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221.

Introduction  

In Egypt, the picture of threats to humans and the environment from the exposure to organic pollutants is still incomplete. Thus the objectives of this study were to assess the occurrence and distribution of polychlorinated biphenyls (PCBs), organochlorine pesticides, and chlorpyrifos in sediments and mussels of Abu Qir Bay and their risks for environment and human health.  相似文献   
222.
Environmental Science and Pollution Research - The objective of the study is to conduct the socio-economic and environmental survey about the feasibility of Saudi Arabia-China-Pakistan Economic...  相似文献   
223.

In this experimental study, the feasibility of using the oil obtained from waste fishing net as a substitute for diesel fuel was investigated. Waste fishing net oil (WFNO) was obtained through pyrolysis process on a laboratory scale setup and used as a fuel in diesel engine. The properties of oil obtained from waste fishing net were examined and compared with conventional diesel fuel. Results indicated that the WFNO possesses excellent fuel properties. The calorific value of WFNO is 44,450 kJ/kg, which is higher than diesel by 1.48%. In order to study the possibility of using WFNO and its blends (WFNO 25%, WFNO 50%, WFNO 75% and WFNO 100%) with diesel as a fuel, an experimental investigation was carried out on a single-cylinder, four-stroke diesel engine. Experimental results proved that WFNO works satisfactorily on a diesel engine without any engine modifications. Brake thermal efficiency was decreased and brake-specific fuel consumption was increased while using WFNO and its blends. Moreover, there was a slight increase in engine emissions like CO, UHC, NO with WFNO and its blends.

  相似文献   
224.
Silver nanoparticles (AgNPs) possess properties that are important for industrial and medical applications. This study is aimed to investigate intra-peritoneal toxicity of AgNPs at 26, 52 or 78 mg/kg/day for 5 days in mice Swiss albino mice. The effects on oxidative stress markers activities of serum superoxide dismutase (SOD) and catalase (CAT), levels of serum glutathione (GSH), apoptosis (TUNEL assay), DNA strand breaks (comet assay) in lymphocytes, as well as histopathological of kidney tissue were determined. AgNPs significantly increased SOD and CAT activities reduced GSH levels. In kidney apoptosis (TUNEL assay) while DNA strand breaks (comet assay) in lymphocytes revealed that AgNPs at concentration 78 mg/kg produced significant apoptosis and DNA damage. AgNPs also produced associated histological renal tissue damage. Evidence suggests that AgNPs-mediated alterations may be attributed to oxidative stress.  相似文献   
225.
Environmental Science and Pollution Research - Since the industrial revolution in the 1800s, plastic pollution is becoming a global reality. This study aims to assess knowledge and attitude about...  相似文献   
226.
Landfills throughout the world are contributing to the global warming problem. This is due to the existence of the most important greenhouse gases (GHG) in landfill gas (LFG); namely, methane (CH4) and carbon dioxide (CO2). The aim of this paper is quantifying the total potential emissions, as well as the variation in production with time of CH4 from a proposed landfill (El Fukhary landfill) in the Gaza Strip, Palestine. Two different methods were adopted in order to quantify the total potential CH4 emissions; the Default methodology based on the intergovernmental panel on climate change (IPCC) 1996 revised guidelines and the Landfill Gas Emissions model (LandGEM V3.02) provided by the United States Environmental Protection Agency (EPA). The second objective of the study has been accomplished using the Triangle gas production model. The results obtained from both Default and LandGEM methods were found to be nearly the same. For 25 years of disposing MSW, El Fukhary landfill expected to have potential CH4 emissions of 1.9542 ± 0.0037 ×109 m3. Triangle model showed that the peak production in term of CH4 would occur in 2043; 28 years beyond the open year. Moreover, the model shows that 50 % of the gas will be produced approximately at the middle of the total duration of gas production. Proper control of Methane emissions from El Fukhary landfill is highly suggested in order to reduce the harmful effects on the environment.

Implications: Although, GHG emissions are extensively discussed in the developed countries throughout the world, it has gained little concern in the developing countries because they are forced most of the time to put environmental concerns at the end of their priority list. The paper shows that developing countries have to start recognizing their fault and change their way of dealing with environmental issues especially GHG emissions (mainly Methane and carbon dioxide). The authors estimated the potential methane emissions from a proposed central landfill that has been approved to be built in Palestine, a country that is classified as a developing country.  相似文献   

227.
An artificial neural network (ANN) can help in the prediction of advanced water treatment effluent and thus facilitate design practices. In this study, sets of 225 experimental data were obtained from a wastewater treatment process for the removal of phosphorus using oven-dried alum residuals in fixed-bed adsorbers. Five input variables (pH, initial phosphorus concentration, wastewater flow rate, porosity, and time) were used to test the efficiency of phosphorus removal at different times, and ANNs were then used to predict the effluent phosphorus concentration. Results of experiments that were conducted for different values of the input parameters made up the data used to train and test a multilayer perceptron using the back-propagation algorithm of the ANN. Values predicted by the ANN and the experimentally measured values were compared, and the accuracy of the ANN was evaluated. When ANN results were compared to the experimental results, it was concluded that the ANN results were accurate, especially during conditions of high phosphorus concentration. While the ANN model was able to predict the breakthrough point with good accuracy, the conventional advection-diffusion equation was not as accurate. A parametric study conducted to examine the effect of the initial pH and initial phosphorus concentration on the effluent phosphorus concentration at different times showed that lower influent pH values are the most suitable for this advanced treatment system.  相似文献   
228.
ABSTRACT

This study examined the vulnerability of smallholder livestock farmers in North-West Ghana to climate change using data obtained from 200 livestock farmers obtained through the administration of a semi-structured questionnaire. The Livelihood Vulnerability Index (LVI) approach was used to examine the levels of vulnerability. The study compared the vulnerability between the Nandom district and the Lawra district. The empirical results revealed that livestock farmers are more vulnerable to climatic extremes in the Nandom district than the Lawra district. The study highlights the critical role of the government regarding education and construction of water resources, among others.  相似文献   
229.
In this work a novel anode configuration consisting of an iron mesh double layer is proposed for the electrochemical treatment of wastewater. The removal of Reactive Black 5 dye(RB5) from synthetic contaminated water was used as a model system. At a constant anode surface area, identical process operating parameters and batch process mode, the iron mesh double layer electrode showed better performance compared to the conventional single layer iron mesh. The double layer electrode was characterized by RB5 and chemical oxygen demand(COD) removal efficiency of 98.2% and 97.7%, respectively, kinetic rate constant of 0.0385/min, diffusion coefficient of 4.9 × 10~(-5)cm~2/sec and electrical energy consumption of 20.53 kWh/kgdye removed. In the continuous flow system, the optimum conditions suggested by Response Surface Methodology(RSM) are: initial solution p H of 6.29,current density of 1.6 m A/cm~2, electrolyte dose of 0.15 g/L and flow rate of 11.47 m L/min which resulted in an RB5 removal efficiency of 81.62%.  相似文献   
230.
Organic carbon (OC) was measured semicontinuously in laboratory experiments of steady-state secondary organic aerosol formed by hydrocarbon + nitrogen oxide irradiations. Examination of the mass of carbon measured on the filter for various sample volumes reveals a systematic offset that is not observed when performing an instrumental blank. These findings suggest that simple subtraction of instrumental blanks determined as the standard analysis without sample collection (i.e., by cycling the pump and valves yet filtering zero liters of air followed by routine chemical analysis) from measured concentrations may be inadequate. This may be especially true for samples collected through the filtration of small air volumes wherein the influence of the systematic offset is greatest. All of the experiments show that filtering a larger volume of air minimizes the influence of contributions from the systematic offset. Application of these results to measurements of ambient concentrations of carbonaceous aerosol suggests a need for collection of sufficient carbon mass to minimize the relative influence of the offset signal.  相似文献   
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