A comparative analysis of wind resource parameters using WAsP and windPRO

This paper investigates the accuracy of the wind resource estimation for a site in a central India region using a latest licensed version of WAsP 11 and windPRO 3.1. Whole one year measured met mast wind data has been taken using anemometer and wind vane at 10 m and 25 m height, respectively above ground level. The digitized elevation and roughness model of the corresponding site shows the roughness class 4 (roughness length 1.2525 m). The wind data has been extrapolated up to 80 m height by using power and log law models which provide the power density near about 120 W/m². As per the micro sitting guidelines for the virtual wind farm installation 5D X 7D mapping has been selected which Indicates the total power output by installing 8 Vestas V-90 1.8 MW wind turbine from WAsP is 31.561 GWh and from windPRO is 28.083 GWh.     

Degradation of diuron by the electro-Fenton process

The degradation of the herbicide diuron has been undertaken by electrochemical advanced oxidation in aqueous solution. This process generates catalytically hydroxyl radicals that are strong oxidizing reagents for the oxidation of organic substances. Hydroxyl radicals degrade diuron in less than 10 min. Kinetic results evidence a pseudo-first-order degradation, with a rate constant of reaction between diuron and hydroxyl radicals of 4.8x10⁹ M^–1 s^–1. Several degradation products were identified by chromatography-mass spectrometry (LC-MS). The mineralization degree of a 1.7x10^–4 M diuron solution reached 93% at 1,000 coulombs.     

Toxicity of Nerium oleander leaf extract in mice

Non-lethal dose of 70% ethanol extract of the Nerium oleander dry leaves (1000 mg/kg body weight) was subcutaneously injected into male and female mice once a week for 9 weeks (total 10 doses). One day after the last injection, final body weight gain (relative percentage to the initial body weight) had a tendency, in both males and females, towards depression suggesting a metabolic insult at other sites than those involved in myocardial function. Multiple exposure of the mice to the specified dose failed to express a significant influence on blood parameters (WBC, RBC, Hb, HCT, PLT) as well as myocardium. On the other hand, a lethal dose (4000 mg/kg body weight) was capable of inducing progressive changes in myocardial electrical activity ending up in cardiac arrest. The electrocardiogram abnormalities could be brought about by the expected Na+, K(+)-ATPase inhibition by the cardiac glycosides (cardenolides) content of the lethal dose.     

Geochemical speciation of trace metals in sediments of the northern Nile Delta Lake by sequential extraction technique

ABSTRACT

The present study was performed to investigate surface sediment samples from Lake Edku of the Nile Delta Lagoons, Egypt. The Lake is important for fishing in the region. The importance of research is to understand the mobility and bioavailability of each studied metal. The study was carried out on 10 sampling sites during 2017. The sediments were subjected to the technique of sequential extraction to examine the chemical forms of some trace metals (Fe, Mn, Zn, Cu, Pb and Ni). Five stage extractions were done as the following order: soluble and exchangeable, carbonate, iron and manganese oxides, organic matter fraction and residual fraction. Attained results from the five fractions showed variations in the concentrations of metal contents of different sites under study. The overall metal concentrations (%) in the initial four extractable fractions (exchangeable, carbonate, oxides and organic matter fractions) were assessed to configure the mobility of each studied metal. The risk assessment code (RAC) represents the summation of exchangeable and carbonate fractions, it was between low and medium risk for aquatic environment. The range percentage of RAC for the metals was in the following order: 1.8–13, 4–23.5, 15–26, 5.7–19.5, 9–25 and 4.8–18.2 for Fe, Mn, Zn, Cu, Pb and Ni, respectively. Approximately 30% of the total copper was associated to the organic fraction, which may represent a high mobility of copper in these sediments. The highest mobility of metals in the sediments could be confirmed by its bioavailability factor (BF), which was within the ranges of 0.32–0.61, 0.36–0.59, 0.64–0.83, 0.36–0.72, 0.37–0.62 and 0.52–0.78 for Fe, Mn, Zn, Cu, Pb and Ni, respectively. The BF exhibited the following order: Zn > Ni > Cu > Pb ≈ Mn?>?Fe. The high levels of BF for the studied metals may represent the potentiality for toxic metals to be easily released into the aquatic environment.     

Determination of Hydrocarbons in Mussels from the Egyptian Red Sea Coast

Mussels (Brachidontes Sp.) collected in April 2000 from the Red Sea coastal of Egypt in order to determine the contamination by hydrocarbons. The study included 11 sampling stations covering about 450 Km of the Egyptian Red Sea coast for the first time. Total concentrations of 20 aliphatics (average 0.105 ng g(-1) of wet weight) and sixteen polycyclic aromatic hydrocarbons (PAHs) (average 5452 ng g(-1) of wet weight) were generally lower in comparison with those reported for some of the published surveillance and monitoring studies of coastal areas from various regions. These results suggest that the coastal area in the Red Sea of Egypt might be considered as a relatively unpolluted.     

Modeling aerosol formation in opposed-flow diffusion flames

The microstructures of atmospheric pressure, counter-flow, sooting, flat, laminar ethylene diffusion flames have been studied numerically by using a new kinetic model developed for hydrocarbon oxidation and pyrolysis. Modeling results are in reasonable agreement with experimental data in terms of concentration profiles of stable species and gas-phase aromatic compounds. Modeling results are used to analyze the controlling steps of aromatic formation and soot growth in counter-flow configurations. The formation of high molecular mass aromatics in diffusion controlled conditions is restricted to a narrow area close to the flame front where these species reach a molecular weight of about 1000 u. Depending on the flame configuration, soot formation is controlled by the coagulation of nanoparticles or by the addition of PAH to soot nuclei.     

Rapid oxidation of sulfide mine tailings by reaction with potassium ferrate

The chemistry of sulfide mine tailings treated with potassium ferrate (K2FeO4) in aqueous slurry has been investigated. The reaction system is believed to parallel a geochemical oxidation in which ferrate ion replaces oxygen. This chemical system utilized in a pipeline (as a plug flow reactor) may have application eliminating the potential for tailings to leach acid while recovering the metal from the tailings. Elemental analyses were performed using an ICP spectrometer for the aqueous phase extract of the treated tailings; and an SEM-EDX for the tailing solids. Solids were analyzed before and after treatments were applied. ICP shows that as the mass ratio of ferrate ion to tailings increases, the concentration of metals in the extract solution increases; while EDX indicates a corresponding decrease in sulfur content of the tailing solids. The extraction of metal and reduction in sulfide content is significant. The kinetic timeframe is on the order of minutes.     

Atrazine distribution measured in soil and leachate following infiltration conditions

Atrazine transport through packed 10 cm soil columns representative of the 0-10 cm soil horizon was observed by measuring the atrazine recovery in the total leachate volume, and upper and lower soil layers following infiltration of 7.5 cm water using a mechanical vacuum extractor (MVE). Measured recoveries were analyzed to understand the influence of infiltration rate and delay time on atrazine transport and distribution in the column. Four time periods (0.28, 0.8, 1.8, and 5.5 h) representing very high to moderate infiltration rates (26.8, 9.4, 4.2, and 1.4 cm/h) were used. Replicate soil columns were tested immediately and following a 2-d delay after atrazine application. Results indicate atrazine recovery in leachate was independent of infiltration rate, but significantly lower for infiltration following a 2-d delay. Atrazine distribution in the 0-1 and 9-10 cm soil layers was affected by both infiltration rate and delay. These results are in contrast with previous field and laboratory studies that suggest that atrazine recovery in the leachate increases with increasing infiltration rate. It appears that the difference in atrazine recovery measured using the MVE and other leaching experiments using intact soil cores from this field site and the rain simulation equipment probably illustrates the effect of infiltrating water interacting with the atrazine present on the soil surface. This work suggests that atrazine mobilization from the soil surface is also dependent on interactions of the infiltrating water with the soil surface, in addition to the rate of infiltration through the surface soil.     

Estimation of the intrinsic maximum substrate utilization rate using batch reactors with denitrifying biofilm: a proposed methodology.

A method for estimation of the maximum substrate utilization rate (q(max)) using batch reactors with denitrification biofilm was introduced and compared with the traditional method of using batch reactors with suspended growth for q(max) estimation. The values of q(max) obtained from the suspended-growth reactors (0.69 to 0.71 g N/g volatile suspended solids [VSS] x d) and from the attached-biomass reactors (0.74 to 0.85 g N/g VSS x d) are similar and within the range of the values reported in the literature (0.23 to 2.88 g N/g VSS x d). Therefore, the intrinsic kinetic parameter, q(max), can be obtained using attached-growth batch reactors, if the effectiveness factor, eta, is approximately equal to 1 and the bulk concentration of the rate-limiting substrate, C, is much higher than the half-velocity constant, K(S). The attached-growth batch reactor method is unique, because the biomass used in the batch tests is the same as that present in the parent reactor under investigation.