Degradation of Organophosphorus Pesticides in Water during UV/H2O2 Treatment: Role of Sulphate and Bicarbonate Ions

Abstract: The photodegradation of two organophosphorus pesticides, malathian and diazinon, by sulfate radicals and bicarbonate radicals in aqueous solution were studied. The effect of the operational parameters such as pH, salt concentration, water type, H2O2 concentration and initial concentration of pesticides was studied. Gas chromatography mass spectroscopy (GC-MS) was used for analyses of pesticides. When salt effect was studied, it was found that sodium bicarbonate was the most powerful inhibitor used, while sodium sulfate was the weakest one. The highest degradation in UV/H2O2 process for malathion was found in alkaline condition and for diazinon in acidic condition. The photodegradation in all waters used in this work exhibited first order kinetics. Photodegradation rate in distilled water was higher than real water. The degradation of pesticides increased with increasing of H2O2 concentration

The Effect of Storage Time, Temperature and Type of Packaging on the Release of Phthalate Esters into Packed Acidic Liquids

Kisele tekućine, poput soka od nezrelog voća, limunovog soka i octa često se konzumiraju u Iranu. Različite vrste kiselih sokova pakiraju se u boce od polietilen tereftalata (PET) i polietilena velike gustoće (HDPE). Postoje dokazi koji upućuju na mogućnost otpuštanja ftalata iz PET i HDPE boca. U ovom je radu ispitan utjecaj trajanja skladištenja, temperature i vrste pakiranja na migraciju ftalata u kisele tekućine, čuvane pri različitim uvjetima, i to prije skladištenja, te nakon 2, 4 i 6 mjeseci. Određene su srednje vrijednosti koncentracije ftalata od <0.04 do 0.501 μg/L u sokovima od nezrelog voća, od <0.04 do 0.231 μg/L u limunovom soku i <0.04 do 0.586 μg/L u octu. Najveće koncentracije dietil ftalata (DEP) i dietil heksil ftalata (DEHP) izmjerene su u PET i HDPE bocama. Rezultati prije i naklon skladištenja pokazuju da su se, pri određenim uvjetima skladištenja, koncentracije DEP, DEHP i dibutil ftalata (DBP) povećale u kiselim tekućinama. Rezultati dokazuju da je moguć prijelaz estera ftalne kiseline iz plastičnih pakiranja u sadržaj spremnika.Acidic liquids such as verjuice, lemon juice and vinegar are frequently consumed in Iran. Different kinds of acidic liquids are packaged in polyethylene terephthalate (PET) and high-density polyethylene (HDPE) bottles. There is evidence indicating that phthalates can leach from PET and HDPE bottles into their contents. In this work the effect of storage time, temperature and bottle type on the migration of phthalates from packaging materials into acidic liquids is studied by analyzing the samples stored under different conditions, before storage and after 2, 4 and 6 months of storage. The determined mean phthalate concentrations in μg/L were: <0.04 to 0.501 in verjuice, <0.04 to 0.231 in lemon juice and <0.04 to 0.586 in vinegar. The highest concentrations of diethyl phthalate (DEP) and diethyl hexyl phthalate (DEHP) were found in PET and HDPE bottles, respectively. Results of analyses before and after storage indicate that under some storage conditions, the concentrations of DEP, DEHP and dibutyl phthalate (DBP) increased in acidic liquids. The possible migration of phthalic acid esters from plastic packaging materials into the contents was indicated by the results of the present study

Organophosphorous Pesticides in Surface Water of Iran

Abstract This research aims to evaluate the presence and distribution of pesticides in Babolrood River of Mazandaran Province in Iran. Mean diazinon levels in surface water ranged from 77.6 to 101.6 lg L-1 with maximum level of 768.9 lg L-1 and mean malathion levels ranged from 55.7 to 75.9 lg L-1 with maximum level of 506.6 lg L-1 . The residues of malathion and diazinon pesticides in all of the stations, 2 weeks after spraying, were more than allowed limits

Trace Analysis of Tributyltin Chloride in Fish Tissue by Electron Capture Gas Chromatography

40-44A method is described for sample preparation by gas chromatography in biological samples. TBT was extracted from samples as chloride under the acidic condition of HCl and was detected by GC-ECD system using an apolar capillary column doped with a dilute HBr-methanolic solution. Derivatization step has been eliminated from sample preparation procedure, but doping of the GC-ECD system with a dilute HBr-methanolic solution has been used to detect the TBT chloride and triphenyltin (TPhT) directly by halogen exchange from chloride to bromide. This combination made it possible to determine TBT as less than the ngg-1 level in fish tissue

Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2≥0.993) over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1. For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2≥0.991) and 0.5 ng g−1, respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350∘C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples

Exposure sources of polychlorinated biphenyls (PCBs) and health risk assessment: a systematic review in Iran

This systematic review aims to identify the sources of exposure to polychlorinated biphenyls (PCBs), portioning, and human health risk assessment in Iran. The literature was searched in the international databases of Web of Science, PubMed, Scopus, Google Scholar, and the national databases of SID and MagIran up to November 14, 2020. Among all 153 articles, 21 eligible papers were identified. Among them, only one article was related to drinking water, the rest was related to food and soil, and no article was found on ambient air. The corrected portion of each exposure source was determined to be 90% for food, 9% for water, and 1% for air. The total hazard quotient (HQ) was determined to be within an unsafe range, and the total excess lifetime cancer risk (ELCR) was determined to be at a high risk of oral carcinogenesis. It is suggested that a comprehensive study be conducted in a specific period for all sources of exposure in all counties of Iran. Moreover, it is recommended that the policymakers set national standards for this pollutant in near future in some sources of exposure (e.g., drinking water) which have no standards in Iran

Effect of sodium bicarbonate residue on some characteristics of processed meat products

Using sodium bicarbonate (SB) in cooking meat products is a controversial subject. The aim of this study was to estimate an effect of different SB concentrations on the quality characteristics and organoleptic properties of meat in Kubideh Kebab, an Iranian popular meat product. Ground meat was divided into four groups (a, b, c, and d). After that, SB was added in ratio 0.25, 0.50, 1.00, and 2.00 g/kg respectively. A sample without SB was considered as a blank sample. The Kebab samples were prepared and cooked properly at 350°C for 4–6 minutes and at 450°C for 2–4 minutes. A significant difference was observed in the pH values and the cooking loss between the blank sample and those Kebab samples that were cooked at 350°C and 450°C and pre-treated with SB in the amount of 0.25–2.00 g per 1 kg of meat (P < 0.05). The amount of residual bicarbonate ions increased significantly in the cooked Kebab samples at both treatment temperatures in the a-d group in comparison with the blank sample, as well as between the groups (P = 0.00). The organoleptic properties did not change in the a-d groups in comparison with the blank sample

Comparison of potentiality of Zinc oxide nanoparticles and hydrogen peroxide in removal of hexavalent chromium from polluted water

Background and Aim: Common sources of chromium in wastewater are electroplating and leather industries. Thus, the present study aimed at investigating and comparing between chemical (H2O2) method and nano-photocatalytical(UV/ZnO) method in removing of Cr(VI) from polluted water. Materials and Methods: In this experimental-analytical study, effective factors on reduction process such as ZnO (0.05–0.15 g/L) , H2O2 (0.5-1.5 mol/L) for UV/H2O2 process and pH(5-9) were investigated. The initial concentration of the substrate was taken 0.1-15mg/L.Stock chromate (V:6) solution was prepared through dissolving Potassium dichromate (K2Cr2O7) in originally distilled water. Residual concentrations of Cr(VI) were measured spectrophotometrically at 540nm. Results: The results indicated that with increasing reduction agent concentration and decreasing pH, the removing efficiency increased. For low initial concentrations of Cr(VI) photocatalytic process was more effective than the chemical one, but for high initial concentration the result was the opposite.In the present study, using of these procedures was applied to natural water samples. Conclusion: The results of this study indicated that H2O2 as a cheap and available agent and also UV/ZnO, as a friendly and without residual environmental treatment process, can be used for effective reduction of Cr(VI) to yield Cr(III)

Dietary and Socio-Demographic Determinants of Serum Persistent Organic Pollutants (POPs) Levels in Pregnant Women in Tehran

Objective: To determine the levels of Polychlorinated biphenyls (PCBs) and Polybrominateddiphenyl ethers (PBDEs) as persistent organic pollutants (POPs) in serum of primiparous women at the third trimester of pregnancy and identify the main determinants of POPs levels such as socio-demographic, lifestyle, and diet in Tehran. Materials and methods: One- hundred eighty five serum samples from two simultaneous case-control studies were collected from September 2013 until August 2015.Ten most abundant PCB congeners (International Union of Pure and Applied Chemistry (IUPAC) congeners 28, 52, 74, 99, 101, 118, 138, 153, 180 and 187) as well as eight PBDE congeners (IUPAC congeners 28, 47, 99, 100, 153, 154, 183 and 209)were analyzed by Gas Chromatography Mass Spectrometry (GC/MS). Multiple linear regression analysis was conducted to explain the relationship between total PCBs and total BPDEs and most detected congeners and some determinants, separately. Results: The mean (SD) age of the participating women was 27.82 ± 5.24 years. The geometric mean (SD) of total PCBs was 2.42 ± 2.26 and total PBDEs was 1.28 ± 1.41 ng/g lipid. Only the PCB 138, PCB 153 and PBDE 153 were detected in 100% of samples. We observed a significant relationship between the time of being indoors and total PBDEs (P = 0.03). Passive smoking was significantly associated with PCB 153 (P = 0.049). The results of the linear regression analysis showed the negative and weak association (P-value < 0.05) between diet (egg and fat and oil consumption) and POPs in this population. Conclusion: It seems the most common route of exposure to PBDEs in our population is indoor pollutants. Meanwhile inhalation of smoke from environment is a route of exposure to PCB 153. Further study is needed to evaluate the effects of socio-demographics and especially dietary intake on POPs level