Mona Mansouri; Aptin Rahnavard; Masood Ghane
Abstract
Background and purpose: Diazinon is an organophosphorus insecticide that is widely used in paddy fields and gardens. The entry of resistant pollutants into drinking water sources, soil, and agricultural products can be harmful to human health and the environment. This study aimed to identify and isolate ...
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Background and purpose: Diazinon is an organophosphorus insecticide that is widely used in paddy fields and gardens. The entry of resistant pollutants into drinking water sources, soil, and agricultural products can be harmful to human health and the environment. This study aimed to identify and isolate diazinon-degrading bacteria and measure the amount of poison decomposed by superior bacteria in liquid and soil environments.Materials and methods: Sampling was conducted from Tonekabon gardens. The strains were identified and sequenced using polymerase chain reaction based on 16S rRNA. The rate of diazinon degradation by the isolated bacteria was measured by gas chromatographyResults: Two strains of diazinon-degrading bacteria, Serratia and Enterobacter cloacae, were identified. Bacteria with diazinon concentrations of 10 and 20 ppm were cultured in broth and soil for 10 days, and the amount of poison decomposition was measured. The results indicated that Serratia bacteria in the broth medium, with initial concentrations of 10 and 20 ppm, consumed 64.3% and 78.4% of diazinon, respectively, while in the soil with the same concentration, it decomposed 90.2% and 98.25% of diazinon. Enterobacter cloacae bacteria consumed and decomposed diazinon in the broth and soil environments, with percentages of 23.1, 17.95, 31.19, and 88.05%, respectively. According to the results, Serratia has a higher decomposition ability compared to Enterobacter.Conclusion: The results of this research showed that some microorganisms in the soil have the ability to decompose diazinon. Utilizing these microorganisms and other biological methods to clean contaminated soils can be a suitable approach.
Sakineh Rostami Tarzm; Farid Gholamreza Fahimi; Reza Amir Nezhad; Aptin Rahnavard; Ahmad Tavana
Abstract
AbstractIntroduction & Purpose: Gold Mining companies are one of the industries that if not properly act in accordance with the sustainable development goals, they will cause a lot of environmental contamination in the environment. In these factories, tailings dams are places where effluents and ...
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AbstractIntroduction & Purpose: Gold Mining companies are one of the industries that if not properly act in accordance with the sustainable development goals, they will cause a lot of environmental contamination in the environment. In these factories, tailings dams are places where effluents and tailings materials from gold mining factories are collected and stored, and if not properly controlled and monitored, they can be a significant source of cyanide and heavy metals contamination. In this study, cyanide and heavy metals contamination of groundwater, soil and tailings of Takab gold mine were studied.Methods: In this descriptive cross-sectional study, 19 stations were selected for sampling of piezometric wells, soils around the mine, and tailings dam of the Takab gold mine during a one-year period. Water samples were transferred to the laboratory after stored at 4 °C. The Heavy metals in water samples, soil, and tailings were measured by Atomic Absorption Spectrophotometry (AAS) method.Results: The amount of cyanide, mercury and arsenic were measured in the range of 0-105, 0-83.7 µg L-1 and 0-120.4 mg L-1 in water samples, respectively. Also the amount of these contaminants (cyanide, mercury and arsenic) in soil samples were in the range of 37.02 - 58 mg kg-1, 0 - 25.6, and 27.6 - 420 µg kg-1, respectively. Conclusion: The results showed that, there was no significant difference in the mean concentration of arsenic in the water samples of the studied wells. But in the case of mercury and cyanide, the studied wells have a significant difference. Tailings samples had the highest concentration of cyanide and heavy metals, and had significant differences with soil and water samples.