Avicenna Journal of Environmental Health Engineering
Volume:5 Issue: 2, Dec 2018

Fluoxetine is used as an effective antidepressant in psychopharmacology. As a pharmaceutical and personal care product (PPCP) found in superficial waters, fluoxetine influences the wildlife that inhabit these waters. This study was conducted to determine the fluoxetine concentration even in trace quantity in the hospital wastewater, using a solid-phase microextraction (SPME) silica fiber layered with single-walled carbon nanotubes (SWCNTs). An instrumental setup including off-line SPME, which uses a simple carbon nanotube (CNT) to bond capillary column combined with fluorescence spectrometry, was arranged as a sensitive method for the quantification of fluoxetine in real sample. A one at-a-time optimization strategy was applied for optimizing extraction parameters such as extraction time, stirring rate, desorption time, pH, and salt effect on the extraction, preconcentration and determination of fluoxetine in aqueous samples. The advantages of the developed method were: being simple to use with shorter amounts of time for analysis, lower equipment costs, thermal stability of fiber, and high relative recovery in contrast to conventional methods of analysis. Linear ranges were within 0.1-30 µg/L and the detection limit for the fluoxetine was 1×10-4 µg/L.

Groundwater resources are an important portion of potable water in Hamedan Province, Iran. Therefore, monitoring the pollutants especially heavy metals in these resources are vital to protect the residents’ health. This study aimed to assess the health risks caused by inorganic arsenic pollution through groundwater drinking pathway in four important agricultural areas of Hamedan Province, Iran. In so doing, a total of 180 groundwater wells were chosen randomly for sampling during the spring and summer seasons in 2015. The samples were filtered (0.45 μm), preserved with HNO3 at a pH level lower than 2, and stored in acid-washed polyethylene bottles at 4°C for further analysis. Finally, arsenic content was determined using inductively coupled plasma- optical emission spectrometry (ICP-OES). The results showed that the mean contents of arsenic (mg/L) in groundwater samples taken during the spring were 0.052 for Asadabad plain, 0.007 for Ghahavand plain, 0.006 for Razan plain, and 0.004 for Toyserkan Plain; whereas, the mean content in groundwater samples taken during the summer from Asadabad, Ghahavand, Razan, and Toyserkan plains were 0.058, 0.009, 0.007, and 0.004, respectively. Moreover, based on the computed values of the noncarcinogenic risk of groundwater samples from Asadabad plain, the hazard quotient (HQ) was greater than 1. Therefore, a non-carcinogenic effect is considered to be possible for the inhabitants of this study area. Accordingly, serious considerations including managing the use of agricultural inputs especially arsenical pesticides or herbicides and treatment of arsenic-contaminated groundwater with some proper methods before water ingestion are recommended.

This study investigated the effect of various parameters on the removal of Reactive Blue 203 dye from wastewater using ferrate(VI) oxidation process, ultraviolet radiation (UV) radiation and MgO nanoparticles under batch mode. Although several studies have been carried out on dye removal, there is no study on the removal of Reactive Blue 203 dye using ferrate(VI) oxidation process, UV radiation, and MgO nanoparticles. Therefore, the aim of this study is to investigate the effect of different factors including pH, temperature, contact time, the intensity of UV radiation and the concentration of MgO nanoparticles on Reactive Blue 203 dye removal using the above-mentioned methods. The results showed that the best pH values for dye removal using UV radiation, ferrate(VI), and MgO nanoparticles were 13, 1 and 13, respectively. The best temperature for Reactive Blue 203 dye removal using ferrate(VI) was 50°C. Hence, temperature variation had no significant effect on Reactive Blue 203 dye removal using UV irradiation and absorption by MgO nanoparticles. Based on the results, the best contact time was 15 minutes using UV radiation. The removal of Reactive Blue 203 dye using ferrate(VI) oxidation process was a quick reaction, and in a fraction of a second, the reactions were completed. The results showed that dye removal using MgO nanoparticles could be described by the Temkin isotherm. Therefore, the contact time was not considered as an effective parameter. In addition, the maximum dye removals were 95, 85 and 94% using UV irradiation, ferrate(VI) and MgO nanoparticles.

Nowadays, due to increasing usage of dye in various industries and its destructive effects on health and environment, it is necessary to remove dyes from industrial wastes. Although few studies can be found on using pine cone for removal of different dyes, it has not been used yet to remove Reactive Blue 203 (RB203) dye. The purpose of this study is to investigate RB203 dye adsorption using activated carbon produced from pine cone. Optimal values of influencing factors for RB203 dye removal were obtained. The results showed that the maximum removal was occurred at a pH of 2, temperature of 30˚C, dye concentration of 30 mg/L, adsorbent dosage of 100 mg/L, and contact time of 15 min. The maximum removal percentage was 98.48%. In order to study the synthesized activated carbon, some characterization methods including scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy and Brunauer-Emmett-Teller (BET) have been used. Investigation of adsorption isotherm models revealed that adsorption of RB203dye can be described through D-R and Temkin isotherm models. Additionally, RB203 dye removal follows the pseudo-first-order kinetic equation.

Contamination with heavy metals and petroleum hydrocarbons is considered as an environmental problem. Thus, this research was done to evaluate the effect of montmorillonite nano-clay on the changes in petroleum hydrocarbon degradation and cadmium (Cd) concentration in plant grown in a Cd-polluted soil. Treatments consisted of two levels of montmorillonite nano-clay (0 and 1% W/W) in a Cd-polluted soil (0, 5, 10 mg Cd/kg soil) and crude oil-polluted soil (0, 1 and 2% W/W). The plant used in this study was Tall Fescue (Festuca arundinacea L.). After 20 weeks, the concentration of Cd in plants was measured by atomic absorption spectroscopy and the total petroleum hydrocarbon (TPHs) in the soil was determined using the GC-mass spectrometry. Soil respiration was determined according to the method used by Qiao et al. ANOVA was used for statistical analysis of data. The least significant difference (LSD) test was used to determine the differences between the means. The application of 1% (w/w) montmorillonite nano-clay in Cd-polluted soil (10 mg Cd) without crude oil decreased Cd concentration in plant and increased microbial respiration by 18% and 34%, respectively. In addition, the application of 1% montmorillonite nano-clay in soil polluted with 1% crude oil and 10 mg Cd enhanced TPHs degradation by 27%. The use of montmorillonite nano-clay increased Cd adsorption in soil which resulted in an increase in microbial respiration and, hence the degradability of petroleum hydrocarbon in the soil.

Bacterial cellulose (BC) which is characterized by numerous original properties including high purity, crystallinity and mechanical strength has the same molecular formula as cellulose from plant source. The aim of this study was to investigate the possibilities of using environmentally friendly BC membranes for membrane separation. BC membranes produced by Acetobacter xylinum were grown in a kombucha tea medium. The effect of cultivation time on filtration properties of BC membranes was tested (from 10 to 30 days). Dead-end filtration was used to determine pure water and permeate fluxes. The hydraulic permeability coefficients (Lp ) of BC membranes were 20.5, 16.1, 4.5 L/m2 h bar for 10, 20, 30 days, respectively. The effects of applied pressure (2.5, 7.5, 12.5 bar) and solution pH (5.0, 7.0, 8.8) were examined on color and chemical oxygen demand (COD) removal. The highest color and COD removals were 85.9 and 73.8% for BC-10 and 90.9 and 75.1% for BC-20 membranes at 12.5 bar pressure and pH 5.0. Moreover, silver nanoparticles with different concentrations (2, 4, and 8 mM) were grown on BC-20 membrane to investigate antibacterial properties of the composite membrane. The results showed that BC membrane could be used to develop eco-friendly antibacterial membranes with potential applications in color and COD removal from textile wastewater.

Ag/ZnO nanotetrapods (AZNTP) are prepared using silver (I)–bis (oxalato) zinc complex and 1, 3-diaminopropane (DAP) under a phase separation system. This crystal structure and lattice constant of the AZNTP was investigated by means of XRD, TEM, and UV-vis spectrum. AZNTP films with 23 nm in arm diameter and high surface activity work at room temperature as humidity sensors. AZNTP have shown some properties including quick response with high sensitivity, a longer life span and recovery, and no need for heat regeneration. Moreover, AZNTP could form OH group with physisorbed water in wet environments. The results of the present study demonstrated that the growth and characterization of AZNTP for environmental humidity sensing and DAP play an original role in the determination of particle morphology. Ultra-thin AZNTP has also been tested as a resistance sensor, having an unusual high sensitivity to moisture.

Perovskite-like BiFeO3 nanoparticles doped with barium and sodium ions were synthesized via the citric acid route by the sol-gel method. The as-prepared Bi0.65Na0.2Ba0.15FeO3 nanopowders were divided into three equal portions and separately annealed at various annealing temperatures of 600, 700 and 800°C. The powders were characterized using X-ray diffraction (XRD) and crystallized with a rhombohedral R3c space group. Scanning electron microscopy was used to determine the morphology of the crystal and Fourier transform infrared spectroscopy was conducted at room temperature to determine the phase purity and the B-site formation in the perovskite structure. The UV-vis diffuse reflectance spectroscopy of all the materials was investigated, showing strong photoabsorption (λ > 420 nm). The doping effect of BiFeO3 enhanced photocatalytic activity while it significantly reduced the energy bandgap to 2.05 eV (for BNBFO at 800°C) which showed strong visible light absorption. The photocatalytic activity of Bi0.65Na0.2Ba0.15FeO3 nanomaterials was tested by monitoring the degradation rate of methylene blue dye pollutant under visible light irradiation in aqueous solution. All powders showed photoactivity after 2 hours of visible light irradiation. The annealing temperature greatly affected the methylene blue degradation, showing the efficiencies of 57, 67 and 75 % for BNBFO at 600, 700 and 800°C, respectively. Kinetic studies were carried out and the rate constants of 6.70 x 10-3, 8.90 x 10-3 and 1.05 x 10-2 min-1 were obtained for powders annealed at 600, 700 and 800°C, respectively. The photocatalytic mechanism of the degradation process was proposed in this study.