SO2 Dispersion and Monthly Evaluation of the Industrial Source Complex Short-Term (ISCST32) Model at Mina Al-Fahal Refinery,Sultanate of Oman

Modeling of air pollutant dispersion has been undertaken for emissions of sulfur dioxide (SO₂) at the Mina Al-Fahal refinery in the Sultanate of Oman. The study was conducted during the period of November 1999 to October 2000. The Industrial Source Complex Short-Term (ISCST32) air pollution model was adopted to predict the ground level concentration of SO₂ in and around the refinery. The modeling results were validated against measured data during the study period. The comparison, based on the monthly average measurements, showed that the model underestimates the observed SO₂ concentrations. However, the predicted ground level concentrations of SO₂ during the months of September, October, November, and June were in better agreement with the observations. The predicted SO₂ values are presented in the form of concentration contours to determine the spatial distribution of SO₂ and to assess the impact on air quality over the survey area. Predicted SO₂ concentrations were found lower than the World Health Organisation (WHO) guideline value of 365 μg/m³, with the maximum ground level concentrations being found to occur relatively close to the sources of emission. Moreover, concentration contour patterns for the modeled area vary with changes in meteorological conditions. On the basis of this study, the refinery is not likely to cause any significant deterioration in air quality, and predicted concentrations of SO₂ are well below those likely to influence health.     

Bioconversion of sugarcane bagasse into a protein-rich product by white rot fungus

The fungus Pleurotus ostreatus NRRL-2366 degraded 56.7% and 45.9% of untreated and chemically pretreated (delignified) sugarcane bagasse, respectively, during 14-day incubation in a submerged fermentation process. The biodegradation percentages of cellulose, hemicellulose and lignin were 33.0%, 72.5% and 14.5%, respectively. An increment of 22.6% of crude protein content in the residual fermented material was observed. Chemical composition of the end-product and its amino acids profile were reported.     

FUZZY DECISION MAKING IN GROUND WATER NITRATE RISK MANAGEMENT1

ABSTRACT: Ground water nitrate contamination is widespread in the United States and especially prevalent in agriculture-intensive areas such as the Midwest. To reduce human health risks (i.e., methemoglobinemia and cancer risks) from nitrates in ground water supplies, several nitrate risk-management strategies can be developed based on acceptable levels of human health risks, the reasonableness of the cost required for risk reduction, and the technical feasibility of nitrate-control methods. However, due to a lack of available information, assessing risk, cost, and technical feasibility contains elements of uncertainty. In this paper, a nitrate risk-management methodology using fuzzy sets in combination with a multicriterion decision-making (MCDM) technique is developed to assist decision makers in evaluating, with uncertain information, possible regulatory actions along with the various nitrate risk-management strategies in order to determine an appropriate strategy. The methodology is illustrated using data from a community with a nitrate water-quality problem.     

ROLE OF WATERSHED SUBDIVISION ON MODELING THE EFFECTIVENESS OF BEST MANAGEMENT PRACTICES WITH SWAT1

Distributed parameter watershed models are often used for evaluating the effectiveness of various best management practices (BMPs). Streamflow, sediment, and nutrient yield predictions of a watershed model can be affected by spatial resolution as dictated by watershed subdivision. The objectives of this paper are to show that evaluation of BMPs using a model is strongly linked to the level of watershed subdivision; to suggest a methodology for identifying an appropriate subdivision level; and to examine the efficacy of different BMPs at field and watershed scales. In this study, the Soil and Water Assessment Tool (SWAT) model was calibrated and validated for streamflow, sediment, and nutrient yields at the outlet of the Dreisbach (623 ha) and Smith Fry (730 ha) watersheds in Maumee River Basin, Indiana. Grassed waterways, grade stabilization structures, field borders, and parallel terraces are the BMPs that were installed in the study area in the 1970s. Sediment and nutrient outputs from the calibrated model were compared at various watershed subdivision levels, both with and without implementation of these BMPs. Results for the study watersheds indicated that evaluation of the impacts of these BMPs on sediment and nutrient yields was very sensitive to the level of subdivision that was implemented in SWAT. An optimal watershed subdivision level for representation of the BMPs was identified through numerical simulations. For the study watersheds, it would appear that the average subwatershed area corresponding to approximately 4 percent of total watershed area is needed to represent the influence of these BMPs when using the SWAT model.     

Acute effects of chlorpyryphos-ethyl and secondary treated e uents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

The acute effects of commercial formulation of chlorpyrifos-ethyl (Dursbanr®) and the secondary treated industrial/urban effluent (STIUE) exposure on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in hepatopancreas and gills of Mediterranean crab Carcinus maenas were investigated. After 2 d of exposure to chlorpyriphos-ethyl, the AChE activity was inhibited in both organs at concentrations of 3.12 and 7.82 μ/L, whereas the BuChE was inhibited only at higher concentration 7.82 μ/L of commercial preparation Dursbanr®. The exposure of crabs to Dursbanr® (3.12 μ/L) showed a significant decrement of AChE activity at 24 and 48 h, whereas the BuChE was inhibited only after 24 h and no inhibition for both enzymes was observed after 72 h. Moreover, a significant repression of AChE activity was observed in both organs of C. maenas exposed to 5% of STIUE. Our experiments indicated that the measurement of AChE activity in gills and hepatopancreas of C. maenas would be useful biomarker of organophosphorous (OP) and of neurotoxic effects of STIUE in Tunisia.     

Tualang honey supplementation improves oxidative stress status among chronic smokers

Free radicals induced by cigarette smoking have been linked to an increase in oxidative stress resulting in smoking-related cardiovascular diseases. However, the possible effect of honey that has antioxidant property in improving oxidative stress status among smokers has not yet been reported. Hence, this study was to determine the effects of 12-week Tualang honey supplementation on F₂-isoprostanes, superoxide dismutase, glutathione peroxidase, catalase, and total antioxidant status among chronic smokers. A total of 32 non-smokers and 64 chronic smokers were recruited from Quit Smoking Clinic and Health Campus, Universiti Sains, Malaysia. Smokers were randomized into two groups (n = 32/group) namely smokers without supplementation and smokers with honey supplementation (20 g/day) for 12 weeks. Blood was obtained from non-smokers and smokers at pre-intervention and from smokers at post-intervention. During pre-intervention, the levels/activity of F₂-isoprostanes, total antioxidant status, and catalase were significantly higher while superoxide dismutase and glutathione peroxidase were lower in smokers than non-smokers. During post-intervention, in supplemented smokers, there were significant decrease in F₂-isoprostanes and increase in total antioxidant status, glutathione peroxidase and catalase levels/activities compared with pre-intervention. This study indicates that honey supplementation improves oxidative stress status suggesting a beneficial role of honey in reducing the risk of cardiovascular diseases.     

Configuration influence in relation to fluid flow of venturi system

Due to its simplicity and accurately measuring the flow rate, the venturi system is a special kind of pipe that is widely used in various applied fluid mixtures. One of the venturi system's important applications is ejectors devices that accurately facilitate adding air to water to sustain oxygen demand target levels in many waterworks engineering systems. This study aims to improve venturi system measurement accuracy through experimental investigation and analytical analysis for the venturi system conditional configuration parameters effect on target aeration operational efficiency. In the experiment work, different runs are implemented to characterize the performance of such aerators by describing the impact of venturi characteristics and configurations, including water flow rate, air inlets orifices diameters, inlet velocities, throat lengths, inlet angles, outlets angles, and outlet diameters on aeration efficiency. Results show that the venturi air vent diameter is an important governing parameter for determining aeration performance value. Additionally, an indicated increase in aeration performance with an increasing throat length to its diameter ratio. Meanwhile, the results revealed a varying noted effect of the venturi system characteristics and configurations on aeration performance. Moreover, the equations that relate venturi system configuration and Reynolds numbers with the aeration operational performance are developed to facilitate the target accurate aeration efficiency estimation.     

Quantitative PCR-based identification of enteric viruses contaminating fresh produce and surface water used for irrigation in Egypt

Environmental Science and Pollution Research - Fresh produce irrigated with surface water that may contain pathogens such as enteric viruses can lead to outbreaks of foodborne viral illnesses. In...     

Catalytic CO2 gasification of rubber seed shell-derived hydrochar: reactivity and kinetic studies

In this study, hydrothermal carbonization (HTC) of a biomass was used as a means to improve the physicochemical properties of rubber seed shell (RSS) and enhance its reactivity in the char-CO₂ gasification reaction, known as the Boudouard reaction (C + CO₂ ? 2CO). Hydrochar samples were developed by hydrothermal treatment of RSS, without separating the solid residue from the liquid product, at 433, 473, 513, and 553 K under autogenous pressure. The CO₂ gasification reactivity of the developed hydrochars was then investigated at different heating rates (5, 10, 20, and 30 K/min) by the non-isothermal thermogravimetric method. The hydrochars revealed higher reactivity and improved gasification characteristics compared to the untreated biomass, while the hydrochar which was filtered from the liquid slurry showed lower reactivity compared to the untreated biomass. This was due to the chemical and structural evolutions of the biomass during hydrothermal treatment as indicated by various analyses. The gasification reactivity of the hydrochar was substantially enhanced by introduction of a catalyst (NaNO₃) during HTC. Kinetic analysis of the char-CO₂ gasification reaction was carried out by applying Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink isoconversional methods, and thermodynamic parameters were also determined. The activation energy of the Na-loaded RSS hydrochar in CO₂ gasification (120–154 kJ/mol) was considerably lower than that of the untreated biomass (153–172 kJ/mol). Thermodynamic studies also confirmed the promoting effect of hydrothermal treatment and catalyst impregnation on enhancement of reactivity of the virgin biomass and reduction of gasification temperature.

     

The ameliorative effects of ceftriaxone and vitamin E against cisplatin-induced nephrotoxicity

Environmental Science and Pollution Research - Nephrotoxicity is a common adverse effect of treatment with cisplatin (CDDP). This study was performed to evaluate the antioxidant and...