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A review for tannery wastewater treatment: some thoughts under stricter discharge requirements Full text
2019
Zhao, Changqing | Chen, Wuyong
To meet the extremely strict requirements of tannery wastewater, scientists need to urgently devise novel methods for controlling the quality of tannery wastewater. With these methods, it would be easier to promote sustainable development in the tannery industry. In this article, we summarize the following aspects of tannery wastewater: (i) the sources and characteristics of tannery wastewater, (ii) the main treatment methods (primary, secondary, and tertiary treatments), and (iii) resource utilization status of wastewater. In a brief introduction, we describe how tannery wastewater is currently subjected to single-pollutant treatment methods that strive to remove various toxic chemicals, including total nitrogen, total phosphorus, chloride ion, chromic salts, sulfur-containing compounds, and dyes. The methods for treating tannery wastewater is proposed. We anticipate that by using a proposed combination treatment techniques, the effluents in tannery wastewater can eventually be controlled to satisfy the stricter standards of wastewater disposal. Moreover, we also focus our efforts on recycling wastewater.
Show more [+] Less [-]Assessing interactions, predicting function, and increasing degradation potential of a PAH-degrading bacterial consortium by effect of an inoculant strain Full text
2019
Macchi, Marianela | Festa, Sabrina | Vega-Vela, Nelson E. | Morelli, Irma S. | Coppotelli, Bibiana M.
A natural phenanthrene-degrading consortium CON was inoculated with an exogenous strain Sphingobium sp. (ex Sp. paucimobilis) 20006FA yielding the consortium called I-CON, in order to study ecological interactions into the bacterial community. DGGE and proteomic profiles and analyses by HTS (High-Throughput Sequencing) technologies demonstrated inoculant establishment and changes on CON composition. Inoculation increased degradation efficiency in I-CON and prevented intermediate HNA accumulation. This could be explained not only by the inoculation, but also by enrichment in Achromobacter genus at expense of a decrease in Klebsiella genus. After inoculation, cooperation between Sphingobium and Achromobacter genera were improved, thereby, some competition could have been generated, and as a consequence, species in minor proportion (cheaters), as Inquilinus sp. and Luteibacter sp., were not detected. Sequences of Sphingobium (corresponding to the inoculated strain) did not vary. PICRUSt predicted a network with bacterial phylotypes connected with enzymes, showing functional redundancy in the phenanthrene pathway, with exception of the first enzymes biphenyl-2,3-diol 1,2-dioxygenase and protocatechuate 4,5-dioxygenase that were only encoded in Sphingobium sp. This is the first report where a natural consortium that has been characterized by HTS technologies is inoculated with an exogenous strain in order to study competitiveness and interactions.
Show more [+] Less [-]Development of a novel wind-assisted centralized spraying dedusting device for dust suppression in a fully mechanized mining face Full text
2019
Peng, Huitian | Nie, Wen | Cai, Peng | Liu, Qiang | Liu, Zhiqiang | Yang, Shibo
Aiming at addressing serious pollution in the No. 30106 fully mechanized coal mining face of Shiquan Coal Mine during coal cutting process, the spraying device between hydraulic supports was improved through the combination of experimental analysis, numerical simulation, and field measurement, and a novel wind-assisted centralized spraying dedusting device was developed. The newly developed device could make the formed spraying field more concentrated on the dust-producing source around the coal shearer’s drum, and thus significantly enhanced the spraying performance. According to numerical simulation results, the spraying performance reached the optimum at a hydraulic pressure of 8 MPa for the spraying device and an air pressure of 1 MPa for the pneumatic motor; under these optimal conditions, the droplet concentration in the spraying field around the coal cutter drum was as high as 24.85 g/m³, and the formed high-concentration spraying field could basically cover the whole section in the spraying field from coal wall to the support pillar. Field measured results revealed that, at a hydraulic pressure of 8 MPa and an air pressure of 1 MPa, the dust suppression rate around coal cutter driver reached up to 87.96%, suggesting that the developed wind-assisted centralized spraying dedusting device had remarkable dust suppression performance and could effectively improve the operating environment in the fully mechanized mining face. Graphical Abstract In this paper, we have designed a novel wind-assisted centralized spraying dedusting device and studied the optimal spray parameters. Firstly, the nozzles were selected according to the multi-factor experimental platform for measuring the spraying field’s atomization characteristics. Secondly, we had a numerical simulation of the fully mechanized mining face. And the third, we tested the effect of dust removal.
Show more [+] Less [-]Physiological damages of Sargassum cymosum and Hypnea pseudomusciformis exposed to trace metals from mining tailing Full text
2019
Costa, Giulia Burle | Ramlov, Fernanda | de Ramos, Bruna | Koerich, Gabrielle | Gouvea, Lidiane | Costa, Patrícia Gomes | Bianchini, Adalto | Maraschin, Marcelo | Horta, Paulo A. Jr
The damages of Mariana’s mining mud in the physiology of the brown algae Sargassum cymosum and its main epiphytic, the red algae Hypnea pseudomusciformis, were evaluated by controlled essays. Seaweeds were exposed to presence or absence of mud, isolated or in biological association, for 5 and 15 days. Measured parameters were growth rates, biochemical descriptors, and the chemical investigation of concentration and metal profile of the mud dissolved in seawater. Results showed that the highest values for metals were Al > Fe > Mn > Zn in both exposure periods. The mud also affected the growth rate with lethality in both isolated and associative treatments with H. pseudomusciformis after 15 days. According to our redundancy analysis (RDA), the profile and concentration of all metallic elements can induce different physiological responses of the organisms. We were able to observe a higher physiological adaptive ability of S. cymosum against the long-term presence of metals by the synthesis of phenolic compounds, while the deviation of metabolic routes in H. pseudomusciformis can be addressed as the main responsible for its lethality. Moreover, the presence of Hypnea in associative treatments reduces Sargassum’s detoxification ability. The present results reinforce the importance of biological interaction studies in a context of physiological resilience against mining mud pollution and mutual influences of species over the individual ability to avoid oxidative stress.
Show more [+] Less [-]The impact of textual and pictorial warnings on tumbac (waterpipe tobacco) boxes on the motivation and intention to quit waterpipe smoking in Lebanon: a cross-sectional study Full text
2019
Hallit, Souheil | Layoun, Nelly | Malaeb, Diana | Outayek, Miguella | Boueid, Marie-Josée | Waked, Mirna | Bacha, Zeina Aoun | Salameh, Pascale
Few published studies have examined the impact of waterpipe tobacco pictorial health warnings worldwide but none of these papers assessed the motivation and intention to quit among Lebanese waterpipe smokers. To examine factors associated with the motivation and intention to quit waterpipe smoking (WS) in Lebanon, particularly the impact of textual vs. pictorial warnings on tumbac boxes. A cross-sectional study was conducted between January and May 2018, involving 520 participants. Having smokers at work (OR = 0.92) and increasing number of waterpipes per week (ORa = 0.94) were associated with decreased motivation to quit WS. Thinking that shocking images on tumbac packages would have more effect than textual warnings (ORa = 2.96) and those who would change the tumbac if the company decides to change the look of the box with shocking images about health damage (ORa = 1.98) were significantly associated with increased motivation to quit WS. Having a high motivation (ORa = 2.61), thinking that using shocking images on tumbac boxes can have more effect than textual warnings (ORa = 2.12), those who stopped smoking because of the warnings (ORa = 2.62), those who would choose pictorial warnings alone (ORa = 2.11), and both pictorial and textual warnings (ORa = 3.41) on tumbac packages were associated with higher intention to quit WS in two months. Pictorial and textual warnings on tumbac packs were associated with higher intention and motivation to stop WS. Public health education programs for this purpose seem warranted.
Show more [+] Less [-]Optimizing irrigation and nitrogen requirements for maize through empirical modeling in semi-arid environment Full text
2019
Ahmad, Ishfaq | Wajid, Syed Aftab | Ashfaq, Ahmad | Cheema, Muhammad Jehanzeb Masud | Judge, Jasmeet
Uncertainty in future availability of irrigation water and regulation of nutrient amount, management strategies for irrigation and nitrogen (N) are essential to maximize the crop productivity. To study the response of irrigation and N on water productivity and economic return of maize (Zea mays L.) grain yield, an experiment was conducted at Water Management Research Center, University of Agriculture Faisalabad, Pakistan in 2015 and 2016. Treatments included of full and three reduced levels of irrigation, with four rates of N fertilization. An empirical model was developed using observed grain yield for irrigation and N levels. Results from model and economic analysis showed that the N rates of 235, 229, 233, and 210 kg ha⁻¹ were the most economical optimum N rates to achieve the economic yield of 9321, 8937, 5748, and 3493 kg ha⁻¹ at 100%, 80%, 60%, and 40% irrigation levels, respectively. Economic optimum N rates were further explored to find out the optimum level of irrigation as a function of the total water applied using a quadratic equation. The results showed that 520 mm is the optimum level of irrigation for the entire growing season in 2015 and 2016. Results also revealed that yield is not significantly affected by reducing the irrigation from full irrigation to 80% of full irrigation. It is concluded from the study that the relationship between irrigation and N can be used for efficient management of irrigation and N and to reduce the losses of N to avoid the economic loss and environmental hazards. The empirical equation can help farmers to optimize irrigation and N to obtain maximum economic return in semi-arid regions with sandy loam soils.
Show more [+] Less [-]Determination of histological, immunohistochemical and biochemical effects of acute and chronic grayanotoxin III administration in different doses in rats Full text
2019
Doğanyiğit, Züleyha | Silici, Sibel | Demirtaş, Abdullah | Kaya, Ertuğrul | Kaymak, Emin
Grayanotoxin (GTX)-III is a Na-channel neurotoxin. Grayanotoxins can be found in the nectar, pollen, and other plant parts of the Rhododendron genus plants from the Ericaceae family. It is widely believed that honey produced from these plants, which are concentrated in the Black Sea region, is traditionally characterized as enhancing sexual performance. It is thought that the effective factor is dose for this compound, which has both beneficial and toxic effects reported. Therefore, it is aimed to evaluate the histological, immunohistochemical, and biochemical effects of acute and chronic impact of GTX-III in different doses on testes tissue in this study. For this purpose, 100 Sprague-Dawley male rats were divided into 5 separate groups for acute and chronic research. While dose groups were (control, 0.1, 0.2, 0.4, ve 0.8 μg/kg/bw) for experimental groups, a single dose (i.p.) was administered for acute impact whereas the same doses were administered daily for 3 weeks to assess chronic effect. At the end of the experiment, Johnsen testicular biopsy scoring was performed on testicular tissue samples, seminiferous tubule diameters were measured, and apoptotic cells were evaluated by TUNEL method. Testosterone, LH, and FSH levels were measured by ELISA method in serum and tissue specimens. It was found that Johnsen score of acute doses was significantly lower than the control group, and the diameter of the seminiferous tubules decreased significantly in acute and chronic dose-administered groups compared to the control. Hemorrhage, epithelial shedding, irregularity in seminiferous epithelium, and vacuolization were observed in acute and chronic dose-administered groups, and increase in apoptotic cells was determined. Hormone levels varied depending on the dose. In conclusion, it was found that dose-dependent acute and chronic effects of GTX-III are different, and this factor should be taken into account in studies to be carried out due to the adverse effects of high doses.
Show more [+] Less [-]Pressure and impact of anthropogenic litter on marine and estuarine reptiles: an updated “blacklist” highlighting gaps of evidence Full text
2019
Staffieri, Eleonora | de Lucia, Giuseppe Andrea | Camedda, Andrea | Poeta, Gianluca | Battisti, Corrado
We report an arrangement on the effect of anthropogenic litter on marine and estuarine reptiles, checking for evidence about different types of impact (ingestion vs. entanglement) and pressure (three size-based categories). From 1976 to 2018, we obtained a “blacklist” of 11 species impacted by marine litter (about 13% of 85 species of marine and estuarine reptiles), belonging to three orders (Testudines, Squamata, and Crocodilia). We obtained only occasional evidence of an impact for Squamata (Hidrophis elegans, Disteira major) and Crocodilia (Crocodylus porosus). Regarding the different types of pressure, the highest number of evidence has been obtained for macro-litter (10 species) and the lowest for micro-litter (4 species, all Chelonidae). Among Testudines, Lepidochelys kempii and Natator depressus evidenced a lack of data for micro-plastic. In Squamata, information is lacking for micro-plastic with only occasional references for meso-plastic (in Hydrophis elegans) and macro-plastic (Disteira major and Crocodylus porosus). We obtained a direct correlation between the research effort and the number of citations regarding different types of pressure and impact of marine litter: therefore, our blacklist of impacted species could be increased, carrying out further research focused on other poorly studied marine and estuarine reptiles. We suggest the use of a standardized nomenclature to reduce the amount of lost information.
Show more [+] Less [-]The impact of globalization and financial development on environmental quality: evidence from selected countries in the Organization for Economic Co-operation and Development (OECD) Full text
2019
Zafar, Muhammad Wasif | Saud, Shah | Hou, Fujun
This study investigates the impacts of globalization and financial development on environmental quality by incorporating energy consumption in the framework of the Environmental Kuznets Curve (EKC) hypothesis for selected countries in the Organization for Economic Co-operation and Development (OECD) over the 1990–2014 time spans. The cross-sectional dependence is determined by using the cross-sectional dependence and Lagrange Multiplier (LM) methods. This study employs second-generation panel unit root tests to check the unit root properties and the Westerlund panel cointegration test to examine the long-run equilibrium relationship among the variables. The results confirm the presence of cointegration in the long run. The Continuously Updated Fully Modified Ordinary Least Square (CUP-FM) and Continuously Updated Bias-Corrected (CUP-BC) approaches are applied to investigate long-term output elasticities of the variables. The results show the stimulating role of energy consumption on Carbon dioxide (CO₂) emissions. This study finds support for the EKC hypothesis as it relates to selected OECD countries. Globalization and financial development increase environmental quality by reducing CO₂ emissions. The causal relationship reveals the presence of a bidirectional relationship between energy consumption and CO₂ emissions. The feedback causal effect runs between economic growth and CO₂ emissions and between globalization and economic growth, while unidirectional causality runs from CO₂ emissions to financial development, from economic growth to energy consumption, from energy consumption to financial development, from globalization to energy consumption, and from globalization to financial development. Policies that support green technology transfer among OECD countries, foreign direct investment in the renewable energy sector, financial development to support green infrastructure, and energy generation using renewable energy sources are recommended.
Show more [+] Less [-]Human health damages related to air pollution in China Full text
2019
Gu, Hejun | Cao, Yuxia | Elahi, Ehsan | Jha, Sunil Kumar
In recent years, air pollution in China has posed serious threats to human health. In this study, we investigate the relationship between air pollution and residents’ health by nesting the household registration data of the China Migrant Dynamic Survey in 2014 with city characteristic data and pollution data. The results indicated that an increase in the concentration of air pollution significantly reduced residents’ health levels. After using the instrumental variable (IV)-Oprobit model to solve endogenous problem, we have found that the negative impact of air pollution on residents’ health remained significant. Moreover, the lag term of environmental indexes was introduced and found that air pollution significantly increased health risk. The results also demonstrated that the impact of air pollution on human health was heterogeneous. Men and urban residents were more sensitive to air pollution and more adversely affected. In addition to air pollution, the study found that, among the influencing factors at the individual level, males’ health was better than females’ health, and education positively impacted on residents’ health. The health effects were consistent with the theoretical predictions of the Grossman model. The financial expenditure and medical input were negatively correlated with residents’ health levels. Based on the results, we suggest the Chinese government should implement rigorous air pollution laws and regulations.
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