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

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.

1999 ◽  
Vol 40 (8) ◽  
pp. 57-62 ◽  
Author(s):  
A. Pun˜al ◽  
J. M. Lema

The start-up and optimisation of a 380 m3 UASB reactor (Up-flow Anaerobic Sludge Blanket) treating wastewater from a fish-canning factory was carried out. At the beginning of the operation the Organic Loading Rate (OLR) was 1 kg COD/m3·d. Then, the load was gradually increased in steps of 50% OLR until the final capacity of the system (4 kg COD/m3·d) was achieved. Wastewater characteristics were highly dependent on the canned product (mussel, tuna, sardines, etc.). In spite of that, a stable operation working at a hydraulic retention time (HRT) of 2 days was maintained. Total Alkalinity (TA) always presented values higher than 3 g CaCO3/l, while the IA/TA ratio (Intermediate Alalinity/Total Alkalinity) was always maintained lower than 0.3. In order to improve granulation conditions, upward velocities from 0.5 to 0.8 m/h were applied. The highest values caused the washout of non-granulated biomass from the reactor, optimum operation being achieved at an upward velocity of 0.7 m/h.


2001 ◽  
Vol 44 (4) ◽  
pp. 83-88 ◽  
Author(s):  
V. Del Nery ◽  
M. H.Z. Damianovic ◽  
F. G. Barros

This work studied the performance of the dissolved air flotation (DAF) system and the start-up and the operation of two 450 m3 UASB reactors in a poultry slaughterhouse in Sorocaba, Brazil. The DAF presented reduction efficiency of grease and fats, suspended solids and COD 50% higher. The reactors were seeded with non-adapted sludge. The average COD of the reactor influent was 2,695mg/L; and the initial organic loading rate (OLR) and the initial sludge loading rate at the start-up were 0.51 kg COD/m3.day and 0.04 kg COD/kg VTS.day, respectively. The start-up period was 144 days. During this time the reactor flow rate and OLR were gradually increased. At the reactor start-up, the maximum OLR value was 2.1 kg COD/m3.day, the COD reduction was higher than 80%, and the concentration of volatile fatsty acids (VFA) was below 100mg/L. The COD reductions, considering the reactor effluent raw COD and soluble COD were similar throughout the period studied in both reactors. The reactor effluent raw COD was approximately 10% higher than the soluble COD until the 225th day of operation. From the 225th day of operation this value increased 20%-30% due to the sludge washout. The effluent soluble COD reduction, the effluent VFA concentration and the operational stability attested the good performance of UASB reactors in poultry slaughterhouse wastewater treatment.


1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
Author(s):  
F. Fdz-Polanco ◽  
M. D. Hidalgo ◽  
M. Fdz-Polanco ◽  
P. A. García Encina

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.


2017 ◽  
Vol 76 (9) ◽  
pp. 2268-2279 ◽  
Author(s):  
Henrique Vieira de Mendonça ◽  
Jean Pierre Henry Balbaud Ometto ◽  
Marcelo Henrique Otenio ◽  
Alberto José Delgado dos Reis ◽  
Isabel Paula Ramos Marques

Abstract New data on biogas production and treatment of cattle wastewater were registered using an upflow anaerobic sludge blanket-anaerobic filter (UASB-AF) hybrid reactor under mesophilic temperature conditions (37 °C). The reactor was operated in semi-continuous mode with hydraulic retention times of 6, 5, 3 and 2 days and organic loading rates of 3.8, 4.6, 7.0 and 10.8 kg CODt m−3 d−1. Biogas volumes of 0.6–0.8 m3 m−3 d−1 (3.8–4.6 kg CODt m−3 d−1) and 1.2–1.4 m3 m−3 d−1 (7.0–10.8 kg CODt m−3 d−1), with methane concentrations between 69 and 75%, were attained. The removal of organic matter with values of 60–81% (CODt) and 51–75% (CODs) allowed methane yields of 0.155–0.183 m3 CH4 kg−1 CODt and 0.401–0.513 m3 CH4 kg−1 CODs to be obtained. Volatile solids were removed in 34 to 69%, with corresponding methane yields of 0.27 to 0.42 m3 CH4 kg−1 VSremoved. The good performance of the novel hybrid reactor was demonstrated by biogas outputs higher than reported previously in the literature, along with the quality of the gas obtained in the various experimental phases. The hybrid reactor investigated in this study presents comparative advantages, particularly in relation to conventional complete mixture units, considering economic factors such as energy consumption, reactor volume and installation area.


2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62


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