秦岭输水隧洞施工期废水水质评价及工艺研究

依据前期对施工废水水质的连续监测和分析检测结果,针对秦岭输水隧洞施工期废水水量较大、高SS等特点,基于水质矩阵分析原理,以废水处理后安全外排为约束,对各污染物进行权重分析,得出污染物对环境影响由高到低依次是SS、COD、Fe、NH3-N、TN、石油类。结果表明SS是制约隧洞施工废水安全外排的控制因子。根据废水污染物的构成,提出了以"混凝+沉淀+锰砂过滤+吸附"为核心的处理工艺,并用施工现场采集的废水以及人工模拟废水进行了实验室静态实验。结果表明,该处理工艺对悬浮物去除率达90%以上,对COD去除率约85%,对氨氮去除率约60%。处理后水质均能满足《地表水环境质量标准》(GB 3838-2002)中Ⅱ类水体指标。     

The air pollution effect of government economic growth expectations: evidence from China’s cities based on green technology

Environmental Science and Pollution Research - Based on the Government Work Report of 265 prefecture-level cities in China from 2004 to 2015, this article combines economic growth expectations data...     

Response of sulfhydryl compounds in subcells of Cladophora rupestris under Pb stress

Environmental Science and Pollution Research - This study aimed to determine the role of sulfhydryl compounds in the subcells of C. rupestris under Pb stress. Different concentrations (0, 0.5, 1.0,...     

宜昌市大气微塑料的分布、呼吸暴露及溯源

微塑料作为一种新兴环境污染物备受关注,但大气微塑料的来源和健康危害尚不明晰.为探究宜昌市不同功能区微塑料的分布特征和人体呼吸暴露风险,分析不同地区大气微塑料的可能来源,于2019年10～12月,采集和分析宜昌市16个观测点的大气微塑料样品,并利用HYSPLIT模型模拟大气后向轨迹.结果表明,宜昌市大气微塑料有纤维状、碎片状和薄膜状这3种形状;透明、红色、黑色、绿色、黄色和紫色这6种颜色;尺寸最小的为10.42μm,最大的为4 761.42μm;平均沉降通量为(4 400±474)n·(m²·d)^-1;种类有：聚酯纤维(PET)、丙烯腈-丁二烯-苯乙烯共聚合物(ABS)、聚酰胺(PA)、橡胶(Rubber)、聚乙烯(PE)、醋酸纤维素(CA)和聚丙烯腈(PAN)这7种.各功能区沉降通量依次为：城市居民区>农业生产区>垃圾填埋场>化工园区>城镇居民区.人体呼吸暴露风险评估模型表明,城市居民区成人和儿童每天大气微塑料摄入量(EDI)高于城镇居民区.大气后向轨迹模拟表明,宜昌市各区县大气主要受周边地区影响,部分大气微塑料可能来...     

Combined pollution of arsenic and Polymyxin B enhanced arsenic toxicity and enriched ARG abundance in soil and earthworm gut microbiotas

Polymyxin B (PMB) is considered as the last line of antibiotic defense available to humans. The environmental effects of the combined pollution with PMB and heavy metals and their interaction mechanisms are unclear. We explored the effects of the combined pollution with PMB and arsenic (As) on the microbial composition of the soil and in the earthworm gut, as well as the spread and transmission of antibiotic resistance genes (ARGs). The results showed that, compared with As alone, the combined addition of PMB and As could significantly increase the bioaccumulation factor and toxicity of As in earthworm tissues by 12.1% and 16.0%, respectively. PMB treatment could significantly increase the abundance of Actinobacteria in the earthworm gut (from 35.6% to 45.2%), and As stress could significantly increase the abundance of Proteobacteria (from 19.8% to 56.9%). PMB and As stress both could significantly increase the abundance of ARGs and mobile genetic elements (MGEs), which were positively correlated, indicating that ARGs might be horizontally transferred. The inactivation of antibiotics was the main resistance mechanism that microbes use to resist PMB and As stress. Network analysis showed that PMB and As might have antagonistic effects through competition with multi-drug resistant ARGs. The combined pollution by PMB and As significantly promoted the relative abundance of microbes carrying multi-drug resistant ARGs and MGEs, thereby increasing the risk of transmission of ARGs. This research advances the understanding of the interaction mechanism between antibiotics and heavy metals and provides new theoretical guidance for the environmental risk assessment and combined pollution management.     

考虑车辆类型变化的中国乘用车排放特征

通过引入Lotka-Volterra模型预测了中国未来30年的乘用车竞争趋势;通过引入CHG、VOC、CO、SO₂、PM_2.5、NO_x6类污染物更新了全生命周期清单;并据此建立了政策影响模型和敏感性模型评估电动化、轻量化和清洁化政策情景减排效果.结果表明,乘用车市场的主要竞争力来源于新能源与传统能源的竞争,且纯电动与混合动力乘用车呈S型曲线发展,汽油乘用车占比由92%减少到1%;全生命周期中,纯电动乘用车对CHG、VOC、CO减排效益最优,为20%~85%;汽油与天然气乘用车对SO₂和PM_2.5的减排效益最优,为50.0%;3类情景下税收补贴类政策敏感性最强,CHG、VOC和CO的最优减排情景为电气化情景,PM_2.5、NO_x的最优减排情景为清洁化情景,而SO₂的最优减排情景则为整车轻量化.     

“三生空间”统筹的科学基础与优化途径探析

党的十八大提出了将优化国土空间开发格局作为生态文明建设的首要举措,以及“促进生产空间集约高效、生活空间宜居适度、生态空间山清水秀”的目标要求。通过文献调研和总结归纳法,系统梳理了“三生空间”统筹优化的研究进展。总结发现,现有工作主要从国土空间利用质量、土地利用适宜性评价、资源环境承载力与比较优势等角度开展了“三生空间”统筹优化研究。但由于对“三生空间”科学内涵的认识不足、定量识别方法与分类体系的构建不完善,目前“三生空间”统筹优化的技术途径存在诸多问题尚待明晰。未来“三生空间”统筹优化的技术途径应以美丽中国建设愿景为目标导向,以人地耦合系统理论为核心,系统构建识别与优化国土空间的理论体系与技术框架。     

Application of a real-ambient fine particulate matter exposure system on different animal models

Simulation of fine particulate matter (PM_2.5) exposure is essential for evaluating adverse health effects. In this work, an ambient exposure system that mimicked real atmospheric conditions was installed in Taiyuan, China to study impacts of chronic PM_2.5 exposure on adult and aged mice as well as Sirtuin3 knockout (Sirt3 KO) mice and wild-type (WT) mice. The real-ambient exposure system eliminated the possible artificial effects caused from exposure experiments and maintained the physiochemical characteristics of PM_2.5. The case studies indicated that aged mice exhibited apparent heart dysfunction involving increased heart rate and decreased blood pressure after 17-week of real-ambient PM_2.5 exposure. Meanwhile, 15-week of real-ambient PM_2.5 exposure decreased the heart rate and amounts of associated catecholamines to induce heart failure in Sirt3 KO mice. Additionally, the increased pro-inflammatory cytokines and decreased platelet related indices suggested that inflammation occurred. The changes of biomarkers detected by targeted metabolomics confirmed metabolic disorder in WT and Sirt3 KO mice after exposed to real-ambient PM_2.5. These results indicated that the real-ambient PM_2.5 exposure system could evaluate the risks of certain diseases associated with air pollution and have great potential for supporting the investigations of PM_2.5 effects on other types of rodent models.     

Disinfection byproduct formation from algal organic matters after ozonation or ozone combined with activated carbon treatment with subsequent chlorination

Algal organic matter (AOM), including extracellular organic matter (EOM) and intracellular organic matter (IOM) from algal blooms, is widely accepted as essential precursors of disinfection byproducts (DBPs). This study evaluated the effect of ozonation or ozone combined with activated carbon (O₃-AC) treatment on characteristic alternation and DBP formation with subsequent chlorination of Chlorella sp.. The effects of pH and bromide concentration on DBP formation by ozonation or O₃-AC treatment were also investigated. Results showed that the potential formation of DBPs might be attributed to ozonation, but these DBP precursors could be further removed by activated carbon (AC) treatment. Moreover, the formation of target DBPs was controlled at acidic pH by alleviating the reactions between chlorine and AOM. Besides, the bromide substitution factor (BSF) value of trihalomethanes (THMs) from EOM and IOM remained constant after AC treatment. However, THM precursors could be significantly decreased by AC treatment. The above results indicated that O₃-AC was a feasible treatment method for algal-impacted water.     

Biodegradation of 2-ethylhexyl-4-methoxycinnamate in river sediments and its impact on microbial communities

Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms, but little is known about their biodegradation in river sediments and their impact on microorganisms. We have set up the sterile and microbiological systems in the laboratory, adding 2-ethylhexyl-4-methoxycinnamate (EHMC), one of organic UV filters included in the list of high yield chemicals, at concentrations of 2, 20 and 200 μg/L, and characterized the microbial community composition and diversity in sediments. Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system (3.49 days) was much shorter than that in the sterile system (7.55 days). Two potential degradation products, 4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system. Furthermore, high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi, Acidobacteria, Bacteroidetes and Nitrospirae; Eukaryota_uncultured fungus dominated the sediment fungal assemblages. Correlation analysis demonstrated that two bacterium genera (Anaerolineaceae_uncultured and Burkholderiaceae_uncultured) were significantly correlated with the biodegradation of EHMC. These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities, which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.