Pretreatment of silk-dyeing industrial wastewater by UASB reactor

2004 ◽  
Vol 50 (8) ◽  
pp. 185-192
Author(s):  
S. Karnchanawong ◽  
T. Sawangpanyangkura
Keyword(s):  
Anaerobic Bacteria ◽  
Color Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Ammonium Ion ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Dyeing Wastewater ◽  
Working Volume ◽  
Apparent Color ◽  
Silk Dyeing

The objective of this study was to investigate the performance of the upflow anaerobic sludge blanket (UASB) reactor as the pretreatment system for silk-dyeing wastewater. Two laboratory-scale UASB reactors, with working volume of 15.59 l, were used during May 1998 to June 1999. The actual wastewater was diluted to reduce ammonium ion toxicity on anaerobic bacteria. The experiments were conducted at the organic loading rates (OLRs) of 0.52, 1.01, 1.04, 1.54 and 2.56 kgCOD/(m3.d), treating only wastewater generated from the acid-dye process of mixed-species raw silk. It took approximately 41/2 months to reach the steady-state conditions. It was found that the COD removal was in the ranges of 74.1-85.3% , except at OLR 2.56 kgCOD/(m3.d) where efficiency significantly dropped to 55.2%. The apparent color removal was in the similar trend as COD. During the study periods, wastewater input had various color shades while the effluent generally looked pale yellowish. The methane generation rates ranged from 0.18-0.31 m3/kg COD removed, with methane composition 81.0-88.1% in biogas. The average granule size in the sludge bed had slowly increased to 0.73 mm in the last experiment. It can be concluded that the UASB reactor is suitable as a pretreatment system for silk-dyeing wastewater. An OLR of 1 kgCOD/(m3.d) and an influent concentration diluted to 2,600 mgCOD/l are suggested while COD and apparent color removal efficiency of 80% and 70%, respectively, can be expected.

Evaluation of sludge properties in a pilot-scale UASB reactor for sewage treatment in a temperate region

2011 ◽  
Vol 64 (10) ◽  
pp. 1959-1966 ◽  
Author(s):  
K. Syutsubo ◽  
W. Yoochatchaval ◽  
I. Tsushima ◽  
N. Araki ◽  
K. Kubota ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Working Volume ◽  
Anaerobic Sludge Blanket

In this study, continuous operation of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor for sewage treatment was conducted for 630 days to investigate the physical and microbial characteristics of the retained sludge. The UASB reactor with a working volume of 20.2 m3 was operated at ambient temperature (16–29 °C) and seeded with digested sludge. After 180 days of operation, when the sewage temperature had dropped to 20 °C or lower, the removal efficiency of both total suspended solids (TSS) and total biochemical oxygen demand (BOD) deteriorated due to washout of retained sludge. At low temperature, the cellulose concentration of the UASB sludge increased owing to the rate limitation of the hydrolytic reaction of suspended solids in the sewage. However, after an improvement in sludge retention (settleability and concentration) in the UASB reactor, the process performance stabilized and gave sufficient results (68% of TSS removal, 75% of total BOD removal) at an hydraulic retention time (HRT) of 9.7 h. The methanogenic activity of the retained sludge significantly increased after day 246 due to the accumulation of Methanosaeta and Methanobacterium following the improvement in sludge retention in the UASB reactor. Acid-forming bacteria from phylum Bacteroidetes were detected at high frequency; thus, these bacteria may have an important role in suspended solids degradation.

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.

scholarly journals Microbial Diversity Dynamics in a Methanogenic-Sulfidogenic UASB Reactor

2021 ◽  
Vol 18 (3) ◽  
pp. 1305
Author(s):  
E. Fernández-Palacios ◽  
Xudong Zhou ◽  
Mabel Mora ◽  
David Gabriel
Keyword(s):  
Paper Industry ◽  
Chemical Species ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Long Run

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

scholarly journals Microbial Removal of Pb(II) Using an Upflow Anaerobic Sludge Blanket (UASB) Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 512
Author(s):  
Jeremiah Chimhundi ◽  
Carla Hörstmann ◽  
Evans M. N. Chirwa ◽  
Hendrik G. Brink
Keyword(s):  
Treatment Process ◽  
Removal Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Anaerobic Sludge Blanket ◽  
Microbial Removal ◽  
Maximum Removal

The main objective of this study was to achieve the continuous biorecovery and bioreduction of Pb(II) using an industrially obtained consortia as a biocatalyst. An upflow anaerobic sludge blanket reactor was used in the treatment process. The bioremediation technique that was applied made use of a yeast extract as the microbial substrate and Pb(NO3)2 as the source of Pb(II). The UASB reactor exhibited removal efficiencies of between 90 and 100% for the inlet Pb concentrations from 80 to 2000 ppm and a maximum removal rate of 1948.4 mg/(L·d) was measured. XRD and XPS analyses of the precipitate revealed the presence of Pb0, PbO, PbS and PbSO4. Supporting experimental work carried out included growth measurements, pH, oxidation–reduction potentials and nitrate levels.

KINETIC MODELS FOR PREDICTION OF COD EFFLUENT FROM UPFLOW ANAEROBIC SLUDGE BLANKET (UASB) REACTOR FOR CANNERY SEAFOOD WASTEWATER TREATMENT

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Sunwanee Jijai ◽  
Chairat Siripatana ◽  
Sompong O-Thong ◽  
Norli Ismail
Keyword(s):  
Palm Oil ◽  
Kinetic Models ◽  
Second Order ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Substrate Removal ◽  
Reactor Kinetic ◽  
Palm Oil Mill ◽  
Anaerobic Sludge Blanket

The three identical lab-scale upflow anaerobic sludge blanket (UASB) reactors were operated continuously for treating cannery seafood wastewater at seven hydraulic retention times (HRTs) of 5, 4, 3, 2, 1, 0.5 and 0.25 days. The different of granule sizes from three sources: a cassava factory (CS), a seafood factory (SS), and a palm oil mill (PS), average sizes in the range 1.5-1.7, 0.7-1.0 and 0.1-0.2 mm respectively were used as inocula for anaerobic digestion. The UASB-R1 used only granules from seafood factory (R1-SS), the UASB-R2 used mixed granules from seafood with cassava factory (R2-SS+CS) and the UASB-R3 used mixed granules from seafood factory with palm oil mill (R3-SS+PS). In this study selected mathematical models including Monod, Contois, Grau second-order and modified Stover-Kicannon kinetic models were applied to determine the substrate removal kinetics of UASB reactor. Kinetic parameters were determined through linear regression using experimental data obtained from the steady-state experiment and subsequently used to predict effluent COD. The results showed that Grau second-order and modified Stover-Kicannon kinetic models were more suitable than that of others for predicting the effluent COD, with high the correlation coefficient (R2). In addition, the UASB-R2 from mixed granules with cassava factory (SS+CS) gave the best performance and highest coefficient value.

Nitrite reduction and methanogenesis in a single-stage UASB reactor

2015 ◽  
Vol 72 (12) ◽  
pp. 2236-2242 ◽  
Author(s):  
L. I. Borges ◽  
C. M. López-Vazquez ◽  
H. García ◽  
J. B. van Lier
Keyword(s):  
Domestic Wastewater ◽  
High Strength ◽  
Single Stage ◽  
Nitrite Reduction ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
N Removal

In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO2−-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO2−-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO2−-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO2− reduction to N2. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

Treatment of raw sewage in a temperate climate using a UASB reactor and the hanging sponge cubes process

1997 ◽  
Vol 36 (6-7) ◽  
pp. 433-440 ◽  
Author(s):  
Lalit K. Agrawal ◽  
Yasuhiro Ohashi ◽  
Etsuo Mochida ◽  
Hiroyuki Okui ◽  
Yasuko Ueki ◽  
...  
Keyword(s):  
Ammonia Oxidation ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Temperate Climate ◽  
Anaerobic Sludge ◽  
Treatment Efficiency ◽  
Oxidation Rates ◽  
Air Intake ◽  
Anaerobic Sludge Blanket ◽  
Digested Sewage Sludge

The treatability of raw sewage in a temperate climate (wintertime around 10–20°C) using an upflow anaerobic sludge blanket (UASB) reactor and the hanging sponge cubes process was evaluated. After being seeded with digested sewage sludge, a 47.1 L UASB reactor was continuously operated for more than 2 years by feeding raw sewage, which had average COD around 300 mg/L (41% soluble). During summertime at an HRT of 7 h, effluent COD approximately 70 mg/L total, 50 mg/L soluble and BOD5 20 mg/L total, 12 mg/L soluble was obtained. During wintertime also, treatment efficiency and process stability was good. With the hanging sponge cubes process using the effluent of the UASB reactor treating raw sewage, the following results were obtained. The ammonia oxidation rates of 1.9 and 3.5 g NH4-N·m−2·d−1 in a downflow hanging sponge cubes biofilter, under natural air intake only were obtained during wintertime and summertime, respectively. With post-denitrification and an external carbon source, 84% in average N (NO3+NO2) was removed with an HRT of less than 1 hour and in the temperature range of 13 to 30°C using an upflow submerged hanging sponge bed bioreactor, under anaerobic conditions. The overall system using a UASB reactor and the hanging sponge cubes process could be quite an attractive treatment alternative.

scholarly journals Organic Matter Removal in a Simultaneous Nitrification-Denitrification Process Using Fixed-Film System.

2021 ◽  
Author(s):  
Perla Gonzalez ◽  
Ana Aguilar Ruiz ◽  
Andrea Reynosa Varela ◽  
Ulises Durán Hinojosa ◽  
Marco Garzón Zuñiga ◽  
...  
Keyword(s):  
Organic Matter ◽  
Nitrogen Compound ◽  
Upflow Anaerobic Sludge Blanket ◽  
Swine Wastewater ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Organic Matter Removal ◽  
Fixed Film ◽  
Suspended Biomass ◽  
Anaerobic Sludge Blanket

Abstract This study focused on evaluating different support media for COD and nitrogen compound removal from an Upflow Anaerobic Sludge Blanket (UASB) reactor fed with swine wastewater. Maximum specific nitrification (MSNA) and denitrification (MSDA) activity tests were performed in two fixed-film systems with (1) polyurethane foam (R1) and (2) polyethylene rings (R2). The results showed that the R2 system performed more efficiently than R1, reaching organic matter removal of 77 ± 8% and nitrogen of 98 ± 4%, attributed to higher specific denitrifying activity recorded (5.3 ± 0.34 g NO3--N/g VTS ∙h). In this sense, MSDA tests indicated that the suspended biomass was responsible for at least 70% of nitrogen removal in the form of ammonium compared with 20% attributed to biomass in the form of biofilm. On the other hand, 40 ± 5% of initial nitrogen could not be quantified in the system effluents, but 10 ± 1% was attributed to loss by volatilization. According to the analyses, the previous information infers the development of simultaneous nitrification-denitrification (SND) routes. Respect to the analyses of microbial diversity and abundance in the biofilm of R2 rings, the presence of the genus Pseudomonas dominated the prokaryotic community of the system in 54.4%.

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