Amir Hossein Baghaie; Mohammad Fereydoni
Abstract
Background: This descriptive study was conducted to evaluate the interaction effects of sewage sludge and its biochar on anthracene biological degradation in a Pb polluted soil under sunflower cultivation Methods: Treatments consisted of applying three rates of anthracene (0, 12.5 ...
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Background: This descriptive study was conducted to evaluate the interaction effects of sewage sludge and its biochar on anthracene biological degradation in a Pb polluted soil under sunflower cultivation Methods: Treatments consisted of applying three rates of anthracene (0, 12.5 and 25 mg/kg soil), two levels of sewage sludge and its biochar (0 and 30 t/ha) in the presence of Azetobacter bacteria and Piriformospora indica (P. indica) fungus. After 60 days, plants were harvested and plant Pb concentration was measured using atomic absorption spectroscopy. In addition, the soil petroleum hydrocarbons concentration and soil microbial respiration were measured by the method described by Besalatpour et al. (2011). The catalyze enzyme activity was assayed. Results: Plant inoculation with P.indica and Azotobacter significantly increased the degradation of anthracene in soil by 12.8% in the soil treated with 25 mg anthracene/kg soil. In addition, the soil Pb availability was decreased by 14.6% in the mentioned treatment. Applying 30 t/ha sewage sludge and its biochar significantly increased the plant biomass and anthracene degradation in the soil treated by 12.5 mg anthracene /kg soil by 13.5% and 12.6%, respectively. Conclusion: Soil treated with sewage sludge and its biochar had a positive effect on plant resistance to abiotic stresses and degradation of anthracene in the soil. Among this, plant inoculation with P. indica and Azotobacter had also an additive effect on bio-remediation of anthracene in the soil that is a positive point in environmental studies. However, soil pollution with heavy metals had an adverse effect on it.
fariba fariba abbasi; Mohammad Reaz Mohammad Reaz Samaei; hossein khodadadi; ali karimi; azadeh binaee haghighi; jamileh ekhlasi
Volume 5, Issue 1 , January 2017, , Pages 7-14
Abstract
Background: Fungi are one of the pollutant emissions from the composting plants which change in variety during the composting process. They are predominant in stabilization stage.Methods: This study assessed the thermotolerant airborne fungi based on NIOSH 0800 on 200 ambient samples from four composting ...
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Background: Fungi are one of the pollutant emissions from the composting plants which change in variety during the composting process. They are predominant in stabilization stage.Methods: This study assessed the thermotolerant airborne fungi based on NIOSH 0800 on 200 ambient samples from four composting processes and outdoor spaces in a composting plant.Results: The concentration of fungi during shredding, separatingand screening washigher than 1000 CFU/m3. The level of fungi in all stages was higher than outdoor(p<0.001). The highest concentration was detected in shredding (6749±1347 CFU/m3) (p=0.007), and the lowest concentration was related to screening (113±32 CFU/m3) (p=0.013). The predominant species was varied during the stages. Yeast andA.niger were predominant species in shredding and separating.Conclusion:The results of this study showed that the concentration of airborne fungi was decreased during composting process. The effect of these aerosols on indoor air was more than that in the outdoor space and workers at this sitewere exposed to high levels of thermotolerantfungi.Therefore,air-condition, ventilation system and safety operations such as respiratory masks are essential. The results of this studycan be used inrisk assessment.