JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Xingxing Peng,Tianyu Li,Qihang Zheng,Yingyuan Lu,Yuzhe He,Yetao Tang,Rongliang Qiu
Hexabromocyclododecane (HBCD) is a typical persistent organic pollutant that is widely detected in the environment. Despite the significant efforts put into its mineralisation , there is still a lack of microorganism resources that can completely mineralise HBCD. Stable isotope analysis revealed that the Citrobacter sp . Y3 can use [ 13 C]HBCD as its sole carbon source and degrade or even mineralise it into 13 CO 2 , with a maximum conversion rate of 100% in approximately 14 days. Strain Y3 could completely mineralise HBCD, which it used as its only carbon source, and six debromination enzymes related to HBCD degradation were found in Y3, including haloalkane dehalogenase (DhaA), haloacid dehalogenase (HAD), etc. A functional gene named HBCD-hd-1 , encoding a HAD, was found to be upregulated during HBCD degradation and heterologously expressed in Escherichia coli . Recombinant E. coli with the HBCD-hd-1 gene transformed the typical intermediate 4-bromobutyric acid to 4-hydroxybutanoic acid and showed excellent degradation performance on HBCD, accompanied by nearly 100% bromine (Br) ion generation. The expression of HBCD-hd-1 in Y3 rapidly accelerated the biodegradation of HBCD. With HBCD as its sole carbon source, strain Y3 could potentially degrade HBCD, especially in a low-nutrient environment.
研究领域:
环境科学
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微生物学
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分子生物学
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PubMed
高影响因子
ENVIRONMENTAL TOXICOLOGY
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2021
·Vol. 36
·期 8
·1674-1682
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IF 4.119
Jun Shi,Xueting Wang,Lulu Chen,Huiping Deng,Min Zhang
Brominated flame retardants (BFRs), such as, 1,2,5,6-tetrabromocyclooctane (HBCD), 1,2-dibromo-4-(1,2-dibromopropyl)cyclohexane (TBECH), and 1 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE), have garnered increasing attention due to their potent biological effects. In the present study, the toxicity of HBCD, TBECH, and BTBPE in human vascular endothelial cells (ECs) was explored. The data showed that HBCD, TBECH, and BTBPE induced cytotoxicity, namely dose–dependent cell viability reduction, cell membrane permeability and apoptosis increase, migration, and lumen formation inhibition. Moreover, HBCD was found to be more toxic than BTBPE or TBECH. Exposure to HBCD, TBECH, and BTBPE led to the production of reactive oxygen species, mitochondrial superoxide generation, and mitochondrial membrane potential collapse, implying that reactive stress caused the cytotoxicity. The ATP content, glutathione content, superoxide dismutase, and MDA activities were reduced, indicating that mitochondrial dysfunction may be the key mechanisms responsible for apoptosis. The present study suggested that mitochondria are a new target of BFRs in ECs and further deepened our understanding of the developmental toxicity of BFRs.
研究领域:
毒理学
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细胞生物学
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环境健康
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PubMed
高影响因子
CHEMOSPHERE
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2019
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IF 5.108
Yuting Jiang,Shiying Yang,Junqin Liu,Tengfei Ren,Yixuan Zhang,Xinrong Sun
Hexabromocyclododecane (HBCD) has been listed in Annex A of the Stockholm Convention on Persistent Organic Pollutants (POPs) in 2013, but till now there is a lack of efficient methods for its degradation. In this study, nanoscale zero-valent aluminum (nZVAl), an excellent reductant with a very low redox potential of E 0 (Al 3+ /Al 0 ) = −1.662 V and strong electron transfer ability, was used to reductively degrade HBCD. Nearly 100% HBCD was degraded within 8 h reaction at 25 °C in ethanol/water (v/v, 50/50) solution without pH adjustment. And about 67% cyclododecatriene (CDT) was obtained, which is the complete debromination product. What’s more, the yield of Br − could achieve nearly 100% after optimizing conditions. The reaction was strongly promoted by increasing the dosages of nZVAl or decreasing the initial concentration of HBCD. The temperature had the most significant influence and the degradation was completed in 40 min with elevating the reaction temperature to 45 °C. The reaction mechanism was further revealed through the characterization of nZVAl particles before and after the reaction by SEM-EDS, TEM , HRTEM , XRD, and XPS. It was found that, after corrosion of the oxide film on the surface of nZVAl, metallic aluminum inside was exposed. The reactive sites were provided and electrons released were transferred from nZVAl to HBCD, causing HBCD degraded to dibromocyclododecadiene (DBCD) and then CDT by reductive debromination. These findings imply that nZVAl can degrade HBCD efficiently with no extra energy input and this offers a new idea for better treatment of HBCD.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN TOXICOLOGY
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2022
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IF 3.973
Juan Wang,Guo-Dong Dai
Brominated flame retardants (BFRs) are ubiquitous industrial chemicals. In China, BFRs that are applied in large quantities include decabromodiphenyl ether (BDE-209), tetrabromobisphenol A (TBBPA), and hexabromocyclododecane (HBCD). Although findings are not always unequivocal, mounting evidence in vivo suggests that the BFRs have potential neurotoxicity. The present study aimed to assess and compare the neurotoxic effects of these three BFRs’ exposure. Male mice were orally exposed to BDE-209, TBBPA, or HBCD at 50 and 100 mg/kg bw/day for 28 days. The cognitive behavior, oxidative stress (ROS, MDA, and GSH), apoptosis-related genes (caspase-3, bax, and bcl-2), memory-related proteins (BDNF and PSD-95), and neurotransmitters (AChE and ChAT) were detected comparatively. Results showed that high doses of BDE-209, TBBPA, and HBCD exposure impaired spatial memory of mice, elevated ROS and MDA and reduced GSH levels of hippocampus, upregulated caspase-3 and bax expressions, decreased BDNF and PSD-95 levels, and disordered AChE and ChAT levels. Notably, BDE-209 caused greater adverse effects > HBCD > TBBPA. This study confirms and extends that these three BFRs had similar neurotoxic effects at current concentrations, although they may be more or less toxic.
研究领域:
毒理学
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环境健康
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神经科学
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DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2019
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IF 4.865
Haibo Chen,Shu Guo,Hui Li,Dong Zhou,Xue Cao,Chen Wang,Yongdi Liu,Mingdeng Xiang,Liangzhong Li,Yunjiang Yu
In order to understand multi-generational effects and changes of stress response by hexabromocyclododecane (HBCD) exposure, the animal model Caenorhabditis elegans was chosen for toxicity study. Multiple endpoints, including the physiological levels (growth, reproduction, and locomotion behaviors), stress-related gene expressions, reactive oxygen species (ROS) production and degree of cell apoptosis, were evaluated on exposed nematodes and their progeny . Prolonged exposure to HBCD at concentrations of 2 nM–200 nM caused adverse physiological effects in the parental generation (F0), and these effects were also observed in the offspring under HBCD-free conditions (F1). HBCD-induced toxicities could be transferred from parent to offspring. The integrated gene expressions profiles showed that exposure to HBCD at concentrations of 20–200 nM resulted in obvious changes in stress-related gene expressions, which were more increased in F0 generation than in F1 generation. The increased expressions were pronounced in several genes related to oxidative stress and cell apoptosis, e.g., hsp-16.2 , hsp-16.48 , sod-1 , sod-3 and cep-1 genes. Exposure to 200 nM of HBCD could significantly increase ROS production and degree of cell apoptosis in the F0 and F1 generations. Therefore, it was speculated that HBCD exposure induced oxidative stress and cell apoptosis, which resulted in the adverse physiological effects. This finding is helpful for understanding the multi-generational effects and evaluating the potential risk of HBCD.
研究领域:
环境毒理学
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分子生物学
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DOI
PubMed
高影响因子
CHEMOSPHERE
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2021
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IF 7.086
Yuting Jiang,Shiying Yang,Manqian Wang,Yichao Xue,Junqin Liu,Yang Li,Dongye Zhao
Hexabromocyclododecane (HBCD) is one of the priority persistent organic pollutants (POPs), yet a cost-effective technology has been lacking for the removal and degradation of HBCD. Zero-valent aluminum (ZVAl) is an excellent electron donor. However, the inert and hydrophilic surface oxide layer impedes the release of the electrons from the core metallic Al, resulting in poor reactivity towards HBCD. In this research, a new type of modified mZVAl particles (AC@mZVAl bm/NaCl ) were prepared through ball milling mZVAl in the presence of activated carbon (AC) and NaCl, and tested for adsorption and reductive degradation of HBCD in water. AC@mZVAl bm/NaCl was characterized with a metallic Al core with newly created reactive surface coated with a thin layer of crushed carbon nanoparticles . AC@mZVAl bm/NaCl was able to rapidly (within 1 h) adsorb HBCD (C 0 = 2 mg L −1 ) and thus effectively enriched HBCD on the carbon surface of AC@mZVAl bm/NaCl . The pre-enriched HBCD was subsequently degraded by the electrons from the core Al, and ∼63.44% of the pre-sorbed HBCD was completely debrominated after 62 h of the contact. A notable time lag (∼12 h) from the onset of the adsorption to the debromination was observed, signifying the importance of the solid-phase mass transfer from the initially adsorbed AC particles to the reactive Al-AC interface. Overall, AC@mZVAl bm/NaCl synergizes the adsorptive properties of AC and the high reactivity of metallic Al, and enables a novel two-step adsorption and reductive degradation process for treating HBCD or likely other POPs.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
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IF 19.503
Mingge Wu,Qianqian Li,Cheng Chen,Guijin Su,Maoyong Song,Bohua Sun,Jing Meng,Bin Shi
The high-efficiency photocatalytic debromination of hexabromocyclododecane (HBCD) as new POPs and discovery of involved mechanisms remain a challenge. Herein, challenging Pd-anchored hollow-rod-like-g-C 3 N 4 (Pd/HR-g-C 3 N 4 ) was constructed as visible-light-driven photocatalyst. Complete destruction of (±)-α, (±)-β and (±)-γ-HBCD with 92.6 % bromine-removal was achieved at 60 min in optimal system of anaerobic methanol-water (70:30) mixture with 0.5 % Pd/HR-g-C 3 N 4 , being superior to most studied HBCD catalytic systems. The higher photocatalytic reduction performance is contributed to enhanced photoexcited-carriers separation and more negative conduction band arising from distinctive 1D-cavity of HR-g-C 3 N 4 , and surface-atomically dispersed Pd. A never-reported degradation pathway in which hydrodebromination and addition ring-opening synergistically occur is proposed according to identified products of ten saturated chain alkanes, C 12 H 19 Br 5 and C 12 H 19 Br 7 . Ulteriorly, hydride-transfer resulted in rapid hydrodebromination of HBCD over Pd/HR-g-C 3 N 4 , where H chiefly derives from methanol instead of water although they synergistically promoted e − utilization. This provided a valuable sight into the cost-effective pollution-removal of HBCD.
研究领域:
环境科学
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化学工程
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材料科学
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催化
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DOI
高影响因子
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