Removal of selected chlorinated micropollutants by ozonation

Abstract

Feasibility of ozone oxidation for the elimination of selected dissolved organic micropollutants from water and wastewaters was studied. Five organochlorine pesticides, i.e. hexachlorobutadiene, pentachlorobenzene, hexachlorobenzene, lindane, and heptachlor, were used as organic contaminants of model water. The first four of them are classified as priority hazardous substances. The oxidation treatment process was performed in a jet loop reactor. Ozone was prepared from pure oxygen. Quantification of the organochlorine pesticides in water was achieved by the gas chromatographic method after liquid-liquid extraction. Significant contribution of stripping to the removal of the investigated compounds during the ozonation treatment was also proven by the results. Effective ozonation time with regard to treatment efficiencies was 30 min, which corresponds to the ozone input of 317 mg per liter of active volume of the ozonation reactor. Single power law kinetic models were used to describe experimental data and kinetic parameters were estimated. The best fit of the experimental degradation data of all studied pollutants was obtained by the second order kinetic model. It can be concluded, based on the results obtained, that the applied ozonation process is a promising procedure for the removal of the investigated pesticides from aquatic environment.

Removal of BTX Contaminants with O3 and O3/UV Processes

“…From the processing of experimental data by simple kinetic models [13,14], removal of oxylene and p-xylene was best achieved by the second-order kinetic model. On the other hand, best fit of experimental data for benzene and toluene was obtained using the first-order kinetic model.…”

“…The objective function was defined as the sum of squares between the measured and calculated values of BTX components divided with the number of measurements reduced by the number of estimated parameters [13,14].…”

The Enhancement of H2O2/UV AOPs for the Removal of Selected Organic Pollutants from Drinking Water with Hydrodynamic Cavitation

“…), with already very low concentrations in the range of μg L -1 to trigger them; therefore they are called micropollutants. 8,6,7 Due to the presence of numerous species, their harmful effects are multiplied by the so-called "cocktail effect". 9 Their persistency in the environment and the bioaccumulation are of further concern, as well as the challenges of drinking and waste water treatment, since they are poorly responsive to the removal by traditional technologies (e.g.…”

“…coagulation, flocculation, oxidation, filtration, biological treatment etc.). 8,6,9 Advanced oxidation processes (AOPs) have already been well-researched and practically applied for the treatment of recalcitrant natural and synthetic organic pollutants in drinking water.…”

“…Synthetic organic compounds (SOCs) originating from various anthropogenic activities induce reactions in the organisms for which no adequate biological response is available seeing that their presence in the environment is relatively new and no mechanism could be developed to adapt to them so quickly. [6][7][8] These chemicals show mostly long-term detrimental effects (carcinogenicity, mutagenicity, genotoxicity, disruption of endocrine system etc. ), with already very low concentrations in the range of μg L -1 to trigger them; therefore they are called micropollutants.…”