Gholamreza Bidhendi; Naser Mehrdadi; Mehdi Asadi Ghalhari
Volume 21, Issue 6 , January and February 2015, , Pages 1205-1213
Abstract
Background: Today, production of energy from renewable sources such as biomass is now receiving serious attention to replace fossil fuels. Accordingly, the aim of this study was electricity production due to wastewater treatment.
Materials and Methods: The pilot of the air Cathode microbial fuel cell ...
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Background: Today, production of energy from renewable sources such as biomass is now receiving serious attention to replace fossil fuels. Accordingly, the aim of this study was electricity production due to wastewater treatment.
Materials and Methods: The pilot of the air Cathode microbial fuel cell (MFC) was used at laboratory scale. The external resistance was determined about 1000 Ω using a polarization curve. The system was operated as batch mode. Voltage produced by the system in 25 and 50 mM phosphate buffer solution (PBS) was determined. Then the output power and current density was calculated. To determine the efficiency of the air cathode MFC in wastewater treatment, COD of wastewater (influent and effluent) was also measured.
Results: COD removal efficiencies of wastewater in both 25 and 50mM PBS were 90.86 ± 1.4 and 90.45 ± 0.48%, respectively. The maximum voltage, power and current density were 587mV, 830mW/m2 and 487mA/m2 in 25mM PBS and 596mV, 843mW/m2 and 502mA/m2 in 50mM PBS, respectively. Duration of the voltage produced in 50mM PBS was higher than 25mM PBS (2 times) due to higher resistance against decrease in pH value.
Conclusion: Air cathode microbial fuel cells in addition to compete with conventional systems such as activated sludge, in wastewater treatment, can produce energy simultaneously.
Mehran Eyvazzadeh; MohammadHasan Rakhshani; Ayyob Rastegar; Ahmad Allahabadi; Ebrahim Manochehriyan; Fatemeh Dareyni; Abolfazl Rahmanisani
Volume 21, Issue 5 , September and October 2014, , Pages 934-941
Abstract
Background: In recent years, crisis of water shortage has become a serious problem in many countries. In this regard, the use of treated wastewater in natural or artificial method in agriculture and the like, has been proposed as an important and practical solution. The natural purification method by ...
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Background: In recent years, crisis of water shortage has become a serious problem in many countries. In this regard, the use of treated wastewater in natural or artificial method in agriculture and the like, has been proposed as an important and practical solution. The natural purification method by the use of artificial canebrakes, compared with other methods of treatment is an appropriate method because of its low cost, and also, because of easy navigation, the requirements of low technology and low energy consumption. Several herbs have been used to increase the efficiency canebrakes which including special plants to purify such wastewater is Vetiveria that has unique genetic, morphological and physiological characteristics. Due to the limited knowledge of the plant's industrial wastewater treatment, in this study, a comparison of filterablity of hospital wastewater was done between Vetivaria and bulrush in tropical areas.
Methods: This experimental study was done in 2013 in the hot season, summer. In this study, was made two pilot glass with dimensions of 50*60*100 Cm. A mixture of soil, sand, gravel, clay soil was selected. The irrigation method in this study was subsurface and continuous. First, hospital wastewater via a 220 liter tank as the primary sedimentation retention time and with time of 2 hours entered into bed with a hydraulic retention time of 4 days to discharge 85/0 liters per hour. To evaluate the efficiency of each plant in the treatment of hospital wastewater, chemical parameters including (PH, TP, TN , TSS, BOD5, COD)were measured according to standard methods of measuring. . Analysis of the data was done by the use of t-test and Mann-Whitney and SPSS software.
Results :Based on the finding of this study, percentage of removal parameter(Bod5,Tss,Tn,Tp) by plant Vetiveria was (88.54,95.71,93.93,99.80) and for bulrush was (82.54,91.13,86.64,99.28).
Conclusion: Due to the unique characteristics of Vetiveria, such as high resistance against unfavorable environmental conditions and its higher efficiency than bulrush, this plant is recommended for the treatment of hospital wastewater.
Farshid Ghanbari; Ashraf Mazaheri; Fayyaz Mahdi pour; Simin dokht Mir Shafieyan; Mahsa Moradi; Hajar Sharifi Malek sara
Volume 20, Issue 5 , March and April 2014, , Pages 716-725
Abstract
Background: Colored wastewaters are major source of aquatic pollution which will cause considerable impacts to the environment if discharge without treatment. In recent years, Electrocoagulation (EC) process has been attracted a great attention for treatment of industrial wastewaters as an appropriate ...
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Background: Colored wastewaters are major source of aquatic pollution which will cause considerable impacts to the environment if discharge without treatment. In recent years, Electrocoagulation (EC) process has been attracted a great attention for treatment of industrial wastewaters as an appropriate method.In this study, the efficiency of electrocoagulation process on color removal of natural dyeing wastewater was investigated.
Material and Methods: This study experimentally was run in a batch electrochemical reactor consisting of a 0.6 L glass beaker, two anodes and two cathodes. The anodesand the cathodeswere made of aluminumand iron or copper respectively which installed in parallel. In each of test, 400mLof wastewater add into the reactor , then effect of three parameters including the current (50-500mA), reaction time (5-40 min) and the pH of wastewater (pH=4-8) on process performance were investigated.
Results:Theresults showed that optimal conditions for Al/Cu and Al/Fe systems was in 400 mA applied current, pH of 4 and 40 minutes. In these conditions, EC with Al/Cu electrodes were capableto remove of almost complete color (98%) and efficiency of COD removal was 28 %, whereas EC with Al/Fe resulted in 97% color removal and 21% COD reduction. Electrical energy consumption and current efficiency of EC process for optimal condition werefound 2.9kWhm-3 and 110% respectively.
Conclusion:According to our finding,it proposed that EC process is very efficient and economic process for color removalfrom wastewater.