate natural coagulants for treating water and wastewater remains relatively low. 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 that can pose risks to public health and the environment. Traditional inorganic coagulants have been effective in wastewater treatment, but they can alter water characteristics and complicate sludge disposal. Natural coagulants are a potential solution owing to their efficient coagulation properties, lack of adverse effects on water characteristics, eco-friendliness, and biodegradability. Although 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 to perform the coagulation experiments. The tested coagulants removed 97% of the turbidity and 30-40% removal of the total dissolved solids and color. The removal of other chemical impurities, along with the aforementioned impurities, was governed by pH. Higher pH values of pharmaceutical wastewater reduced the efficiency of the coagulants. Nevertheless, lower coagulant doses were effective. These findings suggest a sustainable approach for the pretreatment or treatment of industrial wastewater.