Removal of Refractory Organic Compounds from Wastewater by Various Advanced Oxidation Process - A Review

摘要

Per capita average annual freshwater availability is gradually reduced due to increasing population, urbanization and affluent lifestyles. Hence, management of wastewater is of great concern. The wastewater from different industries can be treated byvarious conventional treatment methods but these conventional treatment technologies seem to be ineffective for the complete removal of pollutants especially refractory organic compounds that are not readily biodegradable in nature. Detergents, detergentadditives, sequestering agents like EDTA, Pesticides, Polycyclic aromatic hydrocarbons, etc. are some of the recalcitrant_ organic compounds found in the wastewater. One of the treatment technologies for the removal of recalcitrant organic compounds is Advanced Oxidation Process (AOP). The pro-— duction of hydroxyl free radical is the main mechanism for the AOP. AOP is a promising technology for the treatment of refractory organic compounds due to its low oxidation selectivity and high reactivity of the radical. Hydrogen peroxide (h2o2), Ozonation, Ultra-violet (UV) radiation, h2o2/UV process and Fenton's reaction are extensively used for the removal5 of refractory organic compounds thus reducing Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), phenolic compounds, dyes etc. to great extent. From the studies, we found that Fenton's reagents appear to be most economically practical AOP systems for almost all industries with respect to high pollutant removal efficiency and it is also economical. From the energy point of view, the ozone based process proves to be more efficient but it is costlier than the Fenton's process.