阿卡波糖生产废水的光催化降解工艺研究

在实验室用溶胶-凝胶法合成一种复合光催化剂,以难生化降解的阿卡波糖废水作为降解对象,研究经光催化降解后的废水,对后续生化装置的影响。     

茂名单点系泊系统接卸超巨型油轮的安全论证

通过对30×104t级巨型油轮的吃水深度以及茂名单点系泊缆绳、锚链强度的计算,分析了茂名单点系泊系统接卸30×104t级油轮的安全可靠性.     

Short-term physiological responses to a severe acid stress in three macroinvertebrate species: a comparative study

The present study focuses on the sensitivity among freshwater invertebrate species to acidic stress. Three common macroinvertebrate species in the Vosges Mountains (North-Eastern France), Gammarus fossarum (Amphipoda), Hydropsyche pellucidula (Trichoptera) and Dinocras cephalotes (Plecoptera) were exposed for 24, 72 and 120 h to natural acidified water (pH=4.73+/-0.08, [Ca2+]=39.1+/-0.6 micromol l(-1), [Al(tot)]=28.4+/-1 micromol l(-1)). Short-term exposure to acid stress caused significant decreases both in survival rate and haemolymph ions ([Cl-] and [Na+]). The relative sensitivity to a natural acidic stress slightly differed among the species and was in the following order: G. fossarum, as the most sensitive, then H. pellucidula and D. cephalotes. Results of this study confirm the interest of in situ tests to assess the toxicity of short-term acid exposure. Finally, our results reinforce the hypothesis that transient acidification can offset the recovery of sensitive species of macroinvertebrates in streams chemically recovering from acidification either through liming or declining deposition.     

Freedom Space for Rivers: A Sustainable Management Approach to Enhance River Resilience

River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contrasted rivers in Quebec (Canada). Mobility and flooding spaces are determined for the three rivers, and three levels of “freedom space” are subsequently defined based on the combination of the two spaces. The first level of freedom space includes very frequently flooded and highly mobile zones over the next 50 years, as well as riparian wetlands. It provides the minimum space for both fluvial and ecological functionality of the river system. On average for the three studied sites, this minimum space was approximately 1.7 times the channel width, but this minimum space corresponds to a highly variable width which must be determined from a thorough hydrogeomorphic assessment and cannot be predicted using a representative average. The second level includes space for floods of larger magnitude and provides for meanders to migrate freely over a longer time period. The last level of freedom space represents exceptional flood zones. We propose the freedom space concept to be implemented in current river management legislation because it promotes a sustainable way to manage river systems, and it increases their resilience to climate and land use changes in comparison with traditional river management approaches which are based on frequent and spatially restricted interventions.     

Perfluoroalkyl substances in the Lingang hybrid constructed wetland,Tianjin, China: occurrence,distribution characteristics,and ecological risks

Environmental Science and Pollution Research - In this study, the occurrence, spatial distribution, sources, and ecological risks of perfluoroalkyl substances (PFASs) in the surface waters of the...     

Carbon price impacts on sector cost:based on an input-output model of Beijing

Under the pressure of sustained growth in energy consumption in China,the implementation of a carbon pricing mechanism is an effective economic policy measure for promoting emission reduction,as well as a hotspot of research among scholars and policy makers.In this paper,the effects of carbon prices on Beijing’s economy are analyzed using input-output tables.The carbon price costs are levied in accordance with the products’embodied carbon emission.By calculation,given the carbon price rate of 10 RMB/t-CO₂,the total carbon costs of Beijing account for approximately 0.22-0.40%of its gross revenue the same year.Among all industries,construction bears the largest carbon cost Among export sectors,the coal mining and washing industry has much higher export carbon price intensity than other industries.Apart from traditional energy-intensive industries,tertiary industry,which accounts for more than 70%of Beijing’s economy,also bears a major carbon cost because of its large economic size.However,from 2007 to 2010,adjustment of the investment structure has reduced the emission intensity in investment sectors,contributing to the reduction of overall emissions and carbon price intensity.     

Corrective measures based on pressure control strategies for CO2 geological storage in deep aquifers

A prerequisite to the wide deployment at an industrial scale of CO₂ geological storage is demonstrating that potential risks can be efficiently managed. Corrective measures in case of significant irregularities, such as CO₂ leakage, are hence required as advocated by the recent European directive on Carbon Capture and Storage operations. In this regard, the objective of the present paper is to investigate four different corrective measures aiming at controlling the overpressure induced by the injection operations in the reservoir: stopping the CO₂ injection and relying on the natural pressure recovery in the reservoir; extracting the stored CO₂ at the injection well; extracting brine at a distant well while stopping the CO₂ injection, and extracting at a distant well without stopping the CO₂ injection. The efficiency of the measures is assessed using multi-phase fluid flow numerical simulations. The application case is the deep carbonate aquifer of the Dogger geological unit in the Paris Basin. A comparative study between the four corrective measures is then carried using a cost-benefit approach. Results show that an efficient overpressure reduction can be achieved by simply shutting-in the well. The overpressure reduction can be significantly accelerated by means of fluid extraction but the adverse consequences are the associated higher costs of the intervention operations.