Rapid photodegradation and detection of zolpidem over β-SnWO4 and α-SnWO4 nanoparticles: optimization and mechanism

Environmental Science and Pollution Research - We reported the tin (II) tungstate nanoparticles as the photocatalyst and sensor modifier that were synthesized via chemical precipitation reaction...     

A fuzzy multi-attribute approach to select the welding process at high pressure vessel manufacturing

Metal welding process selection calls for extensive know-how which deals with a huge amount of knowledge. Hence, the automation of knowledge through a knowledge-based system will greatly enhance the decision-making process. Fuzzy analytical hierarchy process (AHP)-TOPSIS investigates the relative welding process selection factors and it can compare and evaluate different welding processes between 0 and 1.This paper describes a knowledge-base system developed for identifying the most appropriate welding processes to suit specific circumstances. In the present study, nine important welding processes were used in the system. Ten parameters namely alloy class, material thickness, deposition rate, design application, joint configuration, operator factor, capital cost, equipment portability, filler metal utilization and welding position, are used to determine the best selection among competitive welding processes for high pressure vessel production. Also the sensitivity analysis was carried out for five cases.     

Kinetics and thermodynamics studies of cobalt,strontium and caesium sorption on marble from aqueous solution

Adsorption onto solid phases plays an important role in the transport of radionuclides and contaminants in the environment. Radionuclides in radioactive waste have been considered to be hazardous pollutants, and their migration with groundwater is strongly affected by sorption on the geologic media. Therefore, the knowledge of radionuclide sorption is of great importance in the management of radioactive wastes. A series of batch sorption experiments were conducted separately to investigate sorption and transport behaviour of cobalt, strontium and caesium on and through marble. Batch-mode kinetic and equilibrium studies have been carried out at different temperatures. Sorption experimental data were analysed by kinetic and isotherm models. Based on the results obtained, it can be concluded that the marble is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides. Therefore, this study could be used as a starting point to establish and consider that rock as a reactive barrier around the disposal facilities at the nuclear activity centres.     

Spongy Ni/Fe carbonate-fluorapatite catalyst for efficient conversion of cooking oil waste into biodiesel

Environmental Chemistry Letters - Biodiesel produced from animal and plant fat oils is sustainable, but there is a need for efficient heterogeneous catalysts for transesterification of crude oils...     

Effect of leachate recirculation on mesophilic anaerobic digestion of food waste

The effects of using untreated leachate for supplemental water addition and liquid recirculation on anaerobic digestion of food waste was evaluated by combining cyclic water recycle operations with batch mesophilic biochemical methane potential (BMP) assays. Cyclic BMP assays indicated that using an appropriate fraction of recycled leachate and fresh make up water can stimulate methanogenic activity and enhance biogas production. Conversely increasing the percentage of recycled leachate in the make up water eventually causes methanogenic inhibition and decrease in the rate of food waste stabilization. The decrease in activity is exacerbated as the number cycles increases. Inhibition is possibly attributed to accumulation and elevated concentrations of ammonia as well as other waste by products in the recycled leachate that inhibit methanogenesis.     

Fuzzy-based wastewater quality indices for pollution classification: a case study in the United Arab Emirates

This paper presents a fuzzy logic-based tool for assessing the pollution concentration of effluents generated by various industrial and commercial activities. The study proposes a fuzzy overall pollution compliance index (FOPCI) (range 0–100) to classify the wastewater discharged from various types of properties present in Ajman, United Arab Emirates. The work mainly focused on three types of pollution that can occur at the inlets of the wastewater treatment plant of Ajman, due to discharge of industrial and commercial effluents, namely pH pollution, salt pollution, and organic pollution. The proposed FOPCI integrates six characteristics, namely pH, Cl^?, SO₄ ^2?, conductivity, chemical oxygen demand (COD), and fats, oils, and greases (FOG) values into a readily understandable scale. The FOPCI is developed by using the Fuzzy Inference System Toolbox available in MATLAB in two steps, in which during the first step, three sub-indices, namely fuzzy pH compliance index, fuzzy salt compliance index, and fuzzy organic compliance index are developed. It is then processed in the second stage to develop the FOPCI. Fuzzy rules are used to classify effluents quality into six categories based on the concentration of pollutant in the effluent, namely “Excellent Quality”, “Good Quality”, “Acceptable Quality”, “Moderately Polluting”, “Highly Polluting”, and “Extremely Polluting”. This linguistic classification using fuzzy logic will be helpful as a decision support system to provide an outline for the prioritization of plans for wastewater management based on the values of the indices developed.     

Impact of industrial wastewater disposal on surface water bodies in Mostord area north Greater Cairo

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Impact of four pesticides on the growth and metabolic activities of two photosynthetic algae

The acute toxicity was determined for soil algae Chlorella kesslerei and Anabaena inaequalis, exposed to pesticides lindane, pentachlorophenol (PCP), isoproturon (IPU), and methyl parathion (MP). Toxicity markers included growth inhibition, chlorophyll biosynthesis, and total carbohydrate content, as a function of dose and time. Concentration response functions (EC50) were estimated by probit data transformation and weighted linear regression analyses. Lindane's toxicity to Chlorella increased sharply with time (EC50 = 7490, 10.3, 0.09 mg L(-1); 24, 48, 72 h), but remained nearly constant through 72 h with Anabaena (8.7-6.7 mg L(-1); 24-72 h). PCP at low concentrations stimulated algal growth and chlorophyll a production, an effect reversed at higher doses. Anabaena was less tolerant of PCP and MP than was Chlorella. The 96-h static EC50 values for Chlorella were: 0.003, 34, 0.05, and 291 mg L(-1) for lindane, PCP, isoproturon, and MP, respectively; for Anabaena, these were 4.2, 0.13, 0.21, and 19 mg L(-1). Carbohydrate production responses were similar to those of cell density (growth) and chlorophyll biosynthesis, with MP having the lowest adverse impact. The overall relative toxicity among the four tested pesticides was: for Chlorella, lindane > IPU > PCP > MP; and for Anabaena, PCP > IPU > lindane > MP. The results confirm that toxicants such as these pesticides may affect individual (though related) species to significantly different degrees.     

Radioactivities related to coal mining

Natural radioactivity concentrations due to the coal mining in Gabal El-Maghara, North Sinai, Egypt, were determined using gamma-ray spectroscopy. Coal, water and soil samples were investigated in this study. The (226)Ra, (232)Th and (40)K activity concentrations in coal before extraction were 18.5 +/- 0.5, 29.5 +/- 1.2 and 149.0 +/- 8.4 Bq kg(-1), respectively. These concentrations were reduced to 18-22% after extraction due to the clay removal of the coal ore. The activity contents of the water and soil samples collected from the surrounding area did not show any evidence of enhancement due to the mining activities. Absorbed dose rate and effective dose equivalent in the mine environment were 29.4 nGy h(-1) and 128.0 microSv a(-1), respectively. The measured activity concentrations in the mine environment and the surrounding areas (5 km away from the mine) are similar to that found in other regions in North and South Sinai. Based on the measurements of gamma-ray emitting radionuclides, the mine activity does not lead to any enhancement in the local area nor represents any human risk.