Treatment of high-strength synthetic sewage in a laboratory-scale upflow anaerobic sludge bed (UASB) with aerobic activated sludge (AS) post-treatment

2013 ◽  
Vol 48 (3) ◽  
pp. 338-347 ◽  
Author(s):  
Qais H. Banihani ◽  
Jim A. Field
Keyword(s):  
Activated Sludge ◽  
High Strength ◽  
Post Treatment ◽  
Laboratory Scale ◽  
Anaerobic Sludge

Evaluation of the alternative treatment processes to upgrade an Opium alkaloid wastewater treatment plant

2000 ◽  
Vol 41 (1) ◽  
pp. 223-230 ◽  
Author(s):  
M.F. Sevimli ◽  
A.F. Aydin ◽  
Ì. Öztürk ◽  
H.Z. Sarikaya
Keyword(s):  
Activated Sludge ◽  
Alternative Treatment ◽  
Treatment Plant ◽  
Post Treatment ◽  
Anaerobic Sludge ◽  
Processing Plant ◽  
Two Stage ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Opium Alkaloid

The aim of this study is to characterize the wastewater from an opium alkaloid processing plant and to evaluate alternative treatment techniques to upgrade an existing full-scale biological activated sludge treatment plant having problems of high residual COD and unacceptable dark brown color. In this content firstly, long term operational records of the two stage aerobic activated sludge treatment plant of the opium alkaloid factory located in Afyon province of Turkiye were evaluated. The operating results for the last three years were statistically analyzed and median and 95-percentile values were determined for the parameters including chemical and biological oxygen demand (COD and BOD5) and treatment efficiencies. Specific wastewater generation was found as 6.7 m3 per ton of the opium capsule processed. In the following stage of the study, three additional treatment processes were experimentally tested: anaerobic pretreatment, post treatment of aerobically treated effluents with lime and ozone. Pilot scale upflow anaerobic sludge blanket reactor (UASBR) experiments have demonstrated that about 70 percent of the incoming COD can be removed anaerobically. Chemical treatability studies with lime for the aerobically treated effluent have shown that about 78 percent color and 46 percent COD removals can be obtained with lime dosage of 25 gl−1. Post treatment of the effluents of the existing two stage aerobic treatment with ozone also resulted in significant color and COD reduction.

Secondary WWTP preceded by UASB reactors - an excellent Brazilian experience

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
E. P. Jordäo ◽  
I. Volschan ◽  
P. Alem Sobrinho
Keyword(s):  
Activated Sludge ◽  
Anaerobic Treatment ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Secondary Treatment ◽  
Nitrogen And Phosphorus ◽  
Trickling Filters ◽  
Operational Costs ◽  
Anaerobic Sludge Blanket

Anaerobic treatment, such as the Upflow Anaerobic Sludge Blanket - UASB - has many advantages: a compact system, with practically no equipment in the anaerobic vessel, low operational costs, very low energy consumption, and low excess sludge produced. However, taking into account its poor effluent quality, and the legal water quality standards, post treatment is a must. Brazil is experiencing the scheme UASB plus aerobic secondary treatment, aiming reduction in investment and mainly in operational costs, with excellent results. Three cases are discussed in this paper: two small plants, Barreto (0,14 m3/s) and Itaipu (0.07 m3/s, 1.6 MGD); and the Rio Preto plant (1.34 m3/s), the first two already operational. All adopt the UASB plus activated sludge process, the last two with denitrification. Several other important plants are in the stage of design or construction in Brazil, with flows as high as 3.35 m3/s, UASB plus activated sludge with nitrogen and phosphorus removal and UASB plus trickling filters. Design criteria for the anaerobic reactor and for the different secondary treatment processes, and available operational data as well, are discussed in the paper. Particular attention is given to special restraints with activated sludge as post treatment, such as the higher sludge age required for nitrification, and the difficulty in denitrifying the anaerobic effluent.

scholarly journals Performance of UASB reactors in two stages followed by post-treatment with activated sludge in wastewater batch of wet-processed coffee

2013 ◽  
Vol 33 (4) ◽  
pp. 808-819 ◽  
Author(s):  
Marcelo Bruno ◽  
Roberto A. de Oliveira
Keyword(s):  
Activated Sludge ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Nitrogen And Phosphorus ◽  
Removal Efficiencies ◽  
Two Stages ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

In this study it was evaluated the efficiency of the treatment of wet-processed coffee wastewater in upflow anaerobic sludge blanket (UASB) reactors in two stages, in bench scale, followed by post-treatment with activated sludge in batch. The first UASB reactor was submitted to an hydraulic retention time (HRT) of 6.2 d and organic loading rates (OLR) of 2.3 and 4.5g CODtotal (L d)-1, and the second UASB reactor to HRT of 3.1 d with OLR of 0.4 and 1.4g CODtotal (L d)-1. The average values of the affluent CODtotal increased from 13,891 to 27,926mg L-1 and the average efficiencies of removal of the CODtotal decreased from 95 to 91%, respectively, in the UASB reactors in two stages. The volumetric methane production increased from 0.274 to 0.323L CH4 (L reactor d)-1 with increment in the OLR. The average concentrations of total phenols in the affluent were of 48 and 163mg L-1, and the removal efficiencies in the UASB reactors in two stages of 92 and 90%, respectively, and increased to 97% with post-treatment. The average values of the removal efficiencies of total nitrogen and phosphorus were of 57 to 80% and 44 to 60%, respectively, in the UASB reactors in two stages and increased to 91 and 84% with the post-treatment.

Application of Three Step-Biological Pond with the Use of Aquatic Plant for Post Treatment of Petroleum Wastewater in Vietnam

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1503-1507 ◽  
Author(s):  
L. M. Triet ◽  
N. T. Viet ◽  
T. V. Thinh ◽  
H. D. Cuong ◽  
J. C. L. van Buuren
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Residence Time ◽  
Aquatic Plants ◽  
Water Hyacinth ◽  
Aquatic Plant ◽  
Post Treatment ◽  
Cod Removal ◽  
Sludge Treatment ◽  
Purification Efficiency

The effluent from activated sludge treatment of petroleum wastewater was treated with the aid of a ponding system using aquatic plants (Water Hyacinth, Chlorella, Reed). A good result was obtained in this study. Pilot pond system shows that the purification efficiency depends on the residence time of about 14 days. The petroleum removal waa 97-98 %, the COD removal was from 88-93 %. The dissolved oxygen amount (with Chlorella) increased from 0.7 mg/l to 9.8 mg/l and the pH increased from 6.9 to 8-8.6. The application of 3 step biological pond with the use of Water Hyacinth, Chlorella, Reeds for post treatment of petroleum wastewater is appropriate in Vietnam.

Low-consistency refining of CTMP targeting high strength and bulk: effect of filling pattern and trial scale

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jan-Erik Berg ◽  
Börje Hellstadius ◽  
Mikael Lundfors ◽  
Per Engstrand
Keyword(s):  
High Strength ◽  
Natural Fibre ◽  
Laboratory Scale ◽  
Process Conditions ◽  
Tensile Index ◽  
Filling Pattern ◽  
Basic Objective ◽  
High Bulk ◽  
Fibre Morphology ◽  
Bulk Effect

AbstractChemithermomechanical pulp (CTMP) is often used in central layers of multiply paperboards due to its high bulk and strength. Such a CTMP should consist of well-separated undamaged fibres with sufficient bonding capacity. The basic objective of this work is to optimize process conditions in low-consistency (LC) refining, i. e. to select or ultimately develop new optimal LC refiner filling patterns, in order to produce fibrillar fines and improve the separation of fibres from each other while preserving the natural fibre morphology as much as possible. Furthermore, the aim is to evaluate if this type of work can be done at laboratory-scale or if it is necessary to run trials in pilot- or mill-scale in order to get relevant answers. First stage CTMP made from Norway spruce (Picea abies) was LC refined in mill-, pilot- and laboratory-scale trials and with different filling patterns. The results show that an LR1 laboratory refiner can favourably be used instead of larger refiners in order to characterize CTMP with regard to tensile index and z-strength versus bulk. A fine filling pattern resulted in CTMP with higher tensile index, z-strength and energy efficiency at maintained bulk compared to a standard filling pattern.

Laboratory-scale assessment of vacuum-degassed activated sludge for improved settling properties

2016 ◽  
Vol 38 (17) ◽  
pp. 2193-2201 ◽  
Author(s):  
Salar Haghighatafshar ◽  
Britt-Marie Wilén ◽  
Andreas Thunberg ◽  
Marinette Hagman ◽  
Annika Nyberg ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Laboratory Scale ◽  
Scale Assessment

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.

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