Effects of Fe2+ on sludge granulation in upflow anaerobic sludge blanket reactors

2000 ◽  
Vol 41 (12) ◽  
pp. 199-205 ◽  
Author(s):  
H. Q. Yu ◽  
H. H. P. Fang ◽  
J. H. Tay

Experiments were performed in parallel using six identical UASB (upflow anaerobic sludge blanket) reactors to examine the effects of iron (Fe2+) on sludge granulation during start-up. Introduction of Fe2+ at concentrations of 300 and 450 mg/L enhanced the granulation process in UASB reactors, while dosage of Fe2+ (150 mg/L) had little effect on the sludge granulation. The Fe2+concentration in granules was nearly proportional to the influent Fe2+concentration. The specific activity of granules decreased with increasing Fe2+/concentration in the feed. For high Fe2+ dosages, a large amount of minerals was deposited within the granules, and FeS and the compounds formed by iron and exopolysaccharide polymers were the main precipitates. This, along with the significant decrease in the water content in granules and the possible toxicity of high-level Fe2+accumulated inside granules, reduced bacterial specific activity.

1986 ◽  
Vol 18 (12) ◽  
pp. 41-53 ◽  
Author(s):  
Look Hulshoff Pol ◽  
Gatze Lettinga

Presently anaerobic wastewater treatment is becoming an accepted simple technology for the treatment of a variety of wastewaters. Of the different treatment systems that have been developed the UASB process (Upflow Anaerobic Sludge Blanket) has found the widest application. Almost all of the more than 60 full scale UASB reactors in operation now, are running satisfactorily. The excellent sludge retention generally found in UASB-reactors is obtained by sludge granulation, which can be seen as a sludge immobilization process. The presently available insight into the sludge granulation process is briefly presented, together with the strategy to be applied for performing a proper first start-up and secondary start-up of UASB reactors, viz. using granular seed sludge. The effect of the presence of SS with regard to the loading potentials of anaerobic treatment systems will be discussed. The experiences obtained with some full scale applications of the UASB-process are presented.


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.


1986 ◽  
Vol 18 (12) ◽  
pp. 55-69 ◽  
Author(s):  
M. E. Souza

This paper describes and discusses the principal ideas and parameters related to the application, design and operation of wastewater treatment systems using the upflow anaerobic sludge blanket reactor (UASB). The differences in the process brought about by the high or low concentration of organic material in the wastewater to be treated are pointed out in each consideration. The purpose of this paper is to make the development of simple, but safe and efficient UASB reactor treatment units, by technicians not necessarily highly specialized in the subject, possible. It also attempts to point out problems which are not yet completely solved in order to help in the preparation of future research and development plans. A number of possible questions that deal with the following subjects are discussed:–types of waste which can be treated by the UASB reactor–concentrated wastes (for example, stillage from sugar-cane) and diluted wastes (for example, domestic sewage)–necessity of pre- and post-treatment–temperature–shape and dimensions of the reactor–criteria and details for design–start-up, operation and control of the unit–forecasts of efficiency, costs, etc.


2004 ◽  
Vol 49 (11-12) ◽  
pp. 69-76 ◽  
Author(s):  
J.E. Schmidt ◽  
D.J. Batstone ◽  
I. Angelidaki

Upflow anaerobic sludge blanket reactors may offer a number of advantages over conventional mixed-tank, SBR, and biofilm reactors, including high space-loading, low footprint, and resistance to shocks and toxins. In this study, we assessed the use of upflow anaerobic sludge blanket (UASB) reactor technology as applied to anaerobic ammonia removal, or Anammox. Four 200 ml UASB reactors were inoculated with 50% (by volume) anaerobic granular sludge and 50% flocular sludge from different sources (all with the potential for containing Anammox organisms). Tools used to assess the reactors included basic analyses, fluorescent in-situ hybridisation, and mathematical modelling, with statistical non-linear parameter estimation. Two of the reactors showed statistically identical Anammox activity (i.e., identical kinetic parameters), with good ammonia and nitrite removal (0.14 kgNHx m-3 reactor day-1, with 99% ammonia removal). The third reactor also demonstrated significant Anammox activity, but with poor identifiability of parameters. The fourth reactor had no statistical Anammox activity. Modelling indicated that poor identifiability and performance in the third and fourth reactors were related to an excess of reduced carbon, probably originating in the inoculum. Accumulation of Anammox organisms was confirmed both by a volume loading much lower than the growth rate, and response to a probe specific for organisms previously reported to mediate Anammox processes. Overall, the UASB reactors were effective as Anammox systems, and identifiability of the systems was good, and repeatable (even compared to a previous study in a rotating biological contactor). This indicates that operation, design, and analysis of Anammox UASB reactors specifically, and Anammox systems in general, are reliable and portable, and that UASB systems are an appropriate technology for this process.


2019 ◽  
Vol 80 (3) ◽  
pp. 418-425 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
L. A. Chamhum-Silva ◽  
C. A. L. Chernicharo

Abstract There are hundreds of full-scale upflow anaerobic sludge blanket (UASB) reactors in operation in various parts of the tropical world, notably in India and Latin America, Brazil being the holder of the largest park of anaerobic reactors for sewage treatment in the world. Despite the recognized advantages of UASB reactors, there are problems that have prevented their maximum operational performance. Neglecting the existence and delaying the solution of these challenges can jeopardize the important advances made to date, impacting the future of anaerobic technology in Brazil and in other countries. This work aims to evaluate the operational performance of five full-scale UASB reactors in Brazil, taking into account a monitoring period ranging between two and six years. The main observed design, construction, and operational constraints are discussed. Some outlooks for important upcoming developments are also provided, considering that most of the observed drawbacks can be tackled without significant increases on reactor costs.


2001 ◽  
Vol 44 (4) ◽  
pp. 79-82 ◽  
Author(s):  
L. F. Lopes ◽  
P. R. Koetz ◽  
M. S. Santos

Parboiled rice industry is one of main food industries in the south of Brazil. The main parts of the processing are the humidification and gelatinization of the grain. This procedure increases the productivity and nutritive and cooking values of the product. Some of these industries in the region utilize upflow anaerobic sludge blanket (UASB) reactors as a biological treatment for carbon removal. For nitrogen removal, the proposed system aims to eliminate an extra denitrification reactor, making this step in the top of the UASB, an anoxic zone of the reactor. Nitrification was performed in aerated mixed reactor of 3,6 L. A fraction of the NR was recycled in the top of UASB reactor above the sludge blanket. Recycled ratio varied from 0; 1:0.5; 1:1.0; to 1:1.5. The maximum removal efficiency of NTK was 80%. The results confirm the viability of the proposed system for denitrification.


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