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Natural disasters, climate change, and their impact on inclusive wealth in G20 countries Texto completo
2019
Fang, Jianchun | Lau, Chi Keung Marco | Lü, Zhou | Wu, Wanshan | Zhu, Lili
This paper uses the 1990–2010 natural disaster and carbon emission data of G20 countries to examine the impact of natural disasters and climate change on the natural capital component of inclusive wealth. Our study shows that climate change and GDP have no positive impacts on the growth of natural capital. By contrast, trade openness and natural disaster frequency contribute to the accumulation of natural capital in G20 countries. There is an inverted U-shaped relationship between the growth of natural capital and the magnitude of natural disaster. Natural capital growth is not affected very much by small disasters. By contrast, large disasters tend to make the growth of natural capital fall sharply.
Mostrar más [+] Menos [-]Correction to: Operator decision support system for integrated wastewater management including wastewater treatment plants and receiving water bodies Texto completo
2019
Kim, Minsoo | Kim, Yejin | Kim, Hyosoo | Piao, Wenhua | Kim, Changwon
The original corresponding authorship was transferred from Changwon Kim to Yejin Kim by Changwon Kim’s request. All the authors agreed to that.
Mostrar más [+] Menos [-]Decomposition analysis of energy-related CO2 emission in the industrial sector of China: Evidence from the LMDI approach Texto completo
2019
Fatima, Tehreem | Xia, Enjun | Cao, Zhe | Khan, Danish | Fan, Jing-Li
Energy consumption and increasing CO₂ emissions in China are mainly indorsed to the industrial sector. The objective of this study was to explore the main factors driving CO₂ emissions in China’s industry throughout 1991–2016. Based on the log-mean Divisia index (LMDI) method, this study decomposes the change of industry-related CO₂ emissions into energy structure effect, income effect, energy intensity effect, carbon emission, and labor effect. The core results indicate that CO₂ emissions in China’s industry experienced a significant increase from 738.5 to 7271.8 Mt during 1991–2013, while it decreased to 6844.0 Mt in 2016. The income effect and labor effect are the top two emitters, which accounted for increases of 351.8 Mt and 57.8 Mt in CO₂ emissions respectively. Additionally, the energy structure effect also played a role in increasing CO₂ emissions. Energy intensity and carbon emission effects are the most important factors in reducing CO₂ emissions. The policy suggestions about the different period-wise analyses in terms of economic growth, energy structure, and energy intensity are provided.
Mostrar más [+] Menos [-]Molecular mechanism for the discrepant inhibition of microcystins on protein phosphatase 1 Texto completo
2019
Wang, Qian | Wang, Xiaoning | Zhang, Shuhan | Zong, Wansong
Due to variable amino acid residues at positions 2 and 4, microcystins (MCs) had diversified variants with different toxicities. To evaluate the discrepant toxicity, the inhibition effects of five typical MC variants (with the changed amino acid residues at position 4) target to PP1 were evaluated. The inhibition sequence was verified as follows: MCLR (IC₅₀ = 2.6 μg/L) > MCLF (IC₅₀ = 4.4 μg/L) > MCLA (IC₅₀ = 5.5 μg/L) > MCLY (IC₅₀ = 7.9 μg/L) > MCLW (IC₅₀ = 13.6 μg/L). To further clarify the inhibition mechanism for variant toxicity, the interactions between MCs and PP1 were evaluated with the assistance of MOE molecule simulation. Results show the hydrophobic interaction (Adda⁵ with PP1) and the hydrogen bonds (especially for Z⁴ → Glu₂₇₅) were positively correlated with MC toxicity, while the hydrogen bonds (Leu² ← Arg₉₆, IsoAsp³ ← Arg₉₆, and IsoAsp³ ← Tyr₁₃₄) and the ion bonds (between Mn²⁺ and His₁₇₃/Asn₁₂₄/Asp₉₂) were negatively correlated with toxicity. However, the hydrogen bonds (Ala¹ → Glu₂₇₅, Mdha⁷ ← Gly₂₇₄, Z⁴ ← Arg₂₂₁, and Adda⁵ ← His₁₂₅), the covalent combination (between Mdha⁷ and Cys₂₇₃), and the ion bonds (between Mn²⁺ and His₂₄₈/Asp₆₄/His₆₆) were weakly correlated with toxicity. By further analysis, the steric hindrance and hydrophobicity introduced by different Z⁴ residues affected the changes for combination area and energy of MC-PP1 complexes, leading to the discrepancies in MC toxicity.
Mostrar más [+] Menos [-]Enhanced NOx removal efficiency for SCR catalyst of well-dispersed Mn-Ce nanoparticles on hexagonal boron nitride Texto completo
2019
Lee, Myeung-jin | Kim, Do-Hyun | Lee, Minwoo | Ye, Bora | Jeong, Bora | Lee, DuckHyun | Kim, Hong-dae | Lee, Heesoo
This research is conducted to improve the dispersion of MnOₓ–CeO₂ catalyst because manganese is easily aggregated during continuous thermal environment at operating temperature. Aggregated MnOₓ particles on the support can be a major reason to degrade the catalyst performance. Therefore, the improved dispersion of MnOₓ particles leads to the enhancement of the catalyst performance by utilizing hexagonal boron nitride (h-BN) which is well known as thermally stable material. Due to the dispersion of MnOₓ–CeO₂ with 5–20 nm particle size, h-BN-supported MnOₓ–CeO₂ catalyst shows the 93% efficiency in NOₓ removal at 200 °C. The structure and properties of MnOₓ–CeO₂/h-BN catalyst are characterized by X-ray diffraction, Fourier transform infrared spectroscopy spectra, and NH₃-temperature programmed desorption. Then, NOₓ removal efficiency of catalyst is evaluated on a fixed bed reactor and h-BN-supported catalyst, (Mn₀.₂–Ce₀.₁)/BN, increases NOₓ removal efficiency up to 20% at 200 °C in spite of 2/3 reduced content of MnOₓ–CeO₂ compared to no-supported catalyst (Mn₀.₃–Ce₀.₁₅).
Mostrar más [+] Menos [-]Effect of cation type in mixed Ca-Na systems on transport of sulfonamide antibiotics in saturated limestone porous media Texto completo
2019
Sun, Kaixuan | Sun, Yuanyuan | Gao, Bin | Xu, Hongxia | Wu, Jichun
Retention and transport of sulfonamides (SAs) in subsurface can strongly affect groundwater quality. In this work, a range of laboratory batch sorption and column transport experiments were conducted to determine the effect of cation type in mixed Ca-Na systems on the retention and transport of two typical SAs, sulfadimethoxine (SDM) and sulfacetamide (SCA), in saturated limestone porous media. Column experimental data showed divalent cation Ca²⁺ played a more important role than monovalent cation Na⁺ in decreasing the transport of only SDM in co-cation systems in the saturated limestone media. Further, in the single-cation (i.e., including either Ca²⁺ or Na⁺) system, increasing ionic strength (IS) of either NaCl or CaCl₂ had little effect on SCA transport; however, increasing of IS of CaCl₂ promoted the retention of SDM in the saturated limestone porous media. This is mainly due to the cation bridging effect of Ca²⁺ on SDM and limestone. Overall, SDM showed much higher retention in the limestone columns than SCA, which can be attributed to the two SAs’ different physicochemical properties. Moreover, limestone showed stronger ability to retain the two SAs than quartz sand. Findings in this study suggest that cation type and the concentration of certain electrolyte (e.g., CaCl₂) as well as medium type play an important role in controlling the environmental fate and transport of antibiotics.
Mostrar más [+] Menos [-]Recent electrochemical methods in electrochemical degradation of halogenated organics: a review Texto completo
2019
Zhang, Meng | Shi, Qin | Song, Xiaozhe | Wang, Hui | Bian, Zhaoyong
Halogenated organics are widely used in modern industry, agriculture, and medicine, and their large-scale emissions have led to soil and water pollution. Electrochemical methods are attractive and promising techniques for wastewater treatment and have been developed for degradation of halogenated organic pollutants under mild conditions. Electrochemical techniques are classified according to main reaction pathways: (i) electrochemical reduction, in which cleavage of C-X (X = F, Cl, Br, I) bonds to release halide ions and produce non-halogenated and non-toxic organics and (ii) electrochemical oxidation, in which halogenated organics are degraded by electrogenerated oxidants. The electrode material is crucial to the degradation efficiency of an electrochemical process. Much research has therefore been devoted to developing appropriate electrode materials for practical applications. This paper reviews recent developments in electrode materials for electrochemical degradation of halogenated organics. And at the end of this paper, the characteristics of new combination methods, such as photocatalysis, nanofiltration, and the use of biochemical method, are discussed.
Mostrar más [+] Menos [-]Effects of neonicotinoids on the emergence and composition of chironomids in the Prairie Pothole Region Texto completo
2019
Williams, Nate | Sweetman, Jon
The use of neonicotinoid pesticides is widespread throughout agricultural regions, including the Prairie Pothole Region of North America. The occurrence of these pesticides to the abundant adjacent wetlands can result in impacts on nontarget insects, and cascading effects through wetland ecosystems. In the current study, field-based mesocosms were used to investigate the effects of multiple pulses of the neonicotinoid imidacloprid on the emergence and chironomid community composition, in an effort to simulate episodic rain events to Prairie Pothole Wetlands. Sediments from two local wetlands were placed into the mesocosm tanks and three imidacloprid pulses added, each 1 week apart at nominal concentrations of 0.2, 2.0, and 20 μg/L. Overall, a significant decrease in the emergence of adult chironomids was observed within the 2.0 μg/L and greater concentrations, with the subfamilies Chironominae and Tanypodinae showing a greater sensitivity than the members of the subfamily Orthocladiinae. The chironomid community also had a dose-related response, followed by a recovery of the community composition near the end of the experiment. Our results provide additional evidence that repeated pulses of imidacloprid may have effects on chironomids and other sensitive aquatic insects living within Prairie Pothole Wetlands, resulting in reduced food availability. We stress the need for continued monitoring of US surface waters for neonicotinoid compounds and the continuation of additional experiments looking into the impacts on aquatic communities.
Mostrar más [+] Menos [-]Factors influencing mercury uptake by leaves of stone pine (Pinus pinea L.) in Almadén (Central Spain) Texto completo
2019
Barquero, José Ignacio | Rojas, Sofía | Esbrí, José María | García-Noguero, Eva M. | Higueras, Pablo
The use of trees for biomonitoring of mercury (Hg) and other atmospheric pollutants is of increasing importance today. Leaves from different species have been the most widely used plant organ for this purpose, but only pine bark, and not leaves, was used to monitor Hg pollution. In Almadén (South Central Spain), the largest cinnabar (HgS) deposits in the world have been mined for over 2000 years to obtain metallic Hg and this activity has caused the widespread dispersion of this toxic element in the local environment. A strip of pine trees, 2750 m in length, adjacent and to the South of the mining town has been studied in order to evaluate pine tree needles as monitors for Hg contamination in this heavily polluted area. The study involved the collection of pine tree leaves from several discrete sites along the strip, as well as samples from other nearby locations, together with soil samples and monitoring of atmospheric Hg in the area during both the day and night. Leaves and soils were analyzed for total Hg concentration by means of atomic absorption spectrometry; the leachable fraction of soil Hg was also analyzed by the CV-AFS technique. The results indicate that soils from the investigated area were not directly affected by mining related pollution, with low total Hg levels (3–280 mg kg⁻¹) found in comparison with the nearby Almadén metallurgical precinct and very low leachable Hg contents (0.27–59.65 mg kg⁻¹) were found. Moreover, pine tree needles have a low uptake capacity, with lower THg levels (0.03–6.68 mg kg⁻¹) when compared to those of olive trees in Almadén. However, pine needles do show significant variability with regard to the distance from the source. Gaseous Hg exhibits a similar pattern, with higher levels close to the source, especially during night time (225 ng m⁻³). A multiple linear regression analysis (MLRA) revealed that gaseous Hg in the nocturnal period is the prime factor that influences the amount of Hg uptake by pine tree needles. This finding makes pine needles a promising candidate to biomonitor gaseous Hg on a local or regional scale worldwide. Almadén pine tree needles have been exposed to a number of different Hg sources, including the primary one, namely the old mine dump, and secondary sources such as polluted roads or illegal urban residual waste. The secondary sources cause some minor discrepancies in the model established by the MRLA. The biomonitoring capacity of pine needles needs to be evaluated in areas far from the source. The process involved in gaseous Hg uptake by pine needles appears more likely to involve sorption in the external part of the needle than uptake through stomas, thus making this process strongly dependent on high atmospheric Hg concentrations.
Mostrar más [+] Menos [-]Analysis of methanogens adsorption and biogas production characteristics from different coal surfaces Texto completo
2019
Guo, Hongyu | Dong, Zhiwei | Liu, Xile | Bai, Yang | Gao, Zhixiang | Xia, Daping
The aim of this study was to examine the biogas production and the adsorption aspect of microorganism from different coals. Coal samples were obtained from Qianqiu mine and Guandi mine. Microbial populations were cultured from the coal mine drainage. After an anaerobic reaction period at about 35 °C, adsorption rate was determined by the spectrophotometer, while a scanning electron microscopy was used to observe the microorganisms on the coal and the headspace methane was analyzed using gas chromatography. Results show that the coal rank and particle size serve as important factors influencing the adsorption of microorganism and biogenic methane production. With decreasing particle size, the Qianqiu coal produced a considerable adsorption rate between 75 and 79%, while the adsorption rate of Guandi coal was between 52 and 74%. Meanwhile, the density of microorganisms from the Qianqiu coal surface demonstrated a higher level of adsorption than that of Guandi coal following the scanning electron microscopy images. Additionally, Qianqiu coal produced a higher level of biogas production (391.766–629.199 μmol/g) than that of Guandi coal (292.835–393.744 μmol/g) and the Qianqiu coal also generated a higher concentration of methane during the incubation. When the adsorption rate decreasing, the biogas production from various pulverized coals appeared to be decreased and demonstrated a positive correlation to the adsorption rate. The results of this study suggest that the adsorption behavior of microorganisms is closely related to the effect of coal biodegradation and contributes to the biogenic methane production potential.
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