Removal of Pb2+ from water using the carbon nanotube-g-poly[(sodium methacrylate)-co- 2-(methacryloyloxy)ethyl acetoacetate]: experimental investigation and modeling

Environmental Science and Pollution Research - A solid polymer, poly[(sodium methacrylate)-co-2-(methacryloyloxy)ethyl acetoacetate], p(MAA-co-MEAA) was synthesized and then grafted onto carbon...     

A modified exergy evaluation of using carbon-black/water/EG nanofluids as coolant of photovoltaic modules

Environmental Science and Pollution Research - To provide the progressive global demand for energy, the use of renewable energies is being rapidly developed. Since solar radiation is available in...     

Efficient synthesis of α,β-unsaturated ketones with trans-selective Horner–Wadsworth–Emmons reaction in water

Organic reactions in aqueous media are being developed because water is environmentally benign. The Horner–Wadsworth–Emmons reaction is a modified Wittig reaction for the synthesis of α,β-unsaturated ketones and other conjugated compounds. Here we prepared high molecular weight ketones by the Horner–Wadsworth–Emmons reaction of dimethyl-2-oxopropylphosphonate and various aldehydes in water at room temperature. The product was precipitated during the reaction process and was separated readily by a simple filtration in 90–99 % yield.     

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Benzene removal evaluated using Fe304 nano continuous condition. A 44 initial benzene concentration, from aqueous solutions was magnetic particles （NM） in factorial design including NM dose, contact time and pH was investigated in 16 experiments （Taguchi OA design）. The results indicated that all factors were significant and the optimum condition was： pH 8, NM dose of 2000 mg.L-1, benzene concentrations of 100 mg.L-1 and contact time of 14min. The maximum benzene uptake and distribution ratio in the optimum situation were 49.4mg.g-1 and 38.4L.g-1, respectively. The nano particles were shown to capture 98.7% of the benzene in optimum batch condition and 94.5% in continuous condition. The isotherm data proved that the Bmnauer-Emmett-Teller model fit more closely and produced an isotherm constant （b） less than one, indicating favorable adsorption. Regeneration studies verified that the benzene adsorbed by the NM could be easily desorbed by temperature, and thereby, NM can be employed repeatedly in water and wastewater management.     

Room temperature aqueous Paal–Knorr pyrrole synthesis catalyzed by aluminum tris(dodecyl sulfate)trihydrate

This article reports a novel procedure to prepare pyrroles using a modification of the Paal–Knorr reaction. Water is a safe solvent meeting environmental considerations, but most organic substrates are not soluble in water. A possible solution to improve the solubility of substrates is the use of surface-active reagents that can form micelles. For instance, combined Lewis acid–surfactant catalyst acts both as a Lewis acid to activate the substrate molecules and as a surfactant to form emulsions in water. Here, we prepared and used aluminum tris(dodecyl sulfate)trihydrate to condense various amines to 2,5-hexadione at room temperature. The sole solid pyrrole was separated by a simple filtration. Our findings thus show a novel and improved modification of the Paal–Knorr reaction in terms of mild reaction conditions and clean reaction profiles, using a simple workup procedure and improved yields with excellent chemo-selectivity.     

Impacts of land use and land cover change on the interactions among multiple soil-dependent ecosystem services (case study: Jiroft plain,Iran)

The spatial and temporal distribution pattern is an outstanding feature of the relationship among ecosystem services (ESs) that explains links between human activities and disturbed chemical composition of ecosystems. This study investigated the spatiotemporal variation of land use/cover changes (LUCC) and quantifies the change in four essential ecosystem services with an emphasis on soil (nutrient delivery ratio, carbon storage, crop production, and water yield) and their relationships in the Jiroft plain, Iran, during 1996–2016 through analytical tools including Land Change Modeler, and the Integrated Valuation of Ecosystem Services and Tradeoff. During the 20-year concentrate period, there was a considerable overall gain in cropland (5396 km²) and urban (1787 km²), loss of unused land (5692 km²), water (2088 km²), and forest (1083 km²). As a result of LUCC, while crop production and nutrient delivery ratio showed a rising trend, overall carbon storage and water yield decreased. The spatiotemporal trade-off between carbon storage and crop production, the temporal trade-off between crop production and water yield, and synergy between water yield and crop production were widespread in Jiroft plain. These results showed that the interaction among ESs mutates over time and can be changed under planning and policies. This study will enrich the research of the geographical distribution of ESs interaction in dryland ecosystems to provide practical ecosystem management under local conditions.

     

Emission and life-cycle assessment of alternative-fuel buses: a case study of the Delaware Authority of Regional Transit

The Energy Policy Act of 1992 motivated transit agencies to utilize alternative-fuel transit buses in addition to their popular diesel buses. Transit agencies have planned to add a significant number of alternative-fuel buses to their current transit fleets. This study is to inform policy makers who may allocate public funds for alternative-fuel bus projects to make a smarter decision in this regard. For each of the eight alternative-fuel buses, technologies introduced by the ACT, fuel efficiency, life-cycle cost (LCC) and emission are estimated and compared with the available information for the ultralow-sulfur diesel (ULSD) fuel buses. A case study in the State of Delaware is presented to demonstrate how the proposed approaches can be employed to evaluate the relative importance of the most viable alternative-fuel transit buses according to the predefined set of criteria. The results show that buses propelled by hybrid-diesel engine have the least LCC and emissions and are the most suitable alternative for the ULSD buses in the short- and midterm.     

Rheological Investigation of Wood-Polypropylene Composites in Rotational Plate Rheometer

In this research work, the rheological properties of Wood-Plastic Composites (WPC) with some selected compositions are investigated. WPC is being recognized as a green composite that, in the past 20?years, has emerged to a commercial product. A study on rheological properties of these materials can give insight into the proper selection of composition and processing condition. Two grades of polypropylene (PP) with two different melt flow indexes (MFI) were selected to prepare WPCs with three different wood contents (50, 60 and 70?% wt.). Four types of rheological experiments were performed utilizing a rotational plate rheometer: (1) strain sweep, (2) frequency sweep, (3) temperature sweep and (4) steady shear rate sweep. The independent variables were chosen as wood content, MFI of polymer (two types), melt temperature, frequency or shear rate, the gap between the plates, and strain percentage. The strain sweep tests specified the linear and non-linear viscoelastic zones of each experiment. The results of frequency sweep experiments indicated that increasing the wood content and frequency and also decreasing the strain percentage and the gap distance, lead to an increase in the storage modulus. Regarding the loss modulus, wood percentage and the gap distance presented positive effects and strain percentage showed a negative effect. The behavior of complex viscosity was almost similar to that of the storage modulus but increasing the frequency caused a decrease in the complex viscosity. In case of temperature sweep experiments, it was observed that the rheological properties exhibit a rapid change near to a temperature of 160?°C. The results also showed that beyond this point, increasing the wood content and also MFI of polypropylene caused an increase in the storage modulus. The results of steady shear rate sweep experiments specified that increasing wood content and also decreasing the MFI of PP, the gap distance and shear rate lead to an increase in both viscosity and shear stress.