Efficiency of Multistep Process of Fenton Oxidation and Bentonite in the Treatment of Ammonia Phenolic Wastewater

Abstract

Industrial production generates enormous amounts of wastewaters with a high content of organic and inorganic substances, which must be treated before discharging into a natural recipient to such a quality that it will not have a negative impact on the aquatic environment. This paper shows the possibility of applying a multi-stage process with Fenton reagents in combination with bentonite as an adsorbent in the treatment of ammonia-phenolic wastewater. The role of bentonite clay in this study was dye removal. The investigation was carried out under laboratory conditions, and the efficiency of the process was determined on the following parameters of COD, ammonia, phenol and thiocyanate. Also, the influence of the pH value, the concentration of oxidant hydrogen peroxide and catalyst iron sulphate heptahydrate was examined. The optimal values obtained for the pH, concentration of hydrogen peroxide and the catalyst iron sulphate heptahydrate was: 3; 30% and 23 g/l, where the efficiency of removal of the COD, ammonia, phenol and thiocyanate was: 96.42 %; 85.17 %; 100 % i 99.13 %.