Research on carbon emissions in China's export trade based on input-output model

Becoming the world’s largest emitter of carbon makes China the object of criticism;however,people may ignore the fact that when China exports low-carbon products,the carbon emissions have been left in the meanwhile,forming the so-called"embodied carbon".Using the input-output model,this paper analyzes the carbon emission intensity and amount of embodied carbon of various sectors in China’s export trade in 2002 and 2007,and filters out high carbon emission sectors.In addition,this paper also points out the problem of carbon emissions’international transfer from developed countries to China through the analysis of national and regional flow of export carbon emissions and changing of the proportion of emissions for exports relative to total emissions,and explains the reason that caused carbon transfer to China by using the treadmill of production theory.Based on that,this paper proposes some measures for carbon reduction in China from the foreign trade perspective.     

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Western China has lagged a lot in terms of industrial structure and economic development, compared with the national average. And China announced its target of CO₂ emission reduction, i.e. by 2020, CO₂ emission per GDP will drop by 40–45% compared with 2005. The target will be incorporated into China’s long-term industrial planning. Against this background, this paper will make a comprehensive examination of the industrial development of Western China, aiming to discover a green and compatible way. First, we analyze the spatiotemporal evolution of regional industrial structure for the period 2000–2010. Second, we try to discover the industrial structure optimization path for Western China by employing the Vector Auto Regression model. Lastly, we try to provide some advice and suggestions for further industrial development in Western China. Our examination shows that further industrial development in Western China should pay full attention to resource conservation and recycling, and develop on a green and compatible path.     

Evolution of soil fertility and nitrogen/phosphorus leaching risk in protected agriculture of the eastern Qinghai-Tibet Plateau北大核心CSCD

Understanding changes in soil fertility and soil environmental risks in protected agriculture with high irrigation and fertilizer inputs are of great significance for ecological protection. In this study, soil samples in the plow layer were collected from greenhouses >100 acres in the eastern Qinghai-Tibet Plateau after different durations of planting time (either ≤ 3, 3-5, 5-10, or 10-20 years) to assess the changing pattern of soil fertility indicators and the potential leaching risk of nitrogen and phosphorus. The results showed that soil organic matter (OM) and total nitrogen (TN) contents in protected agriculture were 17.1 and 1.3 g/kg, respectively, which suggests moderate content levels. Meanwhile, soil alkali-hydrolyzed nitrogen (AN), available phosphorus (Olsen-P), and available potassium (AK) contents were 160.9, 72.0, and 191.2 mg/kg, respectively, which suggests abundant content levels. As the number of planting years increased, the contents of soil OM, TN, AN, and Olsen-P increased significantly, especially after 10 years, with 41.6%, 44.2%, 26.5%, and 67.4% increases, respectively, compared to ≤ 3 years. As seen, Olsen-P had the most marked increase. In contrast, soil AK and pH decreased with planting years, and soil AK after 5 years decreased by 32% compared to ≤ 3 years. Moreover, the soil pH value in 3-5 years decreased by 2.3% compared to that of ≤ 3 years. The leaching risk of soil nitrogen and phosphorus was intensified after 10-20 years, and the probability of leaching was 0.74 and 0.84, respectively. This study indicated that, in protected agriculture, soil OM, AN, and Olsen-P contents improved, accompanied by a high risk of N and P loss, and AK and soil pH values decreased. It is recommended that the input of nitrogen and phosphorus fertilizers should be controlled, and the input of potassium fertilizer should be increased for more than 10 years of facility cultivation. This study provides a scientific basis for the rational fertilization of agricultural facilities. The findings indicate that after facility planting for 10-20 years, soil organic matter, nitrogen, and phosphorus significantly increased, yet the leaching risk of nitrogen and phosphorus increased as well, suggesting that the input of nitrogen and phosphorus fertilizer should be controlled. After 3-5 years of planting, soil AK and pH values decreased significantly, implicating that potassium and organic fertilizer should be supplemented in a timely manner. © 2022 Science Press. All rights reserved.     

Acoustic performance of near-rail low-height noise barriers installed on suburban railway bridges

Environmental Science and Pollution Research - With the large-scale construction of suburban railway viaducts, the noise problem along the viaducts is becoming more and more prominent. Conventional...     

Agricultural factor endowment differences and relative poverty nexus: an analysis of macroeconomic and social determinants

Environmental Science and Pollution Research - Poverty is a significant global ongoing issue that influences a substantial amount of people despite all efforts to eliminate or lessen it. Although...     

Health risk assessment of soil trace elements using the Sequential Gaussian Simulation approach

Environmental Science and Pollution Research - In this study, the performance of the Sequential Gaussian Simulation (SGS) approach was studied with the aim of accurately determining local health...     

An investigation of the pullout behaviors of tire strips embedded in tire-derived aggregate reinforced sand

Environmental Science and Pollution Research - The recycling of scrap tires has become an important issue in the area of environmental protection in the past 20 years. In recent years, tire strips...     

Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membrane fouling control

• Ceramic membrane filtration showed high performance for surface water treatment. • PTC pre-coagulation could enhance ceramic membrane filtration performance. • Ceramic membrane fouling was investigated by four varied mathematical models. • PTC pre-coagulation was high-effective for ceramic membrane fouling control. Application of ceramic membrane (CM) with outstanding characteristics, such as high flux and chemical-resistance, is inevitably restricted by membrane fouling. Coagulation was an economical and effective technology for membrane fouling control. This study investigated the filtration performance of ceramic membrane enhanced by the emerging titanium-based coagulant (polytitanium chloride, PTC). Particular attention was paid to the simulation of ceramic membrane fouling using four widely used mathematical models. Results show that filtration of the PTC-coagulated effluent using flat-sheet ceramic membrane achieved the removal of organic matter up to 78.0%. Permeate flux of ceramic membrane filtration reached 600 L/(m²·h), which was 10-fold higher than that observed with conventional polyaluminum chloride (PAC) case. For PTC, fouling of the ceramic membrane was attributed to the formation of cake layer, whereas for PAC, standard filtration/intermediate filtration (blocking of membrane pores) was also a key fouling mechanism. To sum up, cross-flow filtration with flat-sheet ceramic membranes could be significantly enhanced by titanium-based coagulation to produce both high-quality filtrate and high-permeation flux.     

Efficient degradation of semi-coking wastewater in three-dimensional electro-Fenton by CuFe2O4 heterocatalyst

Semi-coking wastewater contains a rich source of toxic and refractory compounds. Three-dimensional electro-Fenton (3D/EF) process used CuFe₂O₄ as heterocatalyst and activated carbon (AC) as particle electrode was constructed for degrading semi-coking wastewater greenly and efficiently. CuFe₂O₄ nanoparticles were prepared by coprecipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy disperse spectroscopy (EDS). Factors like dosage of CuFe₂O₄, applied voltage, dosage of AC and pH, which effect COD removal rate of semi-coking waste water were studied. The results showed that COD removal rate reached to 80.9% by 3D/EF process at the optimum condition: 4 V, 0.3 g of CuFe₂O₄, 1 g of AC and pH?=?3. Trapping experiment suggesting that hydroxyl radical (?OH) is the main active radical. The surface composition and chemical states of the fresh and used CuFe₂O₄ were analyzed by XPS indicating that Fe, Cu, and O species are involved into the 3D/EF process. Additionally, anode oxidation and the adsorption and catalysis of AC are also contributed to the bleaching of semi-coking waste water. The possible mechanisms of 3D/EF for degrading semi-coking waste water by CuFe₂O₄ heterocatalyst were proposed.

     

Experimental research on atomization process and dust reduction performance of swirl pressure nozzle

Environmental Science and Pollution Research - In this study, experimental studies on atomization process and dust reduction performance of four swirl nozzles with different inlet/outlet diameter...