DOI: https://doi.org/10.55373/mjchem.v27i5.251

Keywords: Chitosan; greywater; Moringa oleifera; pretreatment

Abstract

Greywater is water from non-toilet sources such as sinks, showers, bathrooms, and laundry that does not require harsh chemicals to be pretreated before being discharged into the water bodies. Maintaining high water quality standards is essential, as the treated water will ultimately be distributed back to consumers. Therefore, to address this issue, an innovative solution must be implemented to improve water quality. This research aims to quantify the effectiveness of natural coagulants in treating greywater collected from mosques in Seksyen 18, Shah Alam, Selangor and the key parameters measured include turbidity, temperature, pH, ammonia-nitrogen, chemical oxygen demand (COD), and biochemical oxygen demand (BOD). This study explores the potential of chitosan and Moringa oleifera seeds as natural coagulants in pretreatment to reduce pollutants in the sample effluent. A jar test was performed using 5, 10, and 15 g of each natural coagulant mixed separately into the medium sample. The findings demonstrated significant improvements in water quality parameters, underscoring the potential of chitosan and Moringa oleifera seeds as sustainable and effective solutions for enhancing pretreatment processes. From the experimental results, chitosan significantly reduced turbidity from 25.21 NTU to 8.36 NTU at an optimum concentration—similarly, Moringa oleifera seeds achieved turbidity removal rates of 19.5 NTU. Therefore, from the observation, the lowest turbidity removal was 22.65%, and the maximum was 66.84%. FTIR spectroscopy revealed changes in each coagulant's chemical structure after treatment, particularly in functional groups like hydroxyl (O-H), carbonyl (C=O), and amine (N-H). After treatment, these changes were observed in a scanning electron microscope for both chitosan and Moringa oleifera seeds, highlighting their interaction with contaminants in the effluent. Additionally, isotherm analysis for the adsorption capacity of these bio-coagulants was performed, revealing that the Freundlich isotherm provided a better fit for chitosan, suggesting a multilayer adsorption process on heterogeneous surfaces. The results indicate that these natural coagulants can effectively treat the greywater, offering a sustainable alternative to chemical coagulants.