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Did carbon dioxide emission regulations inhibit investments? A provincial panel analysis of China 全文
2018
Ge, Jianping | Lei, Yalin | Xu, Qun | Ma, Xiangrong
Investments, especially fixed asset investments, greatly affect carbon dioxide (CO₂) emissions. When investments are concentrated in regions with high CO₂ emissions and high fossil energy consumption, the CO₂ emission reduction targets in these areas are difficult to reach in the short term, and the cost of CO₂ emission abatement is high. The current CO₂ emission regulations focus on existing production activities and consumption behaviors. However, whether an investment, which may affect CO₂ emissions in the long term, is effectively inhibited by CO₂ emission regulations has not been investigated in previous studies. Using panel data from 30 provinces in China between 2003 and 2012, we tested whether the amount of provincial investment was constrained or promoted by the provincial CO₂ emission regulations by creating a panel model with provincial samples. The results revealed that CO₂ emission regulations did not inhibit the growth of an investment, but they stimulated investments to varying degrees in different provinces. A relatively positive result is that provinces with stronger CO₂ emission regulations exhibited a relatively small contribution to investment promotion, while provinces with weaker CO₂ reduction policies demonstrated a relatively large contribution to investment growth. We also found that investment was correlated with the growth rate of the gross domestic product (GDP) in the northeastern and western provinces. Finally, we proposed policy implications based on the utilization of policy tools from the perspectives of investment, energy structure, and local protectionism.
显示更多 [+] 显示较少 [-]Sustainable bioreduction of toxic levels of chromate in a denitrifying granular sludge reactor 全文
2018
Kiran Kumar Reddy, G | Nancharaiah, Y V
Biological removal of chromate [Cr(VI)] in the presence or absence of nitrate by granular sludge biofilms was investigated in batch experiments and in a sequencing batch reactor (SBR). Denitrifying granular sludge cultivated from activated sludge was able to directly reduce Cr(VI) in the presence of an electron donor. Bioreduction was dependent on the initial Cr(VI) and the granular sludge concentrations. Bioreduction of Cr(VI) was followed by Cr(III) precipitation or entrapment in the granular sludge which was corroborated with decrease in total soluble Cr and increase in inorganic content of biomass. Batch experiments revealed that Cr(VI) addition has no major influence on high-strength nitrate (3000 mg L⁻¹) denitrification, but nitrite denitrification was slowed-down. However, SBR experiment demonstrated successful denitrification as well as Cr(VI) removal due to enrichment of Cr(VI)-tolerant denitrifying bacteria. In fact, stable SBR performance in terms of complete and sustained removal of 0.05, 0.1, 0.2, 0.3, 0.5 and 0.75 mM Cr(VI) and denitrification of 3000 mg L⁻¹ was observed during 2 months of operation. Active biomass and electron donor-dependent Cr(VI) removal, detection of Cr(III) in the biomass and recovery of ~ 92% of the Cr from the granular sludge biofilms confirms bioreduction followed by precipitation or entrapment of Cr(III) as the principal chromate removal mechanism. Metagenomic bacterial community analysis showed enrichment of Halomonas sp. in denitrifying granular sludge performing either denitrification or simultaneous reduction of nitrate and chromate.
显示更多 [+] 显示较少 [-]Treatment of synthetic textile wastewater containing dye mixtures with microcosms 全文
2018
Yaseen, DinaA. | Scholz, Miklas
The aim was to assess the ability of microcosms (laboratory-scale shallow ponds) as a post polishing stage for the remediation of artificial textile wastewater comprising two commercial dyes (basic red 46 (BR46) and reactive blue 198 (RB198)) as a mixture. The objectives were to evaluate the impact of Lemna minor L. (common duckweed) on the water quality outflows; the elimination of dye mixtures, organic matter, and nutrients; and the impact of synthetic textile wastewater comprising dye mixtures on the L. minor plant growth. Three mixtures were prepared providing a total dye concentration of 10 mg/l. Findings showed that the planted simulated ponds possess a significant (p < 0.05) potential for improving the outflow characteristics and eliminate dyes, ammonium-nitrogen (NH₄-N), and nitrate-nitrogen (NO₃-N) in all mixtures compared with the corresponding unplanted ponds. The removal of mixed dyes in planted ponds was mainly due to phyto-transformation and adsorption of BR46 with complete aromatic amine mineralisation. For ponds containing 2 mg/l of RB198 and 8 mg/l of BR46, removals were around 53%, which was significantly higher than those for other mixtures: 5 mg/l of RB198 and 5 mg/l of BR46 and 8 mg/l of RB198 and 2 mg/l of BR46 achieved only 41 and 26% removals, respectively. Dye mixtures stopped the growth of L. minor, and the presence of artificial wastewater reduced their development.
显示更多 [+] 显示较少 [-]Hemochromatosis: a model of metal-related human toxicosis 全文
2018
Brissot, Pierre | Cavey, Thibault | Ropert, Martine | Gaboriau, François | Loréal, Olivier
Many environmental agents, such as excessive alcohol intake, xenobiotics, and virus, are able to damage the human body, targeting especially the liver. Metal excess may also assault the liver. Thus, chronic iron overload may cause, especially when associated with cofactors, diffuse organ damage that is a source of significant morbidity and mortality. Iron excess can be either of acquired (mostly transfusional) or of genetic origin. Hemochromatosis is the archetype of genetic iron overload diseases and represents a serious health problem. A better understanding of iron metabolism has deeply modified the hemochromatosis field which today benefits from much more efficient diagnostic and therapeutic approaches.
显示更多 [+] 显示较少 [-]Environmental genotoxicity and risk assessment in the Gulf of Riga (Baltic Sea) using fish, bivalves, and crustaceans 全文
2018
Butrimavičienė, Laura | Baršienė, Janina | Greiciūnaitė, Janina | Stankevičiūtė, Milda | Valskienė, Roberta
Environmental genotoxicity in the Gulf of Riga was assessed using different bioindicators (fish, clams, and isopods) collected from 14 study stations. Comparison of genotoxicity responses (micronuclei (MN) and nuclear buds (NB)) in blood erythrocytes of herring (Clupea harengus), eelpout (Zoarces viviparous), and flounder (Platichthys flesus) revealed the species- and site-specific differences. For the first time, the analysis of genotoxicity was carried out in gill cells of isopods Saduria entomon. The highest inductions of MN and NB in gill cells of investigated S. entomon and clams (Macoma balthica) were evaluated in specimens from station 111A (offshore zone). In fish, the highest incidences of MN were measured in eelpout and in herring collected in the southern part of Gulf of Riga (station GOR3/41S). Moreover, in the southern coastal area, the assessment of genotoxicity risk (according to micronuclei levels) indicated exceptionally high risk for flounder, eelpout, and clams.
显示更多 [+] 显示较少 [-]Kinetic and isothermal adsorption-desorption of PAEs on biochars: effect of biomass feedstock, pyrolysis temperature, and mechanism implication of desorption hysteresis 全文
2018
Jing, Fanqi | Pan, Minjun | Chen, Jiawei
Biochar has the potential to sequester biomass carbon efficiently into land, simultaneously while improving soil fertility and crop production. Biochar has also attracted attention as a potential sorbent for good performance on adsorption and immobilization of many organic pollutants such as phthalic acid esters (PAEs), a typical plasticizer in plastic and presenting a current environmental issue. Due to lack of investigation on the kinetic and thermodynamic adsorption-desorption of PAEs on biochar, we systematically assessed adsorption-desorption for two typical PAEs, dimethyl phthalate (DMP) and diethyl phthalate (DEP), using biochar derived from peanut hull and wheat straw at different pyrolysis temperatures (450, 550, and 650 °C). The aromaticity and specific surface area of biochars increased with the pyrolysis temperature, whereas the total amount of surface functional groups decreased. The quasi-second-order kinetic model could better describe the adsorption of DMP/DEP, and the adsorption capacity of wheat straw biochars was higher than that of peanut hull biochars, owing to the O-bearing functional groups of organic matter on exposed minerals within the biochars. The thermodynamic analysis showed that DMP/DEP adsorption on biochar is physically spontaneous and endothermic. The isothermal desorption and thermodynamic index of irreversibility indicated that DMP/DEP is stably adsorbed. Sorption of PAEs on biochar and the mechanism of desorption hysteresis provide insights relevant not only to the mitigation of plasticizer mobility but also to inform on the effect of biochar amendment on geochemical behavior of organic pollutants in the water and soil.
显示更多 [+] 显示较少 [-]Assessment of Lemna minor (duckweed) and Corbicula fluminea (freshwater clam) as potential indicators of contaminated aquatic ecosystems: responses to presence of psychoactive drug mixtures 全文
2018
Bourioug, Mohamed | Mazzitelli, Jean-Yves | Marty, Pierre | Budzinski, Hélène | Aleya, Lotfi | Bonnafé, Elsa | Geret, Florence
The pharmaceutical products are emerging pollutants continuously released into the environment, because they cannot be effectively removed by the wastewater treatment plants. In recent years, questions have been raised concerning the environmental risks related to these pollutants. The goal of this research was to evaluate the responses in Lemna minor after 7 days and in Corbicula fluminea after differing durations (1, 3, 7, and 19 days) of exposure to the psychoactive drug mixture (valproic acid, citalopram, carbamazepine, cyamemazine, hydroxyzine, oxazepam, norfluoxetine, lorazepam, fluoxetine, and sertraline) in different concentrations (0, 0 + ethanol, drug concentration (DC) 1 = river water concentration, DC2 = effluent concentration, and DC3 = 10× effluent concentration). In this aim, growth parameters of L. minor, gluthathione S-transferase (GSTs), catalase (CAT), ethoxyresorufin-O-deethylase (EROD) and/or gene expressions (pi-gst, cat, cytochrome P450 4 (cyp4), multidrug resistant 1 (mdr1), and superoxide dismutase (sod)) were measured. GST activities increased significantly in L. minor exposed to DC3, but no changes were found in CAT activity. In C. fluminea, EROD activity was induced significantly in both gill and digestive gland tissues after 3 days’ exposure to DC3, while a GST increase was observed only in digestive gland tissues, suggesting that these pharmaceuticals induced an oxidative effect. Gene expression analysis revealed transient transcriptomic responses of cyp4, sod, and mdr1 under drug concentrations 2 or 3 and no change of expression for the other genes (cat and pi-gst) or condition (environmental drug concentration) tested. Finally, the data reported in this study represent important ecotoxicological information, confirming that this enzyme family (cyp4, sod, and mdr1) may be considered as a sensible and early indicator of exposure to drugs and emphasizing the involvement of selected genes in detoxification pathways.
显示更多 [+] 显示较少 [-]Soil physical properties response to tillage practices during summer fallow of dryland winter wheat field on the Loess Plateau 全文
2018
Xue, Jian-Fu | Ren, Ai-Xia | Li, Hui | Gao, Zhi-Qiang | Du, Tian-Qing
Soil physical properties are a greatly important part of the soil and indicator of soil quality, which can directly affect soil nutrient turnover and crop yields in dryland. This study was carried out with three tillage practices during the summer fallow season since 2011, including no tillage (NT), plow tillage (PT), and subsoiling (ST) in dryland winter wheat fields of the Loess Plateau. Results showed that soil tillage during the summer fallow had a small effect on soil bulk density (ρ b) in the 0–50-cm soil profile before sowing and after harvesting of winter wheat. Soil ρ b under NT at a depth of 20–30 cm was significantly greater than those under PT in both seasons. Both soil gravimetric water content (θ g) and volumetric moisture content (θ ᵥ) after harvesting increased by 28.8–78.6% and 37.5–87.3%, respectively, compared with those before sowing. Adoption of PT significantly increased soil θ g and θ ᵥ in the entire 0–50-cm profile before sowing compared with NT and ST (P < 0.05). In addition, there was a small effect on soil porosity (e.g., total porosity, air-filled porosity, and capillary porosity) in the profile of 0–50 cm both before sowing and after harvesting. Overall, short-term tillage during summer fallow mainly affected soil water content in the 0–50-cm soil profile, and it had a slight effect on other physical soil properties.
显示更多 [+] 显示较少 [-]The hierarchical porous structure bio-char assessments produced by co-pyrolysis of municipal sewage sludge and hazelnut shell and Cu(II) adsorption kinetics 全文
2018
Zhao, Bing | Xu, Xinyang | Zeng, Fanqiang | Li, Haibo | Chen, Xi
The co-pyrolysis technology was applied to municipal sewage sludge (MSS) and hazelnut shell with alkaline activating agent K₂CO₃ under N₂ atmosphere. The innovative bio-char produced by co-pyrolysis had significant physical and chemical characteristics. The specific surface area reached 1990.23 m²/g, and the iodine absorption number was 1068.22 mg/g after co-pyrolysis at 850 °C. Although hazelnut shell was a kind of solid waste, it also had abundant cellulose resource, which could contribute to porous structure of bio-char during co-pyrolysis with MSS and decrease total heavy metals contents of raw material to increase security of bio-chars. Meanwhile, the residual fractions of heavy metals in bio-char were above 92.95% after co-pyrolysis at 900 °C except Cd to prevent heavy metals digestion, and the bio-char presented significant immobilization behavior from co-pyrolysis technology. Moreover, the yield and the iodine absorption number of bio-chars under different process variables were analyzed, and it was confirmed that appropriate process variables could contribute the yield and the iodine absorption number of bio-char and prevent to etch pore structure excessively to collapse. The changes of surface functional groups and crystallographic structure before and after co-pyrolysis were analyzed by FTIR and XRD, respectively. The hierarchical porous structure of bio-char was presented by SEM and N₂ adsorption-desorption isotherm. The Cu(II) adsorption capacity of the bio-char was 42.28 mg/g after 24 h, and surface functional groups acted as active binding sites for Cu(II) adsorption. Langmuir model and pseudo-second-order model can describe process of Cu(II) adsorption well.
显示更多 [+] 显示较少 [-]User preferences and water use savings owing to washbasin taps retrofit: a case study of the DECivil building of the University of Aveiro 全文
2018
Meireles, Inês | Sousa, Vítor | Adeyeye, Kemi | Silva-Afonso, Armando
During the last decades, achieving water efficiency in buildings has increasingly become an important challenge in the scope of sustainability. Water consumption is directly related to individual conduct. Despite the various technological improvements in fixtures and appliances, their performance will be influenced by human preferences and behavior. As a result, the potential for effective water consumption saving is influenced by behavior change as well as water-efficient fixtures and appliances. This work evaluates the impact of user preferences and behavior change on the water-efficient performance of tap aerators in a case study building: the Department of Civil Engineering building of the University of Aveiro, Portugal. Four aerators with different discharge reductions and types were installed in the toilet’s washbasins and the user’s preferences and behavior change measured through direct and online questionnaires. It was observed that the effective water consumption reduction (15 to 49%) was less than the discharge reduction (30 to 70%), confirming that user factors influence water savings. Water use reductions in the tested range (2.0 to 6.7 l/min) also varied according to gender, with male users using less water than their female counterparts. It was noted that an awareness of sustainability values prevailed amongst the users when confronted with the choice between comfort and water efficiency, although differences were observed in the user preferences regarding the various aerators. When confronted with the information that the lower discharge aerator would contribute to a reduction of about 70% on the water discharge, 25% of the users agreed with its use, even if it resulted in a certain degree of dissatisfaction. In comparison, only 8% of the users completely disagreed with its installation. On average, the water consumption reduction was 46% smaller than the discharge reduction achievable with the aerator alone. This further confirms the user factors inform the degree of water savings that is achievable from water-efficient fittings and fixtures.
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