Systematic review and meta-analysis of studies between short-term exposure to ambient carbon monoxide and non-accidental,cardiovascular, and respiratory mortality in China

Environmental Science and Pollution Research - Although a growing number of original epidemiological studies imply a link between ambient pollution exposure and mortality risk, the findings...     

Disturbed boundaries extraction in coal–grain overlap areas with high groundwater levels using UAV-based visible and multispectral imagery

Environmental Science and Pollution Research - With high groundwater levels, coal–grain overlap areas (CGOAs) are vulnerable to subsidence and water logging during mining activities, thereby...     

Fractionation analysis and risk assessment of potential toxic elements in reservoir sediments in central China

Environmental Science and Pollution Research - The pollution of potential toxic elements (PTEs) in the environment is a persistent issue and draws public attention constantly. However, there is no...     

Study on dust–gas coupling pollution law and selection of optimal purification distance of air duct during tunneling process

During the excavation of high gas mine, gas and dust often exist at the same time. In order to ensure that the gas concentration remains within a safe range and minimize the risk of workers’ pneumoconiosis, we simulated the interaction mechanism of airflow, gas, and dust, explored the pollution law of gas and dust, and obtained the optimal purification distance (L_p) by the CFD method. The reliability of the numerical simulation was verified by field measurements. Firstly, the properties of the gas and dust affected the structure of the airflow field. At the same time, the change in the airflow field affected the concentration distributions of the gas and dust. During the diffusion process, some high-risk regions in which the gas or dust concentrations exceeded 0.80% or 200 mg/m³, respectively, were discovered. Moreover, we have found that the airflow velocity in the top region of the tunnel and at the intersection corner between the cutting face and tunnel wall was the main factor affecting the purification effects. When L_p = 5–8 m, the gas concentration remained below 0.50%. When L_p = 6 m, the dust concentration reached a minimum of 287.5 mg/m³. Therefore, the optimal purification distance was determined to be 6 m; in which case, the gas and dust concentrations decreased by 32.84% and 47.02%, respectively.

     

Chemical and colloidal analyses of natural seep water collected from the exploratory studies facility inside Yucca Mountain,Nevada, USA

Yucca Mountain is being considered as a geological repository for the USA’s spent nuclear fuel and high-level nuclear waste. Numerous groundwater seeps appeared during March 2005 within the exploratory studies facility (ESF), a tunnel excavated in the mountain. Because of the relevance to radionuclide transport and unsaturated zone-modeling studies, we analyzed the seep samples for major anions and cations, rare earth elements, and colloids. Major ion species and elemental concentrations in seep samples reflect interaction of the water with the volcanic rock and secondary calcites. Elemental fractograms from flow-injection field-flow fractionation ICP–MS scans detected Br, Ca, Cl, Cu, Fe, I, Mg, Si, Sr, W, and U at void fractions, suggesting they may be present in the form of dissolved anions. Colloids approximately 10 nm in hydrodynamic diameter, possibly calcite, were also present in the seepage samples. Geochemical calculations indicate, however, these may be an artifact (not present in the groundwater) which arose because of loss of CO₂ during sample collection and storage.     

Biological hydrogen production from organic wastewater by dark fermentation in China: Overview and prospects

Biological hydrogen production by dark fermentation is an important part of biological hydrogen production technologies. China is a typical developing country that heavily relies on fossil fuels; thus, new, clean, and sustainable energy development turns quite urgent. It is delightful that Chinese government has already drawn up several H₂ development policies since 1990s and provided financial aid to launch some H₂ development projects. In this paper, the research status on dark fermentative hydrogen production in China was summarized and analyzed. Subsequently, several new findings and achievements, with some of which transformed into scale-up tests, were highlighted. Moreover, some prospecting coupling processes with dark fermentation of hydrogen production were also proposed to attract more research interests in the future.     

Seasonal variation of nitrogen and phosphorus in Xiaojiang River—A tributary of the Three Gorges Reservoir

A yearlong monitoring program in the backwater area of Xiaojiang River (XBA) was launched in order to investigate the eutrophication of backwater areas in tributaries of the Yangtze River in the Three Gorges Reservoir (TGR) in China, starting after the impoundment water level of the TGR reached 156 m. From March 2007 to March 2008, the average concentration of total nitrogen (TN) and total phosphorus (TP) were (1553±484) μg·L^?1 and (62±31) μg·L^?1, respectively. The mean value of chlorophyll was (9.07±0.91) μg·L^?1. The trophic level of XBA was meso-eutrophic, while the general nutrient limitation was phosphorus. The results indicated that XBA has a strong ability to purify itself and has non-point source pollution from terrestrial runoff. The variation of TN/TP ratio was caused by a variation in TN rather than in TP when TN/TP < 22. N-fixation from cyanobacteria occurred and became an important process in overcoming the nitrogen deficit under a low TN/TP ratio. When TN/TP ? 22, the variation of TP affected the TN/TP ratio more significantly than TN. The increase of TP in XBA was caused mainly by particulate phosphorus, which could originate from a non-point source as adsorptive inorganic forms after heavy rainfall and surface runoff. An increase in the river’s flow could also contribute to an unstable environment for the growth of phytoplankton.     

构建“水-煤-碳”体系 优化煤化工发展

分析了煤化工行业发展的现状及趋势,提出我国现代煤化工发展瓶颈主要是产业发展存在技术风险、产业发展与资源环境的矛盾突出及面临碳减排压力,并提出通过合理构建"水-煤-碳"三大约束指标体系,引导煤化工实现有序发展。     

化学还原法在Cr污染土壤修复中的应用

综述了Cr的地球化学特性和毒理学特性、化学还原反应机理和作用特点,分析了原位和异位化学还原法在Cr污染土壤修复中的应用,并对技术的工程实践提出建议.     

当前企业职工的违章心态及对策

分析指出了职工违章的心态 ,并提出了解决措施