MUNICIPAL SOLID WASTE DUMPING YARD LEACHATE TREATMENT BY SOLAR PHOTOCATALYTIC USING ZnO AS A CATALYST

The landfill leachate is a major issue in the waste management because of its various pollutants presence in the leachate. It will pollute the groundwater and surface waters. The main aim of this research is to study about treatment of leachate by solar photocatalysis. In solar photocatalytic treatment, the natural source of solar radiation is used effectively for the treatment process. ZnO is excellent photocatalytic oxidation material. It can also absorb sun light in wider spectrum. Photocatalytic leachate treatment using catalyst is a well-known advanced oxidation process (AOP) for environmental remediation. With the generation of electron-hole pairs upon radiation with direct solar energy, it can mineralize a wide range of organic compounds into harmless end products such as carbon dioxide, water, and inorganic ions. This study was carried out to examine the percentage of pollutant removal in the leachate sample and also to determine the effects of pH, Catalyst dosage and reaction time in it. The solar photocatalytic experiment was carried out with different ZnO catalyst concentration ranging from 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 g/500ml. The photocatalytic experiment was conducted in 5 hours of time period exposure to sunlight. At pH 5 of the leachate sample, using 1.0 g/500ml ZnO as catalyst capable of removing 81%, 60%, 72%, 51% & 48% of turbidity, total solids, hardness, BOD and COD respectively in leachate sample after 300 min of exposure time in sunlight. At pH 5 of the leachate sample, using 1.2 g/500ml TiO2 as catalyst capable of removing 83%, 60%, 73%, 55% & 50% of turbidity, total solids, hardness, BOD and COD respectively in leachate sample after 300 min of exposure time in sunlight. This experiment reveals that more efficient in organic pollutant removal.