Anoushiravan Mohseni Bandpey; Reza Nemati; Narges Hakimi; Parviz Norouz
Volume 24, Issue 5 , September and October 2018, , Pages 333-338
Abstract
Background: Recent research has shown that an Advanced Oxidation Process known as Persulfate/UV, has a high capability in removing of persistent organic pollutants. Given that the advantages of this process are limited production of harmful byproducts and strong ability for degradation of persistent ...
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Background: Recent research has shown that an Advanced Oxidation Process known as Persulfate/UV, has a high capability in removing of persistent organic pollutants. Given that the advantages of this process are limited production of harmful byproducts and strong ability for degradation of persistent organic thus it seems this process be also suitable for disinfection of municipal wastewater treatment plant effluents.
Materials & Methods: After collection, the effluent samples were transferred to the lab. Then the disinfection experiments were carried out in a 1 L sterile reactor with 0.5 L of sample and various doses were injected. The direct method was used to measure the microbial populations (thermo-tolerant coliforms).
Results: The result of this research indicated that Persulfate and UV irradiation cannot be able to meet the needs of thermo tolerant coliforms inactivation, but simultaneous using of them (Persulfate/UV) could inactivated approximately 5 logs thermo-tolerant coliforms (Persulfate dose <30 mM). While Persulfate (without UV irradiation) even with 300 mM could inactivated less than 3 logs thermo-tolerant coliforms.
Conclusion: The results of this research show UV irradiation has a strong synergistic effect on persulfate disinfection efficiency. Due to the restriction of the use of sulfur compounds in wastewater treatment, it seems that the use of UV irradiation with less amounts of persulfate can largely improve this restriction and significantly reduce the economic and environmental impact of traditional disinfectants.
Ali Reza Rahmani; Amir Shabanlo; Somaye Akbari; Hadi Rezaeivahidian; Monire Tarlani; Zahra Daraee; Halime Almasi
Volume 25, Issue 1 , May and June 2018, , Pages 21-29
Abstract
Abstract Backgrond: Pharmaceutical products, particularly antibiotics such pollutants are evolving due to the cumulative effects, adverse effects and drug resistance is a major concern in the control environment. The purpose of this work is to investigate the feasibility and potential of iron ...
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Abstract Backgrond: Pharmaceutical products, particularly antibiotics such pollutants are evolving due to the cumulative effects, adverse effects and drug resistance is a major concern in the control environment. The purpose of this work is to investigate the feasibility and potential of iron nanoparticles in the aqueous solution being removed antibiotics. Materials and Methods: In this study, the performance activated persulfate with zero-valent Zinc nanoparticles in the presence of ultrasound in the analysis of antibiotics was investigated. The effect of process parameters such as pH of the solution (2.97-10.53), concentration Potassium persulfate (194.33-1200mg/l) and the zero-valent zinc (12.73-147.27mg/l) in reaction time 0-180 min using a batch chamber ultrasonic were studied. A statistical procedure was used to optimize the parameters of the RSM model. Antibiotics are measured based on COD vials and DR-5000 spectrophotometer was used. Results: The results showed that the initial pH of the solution is the most important influential parameters. The addition of potassium persulfate and zero valent zinc in the samples was enhanced performance. Optimum efficiency achieved in 50 mg/l concentration antibiotics, potassium persulfate 1200 mg/l, the zero- zinc 120 mg /l, pH 4.5. Conclusion: The results of this study demonstrate acceptable performance persulfate activated process with zero-valent iron and zinc nanoparticles on ultrasound in the presence of antibiotic.
Amir Shabanlo; mina Khorshidi; Abdolmotaleb Seid Mohammadi
Volume 24, Issue 6 , March and April 2018, , Pages 81-93
Abstract
Background & Objectives: The Azo dyes due to presence of aromatic rings in structure are considered major problems into the environment. In this experimental study, the synergistic effect of persulfate and nano zero-valent iron in degradation of Acid Blue 113 in presence of ultrasonic irradiation ...
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Background & Objectives: The Azo dyes due to presence of aromatic rings in structure are considered major problems into the environment. In this experimental study, the synergistic effect of persulfate and nano zero-valent iron in degradation of Acid Blue 113 in presence of ultrasonic irradiation was investigated.
Materials and Methods: The effect of operating parameter such as initial pH, different concentration of S2O82-, nZVI and initial dye using a batch ultrasound reactor at 40 kHz frequency was investigated. After the optimize process, synergistic dye degradation and COD reduction of colored solution was studied. For characterization of the prepared nZVI particle, transmission electron microscope (TEM) image was used.
Results: To remove 99% dye with initial concentration of 50 mg/L, the optimal condition in the end of 30 min of reaction was pH 3, concentration of S2O82- and nZVI 5 mM and 50 mg/L, respectively. In the same of condition with increasing pH to 11 the dye removal efficiency decreased to 17%, respectively. After 120 min of reaction in the optimal condition, the COD reduction was 95%. Synergistic dye degradation in US/S2O82-/Fe0 process was observed 59%. The TEM image of the synthesized nZVI confirmed the nanoscale Creation.
Conclusion: The US/S2O82-/Fe0 combined process due to high synergistic degradation, can be promising process to industrial wastewater treatment.
Majid Taheri; Mahmoud Abbasi; Mehri Mohammadi; Abolfazl Mohammadbeigi; Abolfazl Jokar; Mohsen Mokhtari; Amir Almasi-Hashiani
Volume 24, Issue 6 , March and April 2018, , Pages 95-102
Abstract
Background & Objectives: Electronic learning is a pre-constructed and programmed use of electronic system and computer for supporting the process of learning. This study aimed to investigate the effect of electronic education on cognitive learning of health pratitioners and compares this new education ...
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Background & Objectives: Electronic learning is a pre-constructed and programmed use of electronic system and computer for supporting the process of learning. This study aimed to investigate the effect of electronic education on cognitive learning of health pratitioners and compares this new education with traditional one in research methodology in Arak University of Medical Sciences in 2014. Materials & Methods: This was a quasi-experimental study with a pre-and-post test design. All of health practitioners of Arak University of Medical Sciences (60 people) were chosen as the study sample, and randomly divided into two, conventional and web-based groups. The intervention method for the first group was a 3-days workshop on research methodology and for the second group it consisted of a web-based education course on same subject. The students’ knowledge in both groups was measured at the beginning and end of each course with pre and post tests and the scores was compared through paired T- test. Results: The cognitive learning is measured with 81% significance in pre and post-test processes (p=0.001). We use the descriptive statistics indexes and T-test to understand the data with purpose of statistics analysis and hypothesis test. The result shows that electronic education in cognitive learning is successful. There is significant different between students with electronic education and traditional one. In addition electronic education increases student’s knowledge (p=0.001) and understanding (p=0.001). Ability of analysis and assessment in students who pass electronic learning is very high in comparison with those who don’t pass it. Conclusion: Using web-based education as a training method causes promotion of student’s cognitive learning and paves the way for using this method along with classic training methods in research methodology. A combination of the mentioned factors is effective on e-learning for higher education.
Mohammad Taghi Ghaneian; Masoumeh Tabatabaee; Mohammad Hasan Ehrampush; Mohammadreza Nafisi; Mohsen Amrollahi; Mahmoud Taghavi
Volume 24, Issue 3 , July and August 2017, , Pages 197-203
Abstract
Background: 2,4-Dichlorophenoxyacetic acid (2,4-D) is a widely used acidic herbicide with high toxicity. So, this study was performed with the aim of investigation of 2,4-D photochemical oxidation by persulfate and UV.
Materials and methods: This study was performed in bench scale and batch condition. ...
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Background: 2,4-Dichlorophenoxyacetic acid (2,4-D) is a widely used acidic herbicide with high toxicity. So, this study was performed with the aim of investigation of 2,4-D photochemical oxidation by persulfate and UV.
Materials and methods: This study was performed in bench scale and batch condition. K2S2O8 was used as oxidant in presence of UV. In this study, effects of pH, oxidant concentration, contact time and initial concentration of 2, 4-D on the process were examined in batch experiments. The concentration of 2, 4-D was determined using spectrophotometer at 285 nm.
Results: The best results were achieved at acidic conditions (pH =3). Increasing dosages of persulfate and contact time increased the degradation of 2,4-D. However, an increase in initial 2,4-D concentration resulted in decreasing of photochemical oxidation efficiency. The maximum photochemical oxidation efficiency of 2,4-D was 96 % for a 2.5 mg/l persulfate, 10 mg/l 2,4-D, pH value of 3.0 and contact time of 240 min. The degradation of 2, 4-D by persulfate is found to follow the pseudo-first-order kinetic model (R2=0.979).
Conclusion: In this study, 2,4-D was effectively degraded in aqueous solutions by the photochemical oxidation using S2O8/UV. From this study, it seems that photochemical oxidation with S2O8/UV can be an effective process for the treatment of contaminated water with 2, 4-D.
Alireza Rahmani; Jamal Mehralipor; Nader Shabanloo; Firoozeh Zaheri; Yosef Poreshgh; Amir Shabanloo
Volume 21, Issue 5 , September and October 2014, , Pages 797-807
Abstract
Background: Usually, to produce radical sulfate, persulfate anions can be activated by heat, UV light and transition metals such as iron ions. The purpose of this study was investigation of performance of persulfate activated with iron produced by electrical method using iron anode electrode in degradation ...
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Background: Usually, to produce radical sulfate, persulfate anions can be activated by heat, UV light and transition metals such as iron ions. The purpose of this study was investigation of performance of persulfate activated with iron produced by electrical method using iron anode electrode in degradation of Acid Blue 113 from aqueous solutions.
Materials and Methods: In this study, a lab-scale electrochemical batch reactor equipped with four iron electrodes and a DC power supply was used for removing of Acid Blue 113. The effect of operating parameters such as initial pH, voltage, persulfate and initial Acid Blue 113 concentration were evaluated. Also, the amount of pH changes during the process, the synergistic effect of processes in the system and Acid Blue 113 UV-Vis spectrum analysis in optimal conditions was investigated.
Results: The results showed, initial pH of solution, initial concentration persulfate and applied voltage has a significant effect on dye removal. Dye removal efficiency was higher in acidic condition and decreased with increasing pH, So that, after 2 min of reaction at pH 3, voltage 10 V and 150 mg/L of persulfate, 98% of the dye was removed, at pH 5, 7, 9 and 11, after 2 min of reaction and in the same condition the dye removal efficiency was, 66, 0, 0 and 13.5%, respectively. With increasing voltage from 1 to 10 V, increased the dye removal efficiency. S2O82- at the end of 20 min of reaction, removed 17% of dye, at the same condition, electrochemical process with iron electrode had only 31% efficiency, but, the combination of these two processes could remove 99.8% of dye.
Conclusion: The use of S2O82- anions in an electrochemical reactor with iron electrodes can be increase the efficiency of process. Therefore, using this process can be promising process to industrial wastewater treatment.