Assessment of intrinsic vulnerability to contamination for Gaza coastal aquifer, Palestine

Gaza coastal aquifer (GCA) is the major source of fresh water for the 1.5 million residents of Gaza Strip, Palestine. The aquifer is under deteriorating quality conditions mainly due to the excessive application of fertilizers. The intrinsic vulnerability of GCA to contamination was assessed using the well-known DRASTIC method. Detailed analysis of the intrinsic vulnerability map of GCA was carried out and did consider different relationships between the vulnerability indices and the on-ground nitrogen loadings and land use classes. In addition, correlation between vulnerability values and the nitrate concentrations in GCA was studied. Based on the vulnerability analysis, it was found that 10% and 13% of Gaza Strip area is under low and high vulnerability of groundwater contamination, respectively, while more than 77% of the area of Gaza Strip can be designated as an area of moderate vulnerability of groundwater contamination. It was found that the density of groundwater sampling wells for nitrate concentration is high for the moderate and high vulnerability zones. The highest first quartile, median, mean, and third quartile of nitrate concentrations are reported in the high vulnerability zones. Results of sensitivity analysis show a high sensitivity of the high vulnerability index to the depth to water table.     

Impact of Fenton and ozone on oxidation of wastewater containing nitroaromatic compounds

Fenton and ozone treatment was investigated at laboratory scale for the degradation of aqueous solutions of nitrobenzene (NB).Effects of reactants concentration (O3,H2O2,and Fe(II)),temperature,and pH on NB degradation were monitored.Reaction kinetic of these processes was also assessed.A rapid reaction took place for Fenton process at higher initial concentration of H2O2,higher temperatures,and more acidic conditions(pH 3).Similarly, ozonation reaction exhibited rapid rates for higher ozone dose,higher temperatures,and more basic conditions(pH 11).Complete NB degradation in 65 min Was achieved using Fenton process.The conditions of complete elimination of 100 mg/L of initial NB concentration,were 250 mg/L of H2O2 concentration,pH 3,and 10 mg/L of Fe(Ⅱ) concentration.Under these conditions,55% organic carbon elimination Was achieved.Total organic carbon mineralization Was attained in 240 min reaction time by Fenton process with 900 mg/L of H2O2 concentration,and 30 mg/L of Fe(II) concentration.Fenton reaction showed a pseudo-first order kinetic;the reaction rate constant Was ranged from 0.0226 to 0.0658 min-1.Complete NB degradation wag also achieyed for an ozone dose of the order of 2.5 g/L.The ozonation Was studied at different ozone doses.different initial pH(7-11)and at difierent temperatures(15-35℃).NB ozonation kinetic Was represented by a bi-molecular kinetic model which was reduced to pseudo-first order kinetic.The pseudo-first order reaction rate constant was determined to increase at 20℃ from 0.004 to 0.020 min-1 as the used ozone increased from 0.4 to 1.9g/L.     

Carbon dioxide separation and capture by adsorption: a review

Environmental Chemistry Letters - Rising adverse impact of climate change caused by anthropogenic activities is calling for advanced methods to reduce carbon dioxide emissions. Here, we...     

Production characteristics of lipopeptide antibiotics in biofilm fermentation of Bacillus subtilis

In biofilm fermentation, from the very early moments, surfactin was produced along with the biofilm development in the lipopeptide antibiotic production medium by using Bacillus subtilis. However, almost no iturin A was produced in its first 24 hours of cultivation and the production of iturin A began much later. Volumes of the nutrient medium and available surface area of the biofilm reactors were found to be important with the relative production of these two antibiotics. Production of iturin A was increased from 12 mg to about 50 mg per reactor when the culture size was increased from 5 mL to 20 mL, as the depth of the medium was increased. The production level was saturated thereafter with larger volumes. On the other hand, surfactin production was remained similar, which was about 10 mg per reactor, from all the 5 mL to 80 mL of biofilm culture. Optimized temperature for iturin A and surfactin production was observed at 25 and 37°C, respectively. In the biofilm fermentation, production of surfactin was increased when the incubation temperature was increased within the temperature range of 25 to 37°C, on the other hand, iturin A production was gradually decreased with the increase of the incubation temperature.     

Application of malt residue in submerged fermentation of Bacillus subtilis

Malt residue is a common waste or byproduct from beer industries after brewing and milling of malted barley. In this work, Bacillus subtilis RB14 was used to study the microbial growth and production of secondary metabolites like lipopeptide antibiotic iturin A in the malt residue for its effective recycling. B. subtilis RB14 could grow in submerged fermentation of malt residue and significant growth (10⁹ CFU/mL) was observed without any supplementation. In submerged fermentation iturin A production using malt residue was about 170 mg/L, which was found to be higher than its production in No.3 (Polypepton, glucose, KH₂PO₄, MgSO₄·7H₂O) medium where production was about 120 mg/L. More than 600 mg/L of iturin A production was observed when malt residue was combinedly used with No.3 medium. This production was significantly higher than their summation of their individual production. However, the growth of B. subtilis in combined medium was found to be similar to that of the submerged fermentation in simple malt residue. Therefore, the remarkable enhancement in production of iturin A in supplemented malt residue was attributed to the nutrients supplied from No.3 medium.     

Experimental investigation of gamma-ray attenuation in Jordanian building materials using HPGe-spectrometer

The capabilities of some building materials used in Jordan to attenuate gamma radiation were tested. Measurements of the attenuation coefficients of limestone, bricks and concrete have been carried out using a HPGe-spectrometer. Narrow beam technique was used, with a multiple gamma radiation source of different energy lines. Results indicate that variations in the attenuation coefficient for all limestone samples, at the same energy line, are within the experimental uncertainties. On the basis of the results achieved, an empirical formula mu(m)=AE(-0.44) was proposed to calculate attenuation at various incident energies. Limestone of average thickness 7cm was found to stop 75% of a gamma beam of energy 662keV. Meanwhile a brick of effective thickness 7cm was found to stop 60% of the same beam. The total attenuation coefficient of concrete calculated at 1333keV was 11.2m(-1), which is less than that of limestone and bricks.     

Inbreeding and the evolution of sociality in arthropods

Animals have evolved strategies to optimally balance costs and benefits of inbreeding. In social species, these adaptations can have a considerable impact on the structure, the organization, and the functioning of groups. Here, we consider how selection for inbreeding avoidance fashions the social behavior of arthropods, a phylum exhibiting an unparalleled richness of social lifestyles. We first examine life histories and parental investment patterns determining whether individuals should actively avoid or prefer inbreeding. Next, we illustrate the diversity of inbreeding avoidance mechanisms in arthropods, from the dispersal of individuals to the rejection of kin during mate choice and the production of unisexual broods by females. Then, we address the particular case of haplodiploid insects. Finally, we discuss how inbreeding may drive and shape the evolution of arthropods societies along two theoretical pathways.     

An equal sex ratio followed by differential sex mortality causes overestimation of females in gall midges: no evidence for sex ratio regulation

Monogeny, the production of unisexual broods by individual females, has been recognized for nearly 80?years. The genetic nature of gall midges' sex determination predicts an equal numbers of male-producing and female-producing females in the populations such that the overall sex ratio is expected to be nearly 1:1. However, observations of some strictly monogenous populations with biased sex ratio, mainly toward females, have raised the question of whether gall midges are able to adjust their offspring sex ratio in response to changes in environmental conditions, and some authors have even considered sex ratio regulation as a strong force in the course of the evolution of monogeny. In this paper, first, by studying the sex ratio variations of the predatory gall midge, Aphidoletes aphidimyza within a generation, we showed that adult males emerge up to 1?day earlier and have shorter life span than females (less than 4?days and up to 6?days, respectively). Although, the sex ratio of A. aphidimyza at the time of emergence was nearly 1:1 (52.41?% males), a simple population simulation indicated that the differential mortality of sexes can lead to a female-biased sex ratio estimation (57.88?% females) under random sampling in the natural environments. Our results imply that the primary sex ratio of monogenous gall midges is nearly 1:1 and that the arrhenogenic/thelygenic gall midges are not able to alter the number of their male/female progenies in response to changes in environmental conditions.     

Morphological relationships of the Wheatears (genus Oenanthe)

The genus Oenanthe comprises approximately 22 species, of which 16 species are restricted to the desert belt of the Palaearctic and Afrotropic regions, where they are often the most conspicuous passerines. Although they have been the subjects of some morphological and ecological studies, no complete morphometrical data has been used to verify their taxonomic relationships, and, the species relationships are still debated. Overall morphometrical similarities between Wheatears and their relationships in size and shape were assessed using measurements of 27 biometrical variables on 417 museum specimens. The 22 Wheatear species comprise some morphological groups: long migratory vegetation-tolerant species (O. pleschanka, O. hispanica, O. cypriaca and O. deserti), ground-dwelling migratory (O. isabellina and O. oenanthe), and sedentary (O. bottae, O. heuglini and O. pileata) of steppe-like habitants, relatively heavy and rock-dwelling species (O. leucura and O. monticola), inhabiting the most arid areas (O. monacha, O. leucopyga and O. alboniger), and finally a central core of medium-sized partial migrants, largely overlapping in morphometric space, that do not present any evident specialization (O. lugens, O. chrysopygia, O. xanthoprymna and O. finschii). It seems Wheatear species are well distributed in a morpho-space of size and shape with moderate overlaps and few hiatuses corresponding to a morphological continuum of species. Furthermore, our results largely hiatuses corresponding to a morphological continuum of species. Furthermore, our results largely differ from previous phylogenetic hypotheses (based on ecological, behavioural, and chromatic characters), but, are in congruence with molecular data.     

Synthesis and optimization of spherical nZVI (20–60 nm) immobilized in bio-apatite-based material for efficient removal of phosphate: Box-Behnken design in a fixed-bed column

In the present study, bio-apatite/nZVI composite was synthesized through Fe(III) reduction with sodium borohydride and was fully characterized by FTIR, XRD, SEM–EDX, TEM, BET, BJH, and pH_PZC. Column experiments were carried out for the removal of phosphate as a function of four operational parameters including initial phosphate concentration (100–200 mg L^?1), initial solution pH (2–9), bed height (2–6 cm), and influent flow rate (2.5–7.5 mL min^?1) using a response surface methodology (RSM) coupled with Box-Behnken design (BBD). 2D contour and 3D surface plots were employed to analyze the interactive effects of the four operating parameters on the column performance (e.g., uptake capacity and saturation time). According to ANOVA analysis, the influent flow rate and bed height are the most important factor on phosphate uptake capacity and saturation time, respectively. A quadratic polynomial model was excellently fitted to experimental data with a high coefficient of determination (>?0.96). The RSM-BBD model predicted maximum phosphate adsorption capacity of 85.71 mg g^?1 with the desirability of 0.995 under the optimal conditions of 135.35 mg L^?1, 2, 2 cm, and 7.5 mL min^?1 for initial phosphate concentration, initial solution pH, bed height, and influent flow rate, respectively. The XRD analysis demonstrated that the reaction product between bio-apatite/nZVI composite and phosphate anions was Fe₃ (PO₄)₂. 8H₂O (vivianite). The suggested adsorbent can be effectively employed up to five fixed-bed adsorption–desorption cycles and was also implemented to adsorb phosphate from real samples.