Optimization of the use of shellfish waste as a coagulant material for liquid waste from the paper industry in waste processing using the knorr method

Abstract

Background: The paper industry, in its process, utilizes a large amount of water, which in turn generates liquid waste containing chemicals with the potential to pollute the environment. The negative impact of this pollution not only impacts the balance of the environmental ecosystem, but also poses a risk to human health. In addition to the paper industry's wastewater problem, another problem is the accumulation of clamshell waste around the Kenjeran coastline. Findings: Poorly managed shell waste can cause air pollution due to unpleasant odors, damage the aesthetics of the beach environment, and become a hotbed of Coli bacteria that can cause diarrheal diseases in local residents. Thus, processing clamshell waste is an attractive solution to overcome the problem of paper industry liquid waste. This study aims to utilize shell waste from Kenjeran beach, Surabaya, to produce chitosan that can be used as a coagulant in the treatment of paper industry wastewater. Methods: The processing of green mussel shell waste (Perna viridis) into chitosan was carried out in several stages, namely: preparation stage, chitin extraction stage from green mussel shells (Perna viridis), chitosan synthesis stage using the Knorr method, and the last stage is the test stage of chitosan use in liquid waste. Conclusion: The shell waste treatment process involves chitin extraction by deproteination and demineralization, followed by chitosan synthesis using the Knorr method. The resulting chitosan, with a yield of 73.7%, proved effective as a coagulant in capturing colloidal particles in the effluent and forming floc precipitation. The use of chitosan at a dose of 600 ppm showed optimal results with a decrease in concentration and turbidity of the effluent reaching 59.35%, and lowering the pH by 0.3. Novelty/Originality of this article: the problem of liquid waste from the paper industry can be overcome with an environmentally friendly approach, while shell waste on Kenjeran Beach, Surabaya can be utilized economically by being converted into chitosan