DECOMPOSITION OF NON-IONIC SURFACTANT SYMPERONIC NP10 BY THE FENTON PROCESS IN THE PRESENCE OF IRON-OXIDE NANOPARTICLES

摘要

Detergents belong to the class of chemical compounds whose consumption is still growing in the world. Getting to surface water they cause a decrease of water surface tension which contributes to foaming. Additionally, they are characterized by toxicity towards aquatic organisms.Methods used to decompose surfactants include oxidation/precipitation in the Fenton process. New trends in the studies on the oxidation of pollutants by the Fenton method include the use of iron nanocompounds in the reaction system. The presence of nanoparticles affects the oxidation of many chemical compounds occurring in water and wastewater. In many cases, the use of iron nanocompounds has an influence on the increase of oxidation efficiency due to which hazardous chemical compounds occurring in water decompose faster and more effectively.The aim of our studies was to determine and optimize the efficiency of decomposition of a non-ionic surfactant Symperonic NP10 by the Fenton method in the presence of iron-oxide nanoparticles and to compare it with the classical Fenton method. Surfactants, including Symperonic NP10, which contain an aromatic ring, have low susceptibility to biodegradation. The novelty of our study is to use iron-oxide nanoparticles as a catalyst in the homogeneous Fenton process.The subject of our studies were water solutions of a nonionic detergent Symperonic NP10 used in textile industry. Water solutions of the surfactant were subjected to treatment by the classical Fenton method and to treatment in the presence of iron (II, III) oxide nanopowder. In samples before and after the treatment COD and TOC were determined. The effect of process conditions such as pH, ferrous sulfate, iron oxide nanopowder and H2O2 doses on the efficiency of detergent decomposition was determined. It was also checked to what extent the addition of iron oxide nanopowder could improve the decomposition rate and efficiency compared to the classical Fenton process.In the nanoFenton process a 20-30% increase of the detergent decomposition was achieved in relation to the classical Fenton process. Iron oxide nanopowder catalyzed the process of detergent decomposition increasing its efficiency and the degree of mineralization. The efficiency of detergent oxidation reached 80%. It was probably connected with the catalytic action of iron oxide nanoparticles and higher concentration of hydroxyl radicals in the reaction system.