Emission source-based ozone isopleth and isosurface diagrams and their significance in ozone pollution control strategies

In the past decade, ozone (O₃) pollution has been continuously worsening in most developing countries. The accurate identification of the nonlinear relationship between O₃ and its precursors is a prerequisite for formulating effective O₃ control measures. At present, precursor-based O₃ isopleth diagrams are widely used to infer O₃ control strategy at a particular location. However, there is frequently a large gap between the O₃-precursor nonlinearity delineated by the O₃ isopleths and the emission source control measures to reduce O₃ levels. Consequently, we developed an emission source-based O₃ isopleth diagram that directly illustrates the O₃ level changes in response to synergistic control on two types of emission sources using a validated numerical modeling system and the latest regional emission inventory. Isopleths can be further upgraded to isosurfaces when co-control on three types of emission sources is investigated. Using Guangzhou and Foshan as examples, we demonstrate that similar precursor-based O₃ isopleths can be associated with significantly different emission source co-control strategies. In Guangzhou, controlling solvent use emissions was the most effective approach to reduce peak O₃ levels. In Foshan, co-control of on-road mobile, solvent use, and fixed combustion sources with a ratio of 3:1:2 or 3:1:3 was best to effectively reduce the peak O₃ levels below 145 ppbv. This study underscores the importance of using emission source-based O₃ isopleths and isosurface diagrams to guide a precursor emission control strategy that can effectively reduce the peak O₃ levels in a particular area.     

关于“五水共治”的若干法律问题的思考

水的经济价值和生态价值对人类社会的发展起到了决定性的作用。随着农业发展和工业进步,水资源匮乏,生活用水不洁净等引发的水危机已经不断地引发社会矛盾。为此浙江省提出了“治污水、防洪水、排涝水、保供水、抓节水———‘五水共治’”的目标,明确了地方政府的责任与义务,但治理效果并不乐观。环保法的修订为“五水共治”提供了坚实的理论基础,并从确立全流域综合生态管理、建立水体保护的综合协调机制等方面提出了浙江省水资源治理策略。     

Non-targeted metabolomics reveals the stress response of a cellulase-containing penicillium to uranium

Human industrial activities have caused environmental uranium (U) pollution, resulting in uranium(VI) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characterized by X-ray fluorescence (XRF), and Fourier transform infrared reflection (FT-IR), as well as by GC/MS metabolomics analysis, to study the response to uranium(VI) stress. The biomass of Penicillium decreased after exposure to 100 mg/L U. Uranium combined with carboxyl groups, amino groups, and phosphate groups to form uranium mineralized deposits on the surface of this fungal strain. The α-activity concentration of uranium in the strain was 2.57×10⁶ Bq/kg, and the β-activity concentration was 2.27×10⁵ Bq/kg. Metabolomics analysis identified 118 different metabolites, as well as metabolic disruption of organic acids and derivatives. Further analysis showed that uranium significantly affected the metabolism of 9 amino acids in Penicillium. These amino acids were related to the TCA cycle and ABC transporter. At the same time, uranium exhibited nucleotide metabolism toxicity to Penicillium. This study provides an in-depth understanding of the uranium tolerance mechanism of Penicillium and provides a theoretical basis for Penicillium to degrade hyper-enriched plants.     

Reagent elution combined with positive pressure filtration: A zero-discharge method for cyanide tailings remediation

At present, the cyanide gold extraction process is still the main technology for gold production. Generated cyanide tailings containing highly toxic substances exhibit potential environmental risks. These tailings are in urgent need of purification treatment, especially after being classified as hazardous waste. In this study, the impacts of elution methods, operating time, tailings/water ratios, reagent types on the elution rates of cyanide were investigated. Furthermore, the composite elution ...     

Mercury accumulation and dynamics in montane forests along an elevation gradient in Southwest China

Understanding atmospheric mercury (Hg) accumulation in remote montane forests is critical to assess the Hg ecological risk to wildlife and human health. To quantify impacts of vegetation, climatic and topographic factors on Hg accumulation in montane forests, we assessed the Hg distribution and stoichiometric relations among Hg, carbon (C), and nitrogen (N) in four forest types along the elevation of Mt. Gongga. Our results show that Hg concentration in plant tissues follows the descending order of litter > leaf, bark > root > branch > bole wood, indicating the importance of atmospheric Hg uptake by foliage for Hg accumulation in plants. The foliar Hg/C (from 237.0 ± 171.4 to 56.8 ± 27.7 µg/kg) and Hg/N (from 7.5 ± 3.9 to 2.5 ± 1.2 mg/kg) both decrease along the elevation. These elevation gradients are caused by the heterogeneity of vegetation uptake of atmospheric Hg and the variation of atmospheric Hg° concentrations at different altitudes. Organic soil Hg accumulation is controlled by forest types, topographic and climatic factors, with the highest concentration in the mixed forest (244.9 ± 55.7 µg/kg) and the lowest value in the alpine forest (151.9 ± 44.5 µg/kg). Further analysis suggests that soil Hg is positively correlated to C (r² = 0.66) and N (r² = 0.57), and Hg/C and Hg/N both increase with the soil depth. These stoichiometric relations highlight the combined effects from environmental and climatic factors which mediating legacy Hg accumulation and selective Hg absorption during processes of organic soil mineralization.     

Urinary concentrations of phenols, oxidative stress biomarkers and thyroid cancer: Exploring associations and mediation effects

Phenols have been shown to influence the cellular proliferation and function of thyroid in experimental models. However, few human studies have investigated the association between phenol exposure and thyroid cancer, and the underlying mechanisms are also poorly understood. We conducted a case-control study by age- and sex-matching 143 thyroid cancer and 224 controls to investigate the associations between phenol exposures and the risk of thyroid cancer, and further to explore the mediating role of oxidative stress. We found that elevated urinary triclosan (TCS), bisphenol A (BPA) and bisphenol S (BPS) levels were associated with increased risk of thyroid cancer (all P for trends < 0.05), and the adjusted odds ratios (ORs) comparing the extreme exposure groups were 3.52 (95% confidence interval (CI): 2.08, 5.95), 2.06 (95% CI: 1.06, 3.97) and 7.15 (95% CI: 3.12, 16.40), respectively. Positive associations were also observed between urinary TCS, BPA and BPS and three oxidative stress biomarkers measured by 8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F_2α (8-isoPGF_2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), as well as between urinary 8-isoPGF_2α and HNE-MA and the risk of thyroid cancer. Mediation analysis showed that urinary 8-isoPGF_2α mediated 28.95%, 47.06% and 31.08% of the associations between TCS, BPA and BPS exposures and the risk of thyroid cancer, respectively (all P < 0.05). Our results suggest that exposure to TCS, BPA and BPS may be associated with increased risk of thyroid cancer and lipid peroxidation may be an intermediate mechanism. Further studies are warranted to confirm the findings.     

Fine particulate matter (PM2.5/PM1.0) in Beijing, China: Variations and chemical compositions as well as sources

Particulate matter (i.e., PM_1.0 and PM_2.5), considered as the key atmospheric pollutants, exerts negative effects on visibility, global climate, and human health by associated chemical compositions. However, our understanding of PM and its chemical compositions in Beijing under the current atmospheric environment is still not complete after witnessing marked alleviation during 2013–2017. Continuous measurements can be crucial for further air quality improvement by better characterizing PM pollution and chemical compositions in Beijing. Here, we conducted simultaneous measurements on PM in Beijing during 2018–2019. Results indicate that annual mean PM_1.0 and PM_2.5 concentrations were 35.49 ± 18.61 µg/m³ and 66.58 ± 60.17 µg/m³, showing a positive response to emission controls. The contribution of sulfate, nitrate, and ammonium (SNA) played an enhanced role with elevated PM loading and acted as the main contributors to pollution episodes. Discrepancies observed among chemical species between PM_1.0 and PM_2.5 in spring suggest that sand particles trend to accumulate in the range of 1–2.5 µm. Pollution episodes occurred accompanied with southerly clusters and high formation of SNA by heterogeneous reactions in summer and winter, respectively. Results from positive matrix factorization (PMF) combined with potential source contribution function (PSCF) models showed that potential areas were seasonal dependent, secondary and vehicular sources became much more important compared with previous studies in Beijing. Our study presented a continuous investigation on PM and sources origins in Beijing, which provides a better understanding for further emission control as well as a reference for other cities in developing countries.     

Highly Oriented Thermoplastic Poly (vinyl alcohol) Films by Uniaxial Drawing: Effect of Stretching Temperature and Draw Ratio

Journal of Polymers and the Environment - With the advantages of excellent processability and biodegradability, polyvinyl alcohol (PVA) becomes an environmentally friendly and biocompatible...     

Response of activity and community composition of nitrite-oxidizing bacteria to partial substitution of chemical fertilizer by organic fertilizer

Environmental Science and Pollution Research - Nitrite oxidation as the second step of nitrification can become the determining step in disturbed soil systems. As a beneficial fertilization...     

省级环境管理部门基础信息网络建设实践与思考

阐述省级环境管理部门基础信息网络建设的重要性及建设应遵循的基本要求,结合实践,讨论设计和实际施工中出现的问题及解决办法,为环境管理部门基础信息网络建设提供有益参考。