Cattle egrets as a biosentinels of persistent organic pollutants exposure

We investigated selected chlorinated pollutants (β-HCH, γ-HCH, DDDs, DDEs, o,p′-DDT, p,p′-DDT, heptachlor, aldrin, dieldrin, and endrin) in the Lahore and the Sialkot districts of Pakistan, using eggs of cattle egret (Bubulcus ibis) collected during May and June 2007. The pollutant with highest level and frequency was ΣDDT, followed by β-HCH, γ-HCH, heptachlor, aldrin, dieldrin, and endrin in descending order. The concentration(s) were significantly higher in Sialkot heronry for all the pollutants (except p,p′-DDT) than in Lahore. The values for DDTs, β-HCH, γ-HCH, and heptachlor were significantly higher (p < 0.05) in the egg(s) than in sediment(s) and in the chicks’ diet, due to biomagnification. Among DDTs analogues, p,p′-DDD was the major contaminant with >60 % of total DDT burden, reflecting the widespread aged as well as recent use of DDT as well as anaerobic degradation (DDD/DDE > 1 in many cases) in the nearby paddy soils. In few samples, p,p′-DDT/(DDD + DDE) > 0.5 suggested the recent emission patterns from surrounding contaminated areas of demolished DDT units and obsolete pesticide stores. The higher levels of HCHs (i.e., β-HCH) in the samples collected from Sialkot indicate exposure from long-term agricultural use. Overall, concentrations of all studied POPs were less than the threshold levels known to affect reproduction. Nevertheless, total DDTs and/or HCHs burdens in some eggs contained concentrations of greater than what would educe adverse effects on birds. This is among few studies on OCPs exposure to avian species, which provide the evidence of Pakistan’s contribution toward the Global POPs emission.     

Application of water extract of slippery elm tree leaves as a natural reagent for selective spectrophotometric determination of trace amounts of molybdenum(VI) in environmental water samples

A novel spectrophotometric method for the determination of molybdenum(VI) by using a natural reagent, water extract of slippery elm tree leaves, is developed. Molybdenum(VI) reacts with this natural reagent to form an orange colored product. The formed product shows maximum absorbance at 418 nm with a molar absorptivity value of 0.57 × 10⁴ L mol^?1 cm^?1, and this method is linear in the 0.4–10 mg L^?1 concentration range. The detection limit value was found to be 0.0350 mg L^?1. The proposed method is simple, clean, low cost, selective, and sensitive. It was applied to the analytic samples with satisfactory results.     

Impact of heavy metals of industrial plant wastewater on benthic communities of Bizerte Lagoon (Tunisia)

ABSTRACT

The aim of this study was to assess the consequences of human impact on the characteristics of sediments heavy metal concentration, grain size and its influence on the structure of the microbial and meiofaunal community assemblages. A survey was carried out in July 2013 within six sites located in the Bizerte Lagoon (Tunisia), both downstream and upstream of industrial effluents. The highest total sediment metal concentrations were detected in stations located close to the industrial sewage discharge points. In these stations, the lowest densities of the total meiofauna (33?±?13?ind/10?cm^?2) and conversely the highest densities of cultivable bacteria that are heavy metal resistant have been reported (16?±?80.34?CFU?g^?1). Univariate (ANOVA) and multivariate (MDS/CCA) analyses demonstrate high dissimilarity (0.06) in meiofaunal and bacterial community structures between downstream and upstream industrial sewages. Furthermore, canonical correspondence analysis CCA results indicated that heavy metal sediment contamination promoted bacteria that are resistant to heavy metals, while heterotrophic bacteria supported the development of meiofauna taxa. The results highlight the importance of bacteria/meiofauna interactions, as both meiofaunal and microbial communities give indications of the ecological impact of heavy metal contamination in sediment.     

Mercury contamination in selected foodstuffs and potential health risk assessment along the artisanal gold mining,Gilgit-Baltistan,Pakistan

This study investigates the mercury (Hg) contaminations in soil and foodstuffs along the artisanal gold mining areas, Gilgit-Baltistan Province, Pakistan. For this purpose, soils were analyzed for Hg concentrations and evaluated for the enrichment/contamination using enrichment factor or contamination factors (CF). The CF values ranged from 18.9 to 153 showed multifold higher levels of Hg contamination as compared to background or reference site. Foodstuffs including vegetables, seeds or grains and fish muscles showed Hg accumulation. Results revealed that Hg concentrations in foodstuffs were higher than the critical human health value set by European Union. The Hg in foodstuffs was consumed and, therefore, evaluated for the risk assessment indices using the daily intake (DI) and health risk index (HRI) for the exposed human population both children and adults. Results of this study revealed that cumulative HRI values through foodstuffs consumption were <1 (within safe limit), but if the current practices continued, then the Hg contamination could pose potential threat to exposed population in near future.     

Changes in chemical forms of lead in temperate and semiarid soils in sterile and unsterile conditions

Sequential extraction has been used as a suitable method for fractionation of chemical forms of trace elements and study of their plant availability. Surface soils were sampled from Guilan and Hamadan provinces in north and northwest of Iran with temperate and semiarid climates. The chemical forms of Pb in the Pb(NO₃)₂-treated (400 μg Pb g⁻¹) soils have been studied in solid state incubation (FC) at 27°C in sterile and unsterile conditions. After 20 min and 3600 h a sequential extraction scheme was also used to fractionate Pb of incubated samples into soluble-exchangeable (Sol-Exch), carbonates associated (ACar), organic matter associated (AOM), Mn oxide associated (AMnOx), Fe oxide associated (AFeOx), and residual (Res) forms. Temperate soil samples had higher clay content, cation exchange capacity (CEC), dichromate oxidable organic carbon (OC), total Kjeldahl-nitrogen (TN), biological activity, amorphous and crystalline Fe and Al, but semiarid soil samples had higher sand content, pH, equivalent calcium carbonate (ECC), available P and K. Soil lead fractionation revealed that in both groups of soils Pb largely changed to exchangeable, carbonates associated and organic associated forms after 20 min. The chemical forms of Pb differed widely among soils after 3600-h incubation. The conversion rate of Pb from more available forms to less available forms was higher in temperate soils with higher Fe–Mn oxides and OM contents compared to semiarid soils. In temperate soils after 3600-h incubation, greater content of Pb was observed in Res (68%), AOM (14%), ACar (7%), and AMnOx (5%) fractions. However, in semiarid soils greater content of Pb was observed in Res (61%), ACar (16%), Sol-Exch (8%), and AOM (8%) fractions. The sum of AMnOx and AFeOx chemical forms for Pb in semiarid soils compared to temperate soils was lower. It was only 7% against 9% in temperate soils. Soil microorganisms in unsterile soils had significant effect on AOM, AFeOx and Res fractions of Pb. They not only increased AOM and AFeOx fractions of Pb in soils but also decreased Res fraction of Pb significantly.     

Green technology for sustainable surface protection of steel from corrosion: a review

Plants contain substances that inhibit corrosion. Here we review biomass-based corrosion inhibitors from plant leaves, nuts, and fruit peels, after treatment with acids, bases or saline solutions. The mechanism of corrosion inhibition involves a monolayer coverage, according to isotherm and Langmuir models. Plant extract-based corrosion inhibitors contain heteroatoms whose electrons pair in the p-electron level in multiple bonds and the vacant d-orbitals of iron. Corrosion inhibition under marine conditions involves various chemical interactions between metals and dissolved ionic components.

     

Phosphorus removal and recovery: state of the science and challenges

Environmental Science and Pollution Research - Phosphorus is one of the main nutrients required for all life. Phosphorus as phosphate form plays an important role in different cellular processes....     

The Distribution and Sources of Polycyclic Aromatic Hydrocarbons in Surface Sediments Along the Egyptian Mediterranean Coast

Coastal marine sediment samples were collected from 31 sampling stations along the Egyptian Mediterranean Sea coast. All sediment samples were analyzed to determine aliphatic and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total concentrations of 16 EPA-PAHs in the sediments were varied from 88 to 6338 ng g⁻¹ with an average value of 154 ng g⁻¹ (dry weight). However, the concentrations of total aliphatic were varied from 1.3 to 69.9 ng g⁻¹ with an average value of 15.6 ng g⁻¹ (dry weight). The highest contents of PAHs were found in the Eastern harbor (6338 ng g⁻¹), Manzala (5206 ng g⁻¹) and El-Jamil East (4895 ng g⁻¹) locations. Good correlations observed between a certain numbers of PAH concentrations allowed to identify its origin. The average total organic carbon (TOC) percent was varied from 0.91 to 4.54%. Higher concentration of total pyrolytic hydrocarbons (∑COMB) than total fossil hydrocarbons (∑PHE) declared that atmospheric fall-out is the significant source of PAHs to marine sediments of the Egyptian Mediterranean coast. The selected marked compounds, a principal component analysis (PCA) and special PAHs compound ratios (phenanthrene/anthracene vs fluoranthene/pyrene; ∑COMB/∑EPA-PAHs) suggest the pyrogenic origins, especially traffic exhausts, are the dominant sources of PAHs in most locations. Interferences of rather petrogenic and pyrolytic PAH contaminations were noticed in the harbors due to petroleum products deliveries and fuel combustion emissions from the ships staying alongside the quays.     

Effect of Humic Acids and Fungal Inoculations on Cesium and Lead Concentrations in Lettuce Plants Grown in Contaminated Soils

A study was carried out to evaluate the effect of humic acid additives, applied either individually or in combination with Fusarium oxysporum fungi, on uptake and translocation of cesium and lead in cultivated Lettuce (Lactuca sativa) grown on Mostorud (clayey) and El‐Gabal El‐Asfar (sandy loam soil) soils in a complete randomized block experimental design. The selected soils from contaminated areas (Mostorud soil was irrigated with contaminated industrial water for more than 30 years and El‐Gabal EL‐Asfar soil was irrigated with sewage effluent for more than 50 years). The results indicated that the cesium and lead content was reduced by all treatments of humic acid application individually or when combined with Fusarium oxysporum inoculations, especially at 200 mmol/kg compared to a control and other treatments. On the other hand, retention of cesium and lead occurred in roots more than shoots. ©2016 Wiley Periodicals, Inc.     

Cleaner production in the management of water use at a poultry slaughterhouse of Vale do Taquari,Brazil: a case study

This study included the layout characterization for the production process of a poultry slaughterhouse using qualitative and quantitative flow charts for water management; analysis of general parameters for pollution load in the wastewater produced in critical stages of the production process and assessment of environmental impact indicators. Prognoses for cleaner production based on water management were established. The diagnostic stage revealed that the scalding, pre-chilling, separated points of wastewater disposal for the wastewater treatment plant and disposal of treated and non-reused wastewater were critical for water management. Dissolved oxygen depletion and eutrophication account for the major environmental impacts of these wastewaters, resulting in an environmental pressure index of 32.1. The opportunities for cleaner production implementation resulting from this study include the reuse of wastewaters from pre-chilling and chilling for pre-washing of carcasses, since average temperatures of these wastewaters range between 4 and 16 °C. This will contribute to lowering the oil and grease pollution load. Another strategy concerns the standardization of cleaning procedures with rational water use in all work shifts and implementation of water meters on a sector-by-sector basis. In the latter case, which has already been implemented, water consumption was reduced by 13%.