نادر بهرامی فر

Human activities produce large amounts of metal emissions that spread all over the environment and contaminate ecosystems and food webs up to the human level. Also, heavy metal pollution has become an important problem in recent years. These metals are potentially harmful to most organisms at some level of exposure and absorption. The aim of this study on one hand is investigating mercury accumulation in primaries and the outermost tail feathers between waterfowl with different diet and the other hand investigating different levels of some Xenobiotic (Hg, Cd and Pb) and Essential (Fe, Cu, Zn and Ni) elements in outermost tail feather segments, wing primaries and breast feathers in four species of waterfowl with different locations in food chain which including Graylag Goose (Anser anser), Common teal (Anas crecca), Pintail (Anas acuta) and Mallard (Anas platyrhynchos).

In this study, Mercury was measured with the AMA 254 Advanced Mercury Analyzer, and other metals were measured by ICP/OES (Inductively coupled plasma/optical emission spectrometry).

The results showed that there is a statistically significant difference between species and segments in mean mercury concentration and other heavy metals (sig<0.001) and in primary concentrations (sig<0.001 for most primaries).

The comparison between segments and primaries in mercury accumulation showed that each of the four species did not differ in trophic-level classification. It showed that they were at the same trophic level.

The entry of colored wastewater with high content of organic pollutants from textile industries is one of the major problems for environmental organisms. The use of effective, economical, and environmentally friendly methods to eliminate or reduce the concentrations of these types of pollutants, especially in the industrial sector, is important. The present study aimed to optimize the dye removal process from textile industrial wastewater using graphite carbon nitride photocatalyst on a laboratory scale in a batch system. The initial pH, reaction time, and photocatalyst dose parameters were optimized using a central composite design (CCD) through response surface methodology (RSM) to achieve the highest level of color removal. The results of analysis using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDAX), and nitrogen adsorption and desorption (BET) showed that the synthesized photocatalyst had a two-dimensional structure with numerous pores and channels in which the C, N, and O elements were well distributed uniformly in the sample. The optimization results of the influencing parameters indicated that the efficiency of color removal has a significant relationship with the initial pH, photocatalyst dose, and reaction time parameters. The maximum efficiency of the graphite carbon nitride in dye removal from textile industrial wastewater is up to 97% at pH 4, a photocatalyst dose of 70 mg, and a reaction time of 100 minutes. The fitting of the proposed model showed good agreement (R2 = 0.968) between the actual and predicted values. The results of the study on the reusability of g-C3N4 photocatalyst also indicated that the synthesized photocatalyst in optimal conditions has a high recovery power and was able to maintain its performance over 10 consecutive cycles by more than 90%. The synthesized photocatalyst with high efficiency and eco-friendly can be considered as a suitable proposal for wastewater treatment in textile and dyeing industries.

In recent years, graphene has garnered significant attention in fields such as electronics and energy storage due to its remarkable properties, including high electrical and thermal conductivity. Producing graphene from bio-waste has emerged as an innovative approach to reducing costs and enhancing environmental sustainability. This method can contribute to resource efficiency and mitigate environmental impacts. However, life cycle assessments of graphene production from bio-waste are limited, and its environmental impacts depend on the synthesis method and the energy sources utilized. In this study, a cradle-to-gate life cycle assessment was conducted with a functional unit of producing 1 kilogram of graphene to evaluate the environmental impacts associated with the production phase. The findings indicate that producing graphene from bio-waste, such as banana peels, wheat straw, and populus wood waste, can reduce environmental impacts. Among the evaluated bio-waste sources, graphene derived from wheat straw exhibited the highest environmental impact in the global warming category, equivalent to 580.91 kilograms of CO2. In contrast, graphene produced from populus wood waste demonstrated the lowest impact in this category, equivalent to 122.49 kilograms of CO2. Future scenario analyses suggest that incorporating renewable energy sources into Iran’s electricity mix could significantly reduce the global warming potential of graphene production between 2030 and 2050. This reduction is particularly notable for populus wood waste, with a projected decrease of 29% to 57% over the analyzed years.

The entry of colored wastewater with high content of organic pollutants from textile industries is one of the major problems for environmental organisms. The use of effective, economical, and environmentally friendly methods to eliminate or reduce the concentrations of these types of pollutants, especially in the industrial sector, is important. The present study aimed to optimize the dye removal process from textile industrial wastewater using graphite carbon nitride photocatalyst on a laboratory scale in a batch system. The initial pH, reaction time, and photocatalyst dose parameters were optimized using a central composite design (CCD) through response surface methodology (RSM) to achieve the highest level of color removal. The results of analysis using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDAX), and nitrogen adsorption and desorption (BET) showed that the synthesized photocatalyst had a two-dimensional structure with numerous pores and channels in which the C, N, and O elements were well distributed uniformly in the sample. The optimization results of the influencing parameters indicated that the efficiency of color removal has a significant relationship with the initial pH, photocatalyst dose, and reaction time parameters. The maximum efficiency of the graphite carbon nitride in dye removal from textile industrial wastewater is up to 97% at pH 4, a photocatalyst dose of 70 mg, and a reaction time of 100 minutes. The fitting of the proposed model showed good agreement (R2 = 0.968) between the actual and predicted values. The results of the study on the reusability of g-C3N4 photocatalyst also indicated that the synthesized photocatalyst in optimal conditions has a high recovery power and was able to maintain its performance over 10 consecutive cycles by more than 90%. The synthesized photocatalyst with high efficiency and eco-friendly can be considered as a suitable proposal for wastewater treatment in textile and dyeing industries.

In recent years, graphene has garnered significant attention in fields such as electronics and energy storage due to its remarkable properties, including high electrical and thermal conductivity. Producing graphene from bio-waste has emerged as an innovative approach to reducing costs and enhancing environmental sustainability. This method can contribute to resource efficiency and mitigate environmental impacts. However, life cycle assessments of graphene production from bio-waste are limited, and its environmental impacts depend on the synthesis method and the energy sources utilized. In this study, a cradle-to-gate life cycle assessment was conducted with a functional unit of producing 1 kilogram of graphene to evaluate the environmental impacts associated with the production phase. The findings indicate that producing graphene from bio-waste, such as banana peels, wheat straw, and populus wood waste, can reduce environmental impacts. Among the evaluated bio-waste sources, graphene derived from wheat straw exhibited the highest environmental impact in the global warming category, equivalent to 580.91 kilograms of CO2. In contrast, graphene produced from populus wood waste demonstrated the lowest impact in this category, equivalent to 122.49 kilograms of CO2. Future scenario analyses suggest that incorporating renewable energy sources into Iran’s electricity mix could significantly reduce the global warming potential of graphene production between 2030 and 2050. This reduction is particularly notable for populus wood waste, with a projected decrease of 29% to 57% over the analyzed years.

Dyes are significant pollutants that pose serious hazards to humans, animals and other organisms. They are not biodegradable through aerobic treatment processes, making their removal from industrial wastewater through photocatalytic processes essential. This research aimed to synthesize an imide-conjugated polymer photocatalyst for the first time and evaluate its effectiveness in removing Rhodamine B dye from aqueous solutions.

In this applied research, an imide conjugated polymer was synthesized and employed as a photocatalyst for the removal of Rhodamine B from aqueous solutions. The polymer was characterized using Scanning Electronic Microscopy (SEM), Transmission electron microscopy (TEM), Atomic force microscopy (AFM), X-Ray Diffraction (XRD), Thermogravimetric Analysis, Fourier transform infrared spectroscopy (FTIR), and Diffuse reflectance spectroscopy (DRS) methods. The study also assessed the influence of variables, including pH (4-9), photocatalyst concentration (0.01-0.04 g/L), and contact time (0-120 min), on the removal efficacy of Rhodamine B.

The findings indicated that removal efficiency increased to 99% at a contact time of 45 minutes and a photocatalyst concentration of 0.02 g/L. The optimal pH for Rhodamine B removal was found to be 7.

The imide conjugated polymer proved to be an effective and accessible photocatalyst for the removal of rhodamine B from industrial wastewater under visible light.

Air pollution has been a problem in the urban environment and transport is the main cause of this pollution. In this study, the air pollution index was investigated in the west of Mazandaran province. The emissions due to fuel consumption and its emission factors were calculated in each city and the air quality of each station was evaluated using air quality index (AQI).   

NO2, SO2, CO and O3 were measured in the 18 stations of the study area using aeroQUAL portable air quality monitoring equipment and the particulate matter PM10 and PM2.5 were also determined by portable HAZ-DUST real-time particulate air monitoring equipment.

A high concentration of NO2 was obtained in the cities of Mahmudabad and Amol (70 and 72 μg/m3, respectively) and a high concentration of CO was found to be 16.77 and 13.88 mg/m3 in the Mokhaberat square of Chalus city and 17 Shahrivar square of Amol city, respectively. At all sampling stations, the concentration of SO2 was less than 10 μg/m3. In addition, the concentration of O3 was determined to be highest in the industrial zone of Chamestan and Noshahr Seaport. The PM2.5 content was detected to be highest in Mahmudabad city. The emission of mobile and stationary sources was shown the highest level for concentrations of CO and NOX, respectively.

Obtained results showed that the air quality of the center of Noor city was recognized the only a good air quality area among the study areas. Mokhaberat square of Chalus had the worst air quality (very unhealthy) due to high levels of CO. In the all cities, the main portion of emissions was produced by the mobile sources. NOx emissions from stationary sources in all cities were higher compare to other pollutants, due to the high consumption of natural gas in the industry and residential areas. Because of the unhealthy air quality of some of the stations and the tourism cities of the study area, periodic evaluation of the air monitoring in urban centers must be suggested. In conclusion, it is suggested to use exhaust back-filter in industry and traffic limitations in order to reduce emission of the air pollutants from the mobile and stationary sources.

The health of the river basin is determined by the health of its ecosystem to provide important and valuable resources and services for human use and the basin itself. However, the changes in the land use pattern, which is an effective reflection of anthropic activities, have greatly disturbed the health of the river and are the main driver of water quality reduction. Examining the relationship between land use patterns and river water quality provides an important basis for water quality safety and effective land use management. Therefore, the aim of this study is to investigate the influence of land use patterns on surface water quality based on the water quality monitoring data and land use data from 38 sampling points in the sub-basin of the Maroon River.

In order to sample from the study area, first, the boundary of the sub-basin of the maroon river was determined, and then the sub-basin was divided into different smaller sub-basins using the hydrological analysis tool in ArcGIS software, and the map of waterways in the region was also prepared. Then, sampling stations were selected from the exit point of each of these sub-basins in the main sub-basin area. In order to measure the water quality parameters of the studied area, sampling was done from 38 monitoring stations in the sub-basins in triplicates in the spring of 2023. The land use map was prepared using Landsat satellite images to evaluate the changes and the impact of land use patterns on the water quality status of the Maroon River sub-basin. Then, using geographic information system and multivariate statistical techniques, the effects of land use on river water quality in the Maroon sub-basin were estimated. In addition, in order to evaluate the quality of river water in different sub-basins, water quality data was analyzed using the water quality index (WQI).

The results of the evaluation of the distribution of land use patterns showed that the use of pasture is the dominant use in the sub-basin of the Maroon River and the water quality parameters exhibited significant changes in the stations covered by agricultural and forest use. The results of correlation analysis and linear regression of water quality parameters and land use patterns in the Maroon River sub-basin showed that agricultural land has a negative relationship with pH and DO parameters and a positive relationship with parameters ,  and Ca2+, forest land has a positive correlation with DO and a negative correlation with , and urban land also showed a negative correlation with DO. WQI values in different monitoring stations were estimated between 73.80 and 288.73 which showed that the health level of the river upstream of the sub-basin was better than downstream. In general, based on the WQI classification, 62.5% of the water quality of the Maroon River sub-basin was in the "poor" class, 25% in the "very poor" class, and 12.5% in the "good" class.

The findings of the research showed that agricultural land was the key factor affecting the water quality parameters and as a result the decrease in water quality in the sub-basin of the Maroon River, so limiting the discharge of runoff from agricultural activities is critical for improving water quality in the study area. This study highlights the importance of LULC changes in water quality for making informed decisions on proper watershed planning and management.

Rainbow trout have found a good place in the household food basket due to their valuable nutritional properties. Therefore, supply in the form of hygienic packaging of this product due to CORONA pandemic in the country will be inevitable. This research has been done in order to provide intelligent packaging with the ability to detect microbial spoilage of rainbow trout. Fish fillet was packaged with H2S gas sensor based on FeCl3/Cellulose acetate. These packages were examined for total bacteria, temperatures swing, H2S producing bacteria and Escherichia coli (1×104 CFU/ml) during storage at 25 ° C for 3 days as well as storage at 4 ° C for 16 days. After imaging the correlation, the color changes of the sensor were calculated and evaluated as the color value. Sensor performance in terms of color change was significant (P <0.05) and the correlation between sensor color value and total bacterial growth in a 3-day period was 0.901. In order to accurately identify the growth of Escherichia coli, the correlation of Pearson color value and bacterial growth was equal to 0.932. Also, in the study the correlation between the color value with the number of total bacteria, temperatures swing bacteria and H2S producing bacteria were 0.835, 0.869 and 0.836, respectively. Using a sensor with a combination of iron (III) chloride and cellulose acetate to determine the microbial spoilage of rainbow trout can be used in the future as a consumer-centric quality control method that can be commercialized.

Air pollution is one of the most important threats to human health and ecosystems. One of the most common pollutant of outdoor and indoor is dust, which is an important source of toxic elements, especially in urban environments. In this study, the concentration of selected elements (cadmium, chromium and lead) and their health risk assessment in indoor and outdoor dust in Ahwaz, South Pars region and Zabol were measured.

100 dust samples were collected from indoor and outdoor the homes of the studied areas during the summer of 2017. Dust samples were digested using an acid digestion method by mixing HClO4-HF-HNO3 acids with 1: 2: 4 ratios. The total concentrations of elements were determined by inductively coupled plasma mass spectrometry (ICP-MS 7800). Risk assessment of selected elements in dust was performed using Environmental Protection Agency (EPA) guidelines.

The results of risk assessment of selected elements from indoor and outdoor dust of homes showed that the highest non-cancerous and cancerous risks in indoor and outdoor dust for both adult and child groups is related to chromium element. While, the lowest cancerous and non-cancerous risks for both adult and child groups is related to lead and cadmium elements, respectively. Furthermore, the study of non-cancerous and cancerous risks caused by selected elements in the studies areas showed that in Ahvaz city, the risk caused by these elements is higher than the other regions.

In general, the results of the hazard index (HI) and total cancer risk (TCR) indicate for selected elements indicate risk and should be subject to control and monitoring conditions.

These days, the most cost-effective and accessible way to monitor air pollutants is the use of bio-monitors. Therefore, this study was conducted to biologically monitor temporal changes in the concentration of heavy metals suspended in the air using the lichen transplant technique. For this purpose, lichens of the genus Ramalina were applied. It was transferred from an uncontaminated area (Tirkan village, Babol city) in Hyrcanian forests to the study area near the transit road in Noor city. After three periods of three, six, and nine months of exposure, concentrations of Aluminum, Iron, Zinc, Copper, Lead, Nickel, Vanadium, Chromium, Arsenic, Selenium, Cadmium, Molybdenum, Cobalt in lichen samples (15samples per period) was determined by ICP-MS device. The results showed that Aluminum and Cadmium had the highest and lowest concentrations in all periods, respectively (mean614.06and 0.18 μg / g, respectively). With increasing exposure time, the concentration of metals also increased and this increase showed a significant difference in all metals for the first and Three periods (p <0.05). It was also found that due to the average exposure of control rate (3.37) which was much higher than the severe accumulation limit (1.75), the selected lichen has an acceptable ability to biologically monitor changes in heavy metal concentrations. In addition, using an exposure of control rate to evaluate the rate of change is a better alternative than the evaluation of the concentration of trace elements alone.

Accumulation of cadmium (Cd) as one of the most toxic pollutants in the soil can lead to the reduction of microbial activities and soil fertility and as a result the death of plants; This issue has always caused global concerns. The present study was conducted with the aim of investigating the resistance to Cd of male (62-167) and female (62-149) individuals of black poplar (Populus nigra L.) based on vegetative and physiological characteristics.

For this purpose, a greenhouse experiment was conducted in the form of a randomized complete block design with factors of cadmium (concentrations of 0, 50, 150 and 200 mg/kg soil) and gender (male and female bases of poplar) for a 120-day period. Physiological variables of seedlings including net photosynthesis rate, transpiration rate, stomatal conductance, water use efficiency, water potential, mesophilic conductance, intracellular CO2 concentration, and vegetative characteristics including root collar diameter growth and height growth, total biomass and leaf area were investigated. The stress treatment was done in late May through irrigation with cadmium salt solution on a weekly basis for the first five weeks. After that, the seedlings were irrigated with rainwater, respecting the soil capacity, at intervals of three days until the end of the period (late September).

Regardless of the root species, with the increase of Cd concentration, the leaf area and height growth of seedlings decreased. The highest height growth (30.4 cm) and leaf area (51.8 cm2) were observed in the control, and the highest total biomass of seedling (59.2 g) was observed at the concentration of 50 mg/kg of Cd. Regardless of the concentration of Cd, the size of collar diameter growth (male 2.1, female 2 mm), seedling height growth (male 21.5, female 19.9 cm), leaf area (male 43.08, female 43.64 cm2), total seedling mass (male 46.48, female 44.19 g), water use efficiency (male 0.31, female 0.26 μmol mmol-1), mesophilic conductance (male 0.003, female 0.002 mol m-2 s-1) and stomatal conductance (male 0.45, female 0.39 mol m-2 s-1) was higher in males than females and only, the amount of transpiration (male 3.31, female 4.01 mol m-2 s-1) was higher in females than in males. Although, with the increase of Cd concentration, the size of most of the physiological and growth characteristics including photosynthesis, water potential, water use efficiency, diameter, height, leaf surface, and biomass decreased in general, the seedlings of both clones maintained their physiological and growth activities to some extent in high Cd concentrations.

It can be concluded that both clones can tolerate high concentrations of Cd; nevertheless, for afforestation development with Populus nigra in Cd-contaminated soils, the use of male individual (clone 62-167) can be more successful than female one (clone 62-149).

Today, the rapid development of industries and the use of hundreds of new chemical compounds in them have led to the creation of huge amounts of industrial wastewater, the discharge of which into the environment, especially watercourses, has caused severe pollution. The discharge of colored wastewater into natural ecosystems has created serious risks such as carcinogenesis, mutagenicity, etc. for aquatic life due to adverse functions. Meanwhile, Reactive Black 5 has many industrial applications, especially in the textile industry worldwide. Fe (VI) was synthesized electrochemically using iron and steel electrodes in potassium hydroxide solution at 65 ° C and then used to remove the reactive Black 5 in the batch removal system. In this study, the surface response method (RSM), the effect of various parameters including initial color pH, Fe (VI) dose and time and then the central composite design (CCD) were used to find the best removal conditions. The optimal values for the three variables of pH, Fe (VI) dose and time were obtained 4.5, 24.5 mg and 25 minutes, respectively. In the present study, by increasing the Fe (VI) dose and after 25 minutes from the start of the reaction, the removal efficiency increased, if the removal was better in acidic conditions than in alkaline conditions. Also, under the optimal conditions of Fe (VI) solution, it was able to remove 97% of reactive black 5. Finally, under the same conditions, real wastewater was also worked on and the removal rate was 95%. The findings of this study showed that Fe (VI) can be used as a suitable, inexpensive and high-performance oxidizing agent in the removal of reactive Black 5 from textile industry effluents.

Environmental pollution has become one of the main problems of today's societies in a way that in addition to natural ecosystems, it also endangers human health. Therefore, in this study, the contamination of heavy metals and organophosphate toxins accumulated in two different types of rice consumed by humans was measured. The risk of carcinogenicity and non-carcinogenicity associated with these toxins for children and adults in rice fields in northern Iran was also assessed. For this purpose, 17 stations were selected for sampling rice consumption from farms in Mazandaran province in the first and second cultivation groups. After sampling, rice samples were wrapped in foil to measure toxins and placed in plastic packs to measure heavy metals. Heavy metals were measured using ICP-MS and toxins were measured using GC-MS and mercury was measured using mercury autoanalyzer. Carcinogenic and non-carcinogenic risk indices for both groups of children and adults in the first and second culture groups were evaluated and calculated. The results showed that nickel and lead showed the highest values in the collected samples at station 14 at 0.38 and at station 6 at 0.17 mg/kg, respectively. In addition, the toxic and carcinogenic metals arsenic, cadmium and mercury in stations 6, 5 and 6 showed values of 0.094, 0.017 and 0.001 mg/kg, respectively. Station 1 and Station 2 have the highest and lowest values of diazinon in the range of 0.038 and 0.004, respectively, and chloroprifus have the highest and lowest values in stations 8 and 14, respectively, in the range of 0.019 and 0.001 mg/kg. The non-carcinogenic risk of the first and second cultures was highest for children and adults for safe toxins and for nickel metal. THQ levels also showed a high risk for consumers. The risk of carcinogenicity for the target groups was highest in different concentrations of chromium and in the second group for children the group had high risk levels. The results of this study showed that rice produced in farms in northern Iran contains different amounts of toxins and heavy metals that have carcinogenic and non-carcinogenic potential for consumers.

In recent years, various studies have been conducted using natural and chemical amendments to reduce runoff and soil loss. However, in many cases, the idea of using special wastes in water and soil conservation has not been considered yet. In this regard, the present study aimed to apply three types of refinery sulfur wastes (i.e., clod, dusty, and mixed with soil) as an additive to evaluate the feasibility of inhibiting soil and water loss on a marl soil from the Marzanabad-Kandolus Region. The experiments were conducted in the Rainfall and Soil Erosion Simulation Laboratory of Tarbiat Modares University between February and July 2021. The study was conducted at a small plot scale with dimensions of 0.5×0.5×0.3 m in three replications. Three levels of one, two, and four g m-2 of any sulfur waste were applied to plots nested on a slope of 25% and subjected to a design rain with an intensity of 70 mm.h-1 and a duration of 30 min. The results showed that the total volume of runoff was significantly (P≤0.04) decreased due to the application of all three levels of sulfur wastes. The different types of sulfur wastes (i.e., clod, dust, and mixed with soil) also had a significant effect (P≤0.03) on runoff volume. Besides, the interaction between application level and type of sulfur waste was more significant (P≤0.00). The application of different levels of sulfur wastes significantly reduced (P≤0.02) soil loss. At the same time, types of sulfur wastes had a non-significant effect (P ≥ 0.06) on soil loss reduction. However, the interaction effect of level and type of sulfur wastes on soil loss reduction was significant (P ≤ 0.01) due to positive impacts of sulfur on quality and hydrologic behavior of the soil. Finally, it is concluded that the consumption of sulfur waste in each level or type is confirmed, preferentially use of 2 g m-2 of dust sulfur.

Hepatotoxins are dangerous biological toxins produced by cyanobacteria. Because of the high consumption of cost and time in the extraction and detection procedure of these toxins, the main aim of the present study is to investigate the performance of a new extraction technique, termed dispersive liquid-liquid microextraction (DLLME) in the extraction of one hepatotoxin with the name Microcystin LR from water samples, using chlorinated organic extraction solvents.

In the first stage, the efficiency of the common method (solid phase extraction) was investigated. Then the mixture of disperser solvents (acetone, ethanol, methanol, and acetonitrile) and extraction solvents (chloroform, dichloromethane, carbon tetrachloride and tetrachloroethylene) were used to investigate the efficiency of DLLME.

The results showed that the efficiency of SPE using a C18 cartridge was 102 %. For high efficiency of DLLME, a cloudy solution should be formed (fine particles of extraction solvent which are dispersed entirely into the aqueous phase). In the present study, only in a mixture of acetone and tetrachloroethylene (with different ratios), a stable cloudy solution was found. The best-observed efficiency was 3 % for DLLME.   

The observations in this study suggest that although based on the obtained efficiency, the chlorinated organic solvents, could not be appropriate extraction solvents in MC-LR extraction, but the DLLME method using other solvents like Ionic liquid extraction solvents is a suitable technique for hepatotoxin extraction because of low consumption of cost, time and solvents in the extraction procedure.

Due to their special molecular structure, industrial effluents, such as effluents containing colored compounds, have one or more benzene rings with a resistant structure. This type of colored compounds is toxic and difficult to decompose. These effluents should be treated before being discharged into the environment, and thus treating the wastes containing dyes is one of the major environmental challenges and need to be conducted using an appropriate approach. In this study, an advanced oxidation method using a non-metallic carbon-nitride photocatalyst was used to remove the Reactive Blue21 dye. Carbon-nitride photocatalyst was prepared from urea-formaldehyde resin precursor with urea to a formaldehyde ratio of 1.25 The structure and properties of the photocatalyst produced were evaluated and confirmed using SEM, FT-IR, XRD and DRS analyses. The efficiency of the as-prepared photocatalyst was evaluated according to its capability for degradation of Reactive Blue21. Finally, to achieve maximum dye removal via the photocatalytic process, the effective parameters such as solution pH, the dose of the photocatalyst, and exposure time were optimized according to response surface methodology (RSM). The results showed that all three parameters are significantly effective in color removal. However, the effect of decreasing pH and color concentration was greater than increasing the amount of photocatalyst. Also, under optimal conditions, the percentage of paint removed was more than 99%. Based on the obtained results, the carbon nitride photocatalyst synthesized in this research can be used as an ideal cheap material to remove textile dyes from industrial wastewater.

Phenol removal has recently become a topic of interest and debate among environmental scientists. In this research, the efficiency of Fe3O4@SiO2@TiO2 magnetic photocatalyst in phenol degradation was evaluated. Also, the effect of effective factors in the degradation of this pollutant was investigated using the surface response methodology. In the present work, photodegradation of phenol in an aqueous solution was studied using Fe3O4@SiO2@TiO2 nanocomposite under ultraviolet. The as-synthesized materials were characterized by UV-Visible diffuse reflectance spectra, scanning electron microscope, Fourier transform infrared,X-ray diffraction, and vibrating sample magnetometer. Based on XRD and VSM, the Fe3O4@SiO2@TiO2 nanocomposite structure contained an anatase TiO2 phase and showed a superparamagnetic behavior (12.07 emu/g). Based on the DRS spectra and bandgap computation, the direct bandgap energy of Fe3O4@SiO2@TiO2 was 3.01 eV. Result of ANOVA showed that the effects of the main variables of photocatalyst concentration, UV light irradiation time and the square of photocatalyst concentration are significant in the model. Significant variables from the most significant to the least significant include: photocatalyst concentration>UV light irradiation time>square of photocatalyst concentration. The findings showed that Fe3O4@SiO2@TiO2 was recycled five times to attain 50% degradation of phenol and the photocatalytic activity did not decrease noticeably after five photocatalytic cycles. The Photocatalytic degradation of phenol was performed by the response surface methodology to study the influence of operational factors on the degradation process. Maximum removal of 55% phenol was obtained at a pH of 8, a photocatalyst dosage of 1.0 g/L, and a phenol concentration of 100 mg/L after 220 min UV irradiation time. Results showed that the Fe3O4@SiO2@TiO2 magnetic nanocomposite has suitable potential for treating phenolic wastewater.

Soil contamination with heavy metals is a serious issue in all the world, and these heavy metals are released from both natural and human resources, especially agricultural activities in the environment. Therefore, in this study, the amount of heavy metals and the indicators of ecological risk potential and integrated pollution in soil samples before rice planting and after rice harvesting in Mazandaran province have been investigated. A mixture of nitric acid, hydrofluoric acid and perchloric acid was used for chemical digestion of soil samples and ICP-MS was used to measure the amount of heavy metals in soil samples. The results of comparing the levels of chromium, zinc, nickel and lead in the soil before rice planting and after rice harvesting with the national and international soil standard show that the levels of these metals in most stations are higher than Domestic and international standard limits were measured. Based on the results, the amount of ecological risk potential index in soil samples showed that in all studied stations ana sampling stages, the amount of this index was calculated in the range of low ecological risk (below 150). Also, the results of PI pollution index and integrated pollution index (IPI) for each studied station in soil samples before rice planting and after rice harvesting show the PI index for arsenic, chromium, cadmium, copper, nickel, zinc and mercury. In all stations in soil samples before rice planting and after rice harvesting in the range of low contamination was calculated, only the amount of this index for lead in all stations and sampling stages, in the range of moderate contamination was obtained. Also, the results of IPI for all studied stations in all stations and sampling stages, show that the level of this index was determined in the low pollution range. In general, the presence of heavy metals in the soil environment, followed by the accumulation of heavy metals in food, has detrimental and irreversible effects on human societies and food security, so more precautions are needed to reduce such effects.

Investigating the spatial variability of runoff and its influencing factors to provide solutions to reduce it is very important. In recent years, many theoretical and field studies have evaluated the spatial production of runoff as heterogeneous.

In this study, to investigate the affecting factors in runoff production of the slope main aspects (northern, southern, eastern, and western) of the Gachsaran and Aghajari formations were selected a part of the Gach Kuhe and Margha watershed in Izeh city. For this purpose, a rain simulator was used in both formations at 16 points with 3 replications at rainfall intensities in 1 and 1.25 mm/min. Also, soil factors of Gachsaran and Aghajari formations such as percentages of gravel, sand, silt and clay, pH, soil salinity, moisture, calcium carbonate, organic matter, and sodium content were investigated. SPSS 17 and EXCEL 2007 software were used for statistical analysis.

The most important factors affecting runoff production were identified using multivariate regression. The results showed that runoff production in Aghajari Formation is more dependent on soil chemical properties, but runoff production in Gachsaran Formation is more dependent on soil physical properties.

The entry of chemical compounds into the environment is considered a serious threat to humans and other living things. One of these compounds is malachite green, which enters water resources and causes problems for humans and public health. The use of Nano sorbents is a new, high-performance method for removing pollutants from aquatic environments. Graphene, due to its unique properties, is one of the materials that can be used to remove some materials. In this study, graphene was prepared from rice straw residue, which is considered as a waste material, and then magnetized by heat solvent method. SEM, BET, Raman and FTIR analysis were performed to detect and evaluate the properties of the synthesized nanocomposites. The nanocomposite was then investigated to remove malachite green from aqueous solutions in a batch system. Effective factors in adsorption such as pH, adsorbent amount, contact time, initial concentration of malachite green and temperature were investigated. The results showed that the maximum adsorption capacity is 993.33 at concentrations of 50 mg/L and the adsorbent is 5 mg/L for 20 minutes. Also, two types of isothermal adsorption models of Freundlich and Langmuir were investigated and since the correlation coefficient of Langmuir model was higher than Freundlich model. Various models have been developed to evaluate the rate of adsorption process. In this study, pseudo-first-order and pseudo-second-order kinetic models were used. Due to the higher detection coefficient of the pseudo-second-order model, the rate of malachite green adsorption process on G/Fe3O4 was well matched with the pseudo-second-order model. Also, thermodynamic studies showed that the adsorption process is spontaneous and the adsorbent collides with malachite green is random. In this study, four types of solvents were investigated. The adsorption-desorption process was repeated over 5 cycles, with a slight reduction in adsorption capacity and the removal efficiency of malachite green from these steps. Finally, considering the suitable adsorption capacity of the synthesized G/Fe3O4 nanocomposite as well as the adsorption capacity of the adsorbent, it can be concluded that this adsorbent can be a suitable adsorbent for removing malachite green from aqueous solutions.

Nanotechnology is one of the emerging and advanced sciences that has been highly developed in recent years and has caused environmental pollution. Therefore, in this study, the toxicity of silver nanoparticles on the green alga Chlorella vulgaris was investigated. Chlorella vulgaris cells were exposed to concentrations of 0, 0.005, 0.001, 0.05, 0.01, 0.5 and 0.1 mg / l silver nanoparticles over a period of 96 hours. The results showed that the cell density of Chlorella vulgaris decreased with increasing concentration of silver nanoparticles compared to the control group and even at the lowest concentration of 0.005 mg / l caused the cell growth inhibition (p<0.05). With increasing concentration of silver nanoparticles, the survival rate decreased compared to the control group and did not change during the 96-hour period. The amount of chlorophyll a, b and total pigments in the concentrations of 0.05 and 0.1 mg / l and the duration of 24 hours were the highest, but the values ​​of carotenoids showed the highest in 96 h and the concentration of 0.01 mg / l of silver nanoparticles. Silver nanoparticles are highly toxic to Chlorella vulgaris and if silver nanoparticles are released, the production, survival and chlorophyll content of this microalgae, as one of the main primary producers in freshwater ecosystems, is damaged.

In addition to health effects, plant extracts can be used as natural preservatives with antioxidant and antimicrobial properties in the food industry. In this study, effect of antioxidant and antimicrobial properties of ethanolic extracts of watercress on the chemical and microbial quality of rainbow trout fillet at refrigerator temperature for 12 days was investigated. After drying the leaves at darkness and room temperature extract was extracted with 45, 65, 75 and 96% ethanol solvents for 24 hours at 65 °C. The results showed a significant difference (P≤0.05) in yields and phenolic content, 0.1 mg /ml of extract 65% with an extraction efficiency of 20% the highest amount of total phenol (88.60 ± 2.46%), DPPH (84.73 ± 0%); and ABTS (83.83 ± 0.06%) were. Also, the growth inhibition of the pathogenic bacteria Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella enteritidis in sample extracted with 65% ethanol had a significant difference with other extracts (P≤0.05). Rainbow trout fillet samples in 65% ethanol extract showed lower levels of TVB-N, PV and TBA to the control treatment during storage (P≤0.05). Rainbow trout fillet samples in 65% ethanol extract showed lower levels of TVB-N, PV and TBA indices of fillets compared to control treatment during storage (P≤0.05). Talking about bacterial index, the amount of total and pseudomonas bacteria in the treatment containing the extract did not reach the maximum allowable limit (106 cfu /g-1) by the twelfth day, Indicates the effectiveness of the extract on increasing the shelf-life of fillets compared to the control.

Soils are severely damaged by acid rain; acid rain also leads to excessive dissolving of minerals and valuable nutrients in the soil, which weakens vegetation. In this study, in order to determine the interaction effect between the slope aspect and precipitation intensity relative to acid rainfall in the Aghajari and Gachsaran formations, a part of Margha and Kuhe Gach watersheds of Izeh city with an area of 1609 and 1202 hectares were selected. A sampling of runoff and sediment was done in 16 points with three replicates in northern, southern, eastern, and western aspects of Aghajari and Gachsaran formations at different rainfall intensity of 1 and 1.25 mm/min and in distilled water, acidity 4 and 5 using Kamphorst rain simulator. The results showed that in both Gachsaran and Aghajari formations, rainfall intensity has the highest effect on runoff and sediment production in three concentrations of precipitation and also The interaction effect between precipitation intensity and slope aspect plays the least effect on in runoff and sediment production, and in Gachsaran and Aghajari formations, a runoff was much more sensitive to sediment production than the interaction effect between slope aspect and precipitation intensity.

Recently, the influx of dyes into water resources has disrupted the natural order of ecologists due to their toxicity to biodiversity. In this study, activated carbon prepared from rice straw was synthesized with potassium hydroxide solution in ratios of 1: 3 and 1: 2 at temperatures of 800 °C and 900 °C, and it was used to absorb reactive yellow 145 dye prepared in a laboratory that has similar properties to the real effluent of Tehran textile industry. Then, the effect of important variables on the adsorption process such as pH (2-8), contact time (15-120 minutes), adsorbent dose (30-60 mg), dye concentration (50-200 mg/L), and temperature (15-45 °C) Checked out. The results showed that the adsorption rate was inversely related to the pH of the solution and the initial dye concentration and was directly related to the adsorbent dose, temperature, and activator saturation ratio. Among the isothermal models, the Redlich-Peterson model (R2 = 0.995) with the equilibrium adsorption capacity of 324.6 mg/g had a better agreement with the experimental adsorption results and the kinetic studies showed that the adsorption process follows the pseudo-second-order model (R2= 0.995). Thermodynamic studies also showed that the adsorption process is spontaneous and the negative slope of the Van-Hoff curve indicates that the reaction is endothermic. Due to the equilibrium time of 60 minutes in the adsorption mechanism, the synthesized adsorbent has a high rate of adsorption of reactive yellow 145 dye. The synthesized adsorbent with properties such as high specific surface area, environmentally friendly, availability of precursors, and suitable performance in dye adsorption can be used effectively in dye effluent treatment systems.