scholarly journals Effect of Influent pH and Hydraulic Retention Time on Bioelectricity Generation in an Integrated Acidogenic Reactor and Microbial Fuel Cell Treating Rice Mill Wastewater

2021 ◽  
Author(s):  
Aryama Raychaudhuri ◽  
Manaswini Behera
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Integrated System ◽  
Operating Conditions ◽  
Electricity Production ◽  
Two Stage ◽  
Bioelectricity Generation ◽  
Rice Mill Wastewater

Abstract An innovative design approach was employed in the present study to enhance the electricity generation and wastewater treatment in a microbial fuel cell (MFC). A dual-chambered MFC with a ceramic separator was coupled with an acidogenic chamber. Acidogenic bioconversion of rice mill wastewater into volatile fatty acid (VFA) represents an interesting approach for wastewater valorization. The VFA containing effluent could be used as an effective substrate for bioelectricity generation in MFCs. A short hydraulic retention time (HRT) can be used for the two-stage anaerobic process (acidogenesis and electrogenesis), thus preventing the proliferation of methanogens. The effect of pH (5.5–7.5) and HRT (0.5 d–0.75 d) were investigated to understand the influence of operational parameters on the performance of the integrated system. The maximum VFA concentration of 1065.15 ± 5.08 mg COD/L was achieved at pH 7.5 and HRT 0.5 d. Under these operating conditions, the general activity of acid-forming microorganisms and exoelectrogens improved remarkably, and the power density obtained from the system was 4.72 ± 0.10 W/m3. The current research indicates excellent potential for simultaneous treatment and electricity production from rice mill wastewater. The use of low-cost, locally manufactured, and customized membranes and the two-stage treatment can pave the way for the practical application of this technology.

Theoretical Study on Two-Stage Anaerobic-Aerobic Biological Treatment of a CTMP Effluent

1996 ◽  
Vol 31 (1) ◽  
pp. 1-20 ◽  
Author(s):  
H.W. Liu ◽  
S.N. Lo ◽  
H.C. Lavallée
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Time Range ◽  
Two Stage ◽  
Cell Age ◽  
Initial Substrate ◽  
Stage System ◽  
Basic Equations ◽  
Monod Kinetic

Abstract Basic equations based upon the Monod kinetic model are presented for a two-stage, sequential anaerobic-aerobic treatment system. The effects of operating conditions, such as hydraulic retention time, mean cell age, concentration of microorganisms and initial substrate concentration, on the behaviour of the two-stage system for the treatment of a CTMP effluent were studied theoretically. This was done in terms of removal of BOD5 and RFA, and sensitivity to changes in operating conditions. The study revealed that unstable operation of the anaerobic process could be due to the treatment being carried out in a time range in which the operation was very sensitive to the variation in either hydraulic retention time or mean cell age.

scholarly journals Assessing the factors influencing the performance of constructed wetland–microbial fuel cell integration

2020 ◽  
Vol 81 (4) ◽  
pp. 631-643 ◽  
Author(s):  
Huang Jingyu ◽  
Nicholas Miwornunyuie ◽  
David Ewusi-Mensah ◽  
Desmond Ato Koomson
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Constructed Wetland ◽  
Retention Time ◽  
Electricity Generation ◽  
Electrode Materials ◽  
Hydraulic Retention Time ◽  
Wetland Plants ◽  
Wide Range

Abstract Constructed wetland coupled microbial fuel cell (CW-MFC) systems integrate an aerobic zone and an anaerobic zone to treat wastewater and to generate bioenergy. The concept evolves based on the principles of constructed wetlands and plant MFC (one form of photosynthetic MFC) technologies, of which all contain plants. CW-MFC have been used in a wide range of application since their introduction in 2012 for wastewater treatment and electricity generation. However, there are few reports on the individual components and their performance on CW-MFC efficiency. The performance and efficiency of this technology are significantly influenced by several factors such as the organic load and sewage composition, hydraulic retention time, cathode dissolved oxygen, electrode materials and wetland plants. This paper reviews the influence of the macrophyte (wetland plants) component, substrate material, microorganisms, electrode material and hydraulic retention time (HRT) on CW-MFC performance in wastewater treatment and electricity generation. The study assesses the relationship between these parameters and discusses progress in the development of this integrated system to date.

scholarly journals Effect of Hydraulic Retention Time on Carbon Sequestration during the Two-Stage Anammox Process

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 717 ◽  
Author(s):  
Xueyan Ma ◽  
Xiaoning Liu ◽  
Bangdong Xiang ◽  
Wenjie Zhang
Keyword(s):  
Carbon Sequestration ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Calvin Cycle ◽  
Nitrogen Loading ◽  
Operating Conditions ◽  
Partial Nitrification ◽  
Ammonium Oxidation ◽  
Two Stage ◽  
Anammox Process

In a biological treatment process, hydraulic retention time (HRT) has a certain effect on the operation of the reactor. This study investigated the effect of HRT on carbon sequestration in a two-stage anaerobic ammonium oxidation (anammox) process using a partial nitrification reactor and anammox reactor to determine the optimal carbon sequestration operating conditions. Molecular biotechnology was used to analyze the sludge in the reactor in order to explore the denitrification performance and to determine the carbon sequestration pathway of the microorganisms. The results show that the partial nitrification stage had the highest carbon sequestration rate (0.319 mg/mg·N) when the nitrogen loading rate (NLR) was 0.44 kg·N/m3/d. The NLR of the anammox stage was 0.13 kg·N/m3/d. When the HRT was 33.4 h, the carbon sequestration of the anammox reaction was at its highest, reaching 0.183 mg/mg·N. The results of microbial analysis show that the carbon-fixing gene cbbLR1 was present in the sludge samples during the anammox and partial nitrification stages, and that there was a Calvin cycle carbon sequestration pathway during the growth process. However, the existence of a gene for reducing and immobilizing CO2 by the acetyl-CoA pathway was not detected; further research is thus needed.

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