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Analysis of the total factor energy efficiency and its influencing factors of the Belt and Road key regions in China Texte intégral
2019
Yang, Zhongshan | Wei, Xiaoxue
Energy cooperation has been emphasized strongly in the Belt and Road (B&R) initiative. Therefore, the energy efficiency of China has attracted much attention from experts. However, relevant studies are still insufficient. This paper analyzes the total factor energy efficiency (TFEE) and its influencing factors of 17 B&R key regions from 2005 to 2015. We use the ratio of target energy input and actual energy input to calculate the regional TFEE under environmental constraints. The Malmquist index and the Tobit model are applied to investigate the internal and external influences of TFEE. Measurement analysis shows that the TFEE of the B&R key regions has not improved in recent years and it is unbalanced during the study period. Regions in the east area have the highest TFEE; regions in the west area have the second high TFEE; and regions in the north area have the lowest TFEE. Regression analysis shows that for the B&R key regions, technical changes, coal consumption, research and development, and environmental pollution have mainly negative effects on TFEE; pure efficiency changes, scale efficiency changes, economic structure, opening up, and government finance have mainly positive effects on TFEE. Finally, precise policy implications are proposed.
Afficher plus [+] Moins [-]Performance of Physically and Chemically Activated Biochars in Copper Removal from Contaminated Mine Effluents Texte intégral
2019
The increasing global demand for metals and minerals justifies the intensive study of treatment options for contaminated mine effluents. The present study evaluated the conversion of wood residues into physically and chemically activated biochars and their subsequent use in the treatment of Cu in synthetic and actual contaminated mine drainage. First, wood residues were converted into biochar by fast pyrolysis. Then, physical (using steam or CO₂) or chemical (using KOH) activation was carried out in a homemade pilot-scale furnace. After activation, highly microporous (KOH materials) and micro/mesoporous activated biochars (CO₂ and steam materials) were obtained. Batch adsorption testing was first conducted with synthetic effluents. Results showed that CO₂-activated biochar was the most Cu effective adsorbent (99% removal) at low concentrations (5–20 mg L⁻¹). The mechanisms of Cu²⁺ adsorption involved physical and chemisorption for biochars and CO₂-activated biochar, while chemisorption for KOH-activated biochars was probably due to the high proportion of functional groups connected to their surface. In multi-metal acid mine drainage, metal adsorption capacities deteriorated for most of the materials, probably due to the effects of ion competition. However, KOH-activated biochar decreased Cu²⁺ concentrations to below the authorized monthly mean allowed by Canadian law (0.3 mg L⁻¹) and decreased Co, Pb, and Mn concentrations up to 95%. These findings indicate that high porosity and oxygenated functional groups connected to the surface of activated biochars are important properties for the enhancement of interactions between carbon materials and metals from mine effluents, as well as for their performance improvement in mine drainage treatment.
Afficher plus [+] Moins [-]Nano-porous Membrane Process for Brackish Groundwater Treatment: Efficiency Analysis Using Response Surface Methodology Texte intégral
2019
Yuzheng Lv, Jihao Zhou, Zhengjun Mai and Jie Liu
Excessively high concentration of inorganic salts in the groundwater is the main threat for residents to drink directly in the remote areas of northwestern China. In this paper, nano-porous membrane process was proposed to removal of diverse ions in such raw water. Through the response surface methodology (RSM), the effects of multiple factors on permeate flux and ion rejection rates were analysed, and the application scope of nanofiltration for various water resource was evaluated. It was found that the factors affecting permeate flux, chloride removal and nitrate removal (response value) followed some typical sequences, and the operating pressure was always the most influential factor. Besides, nanoporous membrane process showed predominant performance in the removal of sulphate, chloride and fluoride; the rejection rates were over 99%, 97% and 95%, respectively, and the produced water could completely satisfy the relevant national standards for drinking water. However, nitrate removal rate was seldom over 80%, and it reduced obviously with the increasing initial concentration of nitrate, thus the nitrate content of raw water should be controlled within 40 mg.L-1.
Afficher plus [+] Moins [-]High Rate Vermicomposting of Coral Vine by Employing Three Epigeic Earthworm Species Texte intégral
2019
S.G. Antony Godson and S. Gajalakshmi
Use of the high-rate vermicomposting system and its relevant technology were successfully applied to accomplish direct vermicomposting of coral vine leaves - devoid of any pre-treatment/composting or amended with cow dung as earlier proclaimed protocols for the vermicomposting of various phytomass had necessitated. Three earthworm species tested were Eisenia fetida, Eudrilus eugeniae and Perionyx excavatus, and they had shown efficient vermicast recovery with few instances of mortality and good reproduction over the 150-day experiment. In this duration, all vermireactors were run in semi-continuous mode at the solid retention time of 15 days. This process enabled us to improve process efficacy of the reactor by the required pointers and systematic process monitoring. This paper substantiates the potential of the high-rate vermicomposting system in direct and potential vermicomposting of coral vine without any pre-treatment/composting or cow dung amendments. The observations have significance for enhancing process economics and therefore, process utility.
Afficher plus [+] Moins [-]Life Cycle Assessment of the Oil Palm Production in the Philippines: A Cradle to Gate Approach Texte intégral
2019
Ma. Theresa M. Espino, Rocky Marius Q. de Ramos and Luzvisminda M. Bellotindos
Despite its small share of 0.15% in the global market, the oil palm production in the Philippines is being contested with environmental issues on continued deforestation, increased emissions from illegal burning of trees, and the marginalization of indigenous communities. As a developing industry, there is a need to further conduct of social and environmental impact studies to gain more acceptance, thereby, pursue growth and expansion. In view of the environmental concerns, this study aimed to conduct a life cycle assessment of the crude oil palm with North Cotabato, Philippines as the case study. Using cradle to gate approach, the potential environmental impacts were established: non-renewable energy of 0.394 MJ/kg oil, carbon footprint of 1.150 kgCO2/kg oil, ozone creation potential of 2.429×10-3 kg NOx /kg oil, acidification potential of 0.0138×10-3 kg SO2 /kg oil and water footprint of 5,797.3 L/kg oil. Compared to six locations in Indonesia, Malaysia and Thailand, the environmental impacts and performance of the oil palm production in North Cotabato were satisfactory given the same topographical conditions. Opportunities to mitigate and decrease the impacts were also identified, namely improving oil extraction rates; increasing ratio of shell as biomass fuel; prudent application of nitrogen fertilizers and optimizing delivery loads and schedules. The results of this study can be a reference for future environmental assessments in other locations.
Afficher plus [+] Moins [-]The Effect of Sublethal Exposure of Chlorpyrifos to Nile Tilapia (Oreochromis niloticus): Case Study of Twin Lakes of West Sumatra, Indonesia Texte intégral
2019
Taufiq Ihsan, Tivany Edwin and Rahma Desri Yanti
Chlorpyrifos is one of the toxic organophosphate insecticides that is often used by farmers in West Sumatra Province. This research was conducted with the aim to analyse the level of consumption, conversion ratio, and growth rate in fish cultivated in the twin lakes of West Sumatra. The concentration variations are 1/7 and 1/14 LC50-96h of chlorpyrifos. The study was conducted for 14 days. Research data analysis found the values of R = 0.75-1 for the relationship of oxygen level, conversion ratio, and growth of tilapia to the duration of exposure which means having a strong correlation. The results obtained were due to chlorpyrifos insecticide exposure on day 1 to day 14. At a concentration of 0.0054 mg/L, there was a decrease in the level of oxygen consumption of 0.0159 mgO2 /L, an increase in feed conversion ratio of 0.8253, and the deviation flow of 2.7048%. Whereas at a concentration of 0.0108 mg/L, there was a decrease in the oxygen level of 0.0213 mgO2 /L, increase in feed conversion ratio of 0.8201, and deviation growth by 2.7048%.
Afficher plus [+] Moins [-]Biomass and Soil Organic Carbon Stocks Under Cedrus deodara Forests in Mandi District of Himachal Pradesh Texte intégral
2019
Manoj Thakur and R. K. Verma
The estimation of carbon sequestration in forest ecosystem is necessary to plan for mitigating the impacts of climate change. The present study was conducted in the Cedrus deodara (CD) forests of Mandi district in Himachal Pradesh to estimate the biomass and soil organic carbon stock at various sites of the study area. Overall, 18 plots of 0.1 ha were laid at six sites randomly in the year 2014-15. In CD forest, the mean stem density was 354 trees/ha and the mean basal area and mean volume were 62.28 m2/ha and 719.71 m3/ha respectively. The mean carbon stock for tree aboveground, tree belowground, understorey and litter were 189.93 ton/ha, 37.99 ton/ha, 1.71 ton/ha and 0.72 ton/ha respectively. The soil organic carbon percentages varied from 1.98-2.83%, 1.72-2.11% and 1.56-1.74% at soil depth of 0-15cm, 15-30cm and 30-45cm respectively, and the soil organic carbon stocks ranged from 24.41-32.22 ton/ha, 21.59-29.03 ton/ha and 19.17-26.78 ton/ha at soil depths of 0-15cm, 15-30cm and 30-45cm respectively. The total mean soil organic carbon (SOC) stock up to a depth of 0-45cm was found to be 76.16 ton/ha. The organic carbon percentage showed a decreasing trend with increasing soil depth.
Afficher plus [+] Moins [-]HPTLC Based Screening of -Sitosterol from Andrographis paniculata Texte intégral
2019
Rajeshwari Prabha Lahare and Anil Kumar
Sterols are secondary metabolites of plants known for their inhibitory effects on cancer cell growth, lower cholesterol and enhance immunity. b-sitosterol belongs to phytosterol which enhances antioxidant enzymes and thus reduces the oxidative stress. In present experiment, b-sitosterol was detected from Andrographis paniculata belonging to family Acanthaceae by using HPTLC. The plant is popularly known as Kalmegha having multiple pharmacological properties used for treatment of several diseases. Leaf, stem and root extracts prepared in chloroform, methanol and petroleum ether were used for detection of b-sitosterol from the plant. The chromatography was performed on TLC plates coated with Al silica gel 60 F254 and solvents used for mobile phase was toluene:ethyl acetate:formic acid (15:4.5:1.5). After development, the plates were derivatized with 10% methanolic sulphuric acid, scanned and quantified at 510 nm. The results showed the presence of b-sitosterol in all the parts with Rf value 0.62. Calibration curve was prepared and the amount of b-sitosterol was quantified in the extracts by comparing the respective peak areas with that of the standard. The correlation coefficient for b-sitosterol against reference sample was found significant (r= 99.769057%) for the concentration range of 0.5 to 4.0 µg. Leaf methanol extract showed the highest concentration of b-sitosterol, i.e., 147.6 µg/mL. The extraction efficiency of b-sitosterol was found higher in methanol followed by petroleum ether and chloroform extract. Thus, our finding shows that Andrographis paniculata has a significant concentration of b-sitosterol, which may be useful for pharmacological application against cancer, hypercholesterolemia, inflammation and for angiogenesis process.
Afficher plus [+] Moins [-]Photodegradation of Congo Red Dye Via Simple and Effective Air Oxidation Using Copper(II) Chloride and Sunlight Texte intégral
2019
Preeja P. Thattil and A. Leema Rose
This paper reports the study of photodegradation of Congo red dye which is a major pollutant in dyeing industry using copper(II) chloride dihydrate as a catalyst. The rate of degradation is improved by direct supply of air instead of using other strong oxidants. The effects of other parameters such as pH, catalyst dosage, initial dye concentration and irradiation time were studied. It was found that over 100% of the dye removal can be effectively achieved within 90 minutes of air oxidation at pH 11 and a catalyst dosage of 0.4g/L. The kinetics on the rate of degradation of the dye has also been examined by using UV-Visible spectroscopic technique. Air oxidation of Congo red dye using CuCl2.2H2O was found to obey pseudo-first-order kinetics with respect to the substrate concentration. The study suggests the use of homogeneous CuCl2.2H2O catalyst for the photodegradation of dyes of reactive azo dye category. Future studies on the use of catalytic activity of CuCl2.2H2O for industrial effluents containing azo dyes as a major pollutant can be affected.
Afficher plus [+] Moins [-]Control of Air Pollutants Emission and Improvement of Incineration Rate During Incineration of Oily Sludge-Based Briquette Texte intégral
2019
Mingming Du, Fengchao Wang, Jinling Li, Tao Yu and Chengtun Qu
The incineration technology of oily sludge-based briquette makes great contributions to oily sludge treatment. In order to resolve these problems, air pollutants (SO2 and organic gas) emission and low incinerating rate during the briquette incineration, the effects of additives (CaCO3, CaO; K2CO3, Na2CO3, NaCl; KMnO4, KNO3, NaNO3; Fe2O3, KClO3) on the generating gas and incinerating rate during incineration were studied. The results show that CaCO3 is more effective than CaO for fixing sulphur into residue, and K2CO3 improved the sulphation efficiency of calcium-based additives, which is more useful than NaCl and Na2CO3 did. As for the incinerating rate of briquette, KMnO4 is more effective than KNO3 and NaNO3. The maximum of incinerating rate of briquette is improved from 0.38 to 0.6 g/ min and Fe2O3 and KClO3 can apparently reduce the release of organic gas during the incineration of briquette. But KClO3 can greatly reduce the release of sulphur. When the adding amount of CaCO3, K2CO3, KMnO4 and KClO3 is 16‰, 12‰, 18‰, 6‰ respectively in the process of briquette preparation, the sulphation efficiency reached the maximum of 95.3%, and there is still an extremely small amount of organic gas in flue gas. CaCO3, K2CO3, KMnO4 and KClO3 used in emission control of air pollutants and full combustion of briquette during incineration of oily sludge based-briquette, demonstrates high efficiency and low emission compared to other additives tested in this study.
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