PHOTOCATALYTIC DEGRADATION OF PAINT WASTEWATER USING PERIWINKLE SHELL AND ROOF TILE AS A PHOTOCATALYST

ABSTRACT

The purpose of this study is to develop a model for the photocatalytic treatment rate of paint wastewater using a composite mixture of locally sourced Periwinkle shell and Roof tile as a photo-catalyst. The study was conducted to assess the effectiveness of both synthetic and locally sourced catalysts (Periwinkle shell and Roof tile) in mineralizing organic pollutants in paint wastewater using sunlight radiation energy for activation. The investigation also examined the impact of operational parameters such as catalyst concentration variation and duration of exposure on the physicochemical properties of paint wastewater. The experimental investigation demonstrated that the optimum adsorbent treatment condition for unmodified Periwinkle shell and Roof tile composite catalyst was a dosage of 10g/l in 300mg/l of paint wastewater over a five-hour exposure duration. Degradation exhibited a linear increase with exposure time, achieving maximal COD and turbidity removal effectiveness of 82.3 percent and 100 percent, respectively. The result of the physio-chemical characteristics of the paint wastewater before treatment are: pH - 8.35, Turbidity - 265NTU, TDS (Total dissolve solids) - 188mg/l, COD (Chemical Oxygen Demand) - 2950mg/l, BOD (Biochemical Oxygen Demand) - 642.5mg/l, Electrical Conductivity(EC) - 372Ns/cm and Salinity - 92.8mg/l. Under the treatment conditions examined in this study, the high value obtained when concentration of photo-catalyst was varied from 2 to 10g and fixed contact time of 5hrs are: Modified Periwinkle shell and Roof tile composite; COD: 2g - 2540mg/l, 4g - 2680mg/l, 6g - 1210mg/l, 8g - 950mg/l and 10g - 630mg/l. Turbidity: 2g - 258NTU, 4g - 269NTU, 6g - 217NTU, 8g - 128NTU and 10g - 132NTU. For the unmodified Periwinkle shell and Roof tile composite catalyst: COD: 2g - 585mg/l, 4g - 542mg/l, 6g - 496mg/l, 8g - 294mg/l and 10g - 204mg/l. Turbidity: 0NTU for 2 to 10g/l. At the end of the study, the unmodified PSA-RT catalyst was found to yield the most efficient set of results.