ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
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2008
·Vol. 31
·期 1
·119-131
·
IF 1.086
Bu Qing Wei,Zhang Zhi Huan,Lu Song,He Feng Peng
Vertical distribution of both the concentration and composition of polycyclic aromatic hydrocarbons (PAHs) in ten profiles in Beijing has been investigated. The results showed that PAH concentrations and compositions in topsoil from different sampling sites were different. PAH concentrations were much higher in topsoil of the investigated urban area, industrial region, and paddy field with wastewater irrigation than in other areas. Moreover, PAH concentrations in topsoil were much higher than those at greater depth, where the concentrations were relatively consistent in most soil profiles. The fingerprints of PAHs in the samples from topsoil (0–30 cm) in the same profiles were similar and were obviously different from those at greater depth, suggesting that PAH sources were consistent in topsoil samples and were discriminating between topsoil and deeper soils. PAHs in topsoil mainly arose from mixed sources of combustion of liquid fuel, coal, and/or wood, as well as wastewater irrigation, while those at greater depth were derived from soil genesis and the process of soil formation.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Rui Ma,Xueqian Yan,Xiaohui Mi,Yaoguo Wu,Jin Qian,Qiuyu Zhang,Guang-Hao Chen
In this study, the Mg-Fe-LDH@biochar composite was firstly fabricated and applied for effectively activation peroxymonosulfate (PMS) for aqueous doxycycline (DOX) degradation. The physiochemical properties of the as-synthesized composite were thoroughly characterized. In the developed Mg-Fe-LDH@biochar/PMS system, the catalytic DOX degradations were evaluated under different conditions. Under the optimal condition (0.75 g/L catalyst loading, 0.75 g/L PMS dosage, pH = 7.0), about 88.76% DOX (35 mg/L) was removed within 120 mins. The results of quenching test and electron paramagnetic resonance (EPR) illustrated that the •OH, SO 4 • - and •O 2 – radicals all contributed to the DOX degradation in the Mg-Fe-LDH@biochar/PMS system, whereas the 1 O 2 -based non-radical degradation played the dominant role in DOX removal. The developed system was almost not adversely affected by the high-strength anions and exhibited high DOX decomposition rates in a wide pH range from 3.0 to 9.0, indicating the great potential in the practical application. The satisfactory reusability of the composite catalyst was demonstrated in the recycling test, with the DOX removal efficiency slightly declined from 90.08 to 84.42% after five runs. Based on the generation of reactive oxidative species and the transformation intermediates identified by HPLC-MS, the possible degradation pathways and reaction mechanism of DOX degradation in Mg-Fe-LDH@biochar/PMS system were proposed.
研究领域:
环境科学
·
化学工程
·
水处理
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Zhilin Zhao,Xiaoying Zheng,Zongshuo Han,Yue Li,Haidong He,Tao Lin,Hang Xu
Microplastics (MPs) commonly coexist with other contaminants and alter their toxicity. Perfluorooctanoic acid (PFOA), an emerging pollutant, may interact with MPs but remain largely unknown about the joint toxicity of PFOA and MPs. Hence, this research explored the single and joint effects of PFOA and polystyrene microplastics (PS-MPs) on microalgae ( Chlorella sorokiniana ) at the cellular and molecular levels. Results demonstrated that PS-MPs increased PFOA bioavailability by altering cell membrane permeability, thus aggravating biotoxicity (synergistic effect). Meanwhile, the defense mechanisms (antioxidant system modulation and extracellular polymeric substances secretion) of Chlorella sorokiniana were activated to alleviate toxicity. Additionally, transcriptomic analysis illustrated that co-exposure had more differential expression genes (DEGs; 4379 DEGs) than single-exposure (PFOA: 2533 DEGs; PS-MPs: 492 DEGs), which were mainly distributed in the GO terms associated with the membrane composition and antioxidant system. The molecular regulatory network further revealed that PS-MPs and PFOA primarily regulated the response mechanisms of Chlorella sorokiniana by altering the ribosome biogenesis, photosynthesis, citrate cycle, oxidative stress , and antioxidant system (antioxidant enzyme, glutathione-ascorbate cycle). These findings elucidated that PS-MPs enhanced the effect of PFOA, providing new insights into the influences of MPs and PFOA on algae and the risk assessment of multiple contaminants. Environmental implication MPs and PFAS, emerging contaminants , are difficult to degrade and pose a non-negligible threat to organisms. Co-pollution of MPs and PFAS is ubiquitous in the aquatic environment, while risks of co-existence to organisms remain unknown. The present study revealed the toxicity and defense mechanisms of microalgae exposure to PS-MPs and PFOA from cellular and molecular levels. According to biochemical and transcriptomic analyses, PS-MPs increased PFOA bioavailability and enhanced the effect of PFOA on Chlorella sorokiniana , showing a synergistic effect. This research provides a basis for assessing the eco-environmental risks of MPs and PFAS.
研究领域:
环境科学
·
毒理学
·
分子生物学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xiaoyue Wang,Jin Wang,Shanjun Liu,Mengmeng Dou,Boru Gao
The sterilization effect of photocatalysis and biotoxicity of nanomaterial catalysts have attracted high attention. In this study, the novel visible-driven defective carbon nitride (VL/DCN) system exhibits non-photoreactivation, non-toxic superior performance compared with traditional ultraviolet radiation (UV) and UV/titanium dioxide (UV/TiO 2 ). The inactivation of antibiotic-resistant bacteria (ARB) by novel VL/DCN still reached 7 log within 4 h, and the reduction rates of aminoglycoside gene strB and tetracycline gene tetA exceeded 0.8 log and 1.2 log, respectively. Further, the sterilization mechanism and nanotoxicity were contrastively and systematically analyzed among above three systems as following. Firstly, in the VL/DCN system, reactive oxygen species (ROSs) generated from photocatalytic process leads to the destruction of cell membranes, resulting in dissolving out of potassium ion (K + ), protein and cell membrane ATP content. Thus, resistant bacteria were completely inactivated and photoreactivation disappears. In contrast, the UV only acted on bacterial DNA and existed the light resurrection. The UV/TiO 2 strictly dependent on ultraviolet light and can be used in limited scenarios. Secondly, in cell viability analysis by human lung cell line BEAS-2B experiments, the 10% inhibition of cell growth when DCN was 600 mg/L much lower than 28% inhibition of cell growth when TiO 2 was only 200 mg/L. The expression of pro-inflammatory cytokines (( Interleukin, IL) -6), IL-8, IL-1β ) under the effect of DCN was 1.5-fold, 5.7-fold and 3.7-fold lower than TiO 2 , respectively. Meanwhile, DCN induced cells to produce less ROSs, malondialdehyde (MDA), and more superoxide dismutase (SOD). Above results demonstrated that DCN has far lower cytotoxicity than TiO 2 . This study provides theoretical support for the application of photocatalytic sterilization technology and the exploration of the toxicity of nanomaterials. Environmental Implication In this study, the novel visible-driven defective carbon nitride (VL/DCN) system exhibits non-photoreactivation, non-toxic superior performance compared with traditional ultraviolet radiation (UV) and UV/titanium dioxide (UV/TiO 2 ). The VL/DCN exhibited excellent sterilization efficiency and a high rate of reduction of the E. coli resistance gene strB. The inactivation of ARB reached 7 log within 4 h without the occurrence of photoreactivation. The reduction rates of the aminoglycoside gene strB and tetracycline gene tetA exceeded 0.8 log and 1.2 log, respectively. This study provides a valuable theoretical basis for the development of a new sustainable and environmentally friendly visible light catalytic sterilization technologies.
研究领域:
环境科学
·
材料科学
·
生物技术
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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