Transport of coliphage PRD1 in a surface flow constructed wetland.

A tracer study was conducted in a 3-ha surface flow constructed wetland to analyze transport performance of PRD1, an enteric virus model. The convection-dispersion equation (CDE), including a first-order reaction model, adequately simulated transport performance of PRD1 in the wetland under an average hydraulic loading rate of 82 mm/d. Convective velocity (v) and longitudinal dispersion coefficient (D) were estimated by modeling a conservative tracer (bromide) pulse through the wetland. Both PRD1 and bromide were simultaneously added to the entering secondary treated wastewater effluent. The mass of bromide and PRD1 recovered was 76 and 16%, respectively. The PRD1 decay rate was calculated to be 0.3/day. The findings of this study suggest that the CDE model and analytical moment equations represent a suitable option to characterize virus transport performance in surface flow constructed wetlands.     

Prenatal evaluation of fetal neck masses in preparation for the EXIT procedure: the value of pulmonary Doppler ultrasonography (PDU)

Sonographic demonstration of normal tracheal diameter and breathing-related lung fluid flow at 30 weeks' gestation in a fetus with a giant neck mass confirmed patent airways, thus avoiding an EXIT procedure. Copyright © 2001 John Wiley & Sons, Ltd.     

A phospho-compost biological-based approach increases phosphate rock agronomic efficiency in faba bean as compared to chemical and physical treatments

Under arid and semi-arid conditions, direct application of phosphate rock (PR) as a source of phosphorus (P) for crop production is likely influenced by agricultural practices and soil properties. Different approaches could be used to improve the agronomic efficiency of low-grade PR over a wider range of soils and crops. In this study, biological, physical, and chemical treatments of low-grade Moroccan PR were investigated and compared through agronomic trials on faba bean grown under alkaline soil conditions. The physical treatment was based on blending PR with triple superphosphate (TSP) at 75:25 and 50:50 ratios, the biological treatments involved co-application of PR with compost at 50:50 ratio and phospho-compost elaborated from PR (20%), sewage sludge (46%), and wheat residues (34%), while the chemical treatment was obtained by a 30% acidulation of PR by phosphoric acid. Control treatments consisting of zero P application (control), PR alone, and TSP alone were considered to assess the effectiveness of the abovementioned techniques to improve PR agronomic efficiency. A pot experiment was conducted in sandy soil (Jorf Lasfar, central Morocco) for 60 days in a completely randomized design considering eight treatments. All treatments, except the control, were amended with 52 mg kg^?1 of P from different PR-based fertilizers before sowing. At the flowering stage (60-day-old plants), results indicated that all PR treatments significantly improved plant growth, root nodulation, and nutrient uptake compared to the control. The relative agronomic efficiency of pretreated PR was significantly higher with phospho-compost treatment (86%) than the partially acidulated PR (78%) or the PR/TSP blend 50:50 (64%). Likewise, P uptake, P use efficiency, number of root nodules, and N uptake all were improved under PR treatments. Our finding revealed that the biological technique based on phospho-compost yielded better compared to chemical and physical treatments.

     

Microfibrillated Cellulose-Silver Nanocomposite Based PVA Hydrogels and Their Enhanced Physical,Mechanical and Antibacterial Properties

Journal of Polymers and the Environment - Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a...     

Evaluation of delta-aminolevulinic acid levels in the urine of Angooran Lead & Zinc Company staff

Currently, attention has shifted to chronic or subclinical disorders attributed to lead (Pb) exposure. The aim of this study was to determine delta-aminolevulinic acid (δ-ALA) levels in urine of Angooran Lead &; Zinc Company workers. This cross-sectional study was conducted on 170 workers, in which 24 h urinary samples were collected and δ-ALA levels were measured spectrophotometrically. Questionnaire forms were completed indicating age, location, and duration of work. The mean δ-ALA level in urine was 5.44 mg L^?1. δ-ALA levels were correlated with age, location, and duration of work in the company. The mean δ-ALA level in the urine of workers was in the upper limit of normal ranges. δ-ALA level in urine may not be the best discriminating factor of Pb exposure from the baseline to the high levels, but is recommended as a regular and routine test for all Pb-exposed workers in addition to the measurement of Pb in blood for subjects with higher δ-ALA levels.     

Experimental and numerical study of methylparaben decomposition in aqueous solution using the UV/H2O2 process

The present paper aims at presenting a kinetic model that is supposed to result in the decomposition of methylparaben in completely mixed batch reactor (CMBR) using the UV/H₂O₂ process. The proposed model incorporates photochemical, chemical reactions and their constant rates to formulate the overall kinetic rate expressions which are integrated into MATLAB. Thus, the changes in pH values during the process of oxidation are taken into consideration. In addition, the effects of hydrogen peroxide (HP) dosage, as well as the concentration of hydroxyl radicals, are examined. Accordingly, the pseudo-first-order rate constant, its variation as functions of HP concentration, incident UV-light intensity and the limitations of the adopted approach are discussed. In line with that, the authors provided evidence of the validity of the kinetic model through the exposure of previous experimental studies as reported in the literature review then through the evidence of the present experimental data.     

Association of benzene exposure with insulin resistance,SOD, and MDA as markers of oxidative stress in children and adolescents

Benzene is a ubiquitous environmental pollutant with various health effects. It is reported that benzene exposure might be associated with insulin resistance in elderly adults. The aim of this study is to investigate the association between urinary benzene metabolite, trans, trans-muconic acid (t,t-ma) and markers of oxidative stress and insulin resistance in children and adolescents. This cross-sectional study was conducted in 2017 among 86 children and adolescents, aged 6–18 years, living in Isfahan, Iran. t,t-ma was measured as urinary benzene metabolite and homeostasis model assessment (HOMA-IR) was determined as an index of insulin resistance. Moreover, malondialdehyde (MDA) and superoxide dismutase (SOD) were assessed as oxidative stress markers. We found significant association between insulin resistance, fasting blood glucose, and fasting blood insulin with t,t-ma (p values?=?0.002, 0.03, and 0.001, respectively). Results of this study indicate that benzene metabolite in higher concentrations in comparison with lower concentrations is associated with increased risk of insulin resistance. Moreover, after adjustment for age, sex, and household passive smoking, statistically significant increase were documented in SOD and MDA (4.49- and 3.54-fold, respectively) in intermediate levels of t,t-ma vs. low levels of t,t-ma (p values?=?0.01 and 0.034, respectively). To the best of our knowledge, this is the first study in its kind in the pediatric age group. It showed that benzene exposures, even in environmental levels, might be associated with insulin resistance and oxidative stress in children and adolescents. Further longitudinal studies are necessary to assess the clinical impacts of this finding.     

Removal of Cr(VI) from aqueous solution using electrosynthesized 4-amino-3-hydroxynaphthalene-1-sulfonic acid doped polypyrrole as adsorbent

Environmental Science and Pollution Research - Polypyrrole (PPy) conducting films, doped with 4-amino-3-hydroxynaphthalene sulfonic acid (AHNSA), were electrosynthesized by anodic oxidation of...