Humic Acid Degradation via Solar Photo-Fenton Process in Aqueous Environment

Control of mutagenic and carcinogenic disinfection by-products, particularly Trihalomethanes (THMs) and Halo Acetic Acids (HAAs) in water treatment process is critical, due to their adverse effects on human health. Generally, reducing the toxicity of these by-products hinges on prior removal of the precursor materials, such as Humic Acid (HA) in drinking water. This study was conducted to investigate the role of some parameters that could affect the removal of HA, including HA (5 and 10 ppm) and H2O2 (20, 40, 60, and 80 ppm) initial concentrations, Iron (II), sulfate heptahydrate dosage (4, 8, 12, and 16 ppm), pH (2, 3, 4 and 5), Oxidation time (5, 10, 15 and 30 min), and Sunlight levels (322±13 kWm-2). To accelerate the process of HA removal, the Solar Photo-Fenton (SPF) process was employed by direct irradiation of converged sunlight in a Parabolic Trough Collectors (PTC), with 3m2 effective area. HA levels were measured via quantifying Dissolved Organic Carbon (DOC) concentrations by means of a TOC Analyzer method. The results showed that the SPF process is under control of the Fe & H2O2 ratio, the Fe2+ dosage and especially the pH quantity. In optimal condition, (pH: 4, oxidation time: 30min, initial HA levels: 50 ppm, H2O2 concentrations: 20 ppm Fe+2 levels: 4 ppm), the study found more than 98% DOC removal. In conclusion, the SPF, as an economically effective technique, could be applied for the removal of HA in aqueous environments

Keywords:

Humic Acid , DOC , Sunlight , Solar Photo-Fenton Process , Hydrogen Peroxide