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Antibiotics in hospital effluents: occurrence, contribution to urban wastewater, removal in a wastewater treatment plant, and environmental risk assessment Полный текст
2019
Aydin, Senar | Aydin, Mehmet Emin | Ulvi, Arzu | Kilic, Havva
The study presented the occurrence of antibiotics in 16 different hospital effluents, the removal of antibiotics in urban wastewater treatment plant (WWTP), and the potential ecotoxicological risks of the effluent discharge on the aquatic ecosystem. The total concentration of antibiotics in hospital effluents was ranged from 21.2 ± 0.13 to 4886 ± 3.80 ng/L in summer and from 497 ± 3.66 to 322,735 ± 4.58 ng/L in winter. Azithromycin, clarithromycin, and ciprofloxacin were detected the highest concentrations among the investigated antibiotics. The total antibiotic load to the influent of the WWTP from hospitals was 3.46 g/day in summer and 303.2 g/day in winter. The total antibiotic contribution of hospitals to the influent of the WWTP was determined as 13% in summer and 28% in winter. The remaining 87% in summer and 72% in winter stems from the households. The total antibiotic removal by conventional physical and biological treatment processes was determined as 79% in summer, whereas it decreased to 36% in winter. When the environmental risk assessment was performed, azithromycin and clarithromycin in the effluent from the treatment plant in winter posed a high risk (RQ > 10) for the aquatic organisms (algae and fish) in the receiving environment. According to these results, the removal efficiency of antibiotics at the WWTP is inadequate and plant should be improved to remove antibiotics by advanced treatment processes.
Показать больше [+] Меньше [-]Effect of sand dust accumulation on photovoltaic performance in the Saharan environment: southern Algeria (Adrar) Полный текст
2019
Mostefaoui, Mohammed | Ziane, Abderrezzaq | Bouraiou, Ahmed | Khelifi, Seyfallah
Many climatic conditions have a negative impact on production of photovoltaic (PV) systems, and sand dust could be one of the main reasons of degradation of PV panels. The objective of this study is to investigate the reduction in the electrical performance caused by sandstorm and the accumulation of sand dust on the photovoltaic module surface installed in the Saharan area of south Algeria (Adrar). For this purpose, four PV modules (ISO-100/24) were selected and their current–voltage characteristics were measured to evaluate the sand dust effect on their performances. Our results show that sandstorm and dust accumulation on the surface of the module reduce the performance in terms of energy and power, due to a decrease of the transmittance. Obtained outcomes show that in sandstorm periods, the particle deposition density is much higher. This study reveals that leaving PV module without any cleaning in the Saharan environmental conditions significantly reduces PV power output, in addition to the presence of the shading mismatch effects in case of partial cleaning.
Показать больше [+] Меньше [-]Manganese tolerance and accumulation characteristics of a woody accumulator Camellia oleifera Полный текст
2019
Yu, Fangming | Liu, Kehui | Ye, Panhua | Zhou, Zhenming | Chen, Chaoshu | Li, Yi
This study intended to help illustrate the Mn accumulation ability of Camellia oleifera and provide it as a novel species for possible use in Mn-contaminated sites. Field surveys have been carried out on Mn accumulation in C. oleifera growing near Mn mining area in Hezhou. Pot growth experiments in soil and sand culture were conducted to investigate Mn tolerance, accumulation, and translocation patterns in C. oleifera. C. oleifera grew well and showed no symptoms of Mn toxicity at a Mn treatment level below 1026 mg kg⁻¹ in soil culture and 15.0 mmol L⁻¹ in sand culture. Mn concentrations in leaves and stems reached a maximum of 9612.8 ± 83.5 and 6134.8 ± 94.0 mg kg⁻¹, respectively, in soil culture and 28,465.8 ± 1276.7 and 15,398.4 ± 1148.6 mg kg⁻¹, respectively, in sand culture. Meanwhile, most of the Mn taken from the substrates was transported to the aboveground tissues in soil and sand culture, e.g., over 92.07% of the total Mn taken up by C. oleifera was translocated to shoots in the 10.0 mmol L⁻¹ treatment. Our findings confirmed that C. oleifera exhibited extraordinary Mn accumulation and toleration abilities, and C. oleifera was a suitable species for phytoremediation of Mn-contaminated sites in Guangxi Province.
Показать больше [+] Меньше [-]The applicability of compost, zeolite and calcium oxide in assisted remediation of acidic soil contaminated with Cr(III) and Cr(VI) Полный текст
2019
Radziemska, Maja | Wyszkowski, Mirosław | Bęś, Agnieszka | Mazur, Zbigniew | Jeznach, Jerzy | Brtnický, Martin
The effect of soil amendments, i.e., compost, zeolite, and calcium oxide, on the chemical properties of soil contaminated with Cr(III) and Cr(VI) and the uptake of selected heavy metals by spring barley (Hordeum vulgare L.) and maize (Zea mays L.) was determined in a pot experiment. The content of all investigated heavy metals in the tested plants varied significantly in response to the tested soil amendments and increasing concentrations of Cr(III) and Cr(VI). Compost, zeolite, and calcium oxide contributed to an increase in the average yield of the aerial parts of maize plants only in treatments contaminated with Cr(III). The concentrations of Cr, Zn, and Ni in the aerial parts of spring barley and maize were higher in treatments contaminated with Cr(III) than in treatments contaminated with Cr(VI). Calcium oxide induced a significant increase in soil pH relative to the control treatment. In treatments without soil amendments, the average Cr content of soil was higher in pots contaminated with Cr(VI). The concentrations of Zn and Cu in non-amended treatments were negatively correlated with increasing doses of Cr(III) and Cr(VI). Calcium oxide decreased the average content of Cr, Cu, and Ni in all experimental variants. Compost increased the average content of Zn in treatments contaminated with Cr(III) and Cr(IV) relative to non-amended soil.
Показать больше [+] Меньше [-]Rural solid waste—characteristics and leachate pollution assessment for different precipitation levels, China Полный текст
2019
Yang, Huiyuan | Yue, Bo | Liu, Yanjun | Wu, Xiaohui | Gao, Hong | Zhang, Zhibin | Yan, Zhuoyi
Open dumping adversely affects the environment and remains the most widely used method for waste disposal in many developing rural areas in China. Information regarding the impact of rural solid waste (RSW) on the environment remains limited. The objectives of this study are to investigate the characteristics of RSW and the impact of different precipitation rates, and to evaluate the contamination potential of RSW using a leachate pollution index (LPI). The study showed that leachate concentration was significantly influenced by precipitation rates at the initial precipitation stages. Precipitation rates of 42.00 mm/day appeared to have the largest dilution effects. In contrast, the concentrations of leachate at rainfall rates of 24.00 mm/day and soaking were steady, and no similar trends were observed. The highest amounts of pollutants in leachate were the result of soaking. In the first week of our experiment, the LPI value for each rural area waste sample rapidly increased with rising precipitation rates from soaking to 42.00 mm/day. However, no significant change in LPI was observed thereafter (after 5 weeks) even with increasing precipitation rates. The values of chemical oxygen demand, biochemical oxygen demand, total nitrogen, and NH₃-N in the leachate after 10 weeks were 4.00, 7.34, 1.87, and 2.21 times higher, respectively, than those of the prescribed leachate quality standards in China. The results of our study suggest the following course of action for the three dump sites investigated: in Banqiao, given the size of the population and the size of the waste amount, landfill might be a suitable way for disposing of RSW. In Machen, building a standardized waste collection site would be an economical solution for reducing potential pollution risks. In Jiuduhe, increasing the transportation rate of solid waste might be an effective solution. The results of this study can help to improve the understanding of leachate pollution in Chinese rural areas.
Показать больше [+] Меньше [-]Estimation of the economic loss due to irrigation water use inefficiency in Tunisia Полный текст
2019
Chebil, Ali | Souissi, Asma | Frija, Aymen | Stambouli, Talel
Estimation of the economic loss due to irrigation water use inefficiency in Tunisia Полный текст
2019
Chebil, Ali | Souissi, Asma | Frija, Aymen | Stambouli, Talel
The main objective of this study is to estimate the total economic loss due to inefficient use of irrigation water in Tunisia. Several approaches have been used for this purpose. The optimal level of water application for different crops is calculated using the actual crop evapotranspiration which is based on FAO-56 method. The residual imputation and yield comparison methods have been used to estimate the economic value of irrigation water for different irrigated crops in different bioclimatic areas. For the empirical analysis, primary data were obtained from a series of surveys that covered 78% of the total irrigated areas and were collected within the framework of the “Virtual Water and Food Security in Tunisia project” (2013–2015). Secondary data about land distribution of crops in Tunisia were taken from the Ministry of Agriculture (2016). Around 724 farms were randomly sampled considering their bioclimatic area, farm type, and production system. The survey included the main 20 crops produced in Tunisia. Results show that most of farmers are either under or over utilizing irrigation water. The value of total direct economic losses, at the country level, of both types of water inefficiencies, was estimated to around 470 million Tunisian Dinars. Therefore, an improvement of water use efficiency at field level through dissemination of information/knowledge on irrigation scheduling and crop water requirements by extension services to farmers is needed to reduce this huge economic loss, reach higher sustainability in water use and improve food security.
Показать больше [+] Меньше [-]Estimation of the economic loss due to irrigation water use inefficiency in Tunisia Полный текст
2019
Chebil, Ali | Souissi, Asma | Frija, Aymen | Stambouli, Talel
The main objective of this study is to estimate the total economic loss due to inefficient use of irrigation water in Tunisia. Several approaches have been used for this purpose. The optimal level of water application for different crops is calculated using the actual crop evapotranspiration which is based on FAO-56 method. The residual imputation and yield comparison methods have been used to estimate the economic value of irrigation water for different irrigated crops in different bioclimatic areas. For the empirical analysis, primary data were obtained from a series of surveys that covered 78% of the total irrigated areas and were collected within the framework of the BVirtual Water and Food Security in Tunisia project^ (2013–2015). Secondary data about land distribution of crops in Tunisia were taken from the Ministry of Agriculture (2016). Around 724 farms were randomly sampled considering their bioclimatic area, farm type, and production system. The survey included the main 20 crops produced in Tunisia. Results show that most of farmers are either under or over utilizing irrigation water. The value of total direct economic losses, at the country level, of both types of water inefficiencies, was estimated to around 470 million Tunisian Dinars. Therefore, an improvement of water use efficiency at field level through dissemination of information/knowledge on irrigation scheduling and crop water requirements by extension services to farmers is needed to reduce this huge economic loss, reach higher sustainability in water use and improve food security.
Показать больше [+] Меньше [-]Innovation stages, knowledge spillover, and green economy development: moderating role of absorptive capacity and environmental regulation Полный текст
2019
Zhao, Shuliang | Jiang, Yanhong | Wang, Shanyong
In the past 20 years, the green economy has increasingly attracted the attention of governments and policy makers. However, most studies have only focused on the relationship between the green economy and innovation, and little attention has been given to the relationship between the different innovation stages and the green economy. This study draws on eco-innovation and institutional theories and proposes a model to empirically investigate the effects between the different innovation stages and green economy. Furthermore, it explores how these effects are mediated by knowledge spillover and moderated by absorptive capacity and environment regulations. We use data from the last 5 years (2012–2016) obtained from different China regions to empirically test the model. Results show that knowledge innovation, research and development (R&D) innovation, and product innovation have the same significant positive impact on knowledge spillovers. R&D and product innovation have a significant positive impact on green economy, whereas knowledge innovation has no significant effect on the development of the green economy. Knowledge spillover partially mediates the relationship between the innovation stage and the green economy. Meanwhile, absorptive capacity positively moderates the relationship between knowledge spillover and the green economy. However, environmental regulation negatively moderates the relationship between knowledge spillover and the green economy. In addition, corresponding measures are proposed based on the conclusions.
Показать больше [+] Меньше [-]Impact of phosphate additive on organic carbon component degradation during pig manure composting Полный текст
2019
Wu, Juan | Zhang, Aiguo | Li, Guoxue | Wei, Yuquan | Jia, Fuya | Liang, Ying | Cheng, Yandong | Liu, Yan
Phosphate, as an additive to composting, could significantly reduce ammonia emission and nitrogen loss but may also cause adverse effects on the degradation of organic matter. However, there is little information about the influence of pH change, salt content, and phosphate on different organic fraction degradation during composting with the addition of phosphate at a higher level. In this study, the equimolar phosphoric acid (H₃PO₄), sulfuric acid (H₂SO₄), and dipotassium phosphate (K₂HPO₄) were added into pig manure composting with 0.25 mol mass per kilogram of dry matter basis addition amount to evaluate the effect of H⁺, PO₄³⁻, and salinity on carbon component transformation and organic matter degradation. The results showed that both H₃PO₄ and K₂HPO₄ additives could lead to shorter duration in the thermophilic phase, lower degradation of lignocellulose, and lesser carbon loss compared to CK, even though had different pH, i.e., acidic and alkaline conditions, respectively. Besides, the addition of H₃PO₄, H₂SO₄, and K₂HPO₄ could increase the degradation of soluble protein and lipid during composting. Redundancy analysis demonstrated that the variation in different organic carbon fractions was significantly correlated with the changes of pH and the presence of PO₄³⁻, but not with SO₄²⁻ and electrical conductivity, suggesting that pH and phosphate were the more predominant factors than salinity for the inhibition of organic matter degradation. Taken together, as acidic phosphate addition produces a true advantage of controlling nitrogen loss and lower inhibition of organics transformation during composting, the expected effects may result in more efficient composting products.
Показать больше [+] Меньше [-]Renewables, food (in)security, and inflation regimes in the coastline Mediterranean countries (CMCs): the environmental pros and cons Полный текст
2019
Alola, Andrew Adewale | Yalçiner, Kürşat | Alola, Uju Violet
In the present (twenty-first) century, the pertinent challenge of attaining the regime of food security with low pollution amidst the drive for sustainable economy and energy efficiency is core to governance and intergovernmental agencies. Therefore, in an attempt to investigate environmental issues among the coastline Mediterranean countries (CMCs) for the first time, the current study examines the dynamic long-run nexus of carbon dioxide (CO₂) emissions with food production and inflation rate over the annual period 1995–2014. Using a dynamic Autoregressive Distributed Lag (ARDL) approach, the consumption of renewable energy in the panel of sixteen (16) CMCs is empirically observed to be an efficient policy vehicle for mitigating CO₂ emissions. Also, in all the examined CMCs, consumption of renewables is observed to cause significant decline in CO₂ emissions, thus securing a sustainable environment. However, in the long run and in the panel of CMCs, the study reveals that increase in food production (a drive toward food security) increases environmental risk. Additionally, the study found that high inflation regime in the panel CMCs is associated with low CO₂ emissions especially in the long-run, thus necessitating efficient policy mechanism. In adopting the genetic resources of the International Treaty on Plant Genetic Resources, as well as employing price control policy, the members of the CMCs might have unearthed a suitable policy directive in effectively sustaining environmental quality.
Показать больше [+] Меньше [-]Adsorption of ibuprofen using cysteine-modified silane-coated magnetic nanomaterial Полный текст
2019
Kollarahithlu, Smitha Chandrashekar | Balakrishnan, Raj Mohan
Industrialization and growth of the pharmaceutical companies have been a boon to the mankind in our day to day life in myriad ways. However, due to the uninhibited release of these active pharmaceutical compounds into the water systems has caused detrimental effects to the genetic pool. In this study, L-cysteine-modified 3-glycidyloxypropyltrimethoxysilane-coated magnetic nanomaterial showed a maximum removal of the efficiency of 82.90% for the nanomaterial dosage of 30 mg at an initial concentration of 50 mg L⁻¹ at pH 6.0. Further, the nanomaterial showed reusability efficiency up to 80% for three cycles. The adsorption kinetics follow the pseudo-second-order reaction and the adsorption isotherm model best fits the Langmuir isotherm proving the adsorption process to be a monolayer sorption on a monolayer surface. This magnetic nanomaterial could serve as a promising tool for the removal of pharmaceutical compounds from aqueous solutions. Graphical abstract ᅟ
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