فهرست مطالب محمد نعیمی جوبنی

In this study, the concentrations of heavy metals in water and aquatic plants Azolla filiculoides and Lemna minor in three special zones of Anzali Wetland located in the north of Iran were investigated. Sampling was performed in summer 2018 and metal concentrations in water and plant samples were measured by ICP-OES. The results showed that the sequence of the average total concentration of metals in water samples is Fe>Mn>Ba>Ni>V>As>Ag>Ti>Co>Cu>Zn>Cr>Hg>Pb>Cd. The highest bioaccumulation was obtained in both plants belonging to Mn, Fe and Ba and the lowest concentrations were obtained for Cd and Ag. BCF results obtained for both plants for all metals were more than 1000 indicating that both plants are powerful hyper accumulators for heavy metals in the region. Although the potential of these species can be used with environmental considerations to reduce pollutants for various effluents, but the presence of these species in the food chain of the wetland might be a serious threat to the species consuming these plants by creating biological magnification.

Tea is not only known as one of the most common beverages in the world but also as a quite favorable and frequently consumed drink in Iran. Accordingly, studying the fresh tea leaves’ heavy metal content is an area of attention considering the environment quality assessment in addition to the public health issues. The research aimed at determining the concentration of heavy metals including lead, cadmium, zinc, nickel, cobalt, and chromium in the fresh leaves of tea and topsoils of the tea fields in Fouman County, Guilan, Iran. To do so, tea fresh leaves and respective topsoils were sampled at 5 sampling sites. After initial preparation, digestion of the taken samples was performed using HCl, HNO3, and H2O2 reagents. The concentration of heavy elements in the samples was determined by inductively coupled plasma (ICP). There have also been statistical tests such as one-way analysis of variance, T-test, principal component analysis (PCA) and cluster analysis (CA) performed using the SPSS software. Based on the results, the average concentrations of lead, cadmium, zinc, nickel, cobalt, and chromium in soil samples were obtained 3.94, 1.06, 60.29, 22.79, 9.49, and 2.77, mg/kg, respectively. According to the metal pollution load index (0<1), the soil quality of the study area was identified at an acceptable level. The levels of lead, cadmium, zinc, nickel, cobalt, and chromium in fresh leaves were obtained 0.44, 0.08, 22.58, 9.93, 0.23, and 0.36 mg/kg, respectively. Compared to the international standards (WHO / FAO), the amount of lead in fresh leaves was higher than permissible levels. By contrast, the amounts of cadmium, zinc, nickel, cobalt, and chromium were at acceptable values. As for soil samples, only the concentration of cadmium was higher than admissible levels based on the given standards. As such, the leaching process and biological uptake (happened by the rest of the flora) should have a part to play justifying the former results.

Contamination of roadside soils with heavy metals is a serious threat to soil ecosystems and organisms and human health. Therefore, the purpose of this study was to determine the concentration of heavy metals in the roadside soils of the Rasht-Qazvin old road.

10 out-of-town sampling sites were selected via the field observation of the entire area. surface soil sampling with three replicates was performed around the Rasht-Qazvin old road.  Heavy metals concentrations were measured using ICP-OES following samples preparation and acid digestion. The pollution level of heavy metals was assessed using geoaccumulation index (Igeo) and potential ecological risk index (PERI).

The results showed that the average concentrations of Zn, Cu, Ni and Pb in the roadside soils were 58.07, 19.96, 20.26 and 23.21 mg/kg, respectively. The findings showed that concentration of Zn and Ni were higher than background values and the amount of Zn exceeded WHO standard limit. The potential ecological risk index (PERI) with an average value of 86.24, indicated low level of pollution for all of the studied metals. The results of geoaccumulation index (Igeo) revealed moderately contamination level of Ni.

Old roads are generally known as one of the sources of pollution for the surrounding lands. Although the concentration of pollutants around the road is expected to be very high, we did not detect elevated levels of heavy metals. This fact can be explained by the current road repairs and widening, agricultural activities on marginal lands and wind blows in mountainous regions which leads to the dispersion of the soil pollutants.

Heavy metals are one of the main factors in pollution of soils around roads and highways. This pollution is a serious environmental problem worldwide. The metals are released by different ways, such as wear and corrosion of various parts of the vehicle and tires, as well as combustion. These products could contaminate roadside topsoil. Thus, the purpose of this research is to determine the contamination of roadside soil by heavy metals in the Rasht-Qazvin Freeway.
The 30 soil samples from 0-20 cm depth at three distances (0-5, 5-15 and 15-30 m) of roadsides were collected. Concentration of heavy metals in samples was measured using ICP-OES. The Ecological Risk Index was calculated for assessing the biological hazard level of metals in the soil.
Mean concentration of Zn, V, Cr, Pb, Cu, Co and Ni were 48.89, 46.63, 23.76, 20.05, 18.47, 11.11 and 9.48 mg kg-1, respectively. The results of potential ecological risk index showed that study area were of low ecological and biological risk.
Agricultural activities, climate conditions and vehicles traffic changes in the study area are important factors influencing the accumulation of heavy metals in the roadside topsoil. In order to pay attention to public health and food safety, it is suggested to evaulate concentration of heavy metals in agricultural products and rivers water in the study area.

Fish is one of the most significant protein resources for human nutrition which is highly appreciated because of having no pollutants. Heavy metals are among the pollutants causing many health problems for aquatics, and consequently humans. This study was done to determine lead and nickel concentrations in the muscle tissue of the trout (Oncorhynchus mykiss) and consumed water in Guilan farms. Totally, 30 pieces of farmed Rainbow Trout and water samples from three farms in western part (Talesh), eastern part (Siahkal), and central part (Fouman) of Guilan were sampled randomly and transported to the laboratory of Health Faculty of Guilan University of Medical Sciences. The levels of the heavy metals were measured by ICP-OES Spectro-Amitec and the results were analyzed by statistical software SPSS16 and Tuki Test. Safety Factor of this study was determined %95 (p=0.05) and T Test was used in order to compare with the standards. The level of Nickel in fish muscle tissue of Fouman farm was more than that in Talesh and Siahkal farms. The amount of Lead in fish muscle tissue of Siahkal farm was more than that in Talesh and Fouman farms. The average of Nickel level in fish muscle in Fouman, Talesh, and Siahkel was measured 1.29 ± 2.0491, 0. 445 ± 0.457, and 0.217± 0.086 (mg/kg), respectively. The average of Lead levels was measured 0.252 ± 0.221, 0.294 ± 0.095, and 0.485 ± 0.444 (mg/kg), respectively. No significant differences were observed (p>0.05). The amount of lead in farm water was reported zero; but the amount of nickel in farm water of Siahkal, Fouman, and Talesh was measured 0.032 ± 0.002, 0.027 ± 0.002, and 0.026 ± 0.005 (mg/l), respectively. The amount of Lead in fish muscle tissue was less than the world standard threshold of WHO, while the amount of Nickel in Talesh and Fouman farms was more than the established world standards; but no significant differences were observed (p>0.05).

A huge volume of wastewater from household، agriculture and industrial sources is released into the environment، which contains high level concentration of organic and inorganic materials such as hydrocarbonic solvents، heavy metals، insecticides and dyes. Heavy metals are one of the most important pollutants discharged by industries such as the electroplating and have adverse effects on environment and human health. Heavy metals such as chromium are found in plating wastewater and is harmful for human health and environment. The purpose of present study was to investigate the adsorption of heavy metals such as chromium onto modified alder sawdust by formaldehyde، sulfuric acid and sodium bicarbonate، as a cheaper adsorbent. This research was an experimental-laboratory type which investigated the removal of hexavalent chromium from aqueous solution by using modified alder sawdust with variation contact time، initial Cr (VI) concentrations pH and adsorbent dose in batch system، the residual Cr (VI) concentration was analyzed by 1،5-diphenylcarbazide method by a spectrophotometer at a wavelength of 540 nm. Then، the results were analyzed by Excel software. Results showed the removal efficiency was decreased by increasing of pH and initial chromium concentration. Also، the results showed the removal efficiency was increased by increasing of adsorbent dose and contact time. Experimental isotherms and kinetic models were assessed by pseudo-first-order and pseudo-second-order kinetics and Langmuir and Freundlich isotherms models. The results show that the data were explained acceptably by pseudo-second-order kinetics and Langmuir isotherms models، respectively. The results showed that the removal of hexavalent chromium from aqueous solution can be done by using modified alder sawdust، both at lower cost and more effectively.

The absence of efficient sewage treatment plant in many cities of Iran and national discharge standards for hospital wastewater makes the hospital wastewater treatment a necessity. Hospital wastewater is loaded with microorganism، heavy metals، toxic chemicals and radioactive elements. It can be hypothesized that the efficiency of activated sludge from industrial wastewater treatment plant can be different from municipal wastewater plant. In this study، the efficiency of activated sludge from dairy industry has been compared with that of municipal activated sludge for hospital wastewater treatment. To assess the efficiency of activated sludge، 1day، 3day and 5day aeration methods have been used. Before and after each aeration step، BOD، COD and MLSS of wastewater and sludge were determined. The most efficient method was found to be 5day aeration and the efficiencies of municipal activated sludge and dairy industry activated sludge were respectively 93. 9%، 93. 3% and 97. 4%، 97. 3% for COD and BOD. Nonparametric tests and paired t-test show that there is no significant difference between municipal and industrial activated sludge efficiencies for hospital wastewater treatment but a significant difference between time lengths of aeration (1day، 3dayes and 5days) was observed. Both the dairy industry and municipal activated sludge could have high efficiency for hospital wastewater treatment.