ENVIRONMENTAL MONITORING AND ASSESSMENT
·
2011
·Vol. 184
·期 5
·3085-3094
·
IF 1.436
Li Yongfang,Yang Zhongzhi,Kong Xiaoduo,He Guangjie
As facile “environmental media”, the outdoor dust may reflect the changes of contaminants in environment more promptly. In the present study, selected organochlorine contaminants (OCs) include hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), and pentachlorobenzene (PeCB) were detected in 20 outdoor dust samples collected from Xinxiang City. The concentrations of ΣHCHs, ΣDDTs, HCB, and PeCB in dust were in the range of 0.18–5.05 ng/g dry weight, 0.44–13.50 ng/g dry weight, 0.13–51.61 ng/g dry weight and ND-0.74 ng/g dry weight, respectively. Long-range transport, historical use, and recent impact of impure pesticides might be the main sources of OCs in the outdoor dust. The results of this study indicated that impure pesticide application maybe an important source of DDTs and HCB in the environment.
研究领域:
环境科学
·
污染生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Zhengnan Tu,Yumeng Qi,Ruijuan Qu,Xiaosheng Tang,Zunyao Wang,Zongli Huo
As one of the first batch of persistent organic pollutants (POPs) included in Stockholm Convention , hexachlorobenzene (HCB) has attracted great attention because of its wide occurrence and great environmental risks. Considering the easy adsorption of HCB on solids and the complexity of natural particles, we systematically investigated the photodegradation of HCB on the surface of silica gel (SG) in aqueous solution in this work to reveal its fate in natural waters. Under mercury lamp irradiation, more than 90% of HCB loaded on SG could be removed after 240 min. Moreover, the effects of solution pH and water constituents were examined, and results showed that the presence of NO 2 − , NO 3 − , Fe 3+ and humic acid (HA) significantly inhibited the reaction due to the scavenging of ROS and/or competitive absorption of light. According to radical quenching experiments and electron paramagnetic resonance (EPR) spectra, hydroxyl radicals and singlet oxygen generated on the surface of SG could participate in the transformation of HCB, but •OH played a dominant role. Based on products identified by high performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS), two main pathways were proposed for the removal of HCB, including dechlorination and hydroxylation which represent direct and indirect photodegradation, respectively, and the occurrence of these two reactions was further supported by density functional theory (DFT) calculations. From the quantitative analysis of penta-chlorobenzene, it was estimated that dechlorination and hydroxylation contributed to approximately 44.4% and 55.6% of initial HCB degradation, respectively. Furthermore, toxicity predictions by the ecological structure–activity relationship model (ECOSAR) suggested that the toxicity of HCB was decreased in the photodegradation process. This study would provide important information for understanding the photochemical transformation mechanism of HCB at the solid/water interface.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Shuyao Yu,Bing Du,Amanjiao Baheiduola,Chao Geng,Jianguo Liu
Municipal solid waste incineration fly ash (MSWI-FA) has been strictly controlled as hazardous waste globally because it contains various heavy metals and dioxins. This study prepared a nanometallic Al/CaO (n-Al/CaO) dispersion mixture via ball-milling as a reductive stabilization reagent for the simultaneous immobilization of heavy metals and detoxification of POPs like substance in MSWI-FA. Under optimal conditions, Cu, Zn, Cd, Cr, Ni, and Pb had been significantly immobilized (over 99.9 %) and the leaching concentration of Zn, Cd, Cr, Ni, and Pb were below the detectable limit. Simultaneously, 82.43 % of HCB can be destructed into alkanes and amorphous carbon. The porous structure of the fly ash and alkaline surface of n-Al/CaO promoted the adsorption and cracking of HCB. The highly active n-Al/CaO interacted with water as the hydrogen donor to promote the reductive dechlorination process. Hydrocalumite was a new mineral formed from the adsorption and complexation of heavy metal. Therefore, n-Al/CaO can strengthen the control of heavy metals in the S/S treatment of MSWI-FA, effectively detoxify chlorinated organics, and reduce environmental health risks.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
·
2017
·
IF 2.991
Lei Bao,Shuyi Fang,Dongdong Hu,Yuan Zong,Ling Zhao,Weikang Yuan,Tao Liu
Several amphiphilic nonfluorinated polymers, poly(vinyl acetate)-block-poly(dimethylaminoethyl methacrylate) (PVAc -b- PDMAEMA) and poly(vinyl acetate- alt -diethyl maleate) (PVDBM) -b- PDMAEMA with different ratios of CO 2 -philic and hydrophilic groups, were synthesized using RAFT/MADIX polymerization and ATRP. Stability measurements revealed that PVDBM 8 -b- PDMAEMA 22 could emulsify 80% CO 2 in H 2 O, with stable CO 2 -in-water (C/W) emulsions observed for more than 48 h under 20.0 MPa at 25 °C, which was 20 times longer than PVAc -b- PDMAEMA did. The optimal degree of polymerization (DP) for CO 2 -philic groups in PVDBM- b -PDMAEMA was 8, because increasing the DP of PVDBM increased the CO 2 -philicity, whereas increased molecular weight limited the miscibility in water. Molecular dynamics simulations were applied to determine the hydrophilic/CO 2 -philic balance (HCB). It was found that enhanced CO 2 -philic tails widened the HCB range, and the optimal range of the HCB was varied with CO 2 -philic tail types. Both experimental and simulation results demonstrated that enhancing the CO 2 -philicty of surfactant tails can improve the stability of C/W emulsions.
研究领域:
材料科学
·
化学工程
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）