Anaerobic treatment of partly acidified wastewater in a two-stage expanded granular sludge bed (EGSB) system at 8°C

1997 ◽  
Vol 36 (6-7) ◽  
pp. 317-324 ◽  
Author(s):  
Jules B. van Lier ◽  
Salih Rebac ◽  
Piet Lens ◽  
Friso van Bijnen ◽  
Stefanie J. W. H. Oude Elferink ◽  
...  
Keyword(s):  
Specific Activity ◽  
Blot Hybridization ◽  
Effective Diffusion ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Two Stage ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Second Stage ◽  
Sucrose Loading

Psychrophilic (8 °C) anaerobic treatment of partly acidified waste water was investigated using a two stage EGSB system with a total volume of 8.6 dm3. The reactor system was operated at an up-flow velocity of 10 m·h−1 and was fed with a sucrose-VFA mixture of 550–1100 mg COD dm−3. The average CODsol and VFA-COD removal efficiencies were 97 and 90 %, respectively, at total organic loading rates (OLR) ranging between 5.1–6.7 g COD dm−3·day−1, sucrose loading rates up to 1 g COD dm−3 day−1 and a hydraulic retention time (HRT) of 4 h. An increase in the sucrose loading rates resulted in a significant wash-out of biomass from the first stage. The second stage satisfactory served as a scavenger of non-degraded VFA from the first stage. Specific activity assays showed an increase of 15 % in the specific methanogenic activity of the sludge present in the second stage and a decrease of 9 % in the first stage. Apparently, an enrichment of methanogens and acetogens in the anaerobic sludge in the second stage took place at temperatures as low as 8°C. The acidogenic population became much more dominant in the first stage, resulting in a higher acidifying activity and a decreased methanogenic activity. 16S rRNA probe-techniques (dot blot hybridization) showed that the acetate consuming Methanosaeta (formerly Methanothrix) and the hydrogenotrophic Methanobrevibacter species (or relatives) were the most abundant methanogens present in the psychrophilic sludge. The ratio between bacterial and methanobacterial hybridization signal of the first stage was 3 times higher than that of the second stage. By using NMR techniques, a higher effective diffusion coefficient was found for the smaller sized granules in both reactors, which is in congruent with the higher maximum specific acetate degrading activity of the smaller granules.

Inhibition of methanogenic activity of starch-degrading granules by aromatic pollutants

1997 ◽  
Vol 35 (8) ◽  
pp. 247-253 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau ◽  
Denis W. C. Chung
Keyword(s):  
Chemical Industry ◽  
Functional Group ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Aromatic Pollutants ◽  
Methanogenic Activity ◽  
Phenolic Pollutants ◽  
Ic50 Values

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols > phenol > hydroxyphenols/phthalate > benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.

Anaerobic treatment of proteinaceous wastewater under mesophilic and thermophilic conditions

1999 ◽  
Vol 40 (1) ◽  
pp. 77-84 ◽  
Author(s):  
H. H. P. Fang ◽  
D. Wai-Chung Chung
Keyword(s):  
Bacterial Species ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Batch Tests ◽  
Thermophilic Conditions ◽  
Anaerobic Sludge Blanket ◽  
Hydrolysis Of

Experiments were conducted in two 2.8 liter UASB (upflow anaerobic sludge blanket) reactors treating proteinaceous wastewaters at 37° and 55°C with 9 hours of hydraulic retention. Results showed that the mesophilic reactor consistently removed 83.5-85.1% of COD (chemical oxygen demand) at loading rates ranging 8-22 g COD l−1 d−1 (corresponding to 3000-8250 mg l−1 of proteinaceous COD in wastewater), whereas the thermophilic reactor removed only 68.5-82.7%. At 32 g COD l−1 d−1 (i.e. 12000 mg COD l−1), the removal efficiencies were lowered to 75.7% in the mesophilic reactor and 65.1% in the thermophilic reactor. At 42 g COD l−1 d−1, severe sludge washout occurred in the mesophilic reactor; at the same loading rate, the thermophilic reactor removed only 53.8% of COD even though sludge washout was under control. The degradation rate in the both reactors was limited by the initial hydrolysis of proteins. However, batch tests showed that thermophilic sludge had slightly higher methanogenic activities than mesophilic sludge in treating proteins and intermediate acids, except propionate. The sludge yields in mesophilic and thermophilic reactors were 0.066 and 0.099 g VSS g COD−1, respectively. Observations by scanning electron microscopy indicated that both types of sludge granules were of irregular shape. There was little noticeable difference between the two granules; both had neither a layered microstructure nor a predominant bacterial species.

Potato Processing Wastewater Treatment at Relatively High Loading Rates Using a Unified Anaerobic Fermenter-Filter

1982 ◽  
Vol 17 (1) ◽  
pp. 63-74 ◽  
Author(s):  
R.C. Landine ◽  
G.J. Brown ◽  
A.A. Cocci ◽  
T. Viraraghavan
Keyword(s):  
Wastewater Treatment ◽  
Room Temperature ◽  
Anaerobic Treatment ◽  
Basic Design ◽  
Potato Processing ◽  
Two Stage ◽  
Filter System ◽  
Loading Rates ◽  
Laboratory Bench ◽  
Scale Design

Abstract A laboratory bench-scale study using a unified anaerobic fermenter-filter system (referred to as a BVF-HAF system) was conducted at room temperature over an 8 month period on potato processing wastewater for the purpose of verifying a proposed full-scale design concept. In addition to two-stage anaerobic treatment, the first stage anaerobic effluent (BVF effluent) was subjected to aerobic polishing in a simulated facultative aerated lagoon with a retention of 4 days. The basic design conditions entailed treatment of a clarified potato wastewater with a COD of 7600 mg/L and a retention of 4 d in the BVF (loading 1.71 kg/m3.d). After over-coming an upset condition believed due to toxicity of the vacuum filtrate feed, the model performed well achieving 78.9% COD removal in the BVF plus 5 3.4% in the HAF for a combined total of 90.2%. When the BVF effluent was aerated the combined BVF - aerated lagoon removal reached 94.8%.

Anaerobic treatment of concentrated latex processing wastewater in two-stage upflow anaerobic sludge blanketA paper submitted to the Journal of Environmental Engineering and Science.

2010 ◽  
Vol 37 (5) ◽  
pp. 805-813 ◽  
Author(s):  
Siriuma Jawjit ◽  
Winai Liengcharernsit
Keyword(s):  
Industrial Effluent ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Optimal Conditions ◽  
Two Stage ◽  
Oxidation Pond ◽  
Treatment Performance ◽  
Anaerobic Sludge Blanket

This study aims to investigate treatment performance of the two-stage upflow anaerobic sludge blanket (UASB) applied to concentrated latex processing wastewater in Thailand. First, optimal conditions including the hydraulic retention time (HRT) in the acid tank and the UASB tank, pH, and temperature (mesophilic and thermophilic) were determined. It was found that the HRT at 24 h and 48 h were the optimal HRT for the acid tank and the UASB tank, respectively. The pH of the system should be controlled at 7 to prevent rubber coagulation and to achieve high treatment performance, and the mesophilic condition (35°C) was found to be the optimal temperature. Second, the two-stage UASB was applied with the optimal conditions mentioned earlier with real wastewater at a latex mill. It was found that methane production was about 0.116 L CH4/g COD removed (16.3–22.8 m3CH4/d), and average chemical oxygen demand (COD) and suspended solids (SS) removal efficiency were about 82% and 92%, respectively. In case of SS removal, the results revealed that the two-stage UASB was capable of overcoming the limitations of the single-stage UASB in treating concentrated latex effluent. The results indicated that application of the two-stage UASB to concentrated latex processing wastewater is feasible. Nevertheless, combination with other treatment systems (e.g., oxidation pond, aerated lagoon) is necessary to meet Thailand's industrial effluent standards (in the case of COD).

Anaerobic Treatment of Slaughterhouse Wastewater in an Expanded Granular Sludge Bed (EGSB) Reactor

1999 ◽  
Vol 40 (8) ◽  
pp. 99-106 ◽  
Author(s):  
L. A. Núñez ◽  
B. Martínez
Keyword(s):  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Slaughterhouse Wastewater ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Feasible Option ◽  
One Year ◽  
Sludge Activity

The performance of an Expanded Granular Sludge Bed (EGSB) reactor for treating slaughterhouse wastewater under mesophilic conditions (35°C), was investigated. The reactor was inoculated with granular sludge from an anaerobic reactor of a brewery factory. The averaged COD removal percentages were 67% for total organic loading rates (BV.TCOD) up to 15 kg COD m−3 d−1 and a hydraulic retention time (HRT) of 5 h. Total suspended solids (TSS) were 90% removed for total solids loads of 6 kg TSS m−3 d−1. Fats were 85% removed and no accumulation of fats on the sludge was observed. The specific methanogenic activity of the sludge, after 140 days, was about three times higher than the sludge inoculated into the reactor. The sludge activity did not significantly change after one year of work. These findings indicate that the anaerobic treatment of slaughterhouse wastewater in an EGSB system appears to be a feasible option.

Start-Up Strategy to Achieve Excellent Efficiency of Degradation Acetate,Ethanol and Propionate in UASB

2011 ◽  
Vol 71-78 ◽  
pp. 2103-2106
Author(s):  
Ming Yue Zheng ◽  
Ming Xia Zheng ◽  
Kai Jun Wang ◽  
Hai Yan
Keyword(s):  
Loading Rate ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Metabolic Intermediate ◽  
Loading Rates ◽  
Start Up ◽  
Anaerobic Sludge Blanket

The performance of upflow anaerobic sludge blanket (UASB) fed with three metabolic intermediate (acetate, ethanol, and propionate) respectively was studied. The degradation of metabolic intermediate were investigated to discuss the reason for propionate inhibition problem in anaerobic treatment. The hydraulic retention time (HRT) in the reactors started with 8.0h.The yield rate of biogas were 237ml/gCOD, 242ml/gCOD, 218ml/gCOD for acetate, ethanol and propionate, respectively when finishing start-up under OLR of 5.0 kgCOD/(m3·d) (HRT=9.6h).The HRT remained constant 9.6h,and the substrate concentration was gradually increased from 1,000 to 16,000mg/L as COD,and the organic loading rates(OLR) was from 3.0 to 40.0 kgCOD/(m3·d).The maximum propionate concentration was 41.6 gHPr-COD/L at the organic loading rate of 43.9 kgCOD/(m3·d) (HRT, 9.6h) as well as acetate and ethanol.

DEGRADATION OF STARCH PARTICULATES IN A HYBRID REACTOR

1994 ◽  
Vol 30 (4) ◽  
pp. 97-104 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Tin-Sang Kwong
Keyword(s):  
Loading Rate ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Hybrid Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Granular Biomass ◽  
Abundant Supply ◽  
Anaerobic Sludge Blanket

The study was conducted over 265 days to study the feasibility of removing starch particulates from wastewater using an 8.5 L reactor which was a hybrid between the upflow anaerobic sludge blanket (UASB) and the anaerobic filter reactors. At pH 7.2-7.5 and 37°C, the reactor was effective for the removal of chemical oxygen demand (COD) from wastewater containing starch particulates equivalent to 5000 mglL of COD with 12 hours of retention time, corresponding to a loading rate of 10 g-COD/L.d. Despite their insoluble nature, the starch particulates did not cause noticeable adverse effeels on the granulation of biomass, probably due to its easy-to-biodegrade nature and the cautious startup strategy. About 5.8% of COD in wastewater remained in the effluent, 82.5% was converted to methane, and the remaining 11.7% was converted to granular biomass with an average sludge yield of 0.09 g-VSS/g-COD. The granules exhibited a layered microstructure. The methanogenic activity of the granular biomass was 0.86 g-methane-COD/g-VSS.d in the reactor, which was considerably lower than the 1.96 g-methane-COD/ g-VSS.d measured in serum vials with an abundant supply of substrate, suggesting that further increase of loading rates was possible for the hybrid reactor.

The anaerobic treatment of low strength wastewaters in UASB and EGSB reactors

1997 ◽  
Vol 36 (6-7) ◽  
pp. 375-382 ◽  
Author(s):  
Mario T. Kato ◽  
Jim A. Field ◽  
Gatze Lettinga
Keyword(s):  
Detrimental Effect ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Organic Loading ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Treatment Performance ◽  
The Media ◽  
Low Strength ◽  
Uasb Reactors

The application of the UASB and EGSB reactors for the treatment of low strength wastewaters was investigated. The effect of dissolved oxygen on the methanogenic activity of granular sludges, the low substrate levels inside reactors and lower temperatures on the treatment performance were evaluated. The results showed that methanogens located in granular sludge have a high tolerance to oxygen. The concentration to cause 50% inhibition to methanogenic activity was between 7% and 41% oxygen in the head space of flasks, corresponding to 0.05 mg/l and 6 mg/l of DO prevailing in the media, respectively. The feasibility of UASB and EGSB reactors at 30°C was demonstrated. In UASB reactors, COD removal efficiencies exceeded 95% at organic loading rates up to 6.8 g COD/l.d and influent COD concentrations ranging from 422 to 722 mg/l, during the treatment of ethanol substrate. In EGSB reactors, efficiencies were above 80% at OLRs up to 12 g COD/l.d with COD as low as 100 to 200 mg/l. The studies confirmed that in practice DO does not constitute any detrimental effect on the reactor treatment performance. Lowering the temperature down to 15°C in EGSB reactors also showed that the potentials of anaerobic technology can be further explored in the treatment of dilute wastewaters.

scholarly journals Two- vs. single-stage anaerobic reactors: evaluation of effluent quality and energy production potential using sucrose-based wastewater

2018 ◽  
Vol 78 (9) ◽  
pp. 1966-1979 ◽  
Author(s):  
V. T. Mota ◽  
M. Zaiat
Keyword(s):  
Suspended Solids ◽  
Fixed Bed ◽  
Anaerobic Treatment ◽  
Single Stage ◽  
Upflow Anaerobic Sludge Blanket ◽  
Superior Performance ◽  
Anaerobic Sludge ◽  
Energy Yield ◽  
Two Stage ◽  
Stage System

Abstract Two- and single-stage anaerobic treatment systems were assessed for treatment performance and for bioenergy production from sucrose-based wastewater. In the two-stage system, a hydrogen-producing upflow anaerobic sludge blanket reactor (HU reactor) was used in the acidogenic phase. The methanogenic reactor of the two-stage system (MF reactor) and the single-stage reactor (SSF reactor) were structured fixed-bed reactors. The two-stage system showed superior performance, evidenced by lower organic acids, chemical oxygen demand (COD) and suspended solids concentrations in the effluent, and higher biogas methane content and yield. Continuous and stable H2 production was obtained in the acidogenic reactor. At the end of operation, the organic loading rates applied to the two- and single-stage systems were 6.4 and 5.2 gCOD L−1 d−1, respectively. Under these conditions, the effluent soluble COD and volatile suspended solids (VSS) concentrations were 165 and 92 mg L−1 in the two-stage system, and 256 and 244 mg L−1 in the single-stage system, respectively. The energy yield of the two-stage system was 20.69 kJ g−1CODadded, which was 34% higher than the yield of the single-stage system. The sequencing analyses showed that the archaeal distribution changed little between the inoculum and sludge from the MF reactor, in which acetoclastic Methanosaeta was predominant. However, hydrogenotrophic Methanospirillum was found most, followed by Methanosaeta, in the sludge from the SSF reactor.

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