The Temperature-Phased Anaerobic Biofilter Process

1994 ◽  
Vol 29 (9) ◽  
pp. 213-223 ◽  
Author(s):  
Sandra K. Kaiser ◽  
Richard R. Dague
Keyword(s):  
System Performance ◽  
Anaerobic Treatment ◽  
Size Ratio ◽  
High Rate ◽  
Phase System ◽  
Optimum Size ◽  
Treatment Technology ◽  
Two Phase ◽  
In Series ◽  
Two Temperature

The “temperature-phased anaerobic biofilter” or TPAB process (U.S. Patent pending), is a new high-rate anaerobic treatment system that includes a thermophilic (56°C) biofilter connected in series with a mesophilic (35°C) biofilter providing for two-temperature, two-phase treatment. Three TPAB systems of different thermophilic:mesophilic reactor size ratios were operated at system HRTs of 24 hrs, 36 hrs, and 48 hrs to characterize performance and to determine if an optimum size ratio exists between the thermophilic and mesophilic phases. The three TPAB systems achieved SCOD reductions in excess of 97% and TCOD reductions in excess of 90% for a synthetic milk substrate over a range of system COD loadings from 2 g COD/L/day to 16 g COD/L/day. There was little difference in performance between the three TPAB systems based on COD reduction and methane production. The 1:7 ratio of thermophilic:mesophilic phase TPAB system performed as well as the 1:3 and 1:1 size ratio TPAB systems. In applications of the process, a relatively small thermophilic first-phase can be used without sacrificing overall two-phase system performance. The TPAB process is a promising new anaerobic treatment technology with the ability to achieve higher efficiencies of organic removals than is generally possible for single-stage anaerobic filter systems operated at equivalent HRTs and organic loadings.

On the Problem of “Two-Phase” Activated Sludge

1991 ◽  
Vol 24 (7) ◽  
pp. 59-64 ◽  
Author(s):  
R. W. Szetela
Keyword(s):  
Activated Sludge ◽  
Single Phase ◽  
Phase System ◽  
Two Phase ◽  
Wastewater Treatment Process ◽  
Sludge Stabilization ◽  
Technological Advantage ◽  
In Series ◽  
State Models ◽  
Activated Sludge Systems

Steady-state models are presented to describe the wastewater treatment process in two activated sludge systems. One of these makes use of a single complete-mix reactor; the other one involves two complete-mix reactors arranged in series. The in-series system is equivalent to what is known as the “two-phase” activated sludge, a concept which is now being launched throughout Poland in conjunction with the PROMLECZ technology under implementation. Analysis of the mathematical models has revealed the following: (1) treatment efficiency, excess sludge production, energy consumption, and the degree of sludge stabilization are identical in the two systems; (2) there exists a technological equivalence of “two-phase” sludge with “single-phase” sludge; (3) the “two-phase” system has no technological advantage over the “single-phase” system.

Two-phase anaerobic treatment of cane-molasses alcohol stillage

1997 ◽  
Vol 36 (6-7) ◽  
pp. 441-448 ◽  
Author(s):  
B. G. Yeoh
Keyword(s):  
Single Phase ◽  
Anaerobic Treatment ◽  
Methane Yield ◽  
Phase System ◽  
Treatment Efficiency ◽  
Two Phase ◽  
Kinetic Evaluation ◽  
Cane Molasses ◽  
Loading Rates ◽  
Phase Process

Anaerobic treatment of cane-molasses alcohol stillage was studied in a thermophilic two-phase system comprising two bioreactors for the acidogenic and methanogenic phases respectively in comparison with the single-phase process. The experiments were conducted with HRT ranging from 36.0 to 9.0 days for single-phase and from 32.7 to 5.6 days for two-phase, corresponding to organic loading rates of 3.452 to 14.487 and 4.646 to 20.022 kgCODm−3day−1 respectively. The treatment efficiency was essentially maintained at BOD5 and COD removal of over 85% and 65% respectively in the two-phase process even with higher substrate loading. The acidogenic phase provided satisfactory conversion of initial COD to VFA averaging 15.6% in the degree of acidification. The methanogenic culture pH of both systems was maintained in a range of 7.4 to 7.8 through self regulation. The methane content of the biogas generated from the two-phase process was significantly higher by about 17% than that from the single-phase process, both decreasing with increasing substrate loading and shorter HRT. The mean overall methane yield was found to be 0.168 m3CH4(STP)kg−1 CODadded or 0.292 m3CH4(STP)kg−1 VSadded from two-phase methanogenesis, compared to 0.055 m3CH4(STP)kg−1CODadded or 0.082 m3CH4(STP)kg−1VSadded from single-phase fermentation. However, methane yield in the two-phase process was enhanced only at COD loading rates higher than 2.9 kgm−3day−1 or VS loading rates higher than 1.8 kgm−3day−1. The ultimate methane yield was evaluated graphically to be 0.216 m3CH4(STP)kg−1CODadded, or 0.401 m3CH4(STP)kg−1 VSadded. This indicated a methane yield efficiency of 73-78% for the two-phase anaerobic digestion of cane-molasses alcohol stillage, which was composed of 24.2% and 28.2% of non-biodegradable COD and VS respectively. Kinetic evaluation of the experimental data provided θm (minumum SRT) and K (kinetic constant) values as 6.6 days and 0.166 respectively based on COD, or 7.0 days and 0.160 respectively based on VS. Application of the two-phase anaerobic process on full scale at an industrial treatment plant for alcohol stillage showed mean treatment efficiency in terms of BOD5 and COD reduction of 84.3% and 63.2% respectively at an average loading rate of 5.1 kgCODm−3day−1, which was in good agreement with the bench-scale studies, considering the great variation in the raw wastewater characteristics typical of an industrial operation.

scholarly journals High-Rate Anaerobic Treatment of Wastewater at Low Temperatures

1999 ◽  
Vol 65 (4) ◽  
pp. 1696-1702 ◽  
Author(s):  
Gatze Lettinga ◽  
Salih Rebac ◽  
Sofia Parshina ◽  
Alla Nozhevnikova ◽  
Jules B. van Lier ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Degradation Rates ◽  
In Series ◽  
Propionate Oxidation ◽  
Stage System ◽  
Specific Degradation

ABSTRACT Anaerobic treatment of a volatile fatty acid (VFA) mixture was investigated under psychrophilic (3 to 8°C) conditions in two laboratory-scale expanded granular sludge bed reactor stages in series. The reactor system was seeded with mesophilic methanogenic granular sludge and fed with a mixture of VFAs. Good removal of fatty acids was achieved in the two-stage system. Relative high levels of propionate were present in the effluent of the first stage, but propionate was efficiently removed in the second stage, where a low hydrogen partial pressure and a low acetate concentration were advantageous for propionate oxidation. The specific VFA-degrading activities of the sludge in each of the modules doubled during system operation for 150 days, indicating a good enrichment of methanogens and proton-reducing acetogenic bacteria at such low temperatures. The specific degradation rates of butyrate, propionate, and the VFA mixture amounted to 0.139, 0.110, and 0.214 g of chemical oxygen demand g of volatile suspended solids−1 day−1, respectively. The biomass which was obtained after 1.5 years still had a temperature optimum of between 30 and 40°C.

Treatment of textile dyes in two-phase and single-phase anaerobic bio-treatment systems

2008 ◽  
Vol 57 (6) ◽  
pp. 863-868 ◽  
Author(s):  
D. Bhattacharyya ◽  
K. S. Singh
Keyword(s):  
Single Phase ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Phase System ◽  
Two Phase ◽  
Anaerobic Reactors ◽  
Anaerobic Sludge Blanket

This research integrates two different concepts of anaerobic biotechnology- two-phase anaerobic treatment and anaerobic granular sludge bed technology, in treatment of colored wastewaters from textile industries. Four anaerobic reactors based on upflow anaerobic sludge blanket (UASB) technology were used as acid reactors and an expanded granular sludge bed (EGSB) reactor was used as a methane reactor. A conventional single-phase anaerobic reactor, working on EGSB technology was run in parallel to compare the performances of the two systems. Reactors were operated at different hydraulic retention times. The results from the study, which span over a period of 400 days, indicated that the two-phase system produces a higher quality of effluent in terms of color, COD and suspended solids than single-phase anaerobic treatment when operated under similar conditions. Alkalinity requirement of two-phase system was also observed to be lower than that of single-phase system which is important regarding design consideration.

Development of a two phase anaerobic digester for the treatment of mixed abattoir wastes

1999 ◽  
Vol 40 (1) ◽  
pp. 69-76 ◽  
Author(s):  
C. J. Banks ◽  
Z. Wang
Keyword(s):  
Anaerobic Digestion ◽  
Retention Time ◽  
High Rate ◽  
Phase System ◽  
Second Phase ◽  
Two Phase ◽  
Single Pass ◽  
Liquid Retention ◽  
Solids Retention ◽  
Overall Performance

A two phase anaerobic digestion system was developed for the treatment of mixed abattoir wastes composed of mixtures of cattle blood and cattle gut fill (rumen paunch contents). The reactor system, and its mode of operation, overcame the problems associated with a single pass anaerobic digestion process by alleviating toxicity problems associated with the accumulation of volatile fermentation intermediates and high ammonia concentrations. The principle of operation of the two phase system was to separate the hydrolysis reactions from those of methanogenesis and, by introducing a hydraulic flush regime, to prevent accumulation of intermediate products in the first phase of the process. The hydraulic flush operates in such a manner whereby the liquid retention time in the first reactor was significantly shorter than the solids retention of the fibrous components of the feedstock. The first phase reactor was run in this mode using solids retention times of 5, 10, 15, 20 and 30 days with a liquid retention time of 2 days. Up to 87% solids reductions were achieved compared to a maximum 50% when control reactors were operated in a single pass mode with solids and liquid retention times of equal duration. The performance of the first phase hydrolysis reactor was also monitored in terms of volatile fatty acid production, COD removal efficiency and ammonia accumulation potential. The liquefied effluent from the hydraulic flush reactor was found to be a suitable substrate for a second phase high rate methanogenic reactor operated over a range of retention times of between 2 - 10 days; this gave equivalent process loadings of 1.4 - 7.0 kg COD/m3/day. Methane conversion efficiencies of around 0.3 m3 CH4/kg COD removed were achieved. By use of the two phase system it was possible to operate at a loading to the first phase of 7.22 kgTS/m3/day with a resultant effluent from the second phase with a COD of 4270 mgl−1. The overall performance of the system showed a process loading of 3.6 kgTS/m3/day was achievable with a methane production rate of 0.27 m3CH4/kgTS added and 63% TS destruction. The results suggest that further optimisation of the two phases might further improve this overall performance.

Dynamic Model Simulation and Verification of a Two-Stage High-Rate Anaerobic Treatment Process with Recycle

1993 ◽  
Vol 28 (11-12) ◽  
pp. 197-207 ◽  
Author(s):  
J. Keller ◽  
M. Romli ◽  
P. L. Lee ◽  
P. F. Greenfield
Keyword(s):  
Sodium Hydroxide ◽  
Flow Rate ◽  
Gas Flow ◽  
Model Simulation ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Continuous Reactor ◽  
Feed Concentration ◽  
Two Phase ◽  
Significant Discrepancy

The effect of overload on a two-phase high rate anaerobic wastewater treatment system with recycle was determined experimentally and simulated dynamically using a structured model. The experimental system consisted of a well mixed continuous reactor, controlled at pH 6 by sodium hydroxide addition, as the acidification stage and a fluidized bed reactor for the methanogenic stage, with an additional recycle connection from the second to the first reactor. Step changes in the feed concentration as well as in the feed flow rate were investigated and compared to simulation predictions. Operation without recycle was modelled accurately, with the simulation data of most process variables matching the experimental results quantitatively. The application of the same model to recycle operation showed significant discrepancy between the experimental and simulated data for the sodium hydroxide consumption rate and the gas flow rate in the acidification reactor. Although the actual values were different, the qualitative responses of the experimental and simulated step changes were similar. Other simulated variables showed good agreement with the experimental measurements. The model provides a useful tool for design and control studies in systems without recycle and, with some modification, for operation with recycle.

High-rate anaerobic treatment of purified terephthalic acid wastewater

2000 ◽  
Vol 42 (5-6) ◽  
pp. 259-268 ◽  
Author(s):  
R. Kleerebezem ◽  
G. Lettinga
Keyword(s):  
Terephthalic Acid ◽  
Ph Control ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Waste Stream ◽  
Gradual Transition ◽  
Organic Substrates ◽  
Start Up ◽  
In Series ◽  
Purified Terephthalic Acid

During production of purified terephthalic acid (PTA) a concentrated waste stream is generated, containing both readily (acetate and benzoate) and slowly (terephthalate and para-toluate) degradable organic substrates. Based on our experimental experiences with the anaerobic treatment of this waste stream, this paper presents an optimized concept for start-up and operation of a two-stage anaerobic bioreactor system. Based on considerations concerning the optimal conditions for cultivation of the specific types of biomass degrading the different substrates, and considerations concerning sodium-hydroxide requirements for pH-control, a gradual transition between initial operation in parallel to operation in series is suggested.

Pond Treatment of Rettery Wastewaters

1987 ◽  
Vol 19 (12) ◽  
pp. 79-83
Author(s):  
K. Bartoszewski ◽  
A. Bilyk
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
New Technology ◽  
Treatment Plant ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Experimental Results ◽  
Aerobic Conditions ◽  
Aerobic Stabilization ◽  
In Series

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.

Taking an Emerging Enhanced High-Rate Treatment Technology from Concept to 100-mgd Reality

2015 ◽  
Vol 2015 (16) ◽  
pp. 1681-1695
Author(s):  
J Fitzpatrick ◽  
J Champion ◽  
J Hutchins ◽  
S McCreary ◽  
C. R O’Bryan ◽  
...  
Keyword(s):  
High Rate ◽  
Treatment Technology
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