Avicenna Journal of Environmental Health Engineering
Volume:7 Issue: 1, June 2020

The wide use of nano-sized metallic materials could result in the release of these particles into the environment. In addition, due to the dissolution of these nano-materials, some of the adverse effects could result from the dissolved metals. On the other hand, dietary supplements play a key role in improving the immunity of consumers; hence, the use of immune stimulants such as mushroom seems to be very necessary. In this study, the dietary effect of Pleurotus ostreatus mushroom was investigated on serum immunity and liver histopathological indices of Oreochromis niloticus exposed to silver nanoparticles (AgNPs). Serum total protein level enhanced with increasing prebiotic concentration. Serum immunoglobulin and albumin levels increased in the group treated with Pleurotus ostreatus. The amount of these indices significantly increased at the concentration of 0.2 mg/kg; however, glucose value decreased in both of the experimental groups. Serum ALT and ALP levels significantly reduced in the combined treatment group (AgNPs and mushroom) at the concentration of 0.2 mg/kg, in contrast with the control group. In the combination treatment group (AgNPs and mushroom), the serum AST level significantly reduced at concentrations of 0.1 mg/kg and 0.2 mg/kg; however, it increased at the concentration of 0.05 mg/kg compared with the control group, indicating that immunological indices could improve due to the combined use of AgNPs and mushroom. The overall conclusion of this study shows that the use of mushroom at 0.2 mg/kg in combination with AgNPs could partially improve the effect of AgNPs on tilapia.

In this study, a new and simple column-mode separation method has been proposed for the pre-concentration and removal of trace amounts of thallium(III) (Tl) from water samples. The procedure was based on sorption of Tl(III) ions by a solid phase extraction column filled with 4-[(2-hydroxy, 3-methoxy benzylidine)4-amino]1,2,4-treeazol-5-thione on microcrystalline naphthalene. The determination was performed directly using flame atomic absorption spectrometry (FAAS) method. The main factors affecting the extraction recovery were investigated and optimized. The interference effect of various ions on the determination of Tl(III) was also studied. In optimum conditions, the precision of the proposed method for sample solutions containing 0.2 μg/mL of Tl(III) was 2.0%, and the enrichment factor was found to be 35. The proposed method was evaluated and employed for pre-concentration and removal of Tl(III) from spiked natural (Tap and well) and industrial water samples.

Some of the microorganisms such as Escherichia coli have the ability to migrate to areas in which the intensity of magnetic fields (MFs) is higher, which is called magnetotactic properties. Magnetotaxis is a process implemented by a group of gram-negative bacteria that involves orienting and coordinating movement in response to magnetic fields. This study was conducted to investigate these properties of Escherichia coli in laboratory conditions. By means of coated wires (30 rounds) placed in two parts of the reactor (with five zones and a volume of 250 mL) and direct current (DC), an intensity of 0.18 mT for 42 minutes has been prepared. The most probable number of E. coli per 100 mL (MPN/100 mL) in each zone of the reactor, before and after exposure, was estimated. According to the results of this study, E. coli has magnetotactic properties, and the mean density of these bacteria in higher MFs (0.18 mT) is higher compared to the other zones in the reactor.

Removal of heavy metals from industrial effluents is one of the most important in environmental research. This research was done to investigate the adsorption effect of multiwall carbon nanotubes (MWNTs) and nano Zn-oxide on decreasing chromium (Cr) and cadmium (Cd) concentration in wheat inoculated with Piriformospora indica (P.indica) that irrigated with wastewater of plating industry. Treatments were consist of applying MWCNs (0 and 0.5 % (W/W)) and nano Zn-oxide (0 and 1.5 % (W/W)) in the soil irrigated with the wastewater of plating industry under wheat inoculated with P.indica. This research was done as a factorial experiment in the layout of completely randomized block design in three replication After 90 days, plants were harvested and plant Cd and Cr were measured using atomic absorption spectroscopy. Using MWCNs had significant effect on increasing cation exchangeable capacity of soil. Applying 0.5 % (W/W) MWCNs in the soil irrigated with waste water significantly decreased the soil Cd concentration by 11.7%, while the plant biomass was increased by 13.4%. In addition, applying 1.5 % (W/W) nano Zn-oxide significantly decreased the negative effect of heavy metal toxicity that can be related to the role of nano Zn-oxide on increasing soil sorption properties. However, the interaction effect of Zn and Cd cannot be ignored. The results of this study showed that applying MWCNs and nano Zn-oxide has a significant effect on decreasing phytoremediation efficiency in soil irrigated with wastewater of plating industries. However, the type and the amount of heavy metals in wastewater cannot be ignored.

Climate change due to global warming is one of the worst environmental disasters in the world, which affects all ecosystems and has led to increasing degradation of coral reefs. The increase of sea surface temperature is inversely related to the resistance of corals and is directly associated with their bleaching. High temperature disrupts the symbiotic relationship between coral and algal symbiont and results in coral bleaching. To evaluate the adaptation of corals to heat stress, in this study, we investigated the thermal stress effect on the expression of genes involved in programmed cell death (PCD), cysteinyl aspartate proteases 3 (will be mentioned as Caspas3 hereafter) and anti-apoptotic pathway, B-cell lymphoma 2 (will be mentioned as Bcl2 hereafter) in Porites lobata (Dana, 1846). Corals were incubated at 25°C for 2 weeks (adaptation period) and then exposed to 34°C (heat shock) for 24 and 48 hours. Then, the expression of genes was measured using real-time PCR. The results revealed that both genes were up-regulated at 24 hours after heat induction. Bcl-2 expression (anti-apoptotic gene) was induced at 24 hours and was down-regulated at 48 hours. In contrast, Caspase3 (apoptotic gene) continued to be expressed up to 48 hours. These results might indicate that coral cells are headed towards bleaching and death with increased temperature. The results of this study, regarding the observed expression patterns, can clarify the response of different genes to a thermal stress in coral reefs. The exposure of corals to acute conditions with high temperatures presented the behavior of the desired genes in the studied conditions.

Since large amounts of agricultural wastes are produced in Iran and these wastes have lignocellulosic nature, the current study was performed to survey the adsorption performance of methylene blue dye from aqueous solutions by means of raw and modified cantaloupe peel. The adsorbents used were characterized using techniques like scanning electron microscope (SEM), as well as Fourier transform infrared spectroscopy (FTIR). In this study, the effects of a few key variables including pH, reaction time, dye concentration, adsorbent dosage and temperature on the adsorption performance were investigated. Optimum values were attained at 0.04 and 0.08 g doses of modified and raw cantaloupe peel, pH of 7 after mixing for 120 and 90 minutes for raw and modified cantaloupe peel, respectively. The equilibrium information was fitted to the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich equations and the respective data for all models were tested. An increase in adsorbent dose and temperature caused the efficiency to rise. The mechanism and rate of adsorption were ascertained by analyzing the experimental data at various contact times according to traditional kinetic equations: pseudo-first-order and second order, Elovich, and intra-particle diffusion. The findings illustrated that the data accorded closely with the pseudo-second-order model. Moreover, it was found that these wastes can be applied to remove environmental pollutants, particularly methylene blue dye.

The performance of electrooxidation (EO) treatment using activated carbon cloth (ACC) electrodes on textile dye bath wastewater was investigated. ACC electrode pairs were used as anode/cathode for EO experiments. The effect of current density (50–150 A/m2 ), operating time (0–90 minutes), and solution pH (6-11) were tested for removal of chemical oxygen demand (COD), color, and chloride, as well as the changes in conductivity. 95.5% COD and color removal efficiencies were obtained at current density (CD) of 100 A/m2 at solution pH of 10 for 90 minutes. Moreover, the chloride concentration decreased from 4254 to 35.5 mg/L and solution conductivity decreased from 160 to 131 mS/cm at the same conditions. Operating cost of the EO process was calculated to be 3.13 US$/m3 for 36 kWh/m3 energy consumption. The results indicated that the EO process with ACC electrodes achieved high pollutant removal from textile dye bath wastewater.