Soil Pollution
Mahmood Kasaei; Nasrin Gharahi; Rafat Zare Bidaki
Abstract
Introduction: Nitrogen is the nutrient in plants production which usually can be added as a fertilizer into the soil. Nitrate is one of the pollutants which is mainly caused by agricultural activities which contaminants groundwater and surface water and threatens human health. Investigating an effective ...
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Introduction: Nitrogen is the nutrient in plants production which usually can be added as a fertilizer into the soil. Nitrate is one of the pollutants which is mainly caused by agricultural activities which contaminants groundwater and surface water and threatens human health. Investigating an effective factor on water and minerals movement in soil and applying the new modifiers such as inorganic nanoparticles and biochar might be useful in reducing nitrate leaching and avoiding underground waters pollutions. Due to this difficulty, some situations to preserve nitrogen in the upper layers of soil such as increasing the absorbent surfaces for minerals, zeolite modifier, and biochar are considered by researchers. As many research have been conducted on using biochar in agricultural systems in terms of organic carbon sequestration in soil and reducing the greenhouse gases, its influence on other processes such as nitrate leaching has been considered as well. The purpose of this study was to investigate the effect of mineral nano-particles and biochar on nitrate leaching in soil and aggregate stability.Materials and Methods: This study had been conducted in the laboratory in faculty of natural resources and geology science, Shahrekord University. Treatments in this study included zeolite, cloisite, and biochar at three levels. PVC pipes with 3 cm in diameter and 40 cm in height were used for the soil columns. Urea fertilizer included 46% pure nitrogen was applied to the soil columns. The amount of the Urea fertilizer was employed as an applied fertilizer for corn plants (200 g Nitrogen per hectare). Urea fertilizer was added as a solution to the soil in irrigation 1, and 5 from irrigation events. At the end of each irrigation event, nitrate effluent was measured using Spectrophotometry method.Results and Discussion: The results showed a significant reduction of nitrate leaching in treatments, 1g biochar, 1g zeolite, and 1g cloisite compared to the control treatment. There was no significant difference between reduction of nitrate leaching in the three treatments, 1g biochar, 1g Zeolite, and 1g cloisite. Furthermore, nitrate leaching in treatments, 5g biochar, 5g zeolite, and 5g cloisite compared to the control treatment was decreased significantly. In all irrigations, 5g biochar had the smallest amount of nitrate leaching comparing 5g zeolite, and 5g Clozite. In general, the results showed that nitrate leaching would be decreased significantly by adding biochar and mineral nano-particles (5%) into the soil. According to the present results and previous findings, it can be mentioned that adding biochar into the soil will cause improving the soil physical properties and reducing nitrate leaching. Thus, we show here, that biochar and nano-particles soil application decreased nitrate leaching and enhanced soil aggregate stability.
Mokarrameh Behmanesh; Atefeh Chamani; Elham Chavoshi
Abstract
Introduction: One of the most important emerging pollutants in aquatic environments that has recently attracted the attention of global researchers in recent years is plastic waste, especially microplastics. Aquatic fauna can ingest microplastics as they confuse it for their prey. Aquatic organisms can ...
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Introduction: One of the most important emerging pollutants in aquatic environments that has recently attracted the attention of global researchers in recent years is plastic waste, especially microplastics. Aquatic fauna can ingest microplastics as they confuse it for their prey. Aquatic organisms can easily ingest microplastics because their size is similar to that of the larvae of several organisms, including plankton. Consequently, the animal may develop a sense of satiety after ingesting microplastics, causing reduced food uptake and decreased energy intake, which in turn may affect growth, survival, fecundity and reproduction rate, impacting general fitness of the organisms. Once ingested, these particles can be transferred to higher trophic levels. Despite the fact that freshwater is the only source of drinking water, knowledge about the effects of microplastic pollution in freshwater environments compared to marine environments is still in its infancy. Therefore, the aim of the present study is too comprehensive investigate the presence and distribution of microplastics in the sediments of Zayandeh-Rud River.Materials and Methods: From upstream to downstream of Zayandeh-Rud River, 21 sampling stations were selected and in each station, sampling was done in an area of 30 x 30 cm to a depth of approximately 10 cm above the sediment in three repetitions. Sample processing was done during two stages of organic material digestion using hydrogen peroxide and density separation using sodium chloride salt. Microplastics were identified using a standard light microscope with magnifications of 40x, 100x and 400x. Different standard protocols such as pressure, tension, additional light or hot needle tests were used to detect microplastics. After identifying the microplastic particles, their type and shape, color and size were determined and recorded. Raman spectrometer was used to determine the polymer composition of microplastics.Results: The average abundance of microplastics was 70.481±29.39 particles in 50 gr/dry sediment. Station 17 with an average number of 363.50±14.849 particles and stations 1, 6 and 7 with an average number of 1.33 ±1.528 particles in 50 gr/dry sediment had the highest and lowest levels of pollution, respectively. The size of all microplastics was in the range of 50-5000 micrometers. Microplastics less than 500 microns were the most abundant with 64.5%. The dominant form of microplastics with the frequency of 34.9%, 33% and 28.8% belonged to line, fragment and fiber, respectively. In total, 4 polymers, polypropylene, polyamide, polyurethane and polyethylene, were identified. The results were compared with the reference spectra provided in the Openspecy database. In total, 3 different polymers including polypropylene (PP), polyethylene (PE) and polyamide (PA) were found in sediments.Discussion: The result of this research indicates microplastics dispersion in the sediments of Zayandeh-Rud River. Polypropylene (PP), polyamide (PA) and polyethylene (PE) polymers found in Zayandeh-Rud River sediments are often used in textiles. The composition of the polymer in the sediments clearly indicates the discharge of wastewater from the washing of synthetic textile into the river. Polypropylene and polyethylene are used to make ropes and fishing nets. In addition, polypropylene fibers are widely used for the production of floor coverings, carpets and rugs, sports clothes, making agricultural mulch, fishing nets, packaging bags and ropes. Due to its high strength and hardness, polyamide is used to produce items such as ropes, safety belts, parachutes, thread and fishing nets, as well as in the production of synthetic fibers such as clothes, socks and carpet fibers.Therefore, it can be stated that human activities, including the discharge of urban and industrial wastewater, plastic waste by tourists on the river and also the use of fishing nets by fishermen, play an important role in microplastic pollution in this area. Therefore, developing a program to monitoring microplastics in the water and sediment of Zayandeh-Rud River will be of great help for management measures to control this pollution.
Mohammad Ibrahim Fazel Valipour; Hanieh Sadat Hosseini
Abstract
Considering the importance of soil and water pollution and their impact on human health and food chain, the present study deals with the role of heavy metals in soil and water in Abdullah Giv area located on Quchan-Neishabour road, Khorasan Razavi province. In this study, 10 samples from water source ...
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Considering the importance of soil and water pollution and their impact on human health and food chain, the present study deals with the role of heavy metals in soil and water in Abdullah Giv area located on Quchan-Neishabour road, Khorasan Razavi province. In this study, 10 samples from water source and 20 samples from surface soils of the region were taken from a depth of 10 to 20 cm and after preparation and analysis were studied in terms of heavy metal concentrations. The results of the study showed that in the waters of the region, the highest concentration is related to Sr and the lowest concentration is related to Cd, but the concentration of all elements is less than the global health standard. The results of the concentration of heavy metals in the soil of the region and its comparison with the standard of the Environmental Protection Organization in alkaline soils showed that the amount of heavy metals Cr and Ni in the soil of the region is more than the standard. The presence of basaltic igneous rocks in the area can play a role in this. Studies show that to the west, the concentration of heavy metals in the region's water and soil resources is increasing.