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An unintended challenge of microplastic pollution in the urban surface water system of Lahore, Pakistan Full text
2020
Irfan, Muhammad | Qadir, Abdul | Mumtaz, Mehvish | Ahmad, Sajid Rashid
Plastics are widely considered to be a major threat particularly in the urban areas owing to extensive use of plastic products. The current study is the first investigation to highlight the microplastics (MPs) pollution from the freshwater (Ravi River) located in the predominant urban center, i.e., Lahore, Pakistan. The concentration profile was quantified from surface water (n = 19) and sediments (n = 19) collected from different drains and canals of predominant freshwater resources in Lahore, Pakistan. The highest content of MPs was observed in the sullage carrier with mean concentration of 16,150 ± 80 MPs/m³ and 40,536 ± 202 MPs/m² in the water and sediments respectively. The lowest level was detected in the link canals with mean concentration of 190 ± 141 MPs/m³ in the water and 683 ± 479 MPs/m² in the sediments. The proportion of large size MPs (300 μm–5 mm) was maximum in the upstream section of Ravi river, whereas fine size MPs (50–150 μm) were dominant in the downstream section. In terms of shapes, the fragments were predominant with a relative abundance of 56.1% and 83.1% followed by fibers with a relative abundance of 38.6% and 11.8% in the water and sediments respectively. The chemical composition analysis showed that most of the fibers, fragments, and beads were polyethylene while the sheets were composed of polypropylene. Nevertheless, the foams isolated from the samples were composed of polystyrene. Within 24 h, about 2.4 ± 2.4 billion microplastic pieces were estimated to be transported from a single water channel into the river. The highest discharge of MPs was estimated from the sullage carrier with about 7 billion pieces/day.
Show more [+] Less [-]Energy conservation potential analysis of Chinese manufacturing industry: the case of Jiangsu province Full text
2020
Cheng, Manli
Improving energy conservation efficiency is one of the prerequisites for China’s manufacturing industry to transform and upgrade. Jiangsu province which presents the maximum economic volume in manufacturing and its economic status in eastern China is comparable to Shanghai. Research on the sustainable development capacity of Jiangsu’s manufacturing industry gives important guidance for upgrading the manufacturing industry all over China. The core of China’s manufacturing transition to a manufacturing power is to enhance its independent innovation capabilities to improve energy efficiency and its position in the global value chain. Therefore, it is important to study the impact of technological factor on energy conservation potential and the transformation and upgrading of manufacturing. In this paper, multivariate regression research method combined with risk analysis is developed to explore the influence of the research and development factor on energy conservation while introducing macroeconomic variables. Additionally, energy conservation of manufacturing in Jiangsu province in 2020 and 2025 based on historical data from 1985 to 2015 is predicted. Compared with the business-as-usual scenario, the advanced scenario could reduce by 44.07 Mtce and 87.60 Mtce in 2020 and 2025, respectively. Thus, the results indicate that there is much room for improvement in terms of the energy efficiency for Jiangsu province.
Show more [+] Less [-]Interfuel substitution, hydroelectricity consumption and CO2 emissions mitigation in Malaysia: evidence from a transcendental logarithm (trans-log) cost function framework Full text
2020
Bello, Mufutau Opeyemi | Solarin, Sakiru Adebola | Yen, Yuen Yee
The main objective of this paper is to estimate the interfuel substitution elasticities between hydropower and the fossil fuels of coal and natural gas used in the generation of electricity for Malaysia. Due to the violation of the assumption behind the ordinary least squares (OLS) method on account of the correlated error terms in the system of equations, the econometrics techniques of seemingly unrelated regression (SUR) was adopted to obtain the parameter estimates using dataset that covers the period 1988 to 2016. The main finding is that there exists substantial substitution possibility between hydropower and fossil fuels in the generation of electricity for Malaysia. CO₂ emissions mitigation scenarios were also conducted to explore the possible effects of substituting fossil fuels for hydropower to generate electricity. The results show that switching from high carbon-emitting fuels to renewable energy such as hydropower will substantially reduce CO₂ emission and assist the country towards achieving the carbon emissions reduction targets. Policy recommendations are offered in the body of the manuscript.
Show more [+] Less [-]Cyclodextrin-based nanostructured materials for sustainable water remediation applications Full text
2020
Kumari, Pratibha | Singh, Parul | Singhal, Anchal | Sen, A.
The problem of water pollution is a burning social issue even though sustainable efforts are being made in recent years. The discharged water from various industries contains a considerable amount of organic and inorganic pollutants. Heavy metals, dyes, and aromatic hydrocarbons constitute a significant portion of water contaminants, and it is challenging to remove contaminants at low concentration value. Cyclodextrin nanomaterials modified with carbon nanomaterials, polymer, and metal nanoparticles have been reported as promising and sustainable tools for water remediation through adsorption and catalytic degradation approaches. The cyclodextrin polymers have been developed as nanoporous and nanosponge materials using different bifunctional linking reagents, which are highly efficient in removing a wide variety of organic and inorganic waste from water bodies through adsorption. Various chemical modifications in cyclodextrin-based nanostructured materials have been reported to enhance its affinity for the contaminants. In the present review, recent advances in cyclodextrin-based nanostructured materials for water remediation application via different mechanisms have been discussed.
Show more [+] Less [-]Estimating potential evapotranspiration based on self-optimizing nearest neighbor algorithms: a case study in arid–semiarid environments, Northwest of China Full text
2020
Feng, Kepeng | Tian, Juncang
Changes in potential evapotranspiration will affect the surface ecology and environment of the land. Accurate and quick estimation of potential evapotranspiration will help to analyze environmental change. In this study, in combination with the canonical correlation analysis (CCA) and k-nearest neighbor algorithm (k-NN), a new method for calculating potential evapotranspiration (CCA-k-NN) based on self-optimizing nearest neighbor algorithm was proposed, in which less meteorological data were used for estimation. By analyzing the basic principles of CCA and k-NN and according to the requirement of estimating ET₀, the CCA-k-NN method was constructed, and its basic principles and key steps were described. In this method, CCA algorithm was used to find the most relevant meteorological data for potential evapotranspiration, and the dimensionality of meteorological data for subsequent estimation of ET₀ was reduced. Then, k-NN algorithm was used to estimate ET₀. The Northwest of China was chosen as the research area to evaluate the applicability of this method. The 148 data stations in the region were divided into training datasets, testing datasets, and validation datasets. ET₀ was estimated on three datasets using the proposed method, and the estimation accuracy of the CCA-k-NN method was evaluated with FAO-56 Penman-Monteith as a reference. The results show that the CCA-k-NN method maintains a high correlation with FAO-56 Penman-Monteith (correlation coefficient is greater than 0.9) and has a good estimation accuracy. RMSE and MAE are both less than 1 mm day⁻¹, and the overall performance of NSCE is greater than 0.5, all of which reach the level of “applicable” and above. At the same time, the CCA-k-NN method has low time complexity O(n). Comparison of the results of the CCA-k-NN method with those of other empirical models showed that the CCA-k-NN method is more accurate and can be employed successfully in estimating ET₀.
Show more [+] Less [-]First approaches to the depuration process of trace metals in the burrowing crab Neohelice granulata from a temperate wetland in South America: Bahía Blanca estuary, Argentina Full text
2020
Simonetti, Pía | Truchet, Daniela M. | Buzzi, Natalia S. | Marcovecchio, Jorge E.
First approaches to the depuration process of trace metals in the burrowing crab Neohelice granulata from a temperate wetland in South America: Bahía Blanca estuary, Argentina Full text
2020
Simonetti, Pía | Truchet, Daniela M. | Buzzi, Natalia S. | Marcovecchio, Jorge E.
Trace metal contamination is among the major concerns of stakeholders due to its potential adverse effects on biota and humans, even at low concentrations. Few studies have recently focused on the ability of organisms to depurate trace metals from different tissues. Therefore, we carried out this study to evaluate the bioconcentration of trace metals (Cd, Zn, Pb, Ni, Mn, Fe, Cr, Cu) and the depuration process of these pollutants in two tissues (soft tissue and carapace) in an estuarine benthic crab model, Neohelice granulata. The results indicate that Cu and Zn were the highest bioconcentrated metals in crab tissues, while other metals, such as Pb and Cr, were found in sediments but were not bioconcentrated. On the other hand, Cd was found in crabs but not in sediments. The depuration indicates a total decline in Ni and a significant decrease in Cu and Fe in the soft tissues after the experiment. However, the concentration of the trace metals in the carapace before and after the depuration did not show any significant variation except in the Mn, in which the levels decreased significantly at the end of the depuration. Thus, we recommend continuing to explore metal detoxification in bioindicator species, such as N. granulata, in order to understand the efficiency of the mechanisms of depuration of trace metals.
Show more [+] Less [-]First approaches to the depuration process of trace metals in the burrowing crab Neohelice granulata from a temperate wetland in South America: Bahía Blanca estuary, Argentina Full text
2020
Simonetti, Pia | Truchet, Daniela María | Buzzi, Natalia Sol | Marcovecchio, Jorge Eduardo
Trace metal contamination is among the major concerns of stakeholders due to its potential adverse effects on biota and humans, even at low concentrations. Few studies have recently focused on the ability of organisms to depurate trace metals from different tissues. Therefore, we carried out this study to evaluate the bioconcentration of trace metals (Cd, Zn, Pb, Ni, Mn, Fe, Cr, Cu) and the depuration process of these pollutants in two tissues (soft tissue and carapace) in an estuarine benthic crab model, Neohelice granulata. The results indicate that Cu and Zn were the highest bioconcentrated metals in crab tissues, while other metals, such as Pb and Cr, were found in sediments but were not bioconcentrated. On the other hand, Cd was found in crabs but not in sediments. The depuration indicates a total decline in Ni and a significant decrease in Cu and Fe in the soft tissues after the experiment. However, the concentration of the trace metals in the carapace before and after the depuration did not show any significant variation except in the Mn, in which the levels decreased significantly at the end of the depuration. Thus, we recommend continuing to explore metal detoxification in bioindicator species, such as N. granulata, in order to understand the efficiency of the mechanisms of depuration of trace metals. | Fil: Simonetti, Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina | Fil: Truchet, Daniela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina | Fil: Buzzi, Natalia Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina | Fil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Tecnológica Nacional. Facultad Regional Bahía Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentina
Show more [+] Less [-]Response of ecosystem functioning to environmental variations in an artificial sand-binding vegetation desert in northwestern China Full text
2020
Zhou, Yuanyuan | Li, Xinrong | Gao, Yanhong | Wang, Yanli | Mao, Zhongchao
The establishment of artificial sand-binding vegetation is one of the main means for restoring damaged ecosystems that are impacted by global change. This study was conducted to evaluate the influence of environmental factors on ecosystem function (net ecosystem exchange (NEE), evapotranspiration (ET), and water use efficiency (WUE)) in an artificial sand-binding vegetation desert (with dominant shrubs, such as Artemisia ordosica and Caragana korshinskii, and herbaceous plants) in northwestern China. NEE, ET, and meteorological data were observed with the eddy covariance (EC) technique. The random forest (RF) method was used to identify major environmental factors that affected NEE, ET, and WUE. Our results showed that the mean annual NEE, ET, and WUE values were − 112.4 g C m⁻², 232.1 mm, and 0.49 g C kg⁻¹ H₂O, respectively, during the 2015 to 2018 growing seasons. At the weekly scale, the most important drivers of NEE were the normalized difference vegetation index (NDVI) and soil water content (SWC). Rainfall, SWC, and NDVI were important drivers of ET. WUE was mainly controlled by rainfall and SWC. Linear regression showed that NEE had significant negative relationships with the NDVI and SWC. ET had positive relationships with rainfall, SWC, and the NDVI. WUE had significant negative relationships with SWC and rainfall. These findings indicate that drought inhibited ET more than carbon absorption, thus promoting the WUE of the ecosystem to some extent. The close relation of the ecosystem function to SWC implies that this ecosystem may be critically regulated by future climate change (specifically, changes in rainfall patterns).
Show more [+] Less [-]Advanced landfill leachate biochemical effluent treatment using Fe-Mn/AC activates O3/Na2S2O8 process: process optimization, wastewater quality analysis, and activator characterization Full text
2020
Liu, Zhanmeng | Pan, Liang | Hu, Fengping | Hu, Yunqi
A novel catalyst of Fe-Mn/AC was prepared and used as a heterogeneous catalyst to activate O₃/Na₂S₂O₈ for landfill leachate biochemical effluent treatment. The experimental results indicated that the highest COD (84%) and color (98%) removal was obtained at Fe-Mn/AC dosage 1.2 g/L, O₃ concentration 1.2 g/L, Na₂S₂O₈ dosage 6 g/L, initial pH 10, and reaction time 100 min. Three-dimensional and excitation emission matrix (3D-EEM) fluorescence spectrometry, Fourier transform infrared spectroscopy (FTIR), and gas chromatography mass spectrometry (GC/MS) of wastewater samples before and after treatment demonstrated that the leachate biochemical effluent contained a large amount of humic and fulvic acid organic compounds. After treatment with this coupling system, both the pollution level of dissolved organic matter (DOM) and the fluorescence intensity declined. The micro morphology of Fe-Mn/AC was characterized using scanning X-ray diffraction patterns (XRD), electron microscope spectra (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. It can be concluded that the microscopic morphology of the catalyst is porous. The main active components are amorphous MnO₂ and multivalent iron oxides. Furthermore, the Fe-Mn/AC catalyst showed great reusability; the removal efficiency of COD was only reduced from 84% to 79% at the fourth reaction. Moreover, the COD removal efficiency could recover to 81% after catalyst regeneration.
Show more [+] Less [-]Assessment of potential human health risk of trace element in wild edible mushroom species collected from Yunnan Province, China Full text
2020
Fu, Zhiqiu | Liu, Gang | Wang, Luxiang
Wild edible mushrooms are rich in nutritions and popular among people, but wild edible mushrooms easily accumulate potentially harmful trace elements, and excessive intake will harm health. The aim of this study was to investigate the potential health hazards of long-term intake of wild edible mushrooms in Yunnan Province, China. The concentrations of trace element (As, Cd, Cr, Cu, Hg, Pb, Ni, and Zn) in 19 species of wild edible mushrooms in Yunnan Province were determined by inductively coupled plasma mass spectrometry (ICP-MS). Further processing of the data, the potential health risk assessments of consumers were evaluated by the target hazard quotient (THQ), hazard index (HI), and incremental lifetime cancer risk (ILCR), respectively. Results showed that concentrations of trace element in wild edible mushrooms decreased in the order of Zn > Cu > As > Ni > Cr > Cd > Pb > Hg. Compared with the maximum standard by the WHO/China, the averages of As, Cd, Cr, Hg, and Zn were significantly greater than the standard. Among the tested wild edible mushrooms, HI values of Leccinum crocipodium, Thelephora ganbajun, Lactarius luteolus, Tricholoma matsutake, and Polyporus ellisii were more than 1. Thus, Leccinum crocipodium, Thelephora ganbajun, Lactarius luteolus, Tricholoma matsutake, and Polyporus ellisii are the main sources of risk. The value of THQ in ascending order was as follows: Pb (0.11) < Cd (0.75) < As (4.27) < Hg (6.87). Thus, Hg are the primary sources of health risk in the wild edible mushrooms in Yunnan Province. ILCR₍Aₛ₎ values of Thelephora ganbajun, Tricholoma matsutake, Laccaria amethystea, and Polyporus ellisii were more than 10⁻⁴, these four samples are the primary sources of health risk. The mean values of ILCR for As in wild mushroom were 1.01 × 10⁻⁴. The results suggest that there was potential health risk to the consumer associated with the long-term consumption of wild edible mushrooms collected from Yunnan Province. We propose that the concentrations of trace element should be periodically monitored in wild edible mushrooms.
Show more [+] Less [-]Highly effective surface modification using plasma technologies toward green coloration of polyester fabrics Full text
2020
Abdelghaffar, Fatma | Abdelghaffar, Rehab A. | Rashed, Usama M. | Ahmed, Hend M.
This study is anchored on the use of an eco-friendly effective plasma technique and cationization treatment to improve the hydrophobic nature of polyester (PET) fabric by incorporating hydrophilic functional groups onto the PET surface. The PET surface was initially treated with three different plasma gases prior to cationization treatment with quaternary ammonium salt (Quat 188). Madder roots were used, to produce natural dyes for the green coloration of PET fabrics in both dyeing and printing processes. The color strength (K/S) was measured to study the influence of both plasma gases and the cationization treatment on the coloration of PET fabric. Exposure to nitrogen plasma gases prior to the cationization treatment showed promising results for efficient PET coloration, resulting in the selection of nitrogen as a working gas at a flow rate of 3 l/min. The results also demonstrated that by combining the nitrogen plasma technique and cationization treatment, PET fabric with a highly effective surface was obtained, resulting in improved coloration, wettability, tensile strength, and roughness properties.
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