Enhanced Removal of Trichloroethylene in Water Using Nano-ZnO/Polybutadiene Rubber Composites

Abstract

An innovative nanoscale ZnO/polybutadiene rubber composite (ZBRC) was developed as a valid alternative to TiO 2 particles or immobilized TiO 2 for the mineralization of chlorinated hydrocarbons without difficulties in the recovery of nanoscale photocatalyst particles. A synergistic increase in the removal of 1,1,2-trichloroethylene (TCE) through the coupled reaction processes (i.e., sorption, photolysis, and photocatalysis) was observed because sorption of TCE to the ultraviolet(UV)-transparent polybutadiene rubber occurred, and was coupled with the heterogeneous photocatalytic reactions with nanoscale ZnO particles on the surface of ZBRC. The removal rate of TCE decreased with an increase in the initial concentration of TCE because of both inhibited generation of electron-hole pairs and deficiency of photons to activate ZnO particles. Also, the TCE removal rate increased as the loading amount of ZBRC increased. Based on satisfactory linear regressions (R 2 ≥ 0.94) between the apparent degradation rate constant (K app ) and the initial concentration vs. the ZBRC loading amount, the K app values can be estimated, a priori, without performing photocatalytic experiments. The removal efficiencies were more significantly affected by the changes in the initial concentration of TCE and the ZBRC loading amounts than by the changes in light intensity and pH in aqueous solutions. From the results of response surface analysis, the greater removal efficiencies of TCE were achieved with higher pH values, greater amounts of ZBRC, and greater intensity of light. Based on these results, newly-developed ZBRC with both high removal efficiency and low cost performs as a valid alternative to TiO 2 particles or immobilized TiO 2 for the mineralization of chlorinated hydrocarbons in various environmental and industrial matrices.

Removal of Crotamiton from Reverse Osmosis Concentrate by a TiO2/Zeolite Composite Sheet

“…Inhibition of the degradation process with high initial crotamiton concentrations may be attributed to competition from intermediates produced by crotamiton degradation [37]. Jang et al, found that the target material (trichloroethylene) saturated the composite catalyst surface and reduced photon efficiency, leading to photocatalyst deactivation [45]. Kuo et al, showed that the degradation rates of codeine and methamphetamine increased with increasing initial concentration (100-250 µg/L) [44,46].…”

High Degradation of Trichloroethylene in Water by Nanostructured MeNPs@CALB Biohybrid Catalysts

“…Despite this, better results were obtained with our Fe catalyst in comparison with the others described in the literature [36]. Furthermore, in the case of ZnO@CALB, the addition of hydrogen peroxide as an oxidant improved the degradation capacity of the catalyst from 41 to more than 80% in 5 min (Table 1, entries 11 and 15), which represent in both cases an improvement compared with other ZnO nanoparticles described in the literature [37].…”