Physicochemical and Microbial Monitoring of UASB Sludge during Start-Up of Mesophilic Reactor

2005 ◽  
Vol 277-279 ◽  
pp. 552-558
Author(s):  
Yeong Hee Ahn ◽  
Young Jin Song ◽  
Hyo Seob Kim ◽  
You Jin Lee ◽  
Sung Hoon Park
Keyword(s):  
Production Rate ◽  
Removal Efficiency ◽  
Methane Production ◽  
Cod Removal ◽  
Laser Scanning Microscopy ◽  
Volume Index ◽  
Maximum Value ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
Methane Production Rate

Anaerobically digested sludge was seeded in a mesophilic UASB reactor and the sludge was monitored for seven months to better understand the start-up process of the reactor. The reactor was fed with synthetic wastewater containing glucose. As the COD loading rate increased stepwise (from 1 to 4 g COD l-1 d-1), the methane production rate increased. COD removal efficiency was maintained to be greater than 90% after day 36. Maximum value of the methane production rate (6.0-6.5 l d-1) was achieved from day 152 and remained stable afterward. Although the reactor showed steady performance in terms of COD removal efficiency and methane production under constant hydraulic retention time (HRT) or COD loading rates, physicochemical and microbial properties of UASB sludge kept changing during the initial 5 months of operation. Specific methanogenic activity was initially negligible but increased until day 150, and then remained constant (0.72 + 0.11 g CH4-COD g-1 VSS d-1) afterward. Sludge volume index showed that the settling ability of UASB sludge gradually improved until it reached a plateau in day 120. Improved settling-ability could provide a basis for keeping bed height constant despite shortened HRT. The mean diameter of the UASB sludge gradually increased until approximately day 150 and maintained a maximum value (0.48 mm) afterward. Confocal laser scanning microscopy revealed F420-based autofluorescence of physical and optical sections of UASB sludge, suggesting the locations of autofluorescent methanogens in the UASB sludge during the start-up period. During the initial operation of the reactor, autofluorescence showed random and uneven distribution inside the sludge. However, autofluorescence appeared as an inner layer near the edge of the sludge with time, suggesting more abundant or active methanogens in this layer. The highest autofluorescence was observed in the range of 20 to 28 µm depth from the surface of granule as determined by optical slicing of UASB sludge. The results obtained in this study provide insight into UASB sludge development that involves dynamic changes in physicochemical and microbial aspects during the start-up period.

Phenolic refinery wastewater biodegradation by an expanded granular sludge bed reactor

2005 ◽  
Vol 52 (1-2) ◽  
pp. 391-396 ◽  
Author(s):  
F.J. Almendariz ◽  
M. Meraz ◽  
A.D. Olmos ◽  
O. Monroy
Keyword(s):  
Toxic Effect ◽  
Removal Efficiency ◽  
Methane Production ◽  
Granular Sludge ◽  
Cod Removal ◽  
Organic Load ◽  
Refinery Wastewater ◽  
Mineral Supplements ◽  
Cod Removal Efficiency

Refinery spent caustics (SC) were diluted with sour waters (SW) in a ratio 1:7, neutralized with CO2 (SC/SWCO2) and 83% of H2S was striped during this procedure, remaining an aromatic portion that contained 2123, 2730 and 1379 mg L−1 of phenol, p-cresol and o-cresol, respectively. The mixture was treated anaerobically in an EGSB reactor fed with 1.5 gCOD L−1 d−1, without mineral supplements causing loss of COD removal efficiency that dropped to 23%, methane production ceased and no phenol or cresols were biodegraded. The EGSB experiments were resumed by feeding the reactor with nutrients and phenol at 1.0 gCOD L−1 d−1. The mixture SC/SWCO2 added to the phenol load, was step increased from 0.10 to 0.87 gCOD L−1 d−1 maximum. When total organic load was increased to 1.6, COD removal efficiency was 90% and at the highest load attained, 1.87, efficiency dropped to 23% attributed to the toxic effect produced by cresols.

scholarly journals Treatment of sago mill effluent for methane production using anaerobic sequencing batch reactor (ASBR)

2018 ◽  
Vol 2 (1) ◽  
pp. 18-22
Author(s):  
Rafiqqah Mohamad Sabri ◽  
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Cod Removal ◽  
Production Yield ◽  
Anaerobic Sequencing Batch Reactor ◽  
Methane Production Rate

In this research, sago mill effluent was treated using anaerobic sequencing batch reactor (ASBR). Seven HRT from 10 to 1.5 days were tested to evaluate the methane production from sago mill effluent. The findings revealed the highest methane production rate was found at 1.288 L CH4/L reactor. d under HRT of 2 days The results showed that COD removals decreased from 70% to 47% as HRT was reduced from 10 to 2 days. The HRT 1.5 days was found critical for the studied system, which leads to decreased in methane production, yield and COD removal. Overall, ASBR was capable to treat sago mill effluent in producing methane by means of anaerobic digestion.

Anaerobic Fluidized-Bed Treatment of Brewery Wastes and Bioenergy Recovery

1989 ◽  
Vol 21 (12) ◽  
pp. 1681-1684 ◽  
Author(s):  
I. Ozturk ◽  
G. K. Anderson ◽  
C. B. Saw
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Utilization Rate ◽  
Specific Substrate ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
Specific Substrate Utilization Rate ◽  
Brewery Wastes

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.

scholarly journals Bioaugmentation as a Tool To Protect the Structure and Function of an Activated-Sludge Microbial Community against a 3-Chloroaniline Shock Load

2003 ◽  
Vol 69 (3) ◽  
pp. 1511-1520 ◽  
Author(s):  
Nico Boon ◽  
Eva M. Top ◽  
Willy Verstraete ◽  
Steven D. Siciliano
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Real Time ◽  
Removal Efficiency ◽  
Real Time Pcr ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Cod Removal ◽  
Shock Load ◽  
Volume Index ◽  
Cod Removal Efficiency

ABSTRACT Bioaugmentation of bioreactors focuses on the removal of xenobiotics, with little attention typically paid to the recovery of disrupted reactor functions such as ammonium-nitrogen removal. Chloroanilines are widely used in industry as a precursor to a variety of products and are occasionally released into wastewater streams. This work evaluated the effects on activated-sludge reactor functions of a 3-chloroaniline (3-CA) pulse and bioaugmentation by inoculation with the 3-CA-degrading strain Comamonas testosteroni I2 gfp. Changes in functions such as nitrification, carbon removal, and sludge compaction were studied in relation to the sludge community structure, in particular the nitrifying populations. Denaturing gradient gel electrophoresis (DGGE), real-time PCR, and fluorescent in situ hybridization (FISH) were used to characterize and enumerate the ammonia-oxidizing microbial community immediately after a 3-CA shock load. Two days after the 3-CA shock, ammonium accumulated, and the nitrification activity did not recover over a 12-day period in the nonbioaugmented reactors. In contrast, nitrification in the bioaugmented reactor started to recover on day 4. The DGGE patterns and the FISH and real-time PCR data showed that the ammonia-oxidizing microbial community of the bioaugmented reactor recovered in structure, activity, and abundance, while the number of ribosomes of the ammonia oxidizers in the nonbioaugmented reactor decreased drastically and the community composition changed and did not recover. The settleability of the activated sludge was negatively influenced by the 3-CA addition, with the sludge volume index increasing by a factor of 2.3. Two days after the 3-CA shock in the nonbioaugmented reactor, chemical oxygen demand (COD) removal efficiency decreased by 36% but recovered fully by day 4. In contrast, in the bioaugmented reactor, no decrease of the COD removal efficiency was observed. This study demonstrates that bioaugmentation of wastewater reactors to accelerate the degradation of toxic chlorinated organics such as 3-CA protected the nitrifying bacterial community, thereby allowing faster recovery from toxic shocks.

scholarly journals Upflow Anaerobic Filter for the Treatment of Wastewater from a Natural Rubber Latex Concentration Unit

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
Nithya Gopinath ◽  
Madhu G. ◽  
Joseph Francis
Keyword(s):  
Production Rate ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Rubber Latex ◽  
Loading Rates ◽  
Anaerobic Filter ◽  
Cod Removal Efficiency ◽  
Concentration Unit

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.

Electrical conductivity as a state indicator for the start-up period of anaerobic fixed-bed reactors

2016 ◽  
Vol 73 (9) ◽  
pp. 2294-2300 ◽  
Author(s):  
A. Robles ◽  
E. Latrille ◽  
J. Ribes ◽  
N. Bernet ◽  
J. P. Steyer
Keyword(s):  
Electrical Conductivity ◽  
Production Rate ◽  
Methane Production ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bicarbonate Concentration ◽  
Fixed Bed Reactors ◽  
Start Up ◽  
On Line ◽  
Methane Production Rate

The aim of this work was to analyse the applicability of electrical conductivity sensors for on-line monitoring the start-up period of an anaerobic fixed-bed reactor. The evolution of bicarbonate concentration and methane production rate was analysed. Strong linear relationships between electrical conductivity and both bicarbonate concentration and methane production rate were observed. On-line estimations of the studied parameters were carried out in a new start-up period by applying simple linear regression models, which resulted in a good concordance between both observed and predicted values. Electrical conductivity sensors were therefore identified as an interesting method for monitoring the start-up period of anaerobic fixed-bed reactors due to its reliability, robustness, easy operation, low cost, and minimum maintenance compared with the currently used sensors.

Evaluation of UASB Reactor Performance During Start-Up Operation Using Glucose Bearing Synthetic Wastewater

2020 ◽  
Vol 9 (1) ◽  
pp. 32-51
Author(s):  
Revanuru Subramanyam
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Granular Sludge ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
Seed Sludge

This research article describes start-up performance of an UASB (Upflow Anaerobic Sludge Blanket) reactor in terms of chemical oxygen demand (COD) removal efficiency, biogas production, sludge loading rate (SLR), volatile fatty acids (VFA), pH, alkalinity, total solids (TS) and volatile suspended solids (VSS), fed with synthetic wastewater with increased concentrations of glucose. The reactor was loaded up to an OLR (Organic Loading Rate) of 15 kg COD m-3 d-1 and achieved a COD removal efficiency of 82 ±3%. The results showed that digested seed sludge was successfully acclimatized and transformed finally into granular sludge within a period of 120 days. An increase in the accumulation of VFA at high OLRs showed that methanogenesis could be the rate-limiting step in the reactor operation. The SLR and VSS/TS ratio were increased with an increase in OLR. During the initial stages, uniform distribution of VSS concentration and later on maximum VSS concentration were found at port number two at a height of 350 mm. The carbon balance depicts that the maximum percentage of influent COD converted to methane COD. An increase in specific methanogenic activity values with the age of sludge confirmed the transformation of the seed sludge in to a granular sludge.

Influence of effluent-recirculation condition on the process performance of expanded granular sludge bed reactor for treating low strength wastewater

2008 ◽  
Vol 57 (6) ◽  
pp. 869-873 ◽  
Author(s):  
W. Yoochatchaval ◽  
K. Nishiyama ◽  
M. Okawara ◽  
A. Ohashi ◽  
H. Harada ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Physical Property ◽  
Granular Sludge ◽  
Cod Removal ◽  
Process Performance ◽  
Methanogenic Activity ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
Effluent Recirculation ◽  
Low Strength

A 2.0 L volume of EGSB reactor was operated at 20°C for more than 500 days with 0.3–0.4 g COD/L of sucrose base wastewater to investigate the influence of effluent-recirculation on the process performance. At the start up period, the reactor was operated in EGSB mode with 5 m/h upflow velocity by continuous effluent recirculation. The COD loading was set to 7.2–9.6 kg COD/m3 day with HRT of 1 hour. However, in this mode, EGSB reactor exhibited insufficient COD removal efficiency, i.e., 50–60%. Therefore, UASB mode (without recirculation, 0.7 m/h upflow velocity) was used for 30 minutes in every 40 minutes cycle to increase the COD concentration in the sludge bed. As a result, an excellent process performance was shown. The COD removal efficiency increased from 65% to 91% and the reactor could maintain a good physical property of retained sludge (sludge concentration: 33.4 g VSS/L and SVI: 25 mL/g VSS). Furthermore, retained sludge possessed sufficient level of methanogenic activity at 20°C.

Process Characteristics Study of Anaerobic Baffled Reactor (ABR)

2010 ◽  
Vol 160-162 ◽  
pp. 1551-1557
Author(s):  
Lu Ning ◽  
Jin Liu
Keyword(s):  
Removal Efficiency ◽  
Ph Value ◽  
Granular Sludge ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Anaerobic Baffled Reactor ◽  
Process Characteristics ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
The Matrix

In this paper, Anaerobic Baffled Reactor (ABR) was applied to treat the synthetic wastewater in the matrix of starch and glucose. the reactor was started using low loading start-up , VLR controlled at 0.59~11.05kgCOD/m3•d, there are some granular sludge appeared after running 18 days. The figure and size of granular sludge in each compartment revealed different characteristics due to the changing of OLRs and shear force between gas and liquid in each compartment. The COD removal efficiency was higher than 90% and steady when the reactor’s start-up finished.When the anaerobic granular sludge appeared in the reactor, the VLR was 1.29kgCOD/(m3•d)、COD removal efficiency was 83％、hydraulic surface loading was 0.078m3/m2.h and an HRT was 30h. The VLR had remarkable influence on COD removal efficiency、VFA、pH and ALK. When VLR was 5.57kgCOD/(m3•d), COD removal efficiency and ALK were the minimum, VFA in the outflow exceeded 1000mg/L, reactor’s efficiency decreased .The reactor recovered after adjusting VLR and ALK value. Compared with the third and fourth compartments, the first and second compartments were less sensitive to changing of VFA. When pH deviated from adapt range, the COD removal efficiency was decreased obviously, so pH value was kept in the range of 6.2 to 6.5 for the later stage of experiments.

Solid mining residues from Ni extraction applied as nutrients supplier to anaerobic process: optimal dose approach through Taguchi's methodology

2006 ◽  
Vol 54 (9) ◽  
pp. 209-219 ◽  
Author(s):  
I. Pereda ◽  
R. Irusta ◽  
S. Montalvo ◽  
J.L. del Valle
Keyword(s):  
Removal Efficiency ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Nitrogen Concentration ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Control Factor ◽  
Anaerobic Process ◽  
Cod Removal Efficiency ◽  
Mining Residues

The use of solid mining residues (Cola) which contain a certain amount of Ni, Fe and Co, to stimulate anaerobic processes was evaluated. The effect over methane production and chemical oxygen demand (COD) removal efficiency was analysed. The studies were carried out in discontinuous reactors at lab scale under mesophilic conditions until exhausted. 0, 3, 5 and 7 mgCola l−1 doses were applied to synthetic wastewater. Volatile fatty acids (VFA) and sucrose were used as substrate, sulphur and nitrogen concentration, being the noise variable. Cola addition at dose around 5 mg l−1, turned out to be stimulating for the anaerobic process. It was the factor that most influenced on methane production rate together with VFA and high content of volatile suspended solids. In the case of methane yield, pH was the control factor of strongest influence. Higher values of COD removal efficiency were obtained when the reactors were operated with sucrose at relatively low pH and at the smallest concentration of nitrogen and sulphur. Solid residues dose and the type of substrate were the factors that had most influence on COD removal efficiency.

Sign in / Sign up

Export Citation Format

Share Document