Desalination and Water Treatment
·
2024
·
IF 1
Xuanran Zhao,Wei Wang,Xin Song,Enwei Cao,Xueqiang Zhu,Shuguang Lyu
In this work, the effect of bromide ion (Br – ) on 1,2,3-trichloropropane (TCP) and trichloroethylene (TCE) degradation in hydrogen peroxide (H 2 O 2 ), peroxymonosulfate (PMS), and peroxydisulfate (PDS) oxidation processes was investigated. In ultrapure water, 100 %, 90 %, and 47.2 % TCE could be removed in H 2 O 2 /Fe(II), PMS/Fe(II), and PDS/Fe(II) systems within 60 min at selected dosages, respectively, while only H 2 O 2 /Fe(II) system was efficient for TCP removal (82.5 %). Compared with TCE, the negative effect of Br – on TCP removal was more obvious due to the poor TCP degradation by reactive halogen species. Besides, hydroxy radical (HO•)-based system (H 2 O 2 /Fe(II)) was more sensitive to Br – than sulfate radical (SO 4 – •)-based systems (PMS/Fe(II) and PDS/Fe(II)), because HO• was prone to react with Br – with a greater reaction rate constant. In the presence of Br – , the addition of citric acid or zero-valent iron (ZVI) promoted TCP and TCE degradation in SO 4 – •-mediated systems, while TCP and TCE removal in HO•-based system could be slightly enhanced by ZVI. In actual groundwater tests, both pre-adjusting solution pH to acidity for TCE removal in HO•-driven system and increasing chemical dosages in SO 4 – •-based systems could effectively degrade the target pollutants in the presence of Br – .
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
ACS ES&T Engineering
·
2025
·
IF 6.7
Baoqiang Hao,Renyuan Zhang,Genye He,Zishi An,Xiaoqing Li,Jing Li
The combined application of UV254 irradiation and chlorination (UV/chlorine) is considered to be a promising method for the disinfection and removal of organic pollutants. However, it is not clear how this process affects the formation of disinfection by-products (DBPs). In this study, the formation of DBPs from 11 of the most commonly used azoles in the UV/chlorine process has been investigated. The study demonstrated that dichloroacetylene, a previously unreported DBP, was identified as a coproduct of azoles. In addition to dichloroacetylene, another toxic DBP, cyanogen chloride (CNCl), was also detected in the process. However, neither dichloroacetylene nor CNCl was detected in the presence of azoles during chlorination alone. The results indicated that •OH and •Cl radicals resulting from UV/chlorine were the key factors in the production of dichloroacetylene and CNCl. Further studies have shown that dichloroacetylene was relatively stable in water with a hydrolysis half-life of 77 h and can be degraded in the presence of UV irradiation or high doses of chlorine. Additionally, bromochloroacetylene was observed in the UV/chlorine system in the presence of bromide. Furthermore, the presence of dichloroacetylene was detected in real UV/chlorine-treated water samples at concentrations ranging from 0.06 to 0.18 μM. This was found to be significantly increased by the addition of pyrazole, as was the case with CNCl. Dichloroacetylene and CNCl were detected in wastewater treatment plants at concentrations ranging from 0.15 to 0.31 μM. This finding suggested that the active species of the UV/chlorine process may alter the DBP formation pathway and lead to the emergence of novel toxic DBPs that have not yet been identified.
研究领域:
环境科学
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公共卫生
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Ying Cao,Wei Qiu,Yumeng Zhao,Juan Li,Jin Jiang,Yi Yang,Su-Yan Pang,Guanqi Liu
The frequent detection of chloramphenicol (CAP) in wastewater and surface water gives rise to concerns on its fatal myelosuppression and aplastic anemia. Recently, the combination of ozone and peroxymonosulfate (O 3 /PMS) has received wide attention in removing pollutants due to the multiple oxidants (i.e., O 3 , hydroxyl radicals ( OH) and sulfate radicals (SO 4 − )) existed therein. This study showed that O 3 /PMS could effectively degrade CAP under various conditions. The second-order rate constant of CAP with O 3 , OH and SO 4 − was 0.291 ± 0.005 , 2.27 ( ± 0.03 ) × 10 9 and 1.02 ± 0.02 × 10 8 M - 1 s - 1 , respectively. The degradation efficiency of CAP was significantly enhanced as PMS concentration or pH increased. Bicarbonate (HCO 3 − ) at concentration of 5 mM slightly inhibited CAP degradation at pH 7. Chloride (Cl − ) at concentration of 0.5 mM enhanced CAP removal at pH 7, while this enhancement gradually weakened as Cl − concentration further increased. The degradation efficiency of CAP first increased with increasing natural organic matter (NOM) concentrations (0.1–0.3 mg/L), while it was completely suppressed at higher NOM concentrations (0.5 mg/L). Four degradation products in total of CAP were identified in O 3 -based processes (i.e., O 3 , O 3 /TBA, O 3 /H 2 O 2 , O 3 /PMS and O 3 /PMS/ tert -butyl alcohol (TBA) systems. Besides, these transformation products by OH, SO 4 − and/or O 3 were also distinguished. Finally, the impact of O 3 /PMS pre-oxidation on the formation of dichloroacetamide (DCAcAm) from CAP during post-chlorination process was investigated. Compared with the traditional O 3 and O 3 /H 2 O 2 processes, O 3 /PMS pre-oxidation generally led to the least generation of DCAcAm under similar conditions, where SO 4 − rather than OH was conducive to relieve the formation of DCAcAm. Moreover, the presence of NOM obviously alleviated the formation of DCAcAm by O 3 /PMS pre-oxidation.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 40
·19165-19176
·
IF 4.682
Liu Jinchang,Shen Chenyang,Liu Qin,Li Yaping,Wang Tong,An Xiaoya,Liang Dingcheng,Xie Qiang
Coal liquefaction residue (CLR) has a high content of carbon and organic substances. However, sulfur and inorganics pose a challenge for the high-value-added utilization of CLR. In this work, general-purpose carbon fiber was successfully prepared by the new method of chlorination–dechlorination using CLR as raw material and benzyl chloride as chlorinating agent. The effect of benzyl chloride addition amount on the property of isotropic pitch precursor and the performance of general-purpose carbon fiber were investigated. The results showed that the as-prepared pitch precursors were dominated by carbon elements and contained small numbers of hydrogen, oxygen, nitrogen, and sulfur. The characteristic peaks generated from chlorine elements were observed in both FTIR and XPS spectra. The peaks at the wavenumbers of 1490 cm −1 and 696 cm −1 corresponded to the vibration of C–Cl bond, and a tiny Cl 2p peak located at 200.0 eV was observed by reducing the noise of XPS spectra. It indicates that the trace chlorine remains in the as-synthesized isotropic pitch precursor even after undergoing dechlorination. The molecular compositions of isotropic pitches were mainly polyaromatic hydrocarbons, and the chlorination–dechlorination promotes the oligomerization of polyaromatic hydrocarbons to form dimers and trimers. Therefore, the polycondensed degree and carbon aromaticity were improved. It is known from 13 C NMR analysis that the effect of chlorine–dechlorination makes the molecular structure of pitches transform more linear, thus enhancing their spinnability. In addition, the higher the amount of benzyl chloride added, the better the property of isotropic pitch was. The pitch of BC-30 and BC-40 showed excellent spinnability, stabilized property, and carbonized property compared to other pitches. The morphology of obtained carbon fiber was homogeneous and smooth without defects in surface and section. The as-prepared general-purpose carbon fiber demonstrated good tensile strength up to 1220 MPa with an average diameter of 8.5 μm. Graphical abstract
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jing Yang,Shiying Fan,Xinyong Li,Yiyuan Tao,Jingang Wang,Guohua Chen
Electrochemical selective dechlorination of dichloromethane (DCM) to chloromethane is a promising and sustainable strategy of resources. However, the current lack of high-performance electrocatalysts and complicated dechlorination mechanisms pose significant challenges. In this study, we report a series of Cu single-atom catalysts (SACs) supported on Co 3 O 4-β spinel with a tube-in-tube nanofiber structure, denoted as Cu x SACs/Co 3 O 4-β , where x represents the theoretical Cu loading (0.26 wt%, 0.30 wt% and 0.50 wt%). These catalysts effectively dechlorinate DCM, producing high-value hydrocarbons like chloromethane and methane. Notably, Cu 0.30 SACs/Co 3 O 4-β exhibited a high chloromethane production rate (2931 μmol g −1 h −1 ) and selectivity (76%) at −2.98 V vs (Ag/AgCl/Me 4 NCl) due to the synergy of cobaltosic oxide (Co 3 O 4 ) spinel and Cu single atom. X-ray photoelectron spectroscopy and electron paramagnetic resonance experiments confirmed the presence of additional surface oxygen vacancies in Cu 0.30 SACs/Co 3 O 4-β , which improved the electrocatalysis performance for DCM dechlorination. Furthermore, a concerted dechlorination mechanism was suggested based on the transfer coefficient α . This research paves the way for the development of novel spinel electrocatalysts and the advancement of dechlorination reactions.
研究领域:
材料科学
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环境科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Yu-Jia Nong,Qian-Yuan Wu,Yun-Peng Wu,Ju-Won Lee,Min-Yong Lee,Wen-Long Wang
The KrCl-excimer lamp, emitting far-UVC light at 222 nm (UV222), offers a promising alternative to conventional UVC light at 254 nm (UV254) for the photolysis of organic pollutants and the activation of radical sensitizers. This study was aimed to investigate the efficiencies of UV222 in the treatment of halogenated aromatics, focusing on its performance in degradation, dechlorination and detoxification. Chlorophenols, representative recalcitrant and toxic halogenated aromatics, were used as target pollutants. The pathways of direct photolysis, photooxidation and photoreduction under UV222 illumination were compared. UV222 outperformed UV254 in photolyzing chlorophenols (1.4−34.1 times faster), especially protonated chlorophenols, due to substantially higher UV absorption (17.1−108.0 times) and quantum yields (2.1−3.4 times). The quantum yields of chlorophenols were influenced by the inducive electron-withdrawing effect of Cl-substitutes. Moreover, UV222 improved the dechlorination of chlorophenols to 95 % compared to 60 % by UV254. The introduction of radical sensitizer (e.g., H 2 O 2 , nitrate, and sulfite) reduced 4-chlorophenol photolysis by competing for UV222 absorption, though the sensitizers partially increased radical oxidation via generating • OH or e aq − . UV222 photolysis of 4-chlorophenol increased the toxicity by 88.6 times through forming toxic intermediates (e.g., hydroquinone and resorcinol). Notably, • OH and e aq − (i.e., UV222/H 2 O 2 and UV222/sulfite) increased the dechlorination and • OH (i.e., UV222/H 2 O 2 ) detoxified the mixture solution. Moreover, UV222 photolysis remained effective for 4-chlorophenol removal in real paper-mill wastewater, indicating the potential application of KrCl* lamp UV222.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Xinwei Xu,Hui Sun,Jueyao Li,Yongming Tang
The reactive species of electrochlorination (E-Cl) in the ultrahigh salinity water (1 %-15 % NaCl) were investigated using pyridine (Pyr) as the model pollutant. No • OH signal can be detected for the E-Cl process in the ultrahigh salinity water. The free radicals are dominantly composed of the reactive chlorine species (RCS) such as Cl • , Cl 2 •− and ClO • . Moreover, the steady concentrations of Cl 2 •− and ClO • , and thus their contributions to the Pyr removal, are higher than that of Cl • . In 15 % NaCl solution, at the current density lower than 3 mA cm −2 , the RCS cannot be generated. Compared with the RCS species, the contribution of free chlorine (FC) to the Pyr removal is slightly higher due to the abundant FC generated during the E-Cl process. However, the reactivity of RCS to Pyr is much higher than that of FC. The second-order reaction rate constants of Cl • , Cl 2 •− , ClO • and FC with Pyr are 4.1 × 10 9 M −1 s −1 , 8.0 × 10 6 M −1 s −1 , 2.2 × 10 5 M −1 s −1 and 1.9 × 10 −3 M −1 s −1 , respectively. Among the background substances, SO 4 2- ions shows the significantly inhibitory effect on the Pyr degradation. Furthermore, the degradation pathway of Pyr was also proposed in the study.
研究领域:
环境化学
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电化学
·
水处理
·
污染物降解
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产品关联
DOI
高影响因子
PLoS One
·
2015
·Vol. 10
·期 7
·e0131450
·
IF 3.234
Hangjun Zhang,Xiaojun Jiang,Liping Lu,Wenfeng Xiao
Polychlorinated biphenyls (PCBs), a class of hazardous pollutants, are difficult to dissipate in the natural environment. In this study, a cyanobacterial strain Anabaena PD-1 showed good resistance against PCB congeners. Compared to a control group, chlorophyll a content decreased 3.7% and 11.7% when Anabaena PD-1 was exposed to 2 and 5 mg/L PCBs for 7 d. This cyanobacterial strain was capable of decomposing PCB congeners which was conclusively proved by determination of chloride ion concentrations in chlorine-free medium. After 7 d, the chloride ion concentrations in PCB-treated groups (1, 2, 5 mg/L) were 3.55, 3.05, and 2.25 mg/L, respectively. The genetic information of strain PD-1 was obtained through 16S rRNA sequencing analysis. The GenBank accession number of 16S rRNA of Anabaena PD-1 was KF201693.1. Phylogenetic tree analysis clearly indicated that Anabaena PD-1 belonged to the genus Anabaena . The degradation half-life of Aroclor 1254 by Anabaena PD-1 was 11.36 d; the total degradation rate for Aroclor 1254 was 84.4% after 25 d. Less chlorinated PCB congeners were more likely to be degraded by Anabaena PD-1 in comparison with highly chlorinated congeners. Meta - and para -chlorines in trichlorodiphenyls and tetrachlorobiphenyls were more susceptible to dechlorination than ortho -chlorines during the PCB-degradation process by Anabaena PD-1. Furthermore, Anabaena PD-1 can decompose dioxin-like PCBs. The percent biodegradation of 12 dioxin-like PCBs by strain PD-1 ranged from 37.4% to 68.4% after 25 days. Results above demonstrate that Anabaena PD-1 is a PCB-degrader with great potential for the in situ bioremediation of PCB-contaminated paddy soils.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 17
·11635-11641
·
IF 3.9
Jiru Guo,Yanxia Zheng,Yuchao Li,Zijian Wen,Xiuxu Shen,Yansong Zhao
4,4′-Dichlorodiphenyl sulfoxide is the main raw material for the manufacture of polysulfone, polyether sulfone and other engineering plastics. It is also an intermediate for medicines, dyes and pesticides, which has been widely utilized in engineering plastics, fine chemicals and other fields. The alkylation of chlorobenzene with thionyl chloride can give 4,4′-dichlorodiphenyl sulfoxide as a product using Lewis acidic ionic liquids. In this work, metal-based methylimidazolium ionic liquids were synthesized, which were found to be efficient catalysts for alkylation reactions. The molar ratio of different metal chlorides to 1-butyl-3-methyl imidazole chloride and the influence of different metal chlorine additives on the catalytic Lewis acid center were investigated. The fissionable species of AlCl3 in ionic liquids will enhance the acidity of ionic liquids and, thus, promote the catalytic performance of ionic liquids. Under the optimized reaction conditions, the conversion rate of excess chlorobenzene was 45.3% and the selectivity of 4,4′-dichlorodiphenyl sulfoxide was 31.9%.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Nature Sustainability
·
2023
·Vol. 6
·期 12
·1685-1692
·
IF 27.6
Cao Ruochen,Zhang Mei-Qi,Jiao Yuchen,Li Yuchen,Sun Bo,Xiao Dequan,Wang Meng,Ma Ding
Catalytic upcycling of plastic wastes to valuable chemicals offers the opportunity to simultaneously address the enormous environmental problems associated with plastics and achieve the circular economy. However, the upcycling of plastic wastes containing polyvinyl chloride (PVC) is particularly challenging due to the interference of chlorine, which can be released during PVC depolymerization and deactivate the catalyst. Here we present a catalytic process for the co-upcycling of PVC and polyethylene terephthalate (PET). By using a chlorine-containing ionic liquid as the catalyst/solvent and ZnCl 2 as Lewis acid catalyst, with in situ utilization of PVC-released chlorine, we successfully converted PET into terephthalic acid and 1,2-dichloroethane with high yields. The results reveal that chlorine from PVC, previously considered detrimental to the transformation of other polymers and the cause of catalyst poisoning, can actually have a positive role in the upcycling of plastic wastes. This work can incentivize further progress in plastics upcycling and pave the way to sustainable plastic wastes management, moving societies one step forward towards realizing the circular economy.
研究领域:
化学工程
·
环境科学
·
材料科学
·
可持续化学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Yifei Zhang,Zhechao Hua,Xuewen Zhang,Kaiheng Guo,Jingyun Fang
Solar photolysis of free chlorine (solar/chlorine) in bromide-containing water occurs under various scenarios, such as chlorinated reservoirs and outdoor swimming pools, and the formation of chlorate and bromate is an important issue in the system. We reported unexpected trends for the formation of chlorate and bromate in the solar/chlorine system. Excess chlorine inhibited the formation of bromate, i.e., increasing chlorine dosages from 50 to 100 μM reduced the bromate yield from 6.4 to 1.2 μM in solar/chlorine at 50 μM bromide and pH 7. The yield of bromate in solar/chlorine at 100 μM chlorine and 50 μM bromide in 240 min was 18.8% of that at 50 μM bromine only. The underlying mechanism was that HOCl can react with bromite (BrO 2 − ) to form HOClOBrO − , whose multi-step transformation finally formed chlorate as the major product and bromate as the minor product. This reaction overwhelmed the oxidation of bromite to form bromate by reactive species, such as • OH, BrO • and ozone. On the other hand, the presence of bromide greatly enhanced the formation of chlorate. Increasing bromide concentrations from 0 to 50 μM enhanced the chlorate yields from 2.2 to 7.0 μM at 100 μM chlorine. The absorbance of bromine was higher than that of chlorine, thus the photolysis of bromine formed higher levels of bromite at higher bromide concentrations. Then, bromite rapidly reacted with HOCl to form HOClOBrO − and it further transformed to chlorate. Additionally, 1 mg L − 1 NOM had a negligible effect on bromate yields in solar/chlorine at 50 μM bromide, 100 μM chlorine and pH 7. This study demonstrated a new pathway of chlorate and bromate formation in the solar/chlorine system with bromide.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Liwei Zhuang,Qinqin Hu,Shujing Wang,Ruyi Lin,Dan Li,Yong Ma,Lingzong Meng,Jiaoyu Peng
The solid–liquid phase equilibria of brine systems containing boric acid are the theoretical basis for the development of boric acid from brine resources. The phase equilibria of the systems NaCl–CaCl2–H3BO3–H2O and CaCl2–H3BO3–H2O at 323.15 K were investigated by the isothermal solution method. The phase diagram for the ternary system is composed of one co-saturation point, two univariant solubility curves, and two singe-salt crystallization fields of CaCl2·2H2O and H3BO3. The dry-salt phase diagram for the quaternary system consists of one invariant point, three univariant solubility curves, and three single-salt crystallization fields for NaCl, CaCl2·2H2O, and H3BO3. In the phase diagrams of the quaternary system at 298.15 and 323.15 K, the areas of sodium chloride and calcium chloride salt regions are enlarged, whereas the area of the H3BO3 region is diminished significantly with the increase of temperature. Using the Pitzer model, the lacking Pitzer parameters for H3BO3 were obtained by fitting the solubilities in the CaCl2–H3BO3–H2O system. The calculated solubilities with the Pitzer model were in accord with the experimental data.
研究领域:
化学热力学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）