BackgroundAnomalous use of antibiotics and their entrance into the environment have increased concerns around the world. These compounds enter the environment through an incomplete metabolism and a considerable amount of them cannot be removed using conventional wastewater treatment. Therefore, the main objectives of this research are evaluation of the feasibility of using ultraviolet radiation (UV-A) and fortified nanoparticles of titanium dioxide (TiO2) doped with Fe+3 to remove penicillin G (PENG) from aqueous phase and determining the optimum conditions for maximum removal efficiency.ResultsThe results showed that the maximum removal rate of penicillin G occurred in acidic pH (pH = 3) in the presence of 90 mg/L Fe+3-TiO2 catalyst. In addition, an increase in pH caused a decrease in penicillin G removal rate. As the initial concentration of penicillin G increased, the removal rate of antibiotic decreased. Moreover, due to the effect of UV on catalyst activation in Fe+3-TiO2/UV-A process, a significant increase was observed in the rate of antibiotic removal. All of the variables in the process had a statistically significant effect (p < 0.001).ConclusionThe findings demonstrated that the antibiotic removal rate increased by decreasing pH and increasing the amount of catalyst and contact time. In conclusion, Fe+3-TiO2/UV-A process is an appropriate method for reducing penicillin G in polluted water resources.

Fungi are one of the bioaerosols in indoor air of hospitals. They have adverse effects on staff and patients. The aim of this study was to investigate the effects of three incubation temperature on the density and composition of airborne fungi in an indoor and outdoor space of hospital. Sabouraud dextrose agar was used for culture the fungi. For improvement of aseptic properties, chloramphenicol was added to this medium. The density of airborne fungi was less than 282 CFU/m. The highest density was detected in emergency room and the lowest of them was in neonatal intensive care unit (NICU) and operation room (OR). Results showed that fungi levels at 25 °C were higher than 37 and 15 °C (p = 0.006). In addition, ten different genera of fungi were identified in all departments. The predominant fungi were Fusarium spp., Penicillium spp., Paecilomyces spp., and Aspergillus niger. Moreover, the density and trend of distribution of Fusaruim spp. in the indoor space was directivity to outdoor space by ventilation system. The present study has provided that incubation temperature had effect on airborne fungi remarkably. We are suggested that more studies would be conducted on incubation temperature and other ambient factors on airborne fungi.

BackgroundIn recent years, pollution of soil and groundwater caused by fuel leakage from old underground storage tanks, oil extraction process, refineries, fuel distribution terminals, improper disposal and also spills during transferring has been reported. Diesel fuel has created many problems for water resources. The main objectives of this research were focused on assessing the feasibility of using photo-Fenton like method using nano zero-valent iron (nZVI/UV/H2O2) in removing total petroleum hydrocarbons (TPH) and determining the optimal conditions using Taguchi method.ResultsThe influence of different parameters including the initial concentration of TPH (0.1-1 mg/L), H2O2 concentration (5-20 mmole/L), nZVI concentration (10-100 mg/L), pH (3-9), and reaction time (15-120 min) on TPH reduction rate in diesel fuel were investigated. The variance analysis suggests that the optimal conditions for TPH reduction rate from diesel fuel in the aqueous phase are as follows: the initial TPH concentration equals to 0.7 mg/L, nZVI concentration 20 mg/L, H2O2 concentration equals to 5 mmol/L, pH 3, and the reaction time of 60 min and degree of significance for the study parameters are 7.643, 9.33, 13.318, 15.185 and 6.588%, respectively. The predicted removal rate in the optimal conditions was 95.8% and confirmed by data obtained in this study which was between 95-100%.ConclusionIn conclusion, photo-Fenton like process using nZVI process may enhance the rate of diesel degradation in polluted water and could be used as a pretreatment step for the biological removal of TPH from diesel fuel in the aqueous phase.

Landfill leachates contain a wide variety of pollutants such as organic matter, refractory compounds, ammonia, particulate and dissolved solids and hazardous metals requiring application of advanced and well designed treatment processes before release to the environment. The main purpose of this research was to evaluate the efficiency of combined air stripping, Fenton oxidation and biological treatment in treating landfill leachate, especially the elimination of ammonia and refractory organics. The laboratory scale set-up consisted of three sequential but separate steps. The optimum conditions for air stripping and the Fenton oxidation were determined for landfill leachate from Karaj city, Iran. The final step was a moving bed bioreactor with HRTs of 18, 12 and 6 h. The highest NH(3)-N removal was 79% in the air stripping process at pH 10.5. At the optimum conditions for the Fenton reaction at a reaction time of 90 min, pH 3 and a H(2)O(2)/Fe(2+) mass ratio of 20, the COD removal was 61% and improved the BOD/COD ratio from 0.42 to 0.78. The overall COD removal including the final biological reactor with a HRT of 6 h resulted in an effluent COD concentration of less than 100 mg L(-1).

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Background: Diesel oil hydrocarbons are the most common contaminants of our biological environment. Considering the fact that Iran is one of the major producers of diesel oil products, it greatly contributes to soil and water pollution. Currently, soil and water pollutions caused by diesel oil products leakage, from distribution stations, is one of the major concerns in Iran. Based on the studies performed in this regard, soil and water pollutions have also been reported around the refineries and transmission lines in Iran. Objectives: Thus, the present research aimed to study the effectiveness of using Acinetobacter Radioresistens in removing n-Hexadecane (n-HXD) from polluted waters. Materials and Methods: In this research, n-HXD (C16H34) was selected as the representative of diesel oil hydrocarbons. Hence, the bacterium Acinetobacter Radioresistens was chosen to remove this compound from the polluted water. Results: According to the results, the total n-HXD removal rates were 57.2, 87.35, and 91.33 in 10, 20, and 30 days, respectively. The initial concentration was 9615 mg/l. The biological (Acinetobacter Radioresistens) removal rates were 35.51, 49.45, and 51.6%, while the non-biological rates were 21.68, 37.9, and 39.73% in 10, 20, and 30 days, respectively. Conclusions: Our results suggested that in the warm weather and salty soil of Iran, normal n-HXD can be removed from the polluted waters through localized bacterial usage, especially Acinetobacter Radioresistens.

Background: Contamination of soil with organic pollutants is one of the most important environmental challenges. Bioremediation is a simple and economical method for treatment of hydrocarbon-contaminated soil.

a b s t r ac tLinear alkylbenzene sulphonate (LAS) is widely used for household and industrial purposes while influencing negatively on the environment. Present paper aimed to study LAS biodegradation among different loading rates and fate of LAS in integrated fixed-film activated sludge (IFAS) using synthetic media. A synthetic wastewater among three LAS loading rates with LAS concentrations of 5, 12 and 20 mg/L was investigated within an operative period of 111 d. In doing so, a kinetic model was developed to explain the biodegradation rate of LAS. Finally, the obtained data were analyzed by analysis of variance statistical test. The mean removal efficiency of LAS among three LAS loading rates were 92.32% ± 2.81%, 95.55% ± 2.74% and 96.22% ± 2.74%, respectively. Nevertheless, in terms of total removal efficiency of LAS, the contributions of LAS biosorption in sludge among the three LAS loading rates were 21.3%, 34.2% and 48.5%. The mean removal efficiency of chemical oxygen demand (COD) in among three LAS loading rates were 92.17% ± 4.32%, 91.53% ± 3.34% and 90.91% ± 2.98%, respectively. Moreover, the higher LAS loading rate, the higher removal efficiency of LAS (p ≤ 0.001) and the lower COD removal efficiency (p ≤ 0.001). The results of Michaelis-Menten model for biodegradation kinetics showed that the LAS biodegradation follows the first-order reaction kinetics (R 2 = 0.9949). In addition, biodegradation kinetic and removal efficiency of LAS showed that following the increased concentration of LAS among different loading rates, the LAS biodegradation rate was increased. Therefore, IFAS system is argued to be applicable for wastewater treatment in low and high concentrations of LAS up to 20 mg/L.