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Enhancing anti-microbial properties of wood-plastic composites produced from timber and plastic wastes Texto completo
2017
Wang, Lei | Chen, Season S. | Tsang, Daniel C. W. | Poon, C. S. (Chi-sun) | Ok, Yong Sik
Considering the resource waste and environmental burden for timber and plastic materials ending up at landfills, this study proposed upcycling wood and plastic waste into value-added wood-plastic composites (WPCs), complying with the standard requirements of flexural strength, thickness swelling, water absorption and thermal insulation. Biological deterioration is a major concern of WPCs. Bacterial survival, fungal attack and algal growth of bactericide-treated WPCs were holistically analysed. Melamine resin was adopted for impregnating anti-microbial agents on the surface. All the agents showed excellent bactericidal rate (Escherichia coli), yet poly-diallyl-dimethyl-ammonium chloride (PolyDADMAC) and silver had the lowest minimum inhibitory concentrations. In terms of weight loss and strength reduction due to fungal decay (Coriolus versicolor), PolyDADMAC, silver and cetyltrimethylammonium bromide (CTAB) imparted the highest resistance on the WPCs. Moreover, PolyDADMAC and copper provided the most protection against algal growth (Chlorella vulgaris), and the former presented durable inhibitory effect. This study presents a value-added solution to wood/plastic waste recycling.
Mostrar más [+] Menos [-]Heavy metal monitoring, analysis and prediction in lakes and rivers: state of the art Texto completo
2017
Elzwayie, Adnan | Afan, Haitham Abdulmohsin | Allawi, Mohammed Falah | El-Shafie, Ahmed
Several research efforts have been conducted to monitor and analyze the impact of environmental factors on the heavy metal concentrations and physicochemical properties of water bodies (lakes and rivers) in different countries worldwide. This article provides a general overview of the previous works that have been completed in monitoring and analyzing heavy metals. The intention of this review is to introduce the historical studies to distinguish and understand the previous challenges faced by researchers in analyzing heavy metal accumulation. In addition, this review introduces a survey on the importance of time increment sampling (monthly and/or seasonally) to comprehend and determine the rate of change of different parameters on a monthly and seasonal basis. Furthermore, suggestions are made for future research to achieve more understandable figures on heavy metal accumulation by considering climate conditions. Thus, the intent of the current study is the provision of reliable models for predicting future heavy metal accumulation in water bodies in different climates and pollution conditions so that water management can be achieved using intelligent proactive strategies and artificial neural network (ANN) techniques.
Mostrar más [+] Menos [-]Preliminary recovery study of a commercial molecularly imprinted polymer for the extraction of glyphosate and AMPA in different environmental waters using MS Texto completo
2017
Claude, Bérengère | Berho, Catherine | Bayoudh, Sami | Amalric, Laurence | Coisy, Emeline | Nehmé, Reine | Morin, Philippe
A commercial molecularly imprinted polymer (MIP) dedicated to glyphosate (GLY) and its main metabolite, aminomethylphosphonic acid (AMPA), was lately assessed as “POCIS-like” sampler on mineral water. The obtained results were encouraging with 111 and 122 mL day⁻¹ as sampling rates for GLY and AMPA, respectively. Therefore, before applying this passive sampler to environmental waters, the commercial phase was tested on different water matrices as a solid-phase extraction (SPE) device. The SPE protocol was carried on 250 mg of MIP with the following three steps: conditioning by Milli-Q water, loading of the sample (15 mL), and elution of the analytes by 4 mL 0.1 M HCl that were evaporated to dryness and recovered in 15 mL of the suitable solvent for analysis. This protocol was first applied to mineral water spiked by GLY and AMPA at environmental concentration levels (25–750 ng L⁻¹). Analyses were carried out by ultra-performance liquid chromatography hyphenated to tandem mass after derivatization of GLY and AMPA by 9-fluorenylmethylchloroformate. The linear correlation between concentrations measured with and without SPE on MIP was proved.Furthermore, other extractions showed that high concentrations of metal ion interferents (lead(II), cadmium(II), and zinc(II)) in groundwaters did not reduce SPE performance of the MIP.Then, concentration assays were undertaken and brought noteworthy results, such as the recovery of 80% GLY and AMPA from groundwater spiked at 10 ng L⁻¹ and concentrated 100 times. For this purpose, ion exclusion chromatography hyphenated to mass was applied without previous derivatization of the analytes. The same concentration factor and analytical method were applied to 100 ng L⁻¹ spiked sea water with recoveries of 96% for GLY and 121% for AMPA.
Mostrar más [+] Menos [-]Influences of operational parameters on phosphorus removal in batch and continuous electrocoagulation process performance Texto completo
2017
Nguyen, Dinh Duc | Yoon, Yong Soo | Bui, Xuan Thanh | Kim, Sung Su | Chang, Soon Woong | Guo, Wenshan | Ngo, Huu Hao
Performance of an electrocoagulation (EC) process in batch and continuous operating modes was thoroughly investigated and evaluated for enhancing wastewater phosphorus removal under various operating conditions, individually or combined with initial phosphorus concentration, wastewater conductivity, current density, and electrolysis times. The results revealed excellent phosphorus removal (72.7–100%) for both processes within 3–6 min of electrolysis, with relatively low energy requirements, i.e., less than 0.5 kWh/m³ for treated wastewater. However, the removal efficiency of phosphorus in the continuous EC operation mode was better than that in batch mode within the scope of the study. Additionally, the rate and efficiency of phosphorus removal strongly depended on operational parameters, including wastewater conductivity, initial phosphorus concentration, current density, and electrolysis time. Based on experimental data, statistical model verification of the response surface methodology (RSM) (multiple factor optimization) was also established to provide further insights and accurately describe the interactive relationship between the process variables, thus optimizing the EC process performance. The EC process using iron electrodes is promising for improving wastewater phosphorus removal efficiency, and RSM can be a sustainable tool for predicting the performance of the EC process and explaining the influence of the process variables.
Mostrar más [+] Menos [-]Erratum to: Sub-chronic exposure to low concentration of dibutyl phthalate affects anthropometric parameters and markers of obesity in rats Texto completo
2017
Majeed, Khalid Abdul | ur Rehman, Habib | Yousaf, Muhammad Shahbaz | Zaneb, Hafsa | Rabbani, Imtiaz | Tahir, Sajid Khan | Rashid, Muhammad Afzal
The correct name of the 1st and corresponding Author is Khalid Abdul Majeed.
Mostrar más [+] Menos [-]Integrated monitoring for environmental health impact assessment related to the genotoxic effects of vehicular pollution in Uberlândia, Brazil Texto completo
2017
Pereira, Boscolli Barbosa | da Cunha, Paolla Brandão | Silva, Guilherme Gomes | de Campos Júnior, Edimar Olegário | Morelli, Sandra | Filho, Cláudio Alves Vieira | de Lima, Euclides Antônio Pereira | Barrozo, Marcos Antônio Souza
The development of parameters to explore the link between air-related diseases and their significant driving forces is an important aim in terms of national economics and public health. In this study, we did an integrated analysis involving multiple environmental health indicators from Uberlândia, Brazil, registered before and during a period when the Brazilian government reduced taxes on new cars in a bid to bolster local manufacturing. In addition, the present study utilized Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA) frameworks to evaluate correlations in environmental health indicators over 10 years (2004–2013), in which the Brazilian government reduced vehicle production taxes beginning in 2008. Significant correlations in all indicators selected were found from 2008 to 2013, corresponding to the tax reduction on new vehicles. The frequency of micronuclei (MN) was significantly higher in the city center compared to the reference site, with the highest MN levels observed during the period of reduced taxes. Results reinforced the need to adopt air quality monitoring programs in major cities.
Mostrar más [+] Menos [-]A two-stage fuzzy chance-constrained water management model Texto completo
2017
Xu, Jiaxuan | Huang, Guohe | Li, Zoe | Chen, Jiapei
In this study, an inexact two-stage fuzzy gradient chance-constrained programming (ITSFGP) method is developed and applied to the water resources management in the Heshui River Basin, Jiangxi Province, China. The optimization model is established by incorporating interval programming, two-stage stochastic programming, and fuzzy gradient chance-constrained programming within an optimization framework. The hybrid model can address uncertainties represented as fuzzy sets, probability distributions, and interval numbers. It can effectively tackle the interactions between pre-regulated economic targets and the associated environmental penalties attributed to water allocation schemes and reflect the tradeoffs between economic revenues and system-failure risk. Furthermore, uncertainties associated with the decision makers’ preferences are considered in decision-making processes. The obtained results can provide decision support for the local sustainable economic development and water resources allocation strategies under multiple uncertainties.
Mostrar más [+] Menos [-]First investigation of trace metal distribution in surface seawater and copepods of the south coast of Sfax (Tunisia) Texto completo
2017
Ben Salem, Zohra | Ayadi, Habib
The increased metal loading from anthropogenic sources has affected aquatic ecosystems and has cascaded through food webs worldwide. Therefore, the evaluation of ecological impacts of anthropogenic metal has become increasingly important. In this paper, we monitored the concentration of six trace metals (Cd, Cu, Fe, Ni, Pb, and Zn) in the three copepod groups (cyclopoida, calanoida, and harpacticoida) and in seawater samples collected from the south coast of Sfax (Tunisia). Results showed that the concentration of Fe and Zn for all copepod groups was higher than that for other metals and that of Cd was the lowest in all groups. The mean increase in bioconcentration factor of metals in copepods ranged from 0.05 to 18.93 and followed the sequence Zn (18.93) > Fe (14.34) > Pb (6.41) > Cd (1.53) > Cu (0.10) > Ni (0.05). The copepods in the south coast of Sfax were found to have a great capacity to accumulate trace metals and act as contamination indicators. Comparative studies with those from the Luza zone indicate considerable bioaccumulation of trace metals (Pb and Ni) in all copepod groups namely in cyclopoida.
Mostrar más [+] Menos [-]A comparative study of hospital admissions for respiratory diseases during normal and dusty days in Iran Texto completo
2017
Geravandi, Sahar | Sicard, Pierre | Khaniabadi, Yusef Omidi | De Marco, Alessandra | Ghomeishi, Ali | Goudarzi, Gholamreza | Mahboubi, Mohammad | Yari, Ahmad Reza | Dobaradaran, Sina | Hassani, Ghasem | Mohammadi, Mohammad Javad | Sadeghi, Shahram
During the last century, most of people around the world moved from communicable to non-communicable diseases, mainly due to air pollution. Air pollutants and dust storm increase risk of morbidity, for cardiovascular and respiratory diseases, and increase the number of deaths. The city of Ahvaz is considered as the focal point of air pollution and dust storm in Iran. The aim of this study was to determine the number of Hospital Admission Respiratory Disease (HARD) including asthma attacks, acute bronchitis and chronic obstructive pulmonary disease attributed to PM₁₀ by a descriptive study during normal and dust event days in Ahvaz during the time period 2010–2012. The hourly PM₁₀ data was collected from the Iranian Environmental Protection Agency and Razi hospital. The annual PM₁₀ mean concentrations reached 282, 288 and 278 μg/m³ in 2010, 2011 and 2012, respectively. The number of HARD attributed to PM₁₀ was 1438, 1945 and 1393 people, respectively, and the highest number of daily admissions was attributed to the highest daily PM₁₀ concentration in Ahvaz. The average number of daily HARD during dusty days was higher than normal days, and a significant positive correlation, between the number of hospital admissions and dusty days, was found. Dust had significant impact on HARD in Ahvaz.
Mostrar más [+] Menos [-]Soil properties and microbial ecology of a paddy field after repeated applications of domestic and industrial sewage sludges Texto completo
2017
Liu, Xiaoyan | Liu, Wuxing | Wang, Qingling | Wu, Longhua | Luo, Yongming | Christie, Peter
The effects of repeated application of two types of sewage sludge, domestic and industrial (petrochemical, PSS) sludges, into paddy fields over a 5-year period on the soil properties and microbial ecology were studied and compared with conventional NPK fertilizer application. Soil organic matter and total nitrogen contents were significantly higher in the two sludge treatments than that in fertilized plots after 5 years. Soil concentrations of potentially toxic metals were low after 5 years of both sludge treatments, but the polycyclic aromatic hydrocarbons (PAHs) showed differences between the two sludge types. Concentrations of high-molecular-weight PAHs were significantly higher (p < 0.05) in the petrochemical sludge treatment than the domestic sludge treatment or the fertilizer control, although the total concentrations of 16 types of PAH in the petrochemical sludge treatment were only slightly higher than in the domestic sludge treatment and the control. The biological toxicity of soil dimethyl sulfoxide extracts from the petrochemical sludge treatment was also significantly higher (p < 0.05) than those from the fertilizer control and the domestic sludge treatment when evaluated using Photobacterium phosphoreum T3. Both types of sewage sludge increased soil microbial activity, but only the petrochemical sludge led to enrichment with specific PAH degraders such as Mycobacterium, Nocardioides, and Sphingomonas.
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