ENERGY EFFICIENCY OF PURIFICATION OF NATURAL WATER AND WASTEWATER FROM ORGANIC MICROPOLLUTANTS USING UV RADIATION OF EXCILAMP
In this study, the energy requirements for removal of modern organic micropollutants from deionized water (DW), synthetic water (SW), lake water (LW) and a wastewater (WW) by direct photolysis (UV) and ultraviolet/hydrogen peroxide (UV/H2O2) methods using a KrCl excilamp (222 nm) were calculated and compared. Para-chlorobenzoic acid (pCBA), atrazine (ATZ), iohexol (IHL), bezafibrate (BZ), bisphenol A (BPA) and carbamazepine (CBZ) were taken as model micropollutants. The highest energy requirements were shown for direct photolysis of pCBA and CBZ in DW and SW (13–17 kWh/m3). The method UV/H2O2 required less than 4,4 kWh/m3 for attaining 90 % purification efficiency. The energy demands for destruction of micropollutants with high values of rate constants for reaction with hydroxyl radicals (pCBA, BZ, BPA and CBZ) by direct UV treatment were significantly decreased in LW and WW, indicating an important role of photosensitized dissolved organic matter. No substantial enhancement of energy-efficiency compared to direct UV was observed for UV/H2O2 treatment of WW. Despite the low UV doses for 90 % removal, the low efficiency of excilamp resulted in higher energy consumptions than reported previously for low pressure mercury lamp.