engleski

Degradation of 1, 2-dichloroethane by Advanced Oxidation Processes

Chlorinated aliphatic hydrocarbons, such as 1, 2 – dichloroethane (DCA), are frequently found in the surface and groundwater sources worldwide. DCA is used primarily as an intermediate in the synthesis of vinyl chloride and in the manufacture of automotive fluids. Due to its poor biodegrability, under natural conditions DCA persists in groundwater. DCA causes circulatory and respiratory failure associated with neurological disorders in human being and in some cases it may even cause cancer. So, it has to be removed in order to prevent environmental pollution and human health damage as well. Several methods have been used to remove DCA from water. That includes aerobic/anaerobic degradation, adsorption and extraction and chemical reduction via sonochemical treatment. Aerobic and anaerobic microbial processes for degrading DCA require long reaction time while zero-valent iron reduction is slow and it is usually used in soil remediation application. Chemical and photochemical methods such as Advanced Oxidation Processes (AOPs) seem to be more promising for degradation of persistent organic compounds. AOPs are a class of processes where highly oxidizing species, such as hydroxyl radicals, are produced. The research was conducted using model DCA wastewater. The efficiency of the following AOPs for DCA degradation has been investigated: Fenton and Fenton "like" processes, Fe2+/H2O2, Fe3+/H2O2 and Fe0/H2O2 respectively as well as combination of these AOPs with UV irradiation. The optimal parameters - concentrations of iron salts, iron powder and hydrogen peroxide, for the each AOPs have been determined. Experiments have been performed in the batch reactor for two hours, at ambient conditions, using magnetic stirring. The efficiency of studied processes has been estimated on the basis of total organic carbon (TOC) measurements. Kinetics of DCA degradation was also studied. Therefore, samples of reaction mixture were taken during the process and immediately after subjected to TOC analysis. It has been found that process of DCA degradation follows pseudo-first order kinetics.

1; 2-dichloroethane; fenton and fenton

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