Multi-electrode microbial fuel cell with horizontal liquid flow

2009 ◽  
Vol 60 (2) ◽  
pp. 347-355 ◽  
Author(s):  
V. Fedorovich ◽  
S. D. Varfolomeev ◽  
A. Sizov ◽  
I. Goryanin

A plug flow multi-electrode bioelectrochemical reactor for wastewater treatment and simultaneous generation of electricity has been developed and its efficiency investigated. It employs a horizontally located anodic zone in which the anodic electrodes comprise porous graphite plates coated with palladium. The aerated immersed cathodic electrodes contain iron(II) phthalocyanine as a catalyst. The parameters of the device were obtained using glycerol and acetate as fuels and anaerobic sludge as an inoculum. The maximal volumetric power and current densities obtained, relative to the total volume of the anodic zone, were: glycerol: 73±1 mA/L; 43±1 mW/L; acetate: 75±1 mA/L; 40±1 mW/L. It was shown that biotransformation of glycerol into volatile fatty acids does not depend on the presence of anodic electrodes in the reaction zone, while acetate degradation takes place only if the reaction zone contains anodic electrodes as a final electron acceptor.

2015 ◽  
Vol 3 (1) ◽  
pp. 9-18
Author(s):  
Ali J. Jaeel

Chicken manure wastewaters are increasingly being considered a valuable resource of organic compounds. Screened chicken manure was evaluated as a representative solid organic waste. In this study, electricity generation from livestock wastewater (chicken manure) was investigated in a continuous mediator-less horizontal flow microbial fuel cell with graphite electrodes and a selective type of membrane separating the anodic and cathodic compartments of MFC from each other. The performance of MFC was evaluated to livestock wastewater using aged anaerobic sludge. Results revealed that COD and BOD removal efficiencies were up to 88% and 82%, respectively. At an external resistance value of 150 Ω, a maximum power and current densities of 278 m.W/m2 and 683 mA/m2, respectively were obtained, hence MFC utilizing livestock wastewater would be a sustainable and reliable source of bio-energy generation .


1997 ◽  
Vol 36 (6-7) ◽  
pp. 325-332 ◽  
Author(s):  
Raghida Lepistö ◽  
Jukka Rintala

The study focused on the effluent quality and sludge characteristics during the start-up and operation of extreme thermophilic (70 to 80°C) upflow anaerobic sludge bed (UASB) reactors, inoculated with mesophilic and thermophilic granular sludge and fed with acetate, volatile fatty acids (VFA), and thermomechanical pulping (TMP) whitewater. Low effluent quality and long start-up periods were observed during the start-up of the 70 to 76°C, VFA-fed UASB reactors inoculated with mesophilic granulae, while better effluent quality and considerably shorter start-up periods were observed when thermophilic (55/70°C) inocula were used. With VFA feed, a significant amount of acetate was removed at 70°C and even at 80°C, while propionate removal was negligible. With TMP whitewater feed, low VFA effluent concentration was obtained at 70°C. The volatile solids (VS) and the VS/total solids (TS) content of the sludge decreased significantly during the first 2–3 months of operation when mesophilic inocula were used. The initial specific methanogenic activity (ISMA) of the extreme thermophilic sludge decreased with increasing temperature and was slightly higher on glucose than on acetate. At 70 to 80°C, various rod-like bacteria were dispersed through the granulae in either individual or in low density micro colonies surrounded with a varying degree of precipitates.


2015 ◽  
Vol 71 (8) ◽  
pp. 1128-1135 ◽  
Author(s):  
Sevcan Aydın ◽  
Bahar Ince ◽  
Orhan Ince

In this study, we aimed to develop an understanding of the triple effects of sulfamethoxazole–erythromycin–tetracycline (ETS) and the dual effects of sulfamethoxazole–tetracycline (ST), erythromycin–sulfamethoxazole (ES) and erythromycin–tetracycline (ET) on the anaerobic treatment of pharmaceutical industry wastewater throughout a year of operation. Concentrations of the antibiotics in the influent were gradually increased until the metabolic collapse of the anaerobic sequencing batch reactors (SBRs), which corresponded to ETS (40 + 3 + 3 mg/L) and ST (25 + 2.5 mg/L), ET (4 + 4 mg/L) and ES (3 + 40 mg/L). Acetate accumulation in the anaerobic SBRs, acetoclastic activity of the anaerobic sludge taken from different antibiotic feeding stages and also expression of acetyl-coA synthetase from the acetoclastic methanogenic pathway on the mRNA level were assessed. The results indicated that, while acetate accumulation and decrease of acetoclastic activity were observed after stage 3 in the ST and ES reactors, and stage 7 in the ETS and ET reactors, the expression of acetyl-coA synthetase was mostly decreased in the last stages in all SBRs, in which antibiotic mixture feeding was terminated. It might be speculated that acetoclastic methanogens have an important role in acetate degradation by expressing acetyl-coA synthetase.


2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62


1986 ◽  
Vol 13 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Jan A. Oleszkiewicz ◽  
Barry L. Hilton

Six parallel upflow anaerobic sludge bed reactors were operated at chemical oxygen demand (COD) loads from 3 to 10 kg COD/(m3∙d). Four reactors (R1–R4) were fed sodium sulfate at loads of 1–3 kg S-SO4/(m3∙d). Reactors R1 and R2 were fed spent cheese whey with R1 being operated in an unstripped and R2 in a stripped mode. At COD loads below 5 kg/(m3∙d), the removal in R1 was 60–80% COD and generally trailed R2 by a margin of 0–15%. At higher COD loads and at higher SO4/COD ratios, the performance of R1 deteriorated significantly. A similar situation was found in the pair R3 (unstripped) and R4 (stripped), which was fed a mixture of spent whey and sulfite cooking liquor. Reactors R5 and R6 were subjected to the same feed as R3 and R4, but no sulfate was added. A comparison of R4 with R6 indicated slightly lower COD removal in R4 with similar amounts of volatile fatty acids accumulating in both reactors in cases of overloading. Key words: anaerobic treatment, sulfides, methanogenesis, inhibition, sludge bed reactor, dairy wastes, pulp and paper wastes, sulfate reduction.


2011 ◽  
Vol 63 (5) ◽  
pp. 877-884 ◽  
Author(s):  
P. Mijalova Nacheva ◽  
M. Reyes Pantoja ◽  
E. A. Lomelí Serrano

The performance of an upflow anaerobic sludge blanket (UASB) reactor operated at ambient temperature (20.9–25.2°C) was analysed for the treatment of slaughterhouse wastewater previously pre-treated for solid separation. The experimental work was carried out in a reactor with 15 L effective volume. Four organic loads were applied and the process performance was evaluated. The COD removal rate increased with the load rise from 4 to 15 kg COD.m−3.d−1. Removal efficiencies of 90% were obtained with a load of 15 kg COD.m−3.d−1. The entrapment of suspended solids in the sludge blanket was greater in proportion during the first two stages due to the low upflow velocities used when loads of 4 and 7 kg COD.m−3.d−1 were evaluated. This phenomenon did not affect the structure of the biological grains or their methanogenic activity. More than 50% of the organic nitrogen was degraded, causing a 3% increase of ammonia concentration. The concentrations of the volatile fatty acids were not high and the wastewater alkalinity was enough to prevent acidification. The yield coefficient of methane production increased with the load rise, reaching 0.266 m3/kg CODremoved at 15 kg COD.m−3.d−1 organic load. The UASB reactor is a good option for the biological treatment of pre-treated slaughterhouse wastewater. However, additional treatment is required in order to accomplish the water quality requirements in discharges to water bodies.


1993 ◽  
Vol 27 (2) ◽  
pp. 201-208 ◽  
Author(s):  
E. D. Negri ◽  
J. Mata-Alvarez ◽  
C. Sans ◽  
F. Cecchi

A mathematical model of a plug-flow reactor with a fluid recycle has been elaborated to simulate the VFA production process treating the organic fraction of the municipal solid waste. An alternative hydrolytic reaction model (homogeneous - heterogeneous) is proposed. The effect of a possible methanization step is also considered. The effect of process parameters (solid retention time (SRT), pH, recycle ratio) on the reactor performance is analyzed for parameters based on fruit and vegetable waste. The sensitivity of the model to proposed parameters (suspended biomass and initial biomass concentration) is also evaluated. It is found that the reactor production is very sensitive to the system pH. At low SRT, the production of volatile fatty acids (VFA) is proportional to this parameter. As the SRT increases methanization can reduce the VFA production. The effect of the recycle is negligible for the system and operating conditions studied. The effect of suspended biomass and initial biomass concentration was found to be also negligible. For the system analyzed, the pH is a critical parameter and a plug-flow arrangement (without recycle) seems to be the more reasonable election.


2018 ◽  
Vol 78 (9) ◽  
pp. 1871-1878 ◽  
Author(s):  
Gustavo Vargas-Morales ◽  
Rolando Chamy ◽  
Santiago García-Gen

Abstract A variable-gain controller for anaerobic digestion of industrial winery wastewater is presented. A control law using both volatile fatty acids (VFA) and methane production rate as controlled variables and organic loading rate (OLR) as manipulated variable is defined. The process state is quantitatively estimated by an empirical function comparing VFA measurements against a setpoint value; then, it is modified with a second empirical function that compares the methane flow rate with a maximum capacity reference, and finally it is adjusted with a third factor considering the actual hydraulic retention time. The variable-gain function determines the extent of the OLR change applied to the system. The controller was successfully validated in a 95 L upflow-anaerobic-sludge-blanket (UASB) reactor, treating industrial wine wastewater at OLR ranged between 2.0 and 39.2 g COD/L d for 120 days at mesophilic conditions. Higher performance was achieved contrasted with a conventional strategy carried out in a parallel UASB unit.


2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Elfiana Elfiana

Upflow Anaerobic Sludge Blanket (UASB) merupakan suatu metode pengolahan limbah secara anaerob di dalam bioreaktor aliran sumbat (PFR, Plug Flow Reactor) yang melibatkan dua kelompok bakteri, yaitu bakteri penghasil asam dan bakteri penghasil metana. Metode ini digunakan untuk mengolah air limbah dengan konsentrasi organik 3.000–25.000 mg/L berdasarkan parameter COD. Keistimewaan metode ini adanya sludge blanket yang aktif pada bagian dasar reaktor dan dilengkapi dengan sistim pemisahan gas dan padatan (separator gas-solid), sehingga metode ini mempunyai cost relatif lebih murah dan sederhana dibanding metode lain. Oleh karena itu metode UASB sangat cocok diterapkan sebagai sistim pengolahan air limbah organik dari industri kecil.Kata Kunci : UASB, anaerob, sludge blanket, Limbah Organik, COD


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