ENVIRONMENTAL POLLUTION
·
2021
·
IF 8.071
Na Liu,Qing Hu,Chao Wang,Lizhi Tong,Chih-Huang Weng,Longzhen Ding
This study demonstrated that nitrogen-doped carbon materials (NCMs) could effectively catalyze the chlorine elimination process in hexachloroethane (HCA) declorination in sulfide-containing environments for the first time. The k obs values of HCA dechlorination by sulfide in the presence of 10 mg/L NCMs were higher than that of no mediator at pH 7.3 by one or two orders of magnitude. The catalytic capabilities of NCMs on HCA dechlorination were evident in common ranges of natural pH (5.3–8.9) and it could be accelerated by the increase of pH but be suppressed by the presence of dissolved humic acid . Moreover, NCMs exhibited much better catalytic capability on HCA dechlorination compared to the carbon materials, mainly owing to the combined contributions of pyridine N, including enhanced nucleophilic attack to HCA molecule by generating newborn C–S–S and activation of HCA molecule by elongating C–Cl bonds. The functions of pyridine N in micron-sized NCMs with mesopores were better than in nano-sized NCMs on HCA dechlorination. These findings displayed the potential of NCMs, when released into sulfide-containing environments, may significantly increase the dechlorination of chlorinated aliphatic hydrocarbons.
研究领域:
环境科学
·
催化化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Tian-Tian Meng,Hua Zhang,Fan Lü,Li-Ming Shao,Pin-Jing He
Polyvinyl chloride (PVC) is one of the most widely used plastics in the world. When PVC is heated, HCl will form, causing equipment corrosion, product quality decline, environmental pollution and other problems. Therefore, more attention is paid to recycling of PVC than other plastics. In this study, the reaction mechanisms of PVC with different metal oxides (MO x : CaO, ZnO, CuO, MgO, Fe 2 O 3 , Al 2 O 3 ) at low temperature (310 °C) were compared, with focus on chlorine capture and dehydrochlorination product (De-Cl PVC) property. The results showed that when the radius of metal ion was smaller, the extrapolated onset temperature ( T i ) of PVC-MO x pyrolysis tended to be lower, such as PVC-ZnO, PVC-CuO and PVC-Al 2 O 3 . Direct reaction of PVC and MO x was deduced for PVC-CuO and PVC-ZnO pyrolysis, based on the lower T i and peak temperature ( T max ) than that of PVC pyrolysis. MO x that did not significantly lower T max was supposed to react with HCl that dissociated from PVC. The addition of ZnO significantly reduced the release of HCl (0.5%) and captured 97.6% of chlorine as inorganic chloride salts. However, the chloride salts produced from PVC-MgO pyrolysis could decompose at low temperature, thus releasing HCl again, and the C atoms in PVC-CuO system could react with copper chloride salts and H 2 O, to form and release HCl. The capture effects of chlorine by Fe 2 O 3 and Al 2 O 3 were not good. With addition of MO x , all De-Cl PVCs were rich in C=C-H and (C) 3 C-H structures. Fe 2 O 3 , MgO and CuO reduced the release of volatile hydrocarbons, while CaO, ZnO and Al 2 O 3 increased the release of volatile hydrocarbons. Except for CaO and CuO, the other MO x increased the amount of residual hydrocarbon (De-Cl PVC).
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Jiaxin Xu,Jing Zou,Jianying Wu,Huiping Zeng,Yixin Huang,Jingxin Yang,Chunming Gong,Siying Chen,Jun Ma
Chlorination, one of the most common oxidation strategies, performed limited degradation capacity towards many emerging organic contaminants under neutral pH conditions. In this study, 2,2′-azinobis(3-ethylbenzothiazoline)-6-sulfonate (ABTS) was discovered to possess an outstanding activation property towards free available chlorine (FAC) during the chlorination of diclofenac (DCF) among pH 6.0–9.5. ABTS radical (ABTS •+ ) primarily accounted for the elimination of DCF in the ABTS/FAC system, although hydroxyl radicals , reactive chlorine species, and singlet oxygen were also generated via the self-decomposition of FAC. ABTS acted as the electron shuttle to degrade DCF in the ABTS/FAC system, where ABTS was firstly oxidized by FAC to ABTS •+ via single electron transfer , and followed by the elimination of DCF with the generated ABTS •+ . Eight DCF degradation intermediates were identified by LC/Q-TOF/MS, and four DCF degradation pathways were proposed. Real water bodies, humic acid , and the coexistent anions of Cl − , HCO 3 − , NO 3 − , and SO 4 2− performed negligible influence on DCF removal in ABTS/FAC system. ABTS/FAC system was much superior to sole chlorination in terms of toxicity reduction and anti-interference capacity. Overall, this study innovatively introduced ABTS as the electron shuttle to enhance the oxidative capacity of FAC under neutral pH conditions and provided a new insight that the ABTS-like organic/synthetic components might play an important role in degrading emerging organic contaminants by chlorination in water treatment .
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
PubMed
高影响因子
Foods
·
2023
·Vol. 12
·期 19
·3598
·
IF 5.2
Jia-Nan Yan,Bin Nie,Zhu-Jun Zhang,Ling-Yi Gao,Bin Lai,Ce Wang,Li-Chao Zhang,Hai-Tao Wu
The gelation of scallopPatinopecten yessoensismale gonad hydrolysates (SMGHs) andκ-carrageenan (KC) subjected to pH (2–8, 3–9) and NaCl/KCl stimuli-response was investigated. SMGHs/KC gels subjected to a NaCl response exhibited an increasing storage modulusG′from 2028.6 to 3418.4 Pa as the pH decreased from pH 8 to 2, with correspondingT23fluctuating from 966.40 to 365.64ms. For the KCl-treated group, SMGHs/KC gels showed an even greaterG′ from 4646.7 to 10996.5 Pa, withT23fluctuating from 622.2 to 276.98msas the pH decreased from 9 to 3. The improved gel strength could be ascribed to the blueshift and redshift of hydroxyl groups and amide I peaks, enhanced enthalpy and peak temperature, and gathered characteristic diffraction peaks from SMGHs, KC, NaCl, and KCl. The CLSM and cryo-SEM images further reflected that SMGHs/KC gels showed more flocculation formation and denser and more homogeneous networks with smaller pore sizes in more acidic domains, especially when subjected to the KCl response. This research gives a theoretical and methodological understanding of the construction of salt- and pH-responsive SMGHs/KC hydrogels as novel functional soft biomaterials applied in food and biological fields.Keywords:scallop;κ-carrageenan;NaCl;KCl;responsive hydrogels
研究领域:
食品科学
·
生物材料学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Nan Zhang,Yang Yang,Lijing Fan,Xiaoxu Zheng,Jinglin Wang,Cancan Jiang,Shengjun Xu,Hui Xu,Dongsheng Wang
Excessive discharge of fluoride can lead to environmental pollution and human hazards. Coagulation is a widely used process for the removal of fluoride. Existing research on the interaction between coagulants and fluoride has primarily concentrated on the removal of fluoride and the selection of coagulants, while studies on floc aging are lacking. Understanding the aging process of flocs can provide valuable insights into the mechanisms of interaction between coagulants and fluoride and further provide guidance for coagulation as well as sludge return processes. This study compares the fluoride removal efficiencies of two coagulants: polyaluminum-titanium chloride (PATC) and polyaluminum chloride (PACl), and examines the change patterns of fluoride ion during aging (0–120 h). Additionally, the study characterizes the impact of Ti or Al-Ti on the aging process using FTIR, XPS, XRD, and ESI-TOF-MS analyses. The results of the study demonstrate that the fluoride removal efficiency of PATC is 20.2% higher than that of PACl at a dosage of 0.8 mmol/L. The introduction of titanium provides additional binding sites for F − , resulting in a more intricate floc structure. Moreover, titanium promotes the hydrolytic polymerization of aluminum, increasing its positive charge and making it more attractive to F − . Upon the complete precipitation of the flocs, F − in the supernatant of PATC (0–6 h) and PACl (6–72 h) competes with -OH for binding sites, while F − attacks the Al-O or Al-O-Ti bond, leading to the disruption of the polymer. As time progresses, PATC flocs (6–120 h) are less affected by aging than PACl flocs (72–120 h). Throughout the aging process, PATC releases less F − at a slower rate, presumably because the introduction of titanium inhibited the dehydration and crystallization of the flocs to delay the release of F − .
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Peipei Gao,Zichao Hu,Yue Sheng,Weitong Pan,Lu Ding,Longfei Tang,Xueli Chen,Fuchen Wang
The release of chlorine during the pyrolysis of actual municipal plastic waste (MPW) was studied. Firstly, thermogravimetry-Fourier transform infrared (TG-FTIR) was analyzed to investigate the chlorine release behavior. Then, the effect of temperature on chlorine migrations was investigated by fast pyrolysis experiments in a fixed bed reactor. Results showed that chlorine released mainly between 241 and 353 °C in the form of HCl or chloroesters during MPW pyrolysis. After pyrolysis, chlorine was mainly distributed in the pyrolytic gas (74.34–82.89 %) and char (10.17–21.29 %). However, the release of chlorine was inhibited due to the melting behavior of MPW at <350 °C. Besides, the relative contents and types of organic chlorinated compounds in liquid products were both decreased with temperature. It was observed that polyethylene terephthalate (PET) was the greatest contributor to the formation of organic chlorinated compounds during MPW pyrolysis. Meanwhile, the pyrolysis of PET was significantly promoted by the HCl released from polyvinyl chloride (PVC). Subsequently, the pathways for the formation of organic chlorinated compounds through the co-pyrolysis of PVC and PET were proposed, including the initial degradation and subsequent chlorination of PET. These findings provided new insights into the release and regulation of chlorine-containing pollutants during actual MPW pyrolysis.
研究领域:
环境科学
·
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
Yubing Cao,Ruitong Gao,Junwei Lei,Yuandong Hou,Min Xu,Shuang Cao,Zhaojun Chen,Yajing Duan,Hui Du
Pyrolysis presents a promising pathway for the chemical recycling of waste plastics. However, the pyrolysis of chlorine-containing plastics can generate hazardous chlorinated compounds. Therefore, it is critical to investigate the migration, transformation, and removal of chlorine during pyrolysis to enable environmentally sustainable recycling. In this study, we combined kinetic analysis with in-situ FTIR and TG-FTIR-MS to elucidate the mechanisms of chlorine migration and transformation during the pyrolysis of chlorinated mixed plastics (CMPs). An efficient dechlorination process using calcium-based additives was also developed. The results indicate that the pyrolysis of CMPs occurs in two distinct stages (Stage Ⅰ and Stage Ⅱ), with average apparent activation energies (Ea) of 166.69 kJ/mol and 243.86 kJ/mol, respectively. The process followed mechanism functions involving diffusion, nucleation, and phase boundary reactions. Initially, weak C–Cl and C–H bonds ruptured preferentially, releasing HCl. This was followed by synergistic cleavage of the main C–C chains, generating radicals such as methyl (·CH₃), butyl (·C₄H₉), propylene (·C₃H₅), and phenyl (·C₆H₅). The combination of these radicals with free chlorine radicals (·Cl) resulted in the formation of diverse and complex chlorinated organic compounds. For dechlorination, Ca(OH)₂ was identified as the optimal calcium-based additive, achieving a chlorine removal efficiency of 97.75 %, attributed to its self-decomposition behavior. This study clarifies the transformation pathways of chlorinated pollutants during pyrolysis and proposes a practical calcium-based dechlorination strategy to support sustainable chlorine management in the valorization of plastic waste.
研究领域:
环境化学
·
废弃物资源化
·
热解技术
·
污染控制
·
材料循环利用
·
反应动力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Mingyue Liu,Renliang Huang,Chuanxi Li,Mingda Che,Rongxin Su,Shuzhou Li,Jing Yu,Wei Qi,Zhimin He
Nanoscale zero-valent iron has been widely applied in environmental remediation and toxic waste treatment, especially for the degradation of persistent organic pollutants (POPs). However, the dechlorination activity of Fe nanoparticles (Fe NPs) can be suppressed by the precipitation of iron oxides generated from the corrosion of Fe-Pd NPs under alkaline conditions, leading to a decreased dechlorination efficiency. Faced with this challenge, we report a highly effective dechlorination system that functions over a broad pH range and especially well under alkaline conditions in this work. Procyanidin (PROC), a natural polyphenol, was utilized as a stabilizer to manipulate the size distribution of Fe-Pd NPs and, more importantly, as a scavenger of Fe ions to prevent iron oxide precipitation. Experiments and theoretical calculations reveal that the generated Fe ions was mainly present in the form of bis- and tris-PROC-Fe complexes in the reaction solution. Compared with pristine Fe-Pd NPs, the PROC-modified Fe-Pd NPs had a dechlorination efficiency that was increased 20-fold (pH 9.0). Notably, a normalized rate constant was enhanced by more than 2 orders of magnitude compared to the previously reported dechlorination systems. The PROC-modified Fe-Pd NPs showed excellent dechlorination efficiency over a wide pH range (2.3–13.0).
研究领域:
环境科学
·
纳米技术
·
化学工程
·
材料科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Junjing Li,Menghua Yin,Yu Wang,Liang Wang
In order to change the mass transfer efficiency of conventional flat plate electrodes in the catalytic process, a new filtered Pd@Ti electrode has been prepared. The results indicated that the filtered Pd@Ti electrode had the best removal efficiency of 99.59% on diclofenac (DCF) at the flux of 40.85 L/m 2 ∙h -1 . Compared to unfiltered Pd@Ti electrodes, the removal efficiency was 1.18 times higher, the current efficiency was 2.15 times higher and the cost of electricity was 69.05% lower. The electrocatalytic hydrodechlorination process of DCF by filtered Pd@Ti electrode mainly relies on indirect reductive dechlorination by H* adsorbed on the electrode surface. The removal efficiency of the filtered Pd@Ti electrode remained above 80% after six cycles. The removal mechanism and reaction pathway of filtered Pd@Ti electrode for dechlorination of different chlorinated PPCPs were proposed. Furthermore, the ecotoxicity of chlorinated PPCPs and their products were evaluated by using the toxicity estimation software tool (T.E.S.T.) model. This study confirmed the promising application of filtered Pd@Ti electrodes for the removal and detoxification of chlorinated PPCPs in wastewater.
研究领域:
环境工程
·
水处理
·
电化学
·
毒理学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Xinkai Li,Qiang Xu,Youjun Cheng,Chunlei Chen,Chaofeng Shen,Chunfang Zhang,Daoqiong Zheng,Dongdong Zhang
Microplastics (MPs) and polychlorinated biphenyls (PCBs) generally coexist in the environment, posing risks to public health and the environment. This study investigated the effect of different MPs on the microbial anaerobic reductive dechlorination of Aroclor 1260, a commercial PCB mixture. MP exposure inhibited microbial reductive dechlorination of PCBs, with inhibition rates of 39.43%, 23.97%, and 17.53% by polyethylene (PE), polypropylene (PP), and polystyrene (PS), respectively. The dechlorination rate decreased from 1.63 μM Cl − d −1 to 0.99–1.34 μM Cl − d −1 after MP amendment. Chlorine removal in the meta-position of PCBs was primarily inhibited by MPs, with no changes in the final PCB dechlorination metabolites. The microbial community compositions in MP biofilms were not significantly different ( P > 0.05) from those in suspension culture, although possessing greater Dehalococcoides abundance (0.52–0.81% in MP biofilms; 0.03–0.12% in suspension culture). The co-occurrence network analysis revealed that the presence of MPs attenuated microbial synergistic interactions in the dechlorinating culture systems, which may contribute to the inhibitory effect on microbial PCB dechlorination. These findings are important for comprehensively understanding microbial dechlorination behavior and the environmental fate of PCBs in environments with co-existing PCBs and MPs and for guiding the application of in situ PCB bioremediation.
研究领域:
环境科学
·
微生物学
·
生态毒理学
·
生物修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY
·
2024
·
IF 9
Chunlei Wu,Qing Wang,Xinmin Wang,Shipeng Sun,Yuqi Wang,Shuang Wu,Jingru Bai,Hongyu Sheng,Jinghui Zhang
Eutectic salts, a promising thermal storage material for the next generation of concentrating solar power plants , have attracted extensive attention. Its thermal performance is a crucial factor affecting the efficient utilization of efficient solar energy. Utilizing NaCl–KCl–LiCl as the phase-change material and introduced Al 2 O 3 nanoparticles to enhance thermal conductivity , thus study explores potential mechanisms for improving heat transfer and thermal storage performance. Experimental and molecular dynamics results consistently showed that doping Al 2 O 3 nanoparticles significantly increased the specific heat and thermal conductivity of eutectic salt. Specifically, at a nanoparticle content of 1.0 wt%, liquid-specific heat and thermal conductivity increased by 44.58 % and 21.43 %, respectively. Experimental and simulation results mutually validated a consistent upward trend. However, nanoparticle introduction unavoidably led to increased viscosity , with a maximum increase of 32.15 %. Subsequently, detailed simulation analysis of a shell-and-tube heat storage unit for composite materials highlighted that heat conduction rate was influenced by both natural convection and heat conduction. Therefore, viscosity and thermal conductivity should be simultaneously considered in the system applications. This scientific strategy holds promise for widespread application of eutectic salts in solar thermal energy storage, further promoting sustainable development of renewable energy.
研究领域:
材料科学
·
能源工程
·
计算模拟
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产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2025
·
IF 6.2
Shubao Song,Lin Zhang,Meishuai Zou,Jiankun Shao
High-temperature gas-phase interactions between chlorine- and nitrogen-bearing species relevant to ammonium-perchlorate (AP) propellant combustion were elucidated by coupling shock-tube laser-absorption measurements with a detailed kinetic model. Time-resolved HCl concentration profiles were obtained for four argon-diluted surrogates—0.3 % NH 3 /0.3 % CCl 4 , 0.5 % NH 3 /0.3 % CCl 4 , 0.2 % NH 3 /0.2 % CCl 4 /0.2 % CH 4 , and 0.2 % NH 3 /0.2 % CCl 4 /0.2 % H 2 —over 1158–1506 K at near-atmospheric pressure. A kinetic model consisting of 164 species and 1358 reactions, assembled from state-of-the-art CCl 4 , H–Cl–O, NH 3 /C 0 –C 2 , and N–Cl sub-models, reproduced the new HCl data alongside literature ignition-delay and speciation measurements with excellent accuracy. Sensitivity and rate-of-production analyses reveal a temperature-robust control structure in which HCl forms almost entirely through Cl-atom abstraction from NH 3 , with Cl supplied by rapid CCl 4 dissociation; the barrierless Cl + H<=>HCl path dominates in H 2 -containing mixtures, whereas competition from Cl + CH 4 <=>CH 3 + HCl moderates HCl growth and channels carbon–nitrogen flux toward toxic HCN when CH 4 is present. Elevated temperature chiefly amplifies Cl production and suppresses NH 2 recombination, accelerating overall reactivity without altering the dominant pathways. The resulting benchmark HCl time-histories and rigorously validated model advance fundamental understanding of chlorine–nitrogen combustion chemistry and provide quantitative guidance for formulating halogenated energetic materials that maximise performance while limiting hazardous by-product formation. Importantly, the mechanism developed here may serve as a transferable gas-phase sub-model for future integration into comprehensive AP combustion frameworks, enabling more predictive simulations of real propellant systems.
研究领域:
燃烧化学
·
推进剂化学
·
反应动力学
·
气体动力学
·
环境化学
·
能源材料
✓ 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）