Photocatalytic Degradation of Organic Pollutants from Secondary Reclaimed Water with Simulated Solar Light
نور, بتول هاشم محمود
An-Najah National University
Waste waters are being purified in Palestine at a large scale in treatment plants in different areas. The plants use secondary treatments for water, and the resulting water may still include different types of soluble organic pollutants. The treated water follows by various methods such as chlorination, peroxidation, ozonation and UV radiation is commonly used globally, however, all these are costly. In the present work we used direct solar light to photo-degrade organic pollutants from secondary treated water. Using the charcoal-supported ZnO (charcoal/ZnO) is as photo-degradation catalyst. This method is safe as the organic contaminant materials are expected to be converted into safe mineral compounds. We have seen promising results as using 0.6g ZnO per 100ml of wastewater, at pH 10 for 1 h. We found that the organic compounds as TOC exist in the claimed water in concentrations with up to 45 ppm as TOC before purification. Out of these organics, 80% have been totally degraded leaving no organic traces, as confirmed by Total Organic Carbon (TOC) analysis, the removal of organic contents was improved when we used ZnO/charcoal, and the TOC reach were 5 ppm, which is a safe limit according to world health organization (WHO). We have studied the properties of the catalyst (commercial zinc oxide) and charcoal supported ZnO (ZnO/charcoal) using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDS). We have studied different parameters (such as catalyst loading, pH and time) to identify optimum condition for the studied parameters. The results show that using 0.6g ZnO per 100ml of wastewater, at pH 10 for 1 h gives best results.