Two-phase anaerobic treatment of cheese whey

1999 ◽  
Vol 40 (1) ◽  
pp. 289-295 ◽  
Author(s):  
Gülüm Yılmazer ◽  
Orhan Yenigün

Performance of two-phase anaerobic digestion of cheese whey was investigated in a system consisting of a continuous stirred tank reactor (CSTR) as the acidogenic reactor and an upflow anaerobic filter (UFAF) as the methanogenic reactor. The acidogenic reactor was operated at various hydraulic retention times (HRTs) between 18 hours and 4 days. The results showed that an optimum HRT for the acidogenic reactor with the same organic loading rate (OLR) between 0.5-2 g COD/MLSS day was 24 hours. At this retention time the acidification rate increased up to a maximum of 50%. Volatile fatty acids (VFAs) produced in the acidogenic reactor operating at an HRT of 24 hours were 52% acetic acid, with 14% propionic, 27% butyric and 7% isovaleric acids. Operating the acidogenic reactor at this HRT, the effluent was fed to the upflow anaerobic filter. Here HRT was varied between 3-6 days for the best COD removal efficiency and biogas production. At an HRT of 4 days a 90% soluble effluent COD removal efficiency was obtained with an outmost biogas yield of 0.55 m3/kg COD removed.

Author(s):  
Nithya Gopinath ◽  
Madhu G. ◽  
Joseph Francis

In this study, wastewater from a centrifuge rubber latex concentration unit was experimentally treated by an up-flow anaerobic filter (UAF) at variable hydraulic detention time to investigate the COD removal efficiency and the gas production rate. The UAF reactors were made of PVC pipe with an inside diameter of 9.5 cm, 180 cm in height, with a bed volume of 12.8 L, and filled with polyethylene media. The initial COD concentration of wastewater was in the range 4620 - 10400 mg.L-1. HRTs were controlled at 20 days, with the organic loading rate varying from 2.9 to 10.5 kg.day.m-3. The findings show that the COD removal efficiency of the system was in the range of 85% to 92% for the varying organic loading rates. In addition, the specific methane production rate varied from 8.2 to 14 L of CH4 produced/g of COD destroyed/day for the different organic loading rates.


A laboratory scale of biphasic anaerobic bioreactor was operated in a total working volume of 36.92l with 6.15l of Acidogenic and 30.77l of Methanogenic reactor for treating Pharmaceutical wastewater in a mesophilic conditions. The Organic Loading Rate for this experimental study was varied from 1.448 to 30.80Kg COD/m3 .d for Acidogenic Reactor and 0.364 to 9.435Kg COD/m3 .d for Methanogenic reactor. The maximum COD removal efficiency was attained 87.54% with OLR of 2.750Kg COD/m3 .d in Methanogenic reactor and 27.39% with OLR of 3.578 Kg COD/m3 .d Acidogenic reactors. The overall reactor reached the maximum COD removal efficiency of 83.52% with an influent COD of 2864mg/l of pharmaceutical wastewater


The present study explores the feasibility of biogas production from dairy wastewater in the UAF reactor with simultaneous wastewater treatment. The study was carried out at different hydraulic retention times (8h, 12h, 16h, 24h). Two different media such as pebble stone media and aggregate media were used as the packed media. The maximum COD removal efficiency of 91.55 % is achieved at the hydraulic retention time of 24 Hours with an organic loading rate of 1.35 kg/m3 /d for aggregate media, whereas for pebble stone media a maximum COD removal efficiency of 76.32 % is achieved. Before the start of the experiments, the COD/BOD ratio is fixed to 1.4 with initial COD and BOD of 1350 mg/L and 960 mg/L. So, from the results it is concluded that the Upflow Anaerobic Filter (UAF) Reactor can be used as a one of the best treatment methods for the diary wastewater treatment.


2013 ◽  
Vol 726-731 ◽  
pp. 2813-2817
Author(s):  
Guang Li ◽  
Jing Li ◽  
Ke Sun

The interior diversion expanded granular sludge bed was concurrently operated for 140d to study the characteristic of the granular sludge bed. The influent COD concentration varied from 2000mg/L to 22300 mg/L, hydraulic retention time was maintained constant at 24 h and the organic loading rate was changed through a change in substrate concentration. The results showed that the reactor had great COD removal efficiency. When the MLSS was 23.1g/L, the influent COD was 18890mg/L, the COD removal efficiency was 80.4%; The interior diversion EGSB could greatly improve the role of gas-dynamic, when the liquid upflow velocity was 3.55m/h, the gas production was 5.96 L/d shows higher sludge bed expansion rate than 2.77 L/d about 9.5%. During the experimental, the anaerobic sludge has the following properties: the average sludge diameter was increased from 0.41mm to 1.66mm. Observed under the scanning electronic microscopy, we found that the sludge appeared obviously granulation, the bacteria amount and species are more than seed sludge after operation of 50d. It was found that rough surface of anaerobic sludge has clear figure with being covered by mucous lamina, with visible hole or cavity on surface.


1990 ◽  
Vol 22 (9) ◽  
pp. 157-166 ◽  
Author(s):  
G. K. Anderson ◽  
I. Ozturk ◽  
C. B. Saw

This paper covers the results of a pilot-plant study on the Anaerobic Fluidized-Bed Reactor (AFBR) treatment of brewery wastes. The AFBR was operated over a wide range of organic and hydraulic loading rates for a study period of more than eight months. The reactor consisted of a clear PVC column with a diameter of 165 mm and 3 m in height. Sand having a median diameter of 0.5 mm was used as the medium. The AFBR was fed with wastewaters collected from a local brewery. A COD removal efficiency of greater than 75% was observed at an organic loading rate (OLR) of 8.9 kg COD/m3 of expended bed/day for 82 days from start-up. The OLR was increased to greater than 14 kg COD/m3.d and a COD to methane conversion of 87% was achieved. Effects of OLR and COD removal efficiency on gas flowrate and on gas composition as well as concentrations of suspended solids (SS) and volatile acids (VA) were investigated. It was observed that biomass distribution along the height of the AFBR was not uniform and a strong stratification of biomass exists between the upper and lower parts of the system. The ecological structure of biomass was examined by SEM and clumps of methanogenic bacteria were identified. The Monod kinetic parameters were determined using steady-state operating data and compared to similar results given in the literature for the same waste.


1989 ◽  
Vol 21 (12) ◽  
pp. 1681-1684 ◽  
Author(s):  
I. Ozturk ◽  
G. K. Anderson ◽  
C. B. Saw

This paper presents the results of a pilot plant study using an Anaerobic Fluidized Bed Reactor (AFBR) for treatment of brewery wastes. A COD removal efficiency of greater than 75% was observed at an organic loading rate (OLR) of 9.5 kg COD/m3-day for a Deriod of 82 days from start-up. COD removal efficiency was greater than 74% at an OLR of 14.6 kg COD/m3 expanded bed (e.b)-day. A COD to methane conversion of 87% was achieved. Experimental results have suggested that the COD removal efficiency of an AFBR is only a function of COD loading, and neither the feed COD nor HRT alone significantly affect the performance of the reactor. A linear relationship was found between the specific substrate utilization rate and the specific methane production rate. It was observed that the distribution of the biomass along the height of the reactor is not uniform, and the biomass hold-up near the top of the reactor may reach concentrations of greater than 20,000 mg/l.


1995 ◽  
Vol 32 (12) ◽  
pp. 121-129 ◽  
Author(s):  
A. Espinosa ◽  
L. Rosas ◽  
K. Ilangovan ◽  
A. Noyola

A laboratory UASB reactor was fed with cane molasses stillage at organic loadings from 5 to 21.5 kg COD/m3 d. With an organic load of 17.4 kg COD/m3 d, an accumulation of VFA, principally propionic acid, was observed due to little bioavailability or lack of trace metals (Fe, Ni, Co and Mo). Associated to this, the performance of the UASB reactor was low (44% COD removal efficiency), with an alkalinity ratio above 0.4. The addition of Fe (100 mg/l), Ni (15 mg/l), Co (10 mg/l) and Mo (0.2 mg/l) to the influent reduced significantly the level of propionic acid (5291mg/l to 251 mg/l) and acetic acid (1100 mg/l to 158 mg/l). The COD removal efficiency increased from 44% to 58%, the biogas production from 10.7 to 14.8 l/d (NTP) and 0.085 to 0.32 g CH4-COD/g SSV d for specific sludge methanogenic activity with propionic acid as substrate. These improved results were obtained with high COD (68.9 g/l) and organic load (21.5 kg COD/m3 d).


2008 ◽  
Vol 58 (2) ◽  
pp. 373-377
Author(s):  
Soosan J. Panicker ◽  
M. C. Philipose ◽  
Ajit Haridas

The Buoyant Filter Bio-Reactor (BFBR) is a novel and very efficient method for the treatment of complex wastewater. Sewage is a complex wastewater containing insoluble COD contributed by fat and proteins. The fat and proteins present in the domestic sewage cause operational problems and underperformance in the Upflow Anaerobic Sludge Blanket Reactor, used now for treating sewage anaerobically. The biogas yield from the BFBR is 0.36 m3/kg COD reduced and the methane content was about 70–80%. Production of methane by anaerobic digestion of organic waste had the benefit of lower energy costs for treatment and is thus environmentally beneficial to the society by providing a clean fuel from renewable feed stocks. The BFBR achieved a COD removal efficiency of 80–90% for an organic loading rate of 4.5 kg/m3/d at a hydraulic retention time of 3.25 hours. The effluent COD was less than 100 mg/l, thus saving on secondary treatment cost. No pretreatment like sedimentation was required for the influent to the BFBR. The BFBR can produce low turbidity effluent as in the activated sludge process (ASP). The land area required for the BFBR treatment plant is less when compared to ASP plant. Hence the problem of scarcity of land for the treatment plant is reduced. The total expenditure for erecting the unit was less than 50% as that of conventional ASP for the same COD removal efficiency including land cost.


2013 ◽  
Vol 67 (11) ◽  
pp. 2549-2559 ◽  
Author(s):  
S. Wang ◽  
J. Hovland ◽  
R. Bakke

The anaerobic biodegradation of reclaimer MEA (monoethanolamine) waste (MEAw) with easily degradable co-substrates was investigated in a laboratory-scale bioreactor at room temperature during a 160 d experimental run. The reactor that was constructed with three phases to facilitate attached biofilm and suspended biomass retention for degradation of the complex and challenging MEAw performed well. A feed strategy of step-wise increasing organic loading rate (OLR) by either increasing feed MEAw concentration or the hydraulic loading rate was applied. The system performance was evaluated by chemical oxygen demand (COD) removal efficiency, methane yield, MEA removal, and the accumulation of ammonia and volatile fatty acid (VFA). The total COD removal efficiency initially was 93% when the feed was mainly easily degradable co-substrate. The total removal dropped to 75% at the end when MEAw constituted 60% of the feed COD. Ion chromatography results show that the MEA and some unidentified feed chemicals were almost completely consumed. The main products of MEAw degradation were ammonia, VFAs and biogas. The ammonia nitrogen concentration reached about 2.0 g/L, which may explain the observed inhibition of acetoclastic methanogenesis leading to acetate accumulation. Methane accounted for up to 80% of the biogas generated. The highest methane yield was 0.34 L/g-COD while the yield was 0.16 L/g-COD at the highest load. This study shows that more than 80% reclaimer MEAw COD degradation with a co-substrate can be maintained in a hybrid anaerobic bioreactor operated in a wide loading range.


2019 ◽  
Vol 14 (3) ◽  
pp. 507-514 ◽  
Author(s):  
Y. Williams ◽  
M. Basitere ◽  
S. K. O. Ntwampe ◽  
M. Ngongang ◽  
M. Njoya ◽  
...  

Abstract The poultry slaughterhouse industry consumes a large volume of potable water for bird processing and equipment cleaning, which culminates in the generation of high strength poultry slaughterhouse wastewater (PSW). The wastewater contains high concentrations of organic matter, suspended solids, nitrogen and nutrients. Most poultry slaughterhouses in South Africa (SA) discharge their wastewater into the municipal sewer system after primary treatment. Due to its high strength, PSW does not meet SA's industrial discharge standards. Discharge of untreated PSW to the environment raises environmental health concerns due to pollution of local rivers and fresh water sources, leading to odour generation and the spread of diseases. Thus, the development of a suitable wastewater treatment process for safe PSW discharge to the environment is a necessity. In this study, a biological PSW treatment process using an Expanded Granular Sludge Bed (EGSB) was evaluated. Response surface methodology coupled with central composite design was used to optimize the performance of the EGSB reactor. The dependant variable used for optimization was chemical oxygen demand (COD) removal as a function of two independent variables, hydraulic retention time (HRT) and organic loading rate (OLR). The interactions between HRT, OLR and COD removal were analysed, and a two factorial (2FI) regression was determined as suitable for COD removal modelling. The optimum COD removal of 93% was achieved at an OLR of 2 g-COD/L/d and HRT of 4.8 days. The model correlation coefficient (R2) of 0.980 indicates that it is a good fit and is suitable for predicting the EGSB's COD removal efficiency.


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