摘要
Various controlled release calcium peroxide nanoparticles (CR-nCPs) were synthesized and their characteristics and effectiveness in trichloroethylene (TCE) degradation were assessed. In this concern, calcium peroxide nanoparticles (nCPs) were initially prepared with four different surface stabilizers (PEG 200, PVP, PVA and DEGMME) to inhibit the irreversible agglomeration of nCPs by chemical precipitation method, then CR-nCPs were further synthesized by the coating of the selected polymers on nCPs. The characterizations of nCPs and CR-nCPs were performed using XRD, FESEM, TEM, FTIR, BET and TGA techniques. The results displayed the prepared nCPs in nano size with good dispersion, reliable purity, and standard surface area. The characterizations of CR-nCPs confirmed the success of polymer coating on nCPs. The H 2 O 2 release profiles of the prepared CR-nCPs were determined by UV spectrophotometer. PVA@nCP-PVA has shown the maximum H 2 O 2 controlled release efficiency (CRE) of 50.2%. The prepared CR-nCPs were tested for TCE degradation at optimum conditions of Fe(II) = 1.1 mM and CR-nCPs = 50 mg/L. The maximum removal percentages of 99.7% after 120 min and 66% after 180 min were achieved by CR-nCPs having moderate CRE (16.0–20.3%) and high CRE (50.2%) respectively. It was found that the CRE of CR-nCPs and their TCE degradation efficiencies have an inverse relationship. The CR-nCPs with moderate CRE were further employed for investigating the effect of polymer coating with increased polymer quantity (1:40). With the increase in polymer coating quantities, TCE removal percentages of 98.17%, 82.02% and 79.29% were obtained by PEG 400@nCP-DEGMME, DEGMME@nCP-DEGMME and PEG 400@nCP-PEG 200 after 360 min, respectively. In conclusion, this work suggests that CR-nCPs with moderate and high CRE are advantageous, in long term effectiveness, to potentially degrade TCE in groundwater remediation practice.
危险品化学品经营许可证（带存储）