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551.
Environmental Chemistry Letters - The rising amount of waste generated worldwide is inducing issues of pollution, waste management, and recycling, calling for new strategies to improve the waste...  相似文献   
552.
Journal of Material Cycles and Waste Management - Boiler ash, produced by burning heavy fuel oil (HFO) in electrical power plants, is one of the most serious environmental problems facing oil-rich...  相似文献   
553.
Due to the increase in the number of urinary calculi disease cases in Jordan, stone samples were collected from patients from various Jordanian hospitals (Princes Basma (PBH), King Abdullah University (KAUH), Al-Basheer (ABH) and Al-Mafraq (AMH)). This study concentrates on the effect of trace metals in patients of urinary calculi. Trace metals were detected in 110 urinary calculi samples using X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS) techniques. Of the calculi examined, 21 were pure calcium oxalate (CaOax), 29 were mixed calcium oxalate/uric acid, 23 were mixed calcium oxalate/phosphate (apatite), 25 were phosphate calculi (apatite/struvite), five were mixed calcium oxalate monohydrate/struvite, four were urate calculi (mixed ammonium acid urate/sodium acid urate) and three were pure cystine calculi. The concentration measurement of Ca and other trace metals levels has been found useful in understanding the mechanism of stone formation and in evaluating pathological factors. It has been found that Ca is the main constituent of the urinary calculi, especially those stones composed of calcium oxalate and calcium phosphate. The concentration of most of the trace metals that were analyzed was (Ca = 48.18, Na = 1.56, K = 0.9, Mg = 3.08, Fe = 1.17, Al = 0.49, Zn = 0.7, Cu = 0.19, Mn = 0.029, P = 10.35, S = 1.88, Sr = 0.306, Mo = 0.2, Cr = 0.146, Co = 0.05, Ni = 0.014)%. In conclusion, metals concentration in Jordanian patient’s urinary calculi samples was higher than its equivalents of other patients’. It has been noted that there is no concentration of toxic trace elements (like Li, V, Pb, Cd, and As). Some heavy metals, however, were detected Mo, Cr, Co and Ni as traces. P and S ions are present in few calculi stones as traces.  相似文献   
554.
555.
An optimization methodology for designing groundwater quality monitoring networks applicable to stochastic flow fields is presented and evaluated. The approach sets itself apart from previous techniques by incorporating the time dimension directly into the objective function. This function is extremized using a directed partial enumeration strategy guided by physical considerations related to transport processes. The result is a set of monitoring well locations and a sampling schedule that minimizes plume characterization error while satisfying constraints on the maximum number of wells and allowable number of active wells. The method is evaluated using hypothetical plumes with varying degrees of heterogeneity. Results indicate that the proposed approach is successful in generating near-optimal sampling networks that satisfy all imposed constraints. Monitoring networks with as little as three active wells and a total of 12 wells are found to provide adequate plume characterization for low toxicity contaminants.  相似文献   
556.
Environmental Science and Pollution Research - Real-time particulate matters (PM1, PM2.5, PM4, PM7, PM10, and TSP) with AEROCET 531S (USA), gaseous pollutants (NO2 and TVOC) with Aeroquel 500 gas...  相似文献   
557.
The behavior of chlorantraniliprole (CAP) and dinotefuran (DNF) insecticides was investigated in clay loam soil, a common type of the Egyptian soil. Effect of temperature, pH and particle size of the soil on the adsorption process was studied. Adsorption isotherm by bulk soil and its constituents; humic acid (HA), clay, silt and sand fractions was measured using batch equilibration technique. The results showed that the adsorption of the insecticides tested was significantly affected by the temperature and was a spontaneous interfacial process in the soil. Freundlich model accurately predicted the adsorption behavior of both insecticides. The interaction between soil and insecticides was endothermic and the highest adsorption for CAP and DNF was obtained at pH 9. However, the effect of pH on the adsorption of DNF was lower than that of CAP. Sorption of CAP and DNF on HA fraction was significantly greater than on clay fraction and bulk soil. In addition, the adsorption was significantly increased with particle size decrease. It could be inferred that the adsorption of CAP and DNF on clay loam soil was physical in nature and greatly influenced by the soil components, pH and temperature.  相似文献   
558.
In this study, activated carbon was prepared from waste tire by KOH chemical activation. The pore properties including the BET surface area, pore volume, pore size distribution, and average pore diameter were characterized. BET surface area of the activated carbon was determined as 558 m2/g. The adsorption of uranium ions from the aqueous solution using this activated carbon has been investigated. Various physico-chemical parameters such as pH, initial metal ion concentration, and adsorbent dosage level and equilibrium contact time were studied by a batch method. The optimum pH for adsorption was found to be 3. The removal efficiency has also been determined for the adsorption system as a function of initial concentration. The experimental results were fitted to Langmuir, Freundlich, and Dubinin–Radushkevich (D-R) isotherm models. A comparison of best-fitting was performed using the coefficient of correlation and the Langmuir isotherm was found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of uranium ions onto waste tire activated carbon was 158.73 mg/g. The thermodynamic equilibrium constant and the Gibbs free energy were determined and results indicated the spontaneous nature of the adsorption process. Kinetics data were best described by pseudo-second-order model.  相似文献   
559.
As a creeping process, salinisation represents a significant long-term environmental risk in coastal and deltaic environments. Excess soil salinity may exacerbate existing risks of food insecurity in densely populated tropical deltas, which is likely to have a negative effect on human and ecological sustainability of these regions and beyond. This study focuses on the coastal regions of the Ganges–Brahmaputra delta in Bangladesh, and uses data from the 2010 Household Income and Expenditure Survey and the Soil Resource Development Institute to investigate the effect of soil salinity and wealth on household food security. The outcome variables are two widely used measures of food security: calorie availability and household expenditure on food items. The main explanatory variables tested include indicators of soil salinity and household-level socio-economic characteristics. The results of logistic regression show that in unadjusted models, soil salinisation has a significant negative effect on household food security. However, this impact becomes statistically insignificant when households’ wealth is taken into account. The results further suggest that education and remittance flows, but not gender or working status of the household head, are significant predictors of food insecurity in the study area. The findings indicate the need to focus scholarly and policy attention on reducing wealth inequalities in tropical deltas in the context of the global sustainable deltas initiative and the proposed Sustainable Development Goals.  相似文献   
560.
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