膜生物法降解TNT弹药销毁废水的重要影响因素

采用水解酸化一好氧膜生物工艺对弹药销毁废水中TNT进行降解试验研究。结果表明,共代谢外加碳源对TNT的生物降解影响显著。无共代谢外加碳源的情况下,HRT=40h,TNT的去除率仅为53．4％。有共代谢外加碳源的情况下,外加碳源COD与TNT提供COD比值宜大于4．8,系统对TNT的去除率可高达99％。温度对水解酸化影响重大,当温度低于15℃时,水解酸化对TNT去除率低于33．3％,而当温度高于20℃时,水解酸化对TNT的去除率不小于83％。     

Study on the co-combustion process and mercury emission characteristics of sewage sludge-coal slime coupled fuel

Journal of Material Cycles and Waste Management - To realize the clean and efficient resource utilization of sewage sludge (SS) and coal slime (CS), single-component and coupled fuels were...     

市政脱水污泥的间接干化动力学研究

以食用油为热介质,在不同油浴温度下,对市政脱水污泥进行间接干化试验,推导出间接干化动力学模型,并对收集的冷凝液进行水质分析。结果表明:冷凝液为高浓度有机废水,TOC占TC的比例为73.2010%~75.5983%;VFAs的主要组分是乙酸、丙酸、丁酸、异丁酸、异戊酸和正戊酸,其中异丁酸所占比例最高(45.597%),其次为丙酸(24.554%);通过动力学模型的参数估值,Z模型(n≠1)因高R~2值和低RSS值而能很好的预测间接干化过程。     

Air pollution and hospital visits for acute upper and lower respiratory infections among children in Ningbo,China: A time-series analysis

Acute upper and lower respiratory infections are main causes of mortality and morbidity in children. Air pollution has been recognized as an important contributor to development and exacerbation of respiratory infections. However, few studies are available in China. In this study, we investigated the short-term effect of air pollution on hospital visits for acute upper and lower respiratory infections among children under 15 years in Ningbo, China. Poisson generalized models were used to estimate the associations between air pollution and hospital visits for acute upper and lower respiratory infections adjusted for temporal, seasonal, and meteorological effects. We found that four pollutants (PM_2.5, PM₁₀, NO₂, and SO₂) were significantly associated with hospital visits for acute upper and lower respiratory infections. The effect estimates for acute upper respiratory infections tended to be higher (PM_2.5 ER = 3.46, 95% CI 2.18, 4.76; PM₁₀ ER = 2.81, 95% CI 1.93, 3.69; NO₂ ER = 11.27, 95% CI 8.70, 13.89; SO₂ ER = 15.17, 95% CI 11.29, 19.19). Significant associations for gaseous pollutants (NO₂ and SO₂) were observed after adjustment for particular matter. Stronger associations were observed among older children and in the cold period. Our study suggested that short-term exposure to outdoor air pollution was associated with hospital visits for acute upper and lower respiratory infections in Ningbo.     

GIS支持下的锡林郭勒盟旱灾救灾区划初探

基于自然灾害系统理论,构建内蒙古锡林郭勒盟的旱灾评价系统模式,表明灾情是致灾因子、孕灾环境和承灾体综合作用的产物。以锡林郭勒盟的旱灾程度、救灾等级、备灾能力（经济水平与社会状况）、应急能力（物资储备及物流通达水平）、恢复能力（恢复与重建）等重要指标为核心,对锡林郭勒盟的旱灾灾前、灾中、灾后三个阶段的响应能力进行评价与地域划分,并与锡林郭勒盟的旱灾等级区划相结合,构建了灾害-响应程度模型。     

Decomplexation of Cr(III)-EDTA and simultaneous abatement of total Cr by photo-oxidation: efficiency and in situ reduction of intermediate Cr(VI)

Environmental Science and Pollution Research - Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly...     

Single and joint oxidative stress–related toxicity of sediment-associated cadmium and lead on Bellamya aeruginosa

Environmental Science and Pollution Research - The biotoxicity of heavy metals in sediments toward benthic organisms has evoked great concern for the health of freshwater ecosystems. This study...     

Effects of SO<Subscript>2</Subscript> contamination on rising CO<Subscript>2</Subscript> drops under high pressure

Although the flow dynamics of pure liquid drops in other liquids has been well researched, little attention has been paid to the impacts of impurities. Hence, most of research is not directly applicable to the real world. To address this gap, we conducted numerical experiments simulating the rise of pure and contaminated drops. It was selected to study liquid CO₂ drops contaminated with SO₂ under high pressure because such mixtures mimic potential scenarios in which drops may leak from carbon capture and storage (CCS) facilities or pipelines. First, numerical simulation experiments were performed to validate our method by comparing our results with previous research on pure drops. Second, the validated numerical approach was applied to simulations of contaminated drops to investigate how contaminants affect rising drops. The results show that the SO₂ contamination caused changes in deformation, breakup phenomena, rising velocities, surrounding flow fields and drag coefficients. Most importantly, the contamination resulted in the formation of smaller “child drops”; such breakup is not observed in pure CO₂ drops. The formation of child drops in turn affects the streamlines, patterns and areas of wakes behind the contaminated drops. The addition of contaminants also enhances the dissolution rate, which is affected by the contaminant concentration and by the flow dynamics of the rising drop. Our results would improve understanding the rise of impure CO₂ drops, such as drops potentially leaked by future CCS operations.     

A non-negative and high-resolution finite volume method for the depth-integrated solute transport equation using an unstructured triangular mesh

This paper proposes a new high-resolution finite volume method for solving the two-dimensional (2D) solute transport equation using an unstructured mesh. A new simple r-factor algorithm is introduced into the Total Variation Diminishing flux limiter to achieve a more efficient yet accurate high-resolution scheme for solving the advection term. To avoid the physically-meaningless negative solutions resulted from using the Green–Gauss theorem, a nonlinear two-point flux approximation scheme is adopted to deal with the anisotropic diffusion term. The developed method can be readily coupled with a two-dimensional finite-volume-based flow models under unstructured triangular mesh. By integrating with the ELCIRC flow model, the proposed method was verified using three idealized benchmark cases (i.e., advection of a circle-shaped solute field, advection in a cyclogenesis flow field and transport of a initially square-shaped solute plume), and further applied to simulate the non-reactive solute transport process driven by irregular tides in the Deep Bay, eastern Pearl River Estuary of China. These cases are also simulated by models using other existing methods, including different r-factor for advection term and the Green–Gauss theorem for diffusion term. The comparison between the results from the new method and those from other existing methods demonstrated the new method could describe advection induced concentration shock and discontinuities, and anisotropic diffusion at high resolution without providing spurious oscillations and negative values.     

根表铁膜对水稻吸收转运稀土元素Ce的影响

采用溶液培养的方法探讨根表铁膜形成对水稻吸收积累和转运稀土元素Ce的影响。结果表明,Ce污染胁迫可抑制水稻根表铁膜的形成,根表铁膜吸附的Ce量随着溶液中Ce浓度的提高而增加。根表铁膜形成可降低水稻根系但提高水稻茎叶对Ce的吸收积累。当溶液中Ce浓度为0.1、0.5和1.0 mmol·L~(-1)时,铁膜诱导组水稻根系Ce含量分别比非诱导组水稻根系Ce含量降低38.60%、45.94%和32.75%,诱导组水稻茎叶Ce含量分别比非诱导组水稻茎叶Ce含量提高42.37%、28.87%和22.62%。根表铁膜形成可影响Ce在水稻植株中的富集和转运能力。非诱导组水稻根系富集Ce的能力远大于茎叶。诱导组水稻根系对Ce的富集能力最强,其次是根表铁膜,最后是水稻茎叶。诱导组水稻根系Ce转运系数显著大于非诱导组的根系,说明根表铁膜形成可促进水稻根部Ce向茎叶中转运。可见,根表铁膜对水稻吸收转运稀土元素的影响机理比较复杂。