HYDROXYL RADICAL EFFECTIVENESS IN WASTEWATER TREATMENT

In this work the efficiency of hydroxyl radical in the treatment of wastewater was investigated. Hydroxyl radical was generated through Fenton reagent. The main objective of this study was to perform the oxidation treatment of selected wastewater in order to increase their biological treatability, expressed as the ratio of BOD5 to COD. Two selected organic wastewater were studied: tannery wastewater and landfill leachate. An inorganic solution containing a mixture of phosphorous compounds was also studied, in order to verify hydroxyl radical activity towards an inorganic substrate. Experimental tests were carried out at room temperature and in acid conditions. Data obtained showed that, in the treatment of organic substrates, hydroxyl radical, because of its high oxidation potential, acts the conversion of recalcitrant compounds in biodegradable ones, so increasing the BOD5 value of the wastewater but decreasing the oxygen chemical demand. The biological treatability was so increased. At the same time, the oxidation of phosphite and hypophosphite rapidly occurs, and an oxidation rate higher than 98% of the initial total phosphorous was achieved in different conditions