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1.
Environ Res ; 241: 117627, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-37967700

ABSTRACT

Arsenic is the hazardous species and still is the global challenge in water treatment. Apatite soil is highly rich in arsenic species, and its mining presents various environmental issues. In this study, novel magnetic microbeads as adsorbent were developed for the elimination of hazardous arsenic ions from apatite soil's aqueous leachate before discharging into environment. The microbeads were fabricated with metformin polyether sulfone after being doped with zero-valent iron (Met-PES/ZVI). The microbeads were characterized using various techniques, including FTIR, XRD, SEM-EDX, VSM, and zeta potential analysis. The developed adsorbent demonstrated a significant elimination in arsenic in aqueous leachate, achieving 82.39% removal after 30 min of contact time, which further increased to 90% after 180 min of shaking. The kinetic analysis revealed that the pseudo-second-order model best represented the adsorption process. The intra-particle diffusion model indicated that the adsorption occurred in two steps. The Langmuir model (R2 = 0.991), with a maximum adsorption capacity of 188.679 mg g-1, was discovered to be the best fit for the experimental data as compared Freundlich model (R2 = 0.981). According to the thermodynamic outcome (ΔG < -20 kJ/mol), the adsorption process was spontaneous and involved physisorption. These findings demonstrate the potential of magnetic Met-PES/ZVI microbeads as an efficient adsorbent for the removal of arsenic from apatite soil aqueous leachate.


Subject(s)
Arsenic , Water Pollutants, Chemical , Water Purification , Arsenic/analysis , Soil , Kinetics , Microspheres , Thermodynamics , Adsorption , Magnetic Phenomena , Water Pollutants, Chemical/analysis , Hydrogen-Ion Concentration , Water Purification/methods
2.
Article in English | MEDLINE | ID: mdl-36231997

ABSTRACT

The drop immerses calcium chloride aqueous solution was utilized to prepare the zero valent iron-doped polyethersulfone beads (PES/ZVI) for the efficient removal of arsenic from apatite-soil treated waters. The proposed beads can assist in promoting uptake efficiency by hindering ZVI agglomeration due to a high porosity and different active sites. The PES/ZVI beads were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and vibrating sample magnetism (VSM). The main objective of this study was to investigate the function of new PES/ZVI beads with an increased removal efficiency for the remediation of arsenic ions from the apatite-soil treated waters. A maximum adsorption removal of 82.39% was achieved when the experiment was performed with 80 mg of adsorbent for a contact time of 180 min. Based on the results, a removal efficiency >90% was obtained after 300 min of shaking time with an arsenic concentration of 20 mg·L-1. The experimental process was fitted with the Langmuir model due to the high R2 (0.99) value compared to the Freundlich model (0.91) with an adsorption capacity of 41.32 mg·g-1. The adsorption process speed was limited by pseudo-second-order (R2 = 0.999) and the adsorption mechanism nature was endothermic and physical.


Subject(s)
Arsenic , Water Pollutants, Chemical , Adsorption , Apatites , Arsenic/analysis , Calcium Chloride , Hydrogen-Ion Concentration , Ions , Iron/chemistry , Kinetics , Magnetic Phenomena , Soil , Spectroscopy, Fourier Transform Infrared , Water/analysis , Water Pollutants, Chemical/analysis
3.
Food Chem ; 240: 634-641, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-28946322

ABSTRACT

A QuEChERS based methodology was developed for the simultaneous identification and quantification of acetamiprid, imidacloprid, and spirotetramat and their relevant metabolites in pistachio by liquid chromatography-tandem mass spectrometry for the first time. First, sample extraction was done with MeCN:citrate buffer:NaHCO3 followed by phase separation with the addition of MgSO4:NaCl. The supernatant was then cleaned by a primary-secondary amine (PSA), GCB, and MgSO4. The proposed method provides a linearity in the range of 5-200µgL-1, and the linear regression coefficients were higher than 0.99. LOD and LOQ were obtained to be 2 and 5µgkg-1 for the studied insecticides, respectively, with the exception of imidacloprid-olefin (5 and 10µgkg-1). Acceptable recoveries (91-110%) were obtained for all the analytes with good intra- and inter-precisions (0.4≥RSD ≤11.0). The method was then used for the pistachio samples collected from a field trial to estimate the maximum residue limits (MRLs) in next step.


Subject(s)
Pistacia , Aza Compounds , Chromatography, High Pressure Liquid , Neonicotinoids , Nitro Compounds , Spiro Compounds , Tandem Mass Spectrometry
4.
Arch Iran Med ; 17(4): 246-52, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24724600

ABSTRACT

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a major health problem in many developing countries including Iran. ESCC has a very poor prognosis, largely due to late diagnosis. As a first step in developing an early detection and treatment program, we conducted a population-based endoscopic screening for ESCC and its precursor lesion, esophageal squamous dysplasia (ESD) in asymptomatic adults from Golestan Province, northern Iran, a high-risk area for ESCC, to evaluate the feasibility of such a program and to document the prevalence and risk factor correlates of ESD. METHODS: This cross-sectional study was conducted among participants of the Golestan Cohort Study (GCS), a population-based cohort of 50,000 adults in eastern Golestan Province. Randomly selected GCS participants were invited by telephone. Those who accepted were referred to a central endoscopy clinic. Eligible subjects were consented and then asked to fill in a brief questionnaire. Detailed information about selected risk factors was obtained from the GCS main database. Endoscopic examination with Lugol's iodine staining was performed, biopsies were taken from unstained lesions as well as the normally stained mucosa of the esophagus, and the biopsies were diagnosed by expert pathologists according to previously described criteria. RESULTS: In total, 1906 GCS subjects were invited, of whom only 302 subjects (15.8%) were successfully enrolled. Esophagitis (29.5%) and ESD (6.0%) were the most common pathological diagnoses. Turkmen ethnicity (adjusted OR = 8.61; 95%CI: 2.48-29.83), being older than the median age (OR = 7.7; 95% CI: 1.99-29.87), and using deep frying cooking methods (OR = 4.65; 95%CI: 1.19-18.22) were the strongest predictors for ESD. There were significant relationships between esophagitis and smoking (p-value<0.001), drinking hot tea (P value = 0.02) and lack of education (P value = 0.004). CONCLUSION: We observed a low rate for participation in endoscopic screening. Overall prevalence of ESD was 6.0%. Developing non-endoscopic primary screening methods and screening individuals with one or more risk factors may improve these rates.


Subject(s)
Early Detection of Cancer , Esophagus/pathology , Precancerous Conditions/ethnology , Precancerous Conditions/pathology , Adult , Age Factors , Aged , Aged, 80 and over , Biopsy , Coloring Agents , Cooking/methods , Cross-Sectional Studies , Educational Status , Esophagitis/epidemiology , Esophagitis/pathology , Esophagoscopy , Female , Humans , Iodides , Iran/epidemiology , Male , Middle Aged , Prevalence , Risk Factors , Smoking/epidemiology , Tea
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