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Showing 3 results for Chemical Oxygen Demand
Evaluating the Effect of Powdered Activated Carbon (PAC) on the Efficiency of Leachate Treatment by Aerobic Sequencing Batch Reactor (ASBR)
Sar Mousavi, M Parvaneh,
Volume 9, Issue 2 (9-2016)
Abstract

Background and Objectives: Conventional methods of leachate treatment are inefficient due to high pollution loads and characteristics of the leachate. In recent years, an integrated method has been developed considerably. The aim of this research was to evaluate the effect of powdered activated carbon on the treatment of landfill leachate of Kermanshah City by a columnar aerobic sequencing batch reactor.

Materials and Methods: This study was carried out in three reactors having a total volume of 2000 mL and each having an effective volume of 600 mL in the bench scale. To the reactors 2 and 3 that were similar from environmental conditions and operation point of view with reactor 1 (with no carbon powder), 5 and 10 g/L of PAC were added, respectively. The effects of different doses of PAC (0, 5, 10 g/L) and hydraulic detention times (HRT = 48, 96, 144 h) were investigated in order to remove the Chemical Oxygen Demand (COD) and ammonia nitrogen (NH3-N) from the leachate. The efficiency was investigated using two -way ANOVA test in SPSS software (Ver. 16).

Results: The results of two-way ANOVA showed that there was a significant difference (P-value=0.001) between the removal efficiency of COD and NH3–N at different HRTs with different doses of PAC. The highest removal efficiency achieved at HRT=144 h for COD and NH3-N was in Reactor 1 were 50.11 ± 4.42 and 19.85 ± 1.49%; in reactor 2: 55.67 ± 1.6 and 25.7 ± 0.89%; and in reactor 3: 58.02 ± 3.99and 25.48 ± 1.7%, respectively.

Conclusion: It can be concluded that the combination of biological - activated carbon compared with the biological process, can remove COD and NH3–N of strong sewages such as landfill leachate, although achieving standard treatments using this method is not possible.


Performance evaluation of electroproxone process in degradation of ceftriaxone pharmaceutical compound from synthetic solution
Mr Samarghandi, Ar Rahmani, Z Darabi, J Mehralipour,
Volume 12, Issue 4 (2-2020)
Abstract
Background and Objective: Electroproxone process is a combination of ozonation process and electrolysis in which the production of hydroxyl radical and ultimately degradation of a pollutant occurs. The aim of this study was to estimate the E-Proxone process in removing ceftriaxone from a synthetic solution.
Materials and Methods: In this experimental study, a semi-continuous reactor equipped with four graphene electrodes having 2 × 10 cm dimension and 3 mm thickness was used. The effect of pH (3-11), concentration of ozone gas (1-5 mg/min), direct electric current (1-3 A), initial concentration of ceftriaxone (5-50 mg/L) and radical scavenger dose (tertbutanol = 20 mmol/L) was studied in a 0-60 minutes reaction time. The Ceftriaxone concentration was measured by HPLC, COD was measured with spectrophotometer (DR6000) and TOC with a TOC analyzer.
Results: The results of this study indicated that this process had sufficient performance in the degradation of the antibiotic and diminishing of COD and TOC. The excellent condition was pH = 3, the electric current of 3 A, the ozone concentration of 5 mg/min, and the sodium sulfate as an electrolyte was 50 mmole/L. The ceftriaxone concentration was 5 mg/L in the duration of the 30 minutes experiment. 99.39% of the Ceftriaxone was destroyed. The process efficiency in COD and TOC removal was highest at 90 minutes. The presence of tertbutanol reduced the process efficiency to 83%.
Conclusion: The E-Proxone process, as one of the advanced oxidation processes, has the ability to reduce the pollution load of pharmaceutical industry, especially the ceftriaxone in this wastewater. This process is considered an environmentally friendly process.
Application of dual chamber microbial fuel cell with aeration cathode for bioelectricity generation and simultaneous industrial wastewater treatment
Farah Rashadi, Nahid Navidjouy, Ali Ahmad Aghapour, Mostafa Rahimnejad,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Microbial fuel cell (MFC) is a new green technology that uses the catabolic ability of microorganisms to produce bioenergy while simultaneously removing organic matter and other wastewater contaminants. Electrode material is one of the factors affecting the performance of microbial fuel cells. The aim of this study was to investigate the performance of microbial fuel cells in COD removal and bioenergy production from synthetic and real beverage wastewater.
Materials and Methods: In this research, a two-chamber microbial fuel cell with Nafion membrane and aerated  cathode was set up using two electrodes made of carbon felt and flat graphite after being contacted by synthetic wastewater with a concentration of COD 5000  mg/L and real beverage wastewater. Organic matter removal efficiency and voltage, power density and maximum current were determine.
Results: Experimental results showed that maximum COD removal efficiency of 92 % was achieved in synthetic wastewater and with a carbon felts electrode. In this condition, maximum voltage, power density and output current density of 469 mV, 175.28 mW/m2, and 855 mA/m2, were obtained, respectively. However, by using real industrial wastewater (beverage), maximum removal efficiency of COD, voltage, power density and output current density, related to carbon felt electrodes ‎were obtaines as 84 %, ‎460 mV, 91/65 mW/m2, and 635 mA/m2, respectively.
Conclusion: The findings showed that synthetic wastewater outperforms microbial fuel cells in terms of bioelectric production and organic matter removal as compared to real wastewater (beverage). The reason for the decrease in the cell performance might be the presence of solids and other confounding pollutants in real wastewater.

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