Pollution, spatial distribution, and health risks assessment of nutrient concentration in surface water resources of Maroon-Jarahi Basin in southwestern Iran.

Nowadays, the introduction of nutrients caused by human activities is considered an environmental issue and a significant problem in river basins and coastal ecosystems. In this study, the concentration of nutrients ( NO 3 - and PO 4 3 - ) in the surface water sources of the Maroon-Jarahi watershed in the southwest of Iran was determined, and the pollution status and health risk assessment were done. The average concentration of nitrate and phosphate in Ludab, Maroon, Zard, Allah, Jarahi rivers, and Shadegan wetland were obtained at 2.25-0.59, 4.59-1.84, 4.07-2.02, 5.40-2.81, 11.51-4.67, 21.63 and 6.20 (mg/l), respectively. A comparison of the results with the World Health Organization (WHO) limit showed that nitrate was lower than in all stations, but phosphate was higher than the limit in some stations of the Maroon, Allah, Jarahi rivers, and Shadegan wetland. Calculation of linear regression analysis showed significant positive relationships between nitrate and phosphate in all surface water sources (except Ludab) and based on the N/P ratio, nitrogen was estimated as the limiting factor in phytoplankton growth (N/P < 16). The evaluation of the status of the Nutrient pollution index (NPI) was observed as: Shadegan > Jarahi > Allah > Maroon > Zard > Ludab that the Jarahi River and Shadegan wetland were in the medium pollution class (1 < NPI ≤ 3) and other waterbodies were in the non-polluted to low pollution state (NPI < 1). Calculation of the chronic daily intake (CDI) showed that water body nutrients cause more non-carcinogenic health risks through the oral route than dermal exposure, and according to HI, children's health is more at risk than adults. Findings showed that surface water resources especially downstream of the Maroon-Jarahi watershed are at eutrophication risk, and to control the nearby human activities and as a result increase the nutrients in these water resources, measures should be taken.

Contamination, ecological, and health risk assessment of heavy metals and organophosphorus pesticides in single, double, and ratoon cropping of rice: a case study in Mazandaran, North of Iran.

This study investigated the contamination and health risk assessment of heavy metals and organophosphorus pesticides in single, double, and ratoon cropping of rice in Mazandaran province, north of Iran. A total of 17 sampling locations in rice farms were selected and soil and rice samples were collected from farms in 5 counties of Mazandaran. Soil and rice samples were then transferred to the lab for further analysis. The concentration of pesticides and heavy metals was then analyzed using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Mercury was analyzed using a Leco mercury analyzer. Target hazard quotient (THQ), total target hazard quotient (TTHQ), carcinogenic risk (CR), and total carcinogenic risk (TCR) in children and adults were used. Potential ecological risk also was used to test the possible hazards of heavy metals to the environment. Heavy metals concentration in rice and soil samples in different farming steps revealed different levels. THQ showed no considerable risk in consuming contaminated rice to adults and children considered, while TTHQ revealed potential non-carcinogenic risks. Ni had the most carcinogenic risks to target human groups, and TCR showed carcinogenicity for carcinogenic heavy metals in all stations. Findings showed no ecological risks of metals to the environment. In conclusion, rice farmers in Mazandaran use the lands multiple times during the year to increase the performance, function, quality, and quantity of rice, but the possible toxic effects of heavy metals and pesticides on consumers and the environment should not be overlooked.

Adsorption of Malachite Green (MG) as a Cationic Dye on Amberlyst 15, an Ion-Exchange Resin.

Crystals of malachite green (MG), being water-soluble, are effective agents applied to combat fungal and parasitic infections in fish. This study was conducted to evaluate the adsorption of MG as a cationic dye by polymeric resin Amberlyst 15. Changes in several parameters were observed, including the concentration of MG, pH, the adsorption rate and extent, and the temperature that might all affect the efficiency of adsorption. The adsorption method was described well by both the Redlich-Peterson and Langmuir isotherms with R 2 of 0.9933 and 0.9880, respectively. The kinetic information is consistent with the Freundlich isotherm model and pseudo-2nd-order kinetics model. Analysis of malachite green was executed by HPLC containing a Eurospher 100-5 C18 (25 cm × 4.5 mm, size of particle 5 µm) column, UV detector was set at 618 nm, and 125 mM ammonium acetate was adapted to pH 4.5 with formic acid-acetonitrile (45 : 55, v/v) as the moving phase. The limit of the discovery factor was 0.02 µgL. The negative value of ΔG° reveals the spontaneity of the absorption method. The positive value of ΔS° (333.1253 J/K mol) gives back randomness at the solid-liquid interface of sorption. The required adsorbent concentration was calculated for removing MG up to an extraction efficiency of 98.27% after 240 minutes.

A novel route to the synthesis of α-Fe2O3@C@SiO2/TiO2 nanocomposite from the metal-organic framework as a photocatalyst for water treatment.

In this study, an attempt was made to synthesize metal-organic frameworks (MOFs) based magnetic iron particles as photocatalysts for textile dye wastewater. Improvement strategy was a novel two-step dry method without using conventional methods to eliminate the consumption of chemical reagents. First, the heterogeneous photocatalyst of Fe-MOFs derived magnetic carbon nanocomposite with carboxylic acid surface functional groups (Fe@C-COOH) was achieved. Next, the α-Fe2O3@C@SiO2/TiO2 was successfully synthesized followed by a sol-gel method to coat the SiO2 shell and a solvothermal method to coat the surface of the intermediate TiO2 particles. The as-synthesized nanocomposite materials were characterized and physicochemical analytical equipment. Further, the investigation on magnetic photocatalytic nanocomposite α-Fe2O3@C@SiO2/TiO2 performance of dye degradation and photocatalytic activity on Reactive yellow 145 (RY145), using as an indicator was conducted. The as-synthesized nanocomposite particles were characterized using X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), X-ray energy dispersive spectroscopy (EDX), and scanning electron microscopy (SEM) techniques. The structural characterization of the as-synthesized materials proved that these methods generate oxygen-containing functional groups, such as, -OH, -CO, and -COOH, which increases the polarity and hydrophilicity of the photocatalyst. The photocatalytic oxidation of RY145 dye under UVc light was discussed by the apparent first-order reaction rate and the kinetic model of the Langmuir-Hinshelwood followed a better fitting. The optimal performance of the composite is at pH = 2, 15 mg/100 mL of photocatalyst dose, 150 mg/L concentration of the dye RY145 at 25 °C temperature under UVc lamp irradiation for 90 min, and with the apparent reaction rate constant was 0.0165 min-1. The thermodynamic analysis of activation parameters computed by the Eyring model and based on transition state theory (TST), an endothermic reaction with a positive value for Δ‡Ho (50.16 kJ mol-1) and a negative value for Δ‡So (-153 J/mol K) both contribute toward achieving positive values for Δ‡Go and a nonspontaneous process. The proposed α-Fe2O3@C@SiO2/TiO2 demonstrated a high capability of photocatalytic degradation up to 97% after five successive cycles at the optimal condition compared to that of Fe3O4@C (18.74%) and Fe@C-COOH (77.9%) without reusability.

Spatio-temporal variation and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface dust of Qom metropolis, Iran.

The objective of this research was to determine seasonal variation, distribution, potential health risk, and source identification of 16 polycyclic aromatic hydrocarbons (PAHs) in the surface dust of eight urban areas of Qom. The total levels of 16 PAHs ranged from 364.83 to 739.26 ng g-1, with an average of 478.27 ng g-1. Sites 1 and 8 showed the highest (491.33 ng g-1) and lowest (465.08 ng g-1) concentrations of PAHs, respectively. The PAHs demonstrated the highest and the lowest levels in autumn (553.41 ng g-1) and summer (402.30 ng g-1), respectively. Naphthalene (Nap) showed the highest amounts in all of the areas (75.57 ng g-1). Source apportionment indicated that vehicular emissions and combustion of fossil fuels (liquid fossil fuel, crude oil, and gas) are the main sources of the PAHs. Toxic equivalency quantities (TEQs) index exhibited a mean concentration of 47.41 ng g-1, and benzo[a]pyrene (BaP) and dibenzo[a,h]anthracene (DBA) together contributed more than 80% of TEQ, indicating high risk potential of these compounds. Total incremental lifetime cancer risk (ILCR) presented higher value (2.62 × 10-7) for children than for adults (2.53 × 10-7), one-fold lower than the threshold (10-6). The spatial ILCR for the study areas and seasons showed the highest cancer risk in site 2 and winter. Taken together, the carcinogenic risk of PAHs to children and adults, respectively, through direct ingestion and dermal contact pathways illustrated values close to the baseline, suggesting that more attention should be paid to the issue in the study area.

Preparation and surface engineering of CM-ß-CD functionalized Fe3O4@TiO2 nanoparticles for photocatalytic degradation of polychlorinated biphenyls (PCBs) from transformer oil.

The aim of the present research is to investigate the efficiency of surface-modified magnetic nanoparticles for photocatalytic degradation of PCBs from transformer oil. Therefore, CMCD-Fe3O4@TiO2 was successfully produced via grafting of carboxymethyl-ß-cyclodextrin (CM-ß-CD) onto the core-shell titania magnetic nanoparticles surface. The photocatalytic efficiency of CMCD-Fe3O4@TiO2 for degradation of PCBs was systematically evaluated using an experimental design and the process parameters were optimized by response surface methodology (RSM). The central composite design (CCD) with four experimental parameters was used successfully in the modeling and optimization of photocatalytic efficiency in removing PCBs from transformer oil. ANOVA analysis confirmed a high R-squared value of 0.9769 describing the goodness of fit of the proposed model for the significance estimation of the individual and the interaction effects of variables. The optimal degradation yields of PCBs was achieved 83 % at a temperature of 25 °C, time of 16 min, the dosage of the catalyst of 8.35 mg and oil: ethanol ratio of 1:5. These findings encourage the practical use of CM-ß-CD-Fe3O4@TiO2 as a promising and alternative photocatalyst on an industrial scale for the cleaning of organic pollutants such as PCBs due to its environmental friendliness, the benefit of magnetic separation and good reusability after five times.

Total mercury and methylmercury concentrations in native and invasive fish species in Shadegan International Wetland, Iran, and health risk assessment.

Human exposure to mercury (Hg) mainly occurs through consumption of aquatics, especially fish. In aquatic systems, the bioaccumulation of Hg across trophic levels could be altered by invasive species through changing community composition. The present study is aimed at measuring total mercury (T-Hg) and methylmercury (MeHg) concentrations in non-native (redbelly tilapia (Tilapia zillii)) and native (Benni (Mesopotamichthys sharpeyi) and common carp (Cyprinus carpio)) fish species throughout Shadegan International Wetland and comparing health risk of their mercury contents to the local population. The concentrations were measured using a direct mercury analyzer (DMA 80). The average values of T-Hg and MeHg for native fishes were 19.8 and 10.49 µg/kg. These concentrations for the invasive fish were 28 and 14.62 µg/kg respectively. Despite having less length and weight than the native fish species, tilapia showed significantly higher T-Hg content, yet the lowest concentration of MeHg was observed in common carp with larger body length and weight. Concerning mercury health risk to consumers, tilapia demonstrated the highest estimated weekly intake (EWI) and percentages of tolerable weekly intake (%TWI) for both T-Hg and MeHg, while the highest hazard quotient (HQ) values were obtained for tilapia and Benni. Taken together, the mercury concentrations in the two native and non-native fishes were acceptable according to the international safety guidelines although the local people shall be warned for consumption of tilapia. Furthermore, the low calculated value of tissue residue criterion (TRC) for the wetland fishes sounds a warning.

Synthesis, characterization and photocatalytic application of Ag-doped Fe-ZSM-5@TiO2 nanocomposite for degradation of reactive red 195 (RR 195) in aqueous environment under sunlight irradiation.

BACKGROUND: Most dyes have aromatic rings in their structures, which make them highly toxic for human being and aquatic life. Heterogeneous photodegradation using TiO2 nanoparticles is one of the most applied methods used for dye removal. The wide band gap of TiO2 nanoparticles disables its use of the visible light and thus the vast potential of sunlight. To overcome this deficiency, Ag doped TiO2 nanoparticles were loaded on Fe-ZSM-5. METHODS: Fe-ZSM-5@TiO2-Ag photocatalyst was synthesized through sol-gel and hydrothermal methods to remove hazardous Reactive Red 195 (RR 195) from aqueous solution. RESULTS: Pure phase of Fe-ZSM-5@TiO2-Ag with specific surface area of 332 m2/g was successfully synthesized. Formation of Ti-O-Ag functional group in the photocatalyst structure confirmed the nanocomposite form of the product. SEM and TEM images portrayed the synthesized zeolite and photocatalyst NPs in a size range of ≤100 nm with homogenous distribution of Ag doped TiO2 on Fe-ZSM-5 surface. The band-gap energy of Fe-ZSM-5@TiO2-Ag was calculated 1.97 eV at λ = 630 nm. Photocatalytic activity of the photocatalyst under natural sunlight was investigated through photodecomposition of RR 195 in an aqueous solution. The dye photodecomposition of about 98% was achieved at photocatalyst concentration of 400 mg/L, pH of 3, and dye concentration of 50 mg/L at ambient temperature after 120 min under sunlight using 0.5 ml of TiO2 and silver ammonium nitrate. The photocatalyst reusability was found significant after 5 frequent cycles. CONCLUSION: The novel Ag-doped TiO2-Fe-ZSM-5 nanocomposite with sunlight sensitivity can be a promising candidate to purify wastewater containing organic pollutants.

A novel facile synthesis of the amine-functionalized magnetic core coated carboxylated nanochitosan shells as an amphoteric nanobiosupport.

We developed a novel synthesis method for a multifunctional nanocomposite with amine-functionalized Fe3O4 core coated with carboxylated nanochitosan shells (NH2-Fe3O4@NCS-COOH) via carbodiimide activation. The chemical structures of chitosan and carboxylated nanochitosan (NCS-COOH) were verified by 1H NMR which confirmed the incorporation of citric acid by the formation of the new signal of the CH2 H-atoms. TEM image displayed the synthesized NH2-Fe3O4@NCS-COOH nanoparticles were in a spherical shape with an average size of 100 nm. The results of XRD revealed that NH2-Fe3O4@NCS-COOH have a good crystalline nature with the face center cubic structure and with the average crystallite size of 17 nm. The characterization using VSM showed that the magnetic nanoparticle had superparamagnetic behavior and the saturation magnetization was up to 30 emu/g. The BET specific surface area of NH2-Fe3O4@NCS-COOH was 45.18 m2/g. The synthesized nanostructure was found to be stable in different ranges of pH due to covalent bonds between nanochitosan and Fe3O4.

Characterization, concentration and risk assessment of airborne particles using car engine air filter (case study: Tehran metropolis).

Atmospheric elements released into the atmosphere can enter the human body through inhalation, ingestion and dermal contact and are then deposited in the body. Trace elements have potential risks to human health. For this purpose, the particulate matter accumulated by car air filters (CAFs) was studied. The morphology and distribution of particle size were examined using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The concentration of elements in CAFs and CAF-estimated air for 30 elements in Tehran, Iran, was analyzed in winter and summer, from February to July 2017. Samples were determined by inductively coupled mass plasma spectrometry. The most abundantly detected elements in both CAFs and air in both seasons were Ca, Mg, Na and Fe. The shape of the particles was mostly irregular and spherical. Most of the particles were between 0.5 and 1.0 µm. The carcinogenic risks of inhalation exposure to Cr and Co in winter and summer were higher than the acceptable level (< 1 × 10-4) for children and adults. The carcinogenic risks of As and Cr in both seasons were higher than 1 × 10-4 for children and adults via dermal contact. Also, the carcinogenic risks of Cr in both seasons of ingestion exposure were higher than 1.00E-04 for children and adults. The integrated noncarcinogenic risks of all trace elements were higher than the safe level (= 1) for children and adults in both seasons.

Application of surface chemical functionalized cellulose nanocrystals to improve the performance of UF adhesives used in wood based composites - MDF type.

The aim of this research was to investigate the effect of functionalized cellulose nanocrystals (CNC) on the performance of urea-formaldehyde (UF) adhesive for the production of medium density fiberboard (MDF). Surface modification of CNC was performed using 3-Aminopropyltriethoxysilane (APTES). Some physical and thermal properties of reinforced and neat UF as well as formaldehyde emission and some mechanical (modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond strength (IB)) and physical properties (thickness swelling (TS) and water absorption (WA)) of the resulting MDF panels were determined. Based on the results, upon incorporation of modified CNC to the system, solid content, density, viscosity and free formaldehyde of UF adhesives decreased while gel time increased. Depending on addition of the modified CNC loading in the panels, the formaldehyde emission values varied from 11% to 17% lower than the panels made from neat UF. In comparison to the control samples, panels made with UF containing 2% modified CNC had 29.3% and 38.2% higher MOR and MOE respectively.

Biological CNP removal from meat-processing wastewater in an innovative high rate up-flow A2O bioreactor.

A high rate up-flow anaerobic, anoxic and oxic (A2O) bioreactor was designed and operated for meat-processing wastewater (MPW) treatment as a single cost-effective system with the aim of simultaneous CNP removal. The influence of three essential factors, HRT, COD/TN ratio and aerated volume fraction on the reactor performance was assessed using response surface methodology (RSM). The required HRT to reach 98.5% COD removal was achieved at 7.5 h. Simultaneous CNP removal under denitrification rate of 199.4 mg/l.d gave high nitrate to nitrogen gas conversion of 74.6 mg/l. An HRT, COD/TN ratio and aerated volume fraction of 10 h, 100:20 and 60%, respectively, was a favored condition for an efficient nitrogen removal with effluent total Kjeldahl nitrogen (TKN) less than 70 mg/l. Under optimum condition, an HRT, COD/TN and aerated volume fraction of 8 h, 100:14 and 65%, respectively, resulted an effluent phosphorus of 43 mg/l, but 93.97 mg/l phosphorus was released in an anaerobic condition at 6 h. An effluent with a low turbidity of about 1.5 NTU and a sludge volume index (SVI) of 75.9 ml/g was achieved using at HRT of 12.5 h, COD/TN ratio of 100: 8 and aerated volume fraction of 50%. Under these conditions, the removal efficiencies for COD, TKN, nitrate-nitrogen (NO3--N), total nitrogen (TN) and phosphorus (PO43--P) were obtained to be 98.33, 92.06, 91.97, 90.48 and 83.48%, respectively. As a result, the application of the up-flow A2O bioreactor is a promising configuration to get hygienic water from wastewater.

Surface chemical functionalization of cellulose nanocrystals by 3-aminopropyltriethoxysilane.

Surface functionalization of cellulose nanocrystals (CNCs) is valuable option to tailor properties as well as increase opportunities for their application. In this study, the surface of CNCs was functionalized with 3-aminopropyltriethoxysilane (APTES), without using hazardous solvents and by a direct, simple and straightforward method. APTES was firstly hydrolyzed in water and then adsorbed onto CNC through hydrogen bonds, finally the chain hydrocarbon was covalently linked to the surface of CNC through SiOC bonds which formed via the condensation reaction between hydroxyl and silanol groups. The chemical modification of the CNCs surface was confirmed by ATR-IR and NMR spectroscopy. Experiments conducted by AFM and XRD showed no significant change in the CNC dimensions and crystalline structure as a result of the modification. The EDX and XPS results confirmed the exsistence of APTES onto the CNCs. Silylated CNC exhibited good thermal stability and a greater amount of residual char was formed at 500 °C compared to non-chemically modified CNC. Thus, The silylation of CNCs may offer applications in composite manufacturing, where these nanoparticles have limited dispersibility in hydrophobic polymer matrices, and as nano-adsorbers due to the presence of amino groups attached on the surface.

Application of response surface methodology for optimization of trace amount of diazinon preconcentration in natural waters and biological samples by carbon mesoporous CMK-3.

Preconcentration of trace amounts of diazinon by carbon mesoporous CMK-3 in water and biological samples and measurement by high-performance liquid chromatography were investigated. CMK-3 was prepared using hexagonal SBA-15 as the template. The synthesized materials were characterized by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy, Brunaur-Emmet-Teller, transmission electron microscopy and Boehm titration method. The preconcentration procedure was optimized using a multivariate optimization approach following a two-stage process. The effect of analytical parameters including the amount of the CMK-3 as an adsorbent, pH, type and volume of eluent and flow rate of eluent and sample were studied by a screening project, then the effective parameters were optimized by response surface methodology based on central composite design. The average extraction efficiency of diazinon under optimal conditions (CMK-3 dosage = 25 mg, sample flow rate = 2.5 mL min-1 , eluent flow rate = 1.25 mL min-1 , volume of methanol as an eluent =3.5 mL and initial pH = 6) was 97.11%, which agrees well with the predicted response value (97.93%). The linearity of the method was in the range of 0.5-100 µg L-1 with a correlation coefficient of 0.997. Enrichment factor, limit of detection and limit of quantification were 285.7, 0.09 and 0.23 µg L-1 , respectively. The relative standard deviation (RSD) under optimum conditions was 2.21% (n = 5). The proposed method was applied to determine diazinon in real water and biological samples. Recovery of diazinon from real samples was between 95.80 and 104.94% with an RSD of 0.19-4.65%. Thus, this method is suitable for the preconcentration and determination of diazinon in real water and biological samples.

Transfer, tissue distribution and bioaccumulation of microcystin LR in the phytoplanktivorous and carnivorous fish in Anzali wetland, with potential health risks to humans.

This study was conducted to determine Microcystin LR concentration in the aquatic ecosystem of the Anzali wetland in Iran. Extraction and detection of MC-LR from the water and fish samples was conducted by the SPE and HPLC-UV apparatus. Our results showed that among toxic cyanobacteria, Anabaena was the dominant genera during the study period. The results indicated that MC-LR content in water ranged from 0.18 to 3.02µg/L in dissolved fraction and undetectable level to 1.13µg/L in cellular fraction, in all three seasons. The results of PCA revealed that the environmental parameters including EC, Chl-a, PO43-, pH and temperature were the most effective factors influencing the MC-LR production. Results further showed the mean concentration of MC-LR in muscle and liver of silver carp ranged from 10.12 to 40.98 and from undetectable to 44.34µg/kg w.w, respectively. The mean concentration of MC-LR in northern pike was 15.18 to 35.1µg/kg w.w in muscle and undetectable to 51.91µg/kg w.w in liver samples. Our results suggest that consumption of fish harvested from the Anzali wetland seems to be unsafe for humans, based on obtained estimated daily intake values which were higher than the tolerable daily intake value recommended by WHO. In addition, bioaccumulation factor of MC-LR in edible tissues of fish was estimated based on lipid normalization. The results showed that the BAF of MC-LR in silver carp (1047±185L/kg of lipid) was lower than the northern pike (1272±185L/kg of lipid), although the difference was not significant.

Detection of Bisphenol A and Nonylphenol in Rat's Blood Serum, Tissue and Impact on Reproductive System.

INTRODUCTION: Bisphenol A (BPA) and Nonylphenol (NP) have estrogen-like activity, and some of their adverse biological effects have been demonstrated. This study was designed to determine the association of plasma and tissue concentrations of BPA and NP and changes in the parameters of the reproductive system in rats. METHODS: Male Wistar rats were administered three doses of BPA and NP (5, 25, and 125 µg/kg) by gavage for 35 consecutive days in 2014-2015, and a 2-ml blood sample was taken from each treated rat. Concentrations of BPA and NP in the blood were determined using the HPLC-fluorescence detection method. The sperm are produced in the epididymis and vas deferens, and they swim up in Ham's F10 solution, and, then, various parameters were evaluated using an invert microscope, and they included the count, motility, and morphology of the sperm. RESULTS: The weight of the testes and prostate in the rats receiving BPA and NP treatment showed significant decreases compared to the control group. Similarly, NP created higher concentration than BPA in the serum (e.g., 5.48 ± 0.65 vs. 1.36 ± 0.25, at 125 µg/kg). Compared to the control group, dose-dependent significant decreases in count and motility in the sperm were observed following the administration of BPA (25 and 125 µg/kg) and NP (all three doses). Morphologic aspects of the rats' sperm were changed in various doses of BPA and NP. CONCLUSIONS: According to our findings, BPA and NP induced dose-dependent toxic effects on various parameters, i.e., sperm toxicity, weight of the testes, and weight of the prostate gland.

Pre-concentration of trace amount of bisphenol A in water samples by palm leaf ash and determination with high-performance liquid chromatography.

Palm leaf ash was characterized and used as low-cost adsorbent for solid-phase extraction and preconcentration of bisphenol A (BPA) in real water samples. Analysis of BPA was carried out using HPLC involving Eurospher 100-5-C18 (25 cm × 4.5 mm, particle size 5 µm) column and water-acetonitrile (40:60, v/v) as mobile phase. The adsorption was achieved quantitatively at a pH of 6 with elution by 3 mL acetonitrile. The limits of detection and enrichment factor were 0.02 µg L(-1) and 333, respectively. Under optimum conditions the relative standard deviation (RSD) was 2% (n = 10). Comparison of qualification criteria of presented preconcentration procedure with other research indicated that palm leaf ash adsorbent was better than many of the adsorbents in terms of cost and reusability. Also, the limit of detection, precision and enrichment factor were comparable and even better than the previously reported methods. Finally, the efficiency of method was computed by determination of trace amounts of BPA in sea, river, mineral and tap waters with recoveries of 93.3-105.5% and RSDs of 0.61-3.12%.. Briefly, the developed solid-phase extraction and Preparative layer chromatography (PLC) methods may be used for bisphenol A monitoring in any environmental water sample. Copyright © 2016 John Wiley & Sons, Ltd.

Pattern of mercury accumulation in different tissues of migratory and resident birds: Western reef heron (Egretta gularis) and Siberian gull (Larus heuglini) in Hara International Wetland-Persian Gulf.

The Hara Mangrove Forest of the Persian Gulf is undergoing increasing pollution from industrial, municipal, and petroleum sources; however, little research in ecotoxicology has been carried out in this ecosystem. In the present study, mercury distribution and accumulation were investigated in muscle, liver, kidney, and feather of the resident Western reef heron (n = 15) and the migratory Siberian gull (n = 15). We also evaluated the relation between Hg concentrations, sex, and age (juvenile vs. adult). Results showed that the highest concentrations of Hg were recorded in the feather (35 ± 0.14-3.0 ± 0.27 mg kg(-1) dw) and at 3.7-, 1.6-, and 1.3-fold in muscle, kidney, and liver, respectively. Concentrations of mercury in tissues of migratory birds were two times higher than in resident birds; geographical differences and feeding habits were used to explain these variations. We found a weak relationship between Hg concentrations in feathers and internal tissues (r ≤ 0.50); conversely, liver presented strong positive correlations with other soft tissues, especially kidney (p > 0.05; r = 0.82). Results showed that sex and age have no significant effects on T-Hg accumulation in these birds (p > 0.05; r < -0.01). Based on these findings, Hg concentrations were low in both species. Therefore, Hg contamination of this aquatic ecosystem is not a threat. Accordingly, we recommend the use of the Western reef heron as a bioindicator of mercury pollution in this region.

Occurrence and distribution of two phthalate esters in the sediments of the Anzali wetlands on the coast of the Caspian Sea (Iran).

This study provides the first data on distribution of phthalate Acid esters (PAEs) in surface sediment samples taken from Anzali Wetland, Iran. These samples were collected from 43 stations. Two PAEs consist of di(2-ethylhexylphthalate) (DEHP) and di-n-butyl phthalate (DnBP) were detected and the total concentrations of these two pollutants ranged from 0.25 to 43.12, 0.12 to 19.02µgg(-1) dry weight, respectively. Among all the 43 samples analyzed, no sample was found to be free of DEHP and DBP, which indicates these two phthalate esters were ubiquitous in sediments. The concentrations in the near urban regions were higher than other regions because of higher discharge of PAEs from plastic materials in urbanized areas. Concentrations of PAEs were positively correlated with total organic carbon (TOC). Generally the median concentrations of DEHP and DnBP in the sediments were 15 and 14 times higher than the ERL. These results show that the Anzali wetland are highly polluted by major PAE congeners consist of DEHP and DnBP.