Catalysts
·
2025
·Vol. 15
·期 3
·274
·
IF 4
Xinglei Zhao,Jiamin Ding,Xin Xiao,Chengbo Zhang,Shengyong Lu,Zhanheng Zhu,Sheng Sun
Fly ash produced by Municipal Solid Waste Incineration (MSWI) contains significant quantities of dioxins, posing a major challenge for safe disposal. Compared to other high-temperature disposal methods, low-temperature pyrolysis (<500 °C) can efficiently degrade dioxins in fly ash at relatively low temperatures. To better understand the effects of water-washing and catalysts on dioxin decomposition during low-temperature pyrolysis, this study investigates the impact of water-washing and three different catalysts (V2O5-WO3/TiO2, Fe/C, and CaO) on the decomposition of dioxins in washed fly ash (WFA). The results indicate that, despite the fact that water-washing pretreatment causes dioxin enrichment in WFA, the toxic equivalent quantity (TEQ) of dioxins within WFA remains lower at the identical pyrolysis temperature when contrasted with that in raw fly ash (RFA). Low-temperature pyrolysis carried out at 250 °C is capable of degrading 99.3% of the dioxins present in water-washed fly ash, achieving a significantly better performance compared to the raw fly ash, which has a degradation efficiency of merely 80%. Nevertheless, when the temperature is set at 210 °C, the degradation efficiency of the WFA turns out to be relatively low, only reaching 29%. The addition of catalysts remarkably promoted dioxin degradation at 210 °C. Among them, CaO exhibited the most outstanding performance, achieving a degradation efficiency as high as 94.8%. It should be emphasized that the catalyst ratio plays a pivotal role in the degradation process. Specifically, the proportion of CaO should not to be less than 10 wt.%.
研究领域:
环境科学
·
废物处理
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xiaoxiao Ding,Yatao Yang,Weihong Jiao,Zequan Zeng,Zhanggen Huang
The heteroatom doping into the activated carbon (AC) has been proved to be one of powerful tools to remove dioxins from sintering flue gas. However, the fact that the intrinsic enhanced mechanism of specific nitrogen species still remains unanswered makes the choice and design of AC suitable for dioxins elimination difficult. Herein, nitrogen-doping AC with alterable N species were prepared by melamine modification to in-depth illuminate the promotional roles of N-containing groups on the adsorption of chlorobenzene (CB) (a model compound for dioxins) over ACs through experimental and density functional theory (DFT). The results demonstrated that the N-doping was obviously conducive to CB adsorption, and pyrrole N group with the strongest adsorption energy (−0.84 eV) between AC-pyrrole and CB was determined to be the key adsorption sites for CB. ACM600 with more pyrrole N group prominently improved the chemical adsorption of total adsorption amount from 8.18 % to 15.12 %. The adsorption mechanism of CB onto ACs was governed by physical adsorption and weak chemical adsorption, which was attributed to the synergistic effects of π-π stacking interaction and hydrogen bonds, and the π-π stacking interaction dominated the adsorption interactions. The introduction of heteroatom N enhanced the adsorption capacity by promoting the chemical reactivity and π-electron density distribution of AC, and forming more significant π-π stacking interaction with the π-acceptor. The study provided a sound theoretical guideline and scientific foundation for the design and estimation of carbonaceous materials for dioxins abatement.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Fawei Lin,Li Xiang,Bingyan Sun,Jiantao Li,Beibei Yan,Xiaopeng He,Gang Liu,Guanyi Chen
Oily sludge (OS) is recognized as the hazardous waste and presence of Cl containing compounds causes severe potential environmental risks. This paper systematically analyzed the distribution of Cl-containing pollutants (CPs) in oil and gas that are ignored previously but have high toxicity. Three model additives, NaCl, PVC, and DCB, were selected to represent inorganic chlorine salt, organic polymers, and Cl-hydrocarbons, respectively. NaCl could retain 99 % of total Cl in the solid residue while PVC released more proportional Cl into gas, ca. 33%. A variety of organic CPs were detected in pyrolytic oil and gas with CH 2 Cl 2 and C 6 H 4 Cl 2 dominant. The synergy between OS and PVC strengthened with more PVC addition, which promoted carbonization and polymerization to generate more carbon matrix in solid residue. Pyrolysis effectively prevented formation of PCDFs compared with combustion thus exhibiting superiority on inhibiting formation of dioxins. Future work should devote to solve the environmental risks from CPs in pyrolytic products with the strategies including stabilization of Cl in solid residue and cracking of Cl-macromolecules into HCl.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 23
·19031-19043
·
IF 2.741
Mubeen Ishrat,Buekens Alfons,Chen Zhiliang,Lu Shengyong,Yan Jianhua
Municipal solid waste incineration (MSWI) fly ash has been classified as hazardous waste and needs treatment in an environmentally safe manner. Mechanochemical (MC) treatment is such a detoxification method, since it destroys dioxins and solidifies heavy metals. Milling, however, also introduces supplemental metals (Fe, Ni, Cr, Mn…), following wear of both steel balls and housing. Milling moreover reduces the particle size of fly ash and disperses catalytic metal, potentially rising the reactivity of fly ash to form and destroy ‘dioxins’, i.e. polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD + PCDF or PCDD/F). To test this issue, model fly ash (MFA) samples were composed by mixing of silica, sodium chloride, and activated carbon, and doped with CuCl 2 . Then, these samples were first finely milled without any additives for 0 h (original sample), 1 h and 8 h, and the effect of milling time (and hence particle size) was investigated on the formation of polycyclic aromatic hydrocarbons (PAHs), and of polychlorinated phenols (CP), benzenes (CBz), biphenyls (PCB) and dioxins (PCDD + PCDF) during de novo tests at 300 °C for 1 h, thus simulating the conditions prevailing in the post-combustion zone of an incinerator, where dioxins are formed and destroyed. These compounds are all characterized by their rate of generation (ng/g MFA) and their signature, i.e. internal distribution over congeners as a means of gathering mechanistic indications. PAH and CBz total yield did not decrease in MC treated MFA with milling time, while total pentachlorophenol (PeCP), PCB and PCDD/F yield decreased up to 86, 94 and 97%, respectively. International Toxic Equivalents (I-TEQ) concentration decreased more than 90%, while degree of chlorination varied inconsistently for PCB and PCDD/F, and average congener patterns of PCDD/F do not vary considerably with milling time for both gas and solid phase.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Wenjing Dong,Feng Wang,Mingliang Fang,Jie Wu,Shuaiyu Wang,Ming Li,Jingfeng Yang,Melissa Chernick,David E. Hinton,De-Sheng Pei,Hongxing Chen,Na Zheng,Jingli Mu,Lingtian Xie,Wu Dong
Bohai Bay, in the western region of northeastern China's Bohai Sea, receives water from large rivers containing various pollutants including dioxin-like compounds (DLCs). This study used the established zebrafish ( Danio rerio ) model, its known developmental toxicity endpoints and sensitive molecular analyses to evaluate sediments near and around an industrial effluent site in Bohai Bay. The primary objective was to assess the efficacy of rapid biological detection methods as an addition to chemical analyses. Embryos were exposed to various concentrations of sediment extracts as well as a 2, 3, 7, 8-tetrachlorodibenzo- p -dioxin (TCDD) positive control. Exposure to sediment extract nearest the discharge site (P1) resulted in the most severe- and highest rates of change in embryos and larvae, suggesting that DLC contaminated sediment probably did not occur much beyond it. P1 extract resulted in concentration dependent increases in mortality and pericardial edema. Its highest concentration caused up-regulation of P-450 (CYP)-1A1( CYP1A ) mRNA expression at 72 h post fertilization (hpf), an increase in its expression in gill arches as observed by whole mount in situ hybridization, and an increased signal in the Tg ( cyp1a: mCherry ) transgenic line. The pattern and magnitude of response was very similar to that of TCDD and supported the presence of DLCs in these sediment samples. Follow-up chemical analysis confirmed this presence and identified H7CDF, O8CDF and O8CDD as the main components in P1 extract. This study validates the use of biological assays as a rapid, sensitive, and cost-effective method to evaluate DLCs and their effects in sediment samples. Additionally, it provides support for the conclusion that DLCs have limited remobilization capacity in marine sediments .
研究领域:
环境生物学
·
毒理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AQUATIC TOXICOLOGY
·
2025
·
IF 4.3
Wanglong Zhang,Yanjiao Zong,Ruize Sun,Zhenhong Xue,Wenhui Wan,Anran Ren,Yongchao Ma,Wenjing Tian,Renjun Wang
The global water pollution now calls for precise risk assessment of chemicals, e.g., dioxins and the dioxin-like compounds (DLCs). The freshwater and marine medaka have been widely implemented in the toxicity testing, and perhaps give mechanistic information for comparative biology. The question that ‘will they report equal results due to their close phylogenetic relation’ has been raised, therefore, we explored their physiological and molecular responses to dioxin. As the mediator of the dioxin toxicity, the aryl hydrocarbon receptor (AHR) of marine medaka ( Oryzias melastigma ) has not been functionally characterized and might be species-specific. In terms of sensitivity to dioxin—2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD), the EC 50 values of omeAHR1a (0.16±0.12 nM), omeAHR1b (2.96±2.96 nM), omeAHR2a (0.44±0.30 nM), and omeAHR2b (9.00±6.88 nM) exhibit marked variations. The omeAHR2a and omeAHR1a display heightened sensitivity compared to the freshwater Japanese medaka ( Oryzias latipes ) counterparts olaAHR2a and olaAHR1a, respectively. The results indicate the in vitro sensitivity of AHR among species can vary by one or two orders of magnitude. Further mechanistic investigations using additional ligands and computational modeling reveal that: 1) most of omeAHR2a, olaAHR2a, dreAHR2, and hsaAHR interact with ligands in the affinity order of TCDD > PCB126 > BNF > indole, mirroring their AHR transactivation potency, but the docking poses and dynamics can vary; 2) one AHR subform's high sensitivity to dioxin—TCDD may extend to DLCs but not to other types of ligands. Beyond the in vitro study, the preliminary in vivo LC 50 data indicate that marine medaka (LC 50 : 1.64 ng/L (95% CI: 1.05-2.55 ng/L)) has similar sensitivity, and possibly slightly greater (not statistically determined yet), to TCDD in comparison with Japanese medaka (LC 50 : 3.42 ng/L (95% CI: 1.37-6.48 ng/L)).These insights underscore the difference of AHR biology among species even the close relative species, and point out the necessity for meticulous consideration when evaluating the toxicity of compounds and when extending predictive toxicity assessments to more species.
研究领域:
环境科学
·
分子生物学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Emerging Contaminants
·
2025
·
IF 6.9
Wei Xiang,Fuhua Fu,Xuebo Shang,Jian Xu,Fengxiang Yu,Dengni Lai,Yang Shan
Dioxins are among the common persistent organic pollutants in crabs. To clarify the potential risk of dioxins pollution in Chinese mitten crab, eight types of samples were collected in the South Dongting Lake area for the analysis of 17 PCDD/Fs and 12 dl-PCBs. The results indicate that the concentration of Σ PCDD/Fs and Σ dl-PCBs in crabs was between 0.993–10.8 and 35.0–282 pg/g w.w., respectively. The mean WHO-TEQ value of Σ PCDD/Fs in crabs was 0.248 ± 0.205 pg TEQ/g w.w., and the mean WHO-TEQ value of Σ PCDD/Fs+dl-PCBs in crabs was 0.359 ± 0.280 pg TEQ/g w.w.. The total toxic equivalent of bottom sediment, surrounding soil, crab brown meat and juvenile crab were relatively high, which were 2.88, 2.67, 1.50 and 1.30 pg TEQ/g w.w., respectively. In the case of 99th percentile, the WHO-TEQ values of Σ PCDD/Fs and Σ PCDD/Fs+dl-PCBs in crab white meat were all within the maximum permitted levels as specified in commission regulation (EU) 2023/915. The HQ values of 99th percentile of Σ PCDD/Fs+dl-PCBs were 0.0783, 0.00703 and 0.0853 for eating brown meat products, eating white meat products and eating whole crabs, respectively. The coordinate points of the samples are connected to the origin by a straight line in the correspondence analysis map. The angle formed by the straight lines of crab brown meat/crab white meat and juvenile crab was acute angle, as did the feed. The angles between the straight line of bottom sediment/surrounding soil and that of other samples were all obtuse angles. In conclusion, although the dioxins of bottom sediment and surrounding soil are obvious, the dioxins of adult crabs are mainly related to that of the juvenile crabs and feed. At present, the intake of dioxins from Chinese mitten crab by Chinese residents is at a safe level because of low annual consumption. It is recommended that adults limit their weekly crab consumption to 1–4 crabs, or only 23.1–105 g of crab brown meat per week, or solely 435–1242 g of crab white meat per week.
研究领域:
环境科学
·
食品安全
✓ 已验证
DOI
高影响因子
PEDOSPHERE
·
2022
·
IF 5.514
Bing XIA,Dan HUANG,Mao YE,Hao QIU,Hongfeng CHEN,Keqiang ZHAO,Rongliang QIU,Rongrong YING
Biosurfactant rhamnolipid and “soil ecosystem engineers” earthworms are often used to remediate contaminated soils. However, the effect of rhamnolipid on earthworm intestinal flora and microbial community in soil with earthworms is not understood. In our study, microcosm experiments were carried out to reveal the rhamnolipid on microbial abundance, composition, metabolism and contaminant degradation capacity. The results showed that both rhamnolipids and earthworms could have positive effects on soil bacteria. Bacteria in soil with rhamnosis have higher abundance and metabolic activity than in earthworm-only soils, while the improvement of rhamnolipid in bacterial composition and their contaminant degradation capacity were lower than earthworms. Notably, these changes were further amplified when rhamnolipids and earthworms coexisted. Specifically, the (log(copies/g) value increased from 9.50 (CK) to 10.25 (E), 10.50 (R) and 11.00 (RE). Comparing the soil with only earthworms (E), the relative abundance of dominant phyla Proteobacteria increased from 41.66% to 51.67% in the soil with both rhamnolipid and earthworms (RE), and more pollutant-degrading bacteria were also enriched in soil RE. Therefore, the increase in bacterial abundance and the enrichment of degrading bacteria lead that the removal rate of soil dioxins was earthworms + rhamnolipid (RE, 77.28%) > earthworms (E, 59.83%) > rhamnolipid (R, 24.65%) > control treatment (4.71%). Moreover, the addition of rhamnolipid enhanced the abundance of bacterial functional genes involved in “Metabolism” and “Environmental information processing”. In addition, the composition and diversity of bacteria in earthworms’ gut was conspicuously affected by rhamnolipid too, and the relative abundance of Microbacterium and Shewanella increased significantly (p<0.05). In conclusion, this study reveals that rhamnolipid will prominently influence the abundance, composition and metabolism of the microbial community in earthworms’ gut and soil, further promoting the degradation rate of dioxins. This study provides theoretical support for optimizing the combined application of rhamnolipid and earthworms in bioremediation engineering and the assessment of the ecological impacts of rhamnolipids.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2023
·Vol. 17
·期 11
·1-12
·
IF 6.4
Chen Meiling,Yin Mengjie,Su Yuetan,Li Ruizhe,Liu Kezhou,Wu Zhongbiao,Weng Xiaole
Despite the large emission of chlorinated volatile organic compounds (CVOCs) into the atmosphere, the ultimate fate of these compounds remains largely unknown. Herein, we explore the photochemical conversion of an important class of CVOCs, namely chlorobenzene (CB), on mineral α-Fe 2 O 3 particulates under atmospheric relevant conditions. A series of chamber reactions composed of the CB with/without SO 2 or NO 2 are performed, followed by in situ diffuse reflectance infrared Fourier transform spectroscopy measurements and density functional theory calculations. We show that CB can be considerably degraded by α-Fe 2 O 3 under light irradiation, whereas the reaction is markedly suppressed by adding SO 2 or NO 2 owing to their competitive adsorption and surface acidification. In particular, we discover that CB can be ultimately converted into polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) under dark state or light irradiation, suggesting a possible origin of atmospheric PCDD/Fs from this overlooked photochemical source.
研究领域:
大气科学
·
环境化学
✓ 已验证
DOI
高影响因子
WASTE MANAGEMENT
·
2018
·
IF 4.723
Ming-Xiu Zhan,Long-Jie Ji,Yu-Feng Ma,Wang-Ruochen Chen,Sheng-Yong Lu
Catalytic oxidation is regarded an effective technique to control the emissions of chlorinated benzenes (CBzs) and polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) from waste incinerators . Among the numerous factors affecting the degradation efficiency of CBzs and PCDD/Fs, limited attention has been paid to the impact of hydrochloric acid (HCl) present in the flue gas . This study investigates how HCl affects the catalytic degradation of 1,2-dichlorbenzene (1,2-DCBz) at different reaction times and temperature regimes. The results showed that the removal efficiency of 1,2-DCBz, which was achieved by the V 2 O 5 /WO 3 -TiO 2 (VWTi) catalyst, decreased the largest by 10% in the presence of HCl. Furthermore, it was found that the increasing concentration of water vapor hindered the degradation efficiency of 1,2-DCBz. No relationship between the process temperature and the destruction efficiency of PCDD/Fs was observed in the presence of HCl. Potential increasing of the removal efficiency of 1,2-DCBz was confirmed by adding different amount of activated carbon (AC) in the presence of HCl.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Xiaoxiao Ding,Yatao Yang,Zequan Zeng,Zhanggen Huang
Dioxins in the sintering flue gas are usually removed through integrated elimination technologies by carbonaceous catalysts. However, the regeneration of the used catalyst is poorly investigated, leading to the risk of leakage of dioxins. Herein, the influences of cyclic regenerations on the dioxin removal performance of a catalyst (V2O5/AC) were investigated systematically with dibenzofuran (DBF) as a model pollutant. It was demonstrated that the adsorption capacity and oxidation activity of catalysts significantly declined after several regeneration cycles due to the decreasing external specific surface area and V5+, respectively. Compared with 79.12% DBF directly emitted from a regenerator during N2 regeneration, the emission of DBF was only 29.93% with the modification of the regeneration process through O2 addition and temperature adjustment. The possible regenerated products were also analyzed to disclose the transformation behaviors of DBF. The regeneration mechanisms of DBF followed the transformation pathway of dibenzofuranol, benzofuran, anhydride species, and ultimately to CO2 and H2O. Moreover, the accumulated heavy aromatics on the surface could be decomposed by introducing O2. This research provides a comprehensive understanding of dioxin transformation behavior and a theoretical basis for efficient control of dioxin removal in the whole integrated removal technologies.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jingyi Zhao,Ai Zhang,Yinyin Zhang,Paul Héroux,Luxiang Zhu,Xiang Li,Pan Li,Yanan Liu
Soil contaminated by PCBs from the electronic processing industries has attracted global concern because of their potentially persistent risks to human and ecological health. In this study, remediation of PCBs polluted soil using dielectric barrier discharge plasma (DBD) focused on 3,3′,4,4′-tetrachlorobiphenyl (PCB77) and 2,2′-dichlorobiphenyl (PCB4). About 90 % of PCB77 and PCB4 were degraded under input power of 120 W within 30 min. The carbon dioxide mineralization of PCB77 achieved at 18.2 % in 10 min treatment. Greater PCBs degradation was obtained with higher input power, lower moisture content, weaker acidity and presence of oxygenated gas. Increasing initial concentration of PCBs had no significant effect on PCB77 degradation, but contributed to PCB4 removal. PCBs degradation reactions were initiated by high-energy electrons. Reactive oxygen species (ROS) played major roles in PCBs degradation, which was also promoted by reactive nitrogen species (RNS) such as peroxynitrous radicals (HOONO). Multiple spectroscopies showed that chlorine radicals participated in PCBs degradation reactions. Chlorine substitution, ring-opening and bridge cleavage reactions were the main degradation pathways for PCB77. The production and re-degradation of trace dioxin-like substances ensured the safety of DBD use in the remediation of PCBs-contaminated soils.
研究领域:
环境科学
·
污染治理
✓ 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）