Thesis (B.S.) -- Cagayan State University, 2023.
Includes bibliographical references.

Microplastics have gained global attention as a significant emerging pollutant due to their adverse effects on marine ecosystems. The use of chemical coagulation techniques employing iron and aluminum-based salts for microplastic removal raises environmental concerns and generates toxic sludge. As a result, there is growing interest in exploring natural alternatives, including mucilage derived from Corchorus olitorius leaves, as potential solutions. This comprehensive study aims to evaluate the potential of utilizing C. olitorius mucilage as a natural coagulant and flocculant for microplastic removal in water at pH 6. The research findings revealed that higher dosages of C. olitorius mucilage extract powder led to increased efficiency in microplastic removal with the best dosage of 1.5 g/L within the range of 0.5 to 1.5 g achieving a remarkable removal potential of 92.82% (p=0.002). The study further assessed the impact of C. olitorius mucilage on various physicochemical water quality parameters including turbidity, color, pH, and total suspended solids. The addition of mucilage extract led to a slight increase in pH and elevated water turbidity and color, necessitating additional treatment measures to meet turbidity standards. Additionally, higher dosages of extract resulted in reduced TSS levels. C. olitorius mucilage also exhibited superior viscoelastic properties and contained functional groups such as hydroxyl groups, aliphatic hydrocarbons, aromatic compounds, methyl groups, carbohydrates, and polysaccharides, which contribute to its coagulation and flocculation capabilities. The analysis of flocs using FTIR spectra demonstrated the preservation of essential components and the incorporation of microplastics within the flocs. The coagulation-flocculation mechanism of the mucilage extract indicated that polymer bridging is the predominant mechanism involved, supported by observed changes in zeta potential measurements. Comparative performance analysis revealed that C. olitorius mucilage achieved a remarkable microplastic removal potential of approximately 90%, surpassing the potential of the combination of conventional chemical coagulant (Polyaluminum chloride) and flocculant (polyacrylamide) at around 65% (p=0.001). Hence, the powdered mucilage extract from C. olitorius leaves has potential as a natural coagulant and flocculant in water treatment processes, although considerations should be given to its impact on water turbidity, color, and other water quality parameters.

Keywords: Corchorus olitorious, powdered mucilage extract, natural coagulant/flocculant, pristine polystyrene microplastic, water treatment, polymer bridging.