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Background: Nowadays, international concern about the impact of antibiotic residues on the environment increased and their removal has received a lot of consideration. The aim of this study was to investigate the efficiency of Fenton’s advanced oxidation process (H2O2/Fe+2) in sulfadiazine antibiotic removal from aqueous solutions. Materials and Methods: An experimental-laboratory scale study was done on a synthetic wastewater containing sulfadiazine antibiotic with 0.079, 0.19, and 0.47 mM concentrations under Fenton’s process. Then optimal values of affecting parameters, such as initial antibiotic concentration, molar ratio of reagents, [Fe+2] and [H2O2] concentration, detention time, and pH, were determined. The discharged effluent analyzed by HPLC-UV to identify the antibiotic residues. Results: The results showed that the optimal parameters in the Fenton’s oxidation process to remove the sulfadiazine included antibiotics at pH 3.5, molar ratio of [H2O2] / [Fe +2] equal to 1.5, and contact time of 15 minutes, respectively. In these optimal conditions, the efficiency of removal of antibiotic in concentrations of 0.079, 0.19, and 0.47 mM were 99.82%, 97.97% and 78.23% and the wastewater COD removal degrees were 83.33%, 78.57%, and 78.57%, respectively. Conclusion: The experiments showed the efficient removal of sulfadiazine antibiotic in wastewater by Fenton’s oxidation process. The efficiency of this method can also be considered in eliminating other antibiotics resistant to biological treatment

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Background: Remaining of crude oil in storage tanks usually lead to accumulation of oily sludge at the bottom of the tank which should be treated and disposed of in a suitable manner. In this research the feasibility of chemical oxidation with H2O2 and Fenton's reagent for removal of total petroleum hydrocarbons (TPH) from composted storage tank sludges was investigated.

Materials and Methods: The sludge was mixed with immature compost at various sludge to compost ratios including 1:2, 1:4, 1:6, 1:8 and 1:10 and composted for 82 days. Then, hydrogen peroxide and Fenton’s reagent were added to the composted mixture in six concentrations including 2%, 5%, 10%, 15%, 20% and 30% w w-1 for a period of 24 and 48 hr.

Results: TPH removal in composting reactors with the ratios of 1:2, 1:4, 1:6, 1:8 and 1:10 were 66.59, 73.19, 74.81, 80.20 and 79.91 percent, respectively. The mean TPH removal of 1:8 composted mixtures with 2%, 5%, 10%, 15%, 20% and 30% of oxidant concentrations were 1, 5.09, 19.37, 28.16, 34.37 and 38.05 percent, respectively. The highest removal efficiency was achieved in stepwise addition to the sludge. As well, increasing oxidation time from 24 to 48 hr had a little effect on TPH removal increase and the removal efficiencies of H2O2 and Fenton were nearly similar.

Conclusion: Chemical oxidation with hydrogen peroxide and Fenton as a post-treatment step is an acceptable process in TPH removal from bottom sludge of storage tanks.

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Background: The growth of population, improvement of quality of life and the development of industries have led to increase in the rate of urban and industrial waste. As the leachate of the waste has a lot of pollution, influences harmfully human health and the environment. Researches have shown that the advanced oxidation processes (AOPs) such as Fenton and Fenton-related processes can reduce chemical oxygen demand (COD) of the leachate effectively.

Materials and Methods: In this paper, the rate of decrease in the total suspended solids (TSS) of leachate from a composting facility in Isfahan was studied using electrochemical, Fenton and electro-Fenton processes. These processes were conducted at reaction times 0, 20, 40, and 60 minutes, with the currents of 0.5, 1 and 1.5A and hydrogen peroxide dosages 1000, 2000, and 3000 mg/L.

Results: In the three mentioned processes, the most TSS removal was observed at the first 40 minute of the reactions. Among the studied processes, the electro-Fenton removed up to 92.4% of the TSS and was recognized as the most effective method. Furthermore, electrochemical and Fenton removed 41.7% and 60.3% of the TSS, respectively.

Conclusion: Therefore, decreasing the TSS of leachate could change its qualities and reduce the leachate pollution and the adverse environmental effects.

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Background: and Aim The leachate from oil sludge compost into the environment, which is resistant to decomposition, causes several environmental problems. Therefore, it needs to be treated using efficient processes. This study aimed to investigate the efficiency of the modified Fenton process for treating these oil sludge leachates.
Methods & Materials: In this experimental study, leachate samples were collected, and then modified Fenton solution was prepared by adding Fe2 (SO4) 3 to H2O2. Then the effect of time parameters (15, 30, 60, 90, and 120 minutes), modified Fenton concentration of 20, 50, 100, and 200 mg/l with pH 3, 5, 9, and three initial concentration of COD (500, 1000 and 1500 mg/l) was examined.
Ethical Considerations: This study has been registered in Arak University of Medical Sciences with codes 2645 and 2765.
Results: The reduction of COD and TPH in the optimal time of 60 minutes, initial COD of 500 mg/l, pH of 3, and Fenton concentration of 200 mg/l were 9.04 and 77.42%, respectively. The experiments showed that the removal efficiency of COD and TPH with increasing residence time and the concentration of modified Fenton are directly proportional and with decreasing, the initial concentration of COD and pH is inversely proportional.
Conclusion: The use of modified Fenton is an efficient method for treating leachate from petroleum sludge compost.