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 ...
Read More
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 ...
Read More
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.
Mitra Gholami; MahmoudAli Mohammadi; Ramin Nabizadeh; Arezoo Heidari; AmirHossein Mahvi
Volume 21, Issue 3 , July and August 2014, , Pages 424-430
Abstract
Background: Disintegration and dewatering of produced sludge during wastewater treatment is one of the main challenges in wastewater treatment process. The aim of this study is to investigate the efficiency of ultrasonic method on dewatering of bio sludge in wastewater treatment plant under different ...
Read More
Background: Disintegration and dewatering of produced sludge during wastewater treatment is one of the main challenges in wastewater treatment process. The aim of this study is to investigate the efficiency of ultrasonic method on dewatering of bio sludge in wastewater treatment plant under different conditions and select the best conditions.
Materials and Methods: In the present study, sludge disintegration and sludge dewatering after undergoing different conditions of frequency (35 and 130 KHz) and detention time (3, 5, 10 and 30 min) were investigated and finally the changes of SCOD, CST and SRF were determined.
Results: The results illustrated that the maximum ability of dewatering was obtained at a detention time of 5 min and frequency of 35 KHz for ultrasonic. Under this conditions SCOD%, CST and SRF were achieved to 4.3%, 151 S and 2.1×1013 m/kg respectively.
Conclusion: According to the results, ultrasonic method significantly increases the sludge disintegration and improves the sludge dewatering.