Anaerobic Wastewater Treatment in Downflow Stationary Fixed Film Reactors

1991 ◽  
Vol 24 (8) ◽  
pp. 157-177 ◽  
Author(s):  
K. J. Kennedy ◽  
R. L. Droste

Design features and performance of the downflow stationary fixed film reactor for anaerobic wastewater treatment are reviewed. Media characteristics, feed characteristics and loading rates found to provide rapid start-up and maximum treatment efficiency are discussed. It is concluded that the reactor is a useful research tool for studying anaerobic treatment. The reactor is not as sensitive to waste characteristics as other second generation anaerobic reactors. The reactor is able to handle wastes with high suspended solids content and provide efficient treatment with a minimum clogging potential. DSFF operation is simple and stable; however, loading rates attainable in this reactor are not as high as those attained with other processes due to lower biomass retention capacity.

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1546
Author(s):  
Monika Vítězová ◽  
Anna Kohoutová ◽  
Tomáš Vítěz ◽  
Nikola Hanišáková ◽  
Ivan Kushkevych

Over the past decades, anaerobic biotechnology is commonly used for treating high-strength wastewaters from different industries. This biotechnology depends on interactions and co-operation between microorganisms in the anaerobic environment where many pollutants’ transformation to energy-rich biogas occurs. Properties of wastewater vary across industries and significantly affect microbiome composition in the anaerobic reactor. Methanogenic archaea play a crucial role during anaerobic wastewater treatment. The most abundant acetoclastic methanogens in the anaerobic reactors for industrial wastewater treatment are Methanosarcina sp. and Methanotrix sp. Hydrogenotrophic representatives of methanogens presented in the anaerobic reactors are characterized by a wide species diversity. Methanoculleus sp., Methanobacterium sp. and Methanospirillum sp. prevailed in this group. This work summarizes the relation of industrial wastewater composition and methanogen microbial communities present in different reactors treating these wastewaters.


1994 ◽  
Vol 30 (12) ◽  
pp. 425-432 ◽  
Author(s):  
M. C. Veiga ◽  
R. Méndez ◽  
J. M. Lema

An anaerobic filter (AF) and a downflow stationary fixed film (DSFF) reactor were used for the treatment of a tuna processing wastewater. Start-up of the anaerobic reactors was improved using lactose as co-substrate. The AF removed up to 75% of the influent COD concentrations at organic loading rates (OLR) of 11-13 kg COD m−3 d−1, whereas the DSFF reactor removed 70% at 3 kg COD m−3 d−1. Based on these results it appears that anaerobic treatment systems are applicable to tuna processing industry wastewaters and that the AF shows a much better performance, allowing higher organic loadings and COD removal efficiencies than the DSFF reactor.


1989 ◽  
Vol 21 (4-5) ◽  
pp. 87-95
Author(s):  
J. De Santis ◽  
A. A. Friedman

Overloaded anaerobic treatment systems are characterized by high concentrations of volatile fatty acids and molecular hydrogen and poor conversion of primary substrates to methane. Previous experiments with fixed–film reactors indicated that operation with reduced headspace pressures enhanced anaerobic treatment. For these studies, four suspended culture, anaerobic reactors were operated with headspace pressures maintained between 0.5 and 1.0 atm and a solids retention time of 15 days. For lightly loaded systems (0.4 g SCOD/g VSS-day) vacuum operation provided minor treatment improvements. For shock organic loads, vacuum operation proved to be more stable and to support quicker recovery from upset conditions. Based on these studies and a companion set of bioassay tests, it was concluded that: (a) a loading rate of about 1.0 g SCOD/g VSS-day represents a practical loading limit for successful anaerobic treatment, (b) a headspace pressure of approximately 0.75 atm appears to be an optimum operating pressure for anaerobic systems and (c) simple modification to existing systems may provide relief for organically overloaded systems.


2001 ◽  
Vol 44 (8) ◽  
pp. 15-25 ◽  
Author(s):  
J.B. van Lier ◽  
F.P. van der Zee ◽  
N.C.G. Tan ◽  
S. Rebac ◽  
R. Kleerebezem

Anaerobic wastewater treatment (AnWT) is considered as the most cost-effective solution for organically polluted industrial waste streams. Particularly the development of high-rate systems, in which hydraulic retention times are uncoupled from solids retention times, has led to a world-wide acceptance of AnWT. In the last decade up to the present, the application potentials of AnWT are further explored. Research shows the feasibility of anaerobic reactors under extreme conditions, such as low and high temperatures. Also toxic and/or recalcitrant wastewaters, that were previously believed not to be suitable for anaerobic processes, are now effectively treated. The recent advances are made possible by adapting the conventional anaerobic high-rate concept to the more extreme conditions. Staged anaerobic reactor concepts show advantages under non-optimal temperature conditions as well as during the treatment of chemical wastewater. In other situations, a staged anaerobic - aerobic approach is required for biodegradation of specific pollutants, e.g. the removal of dyes from textile processing wastewaters. The current paper illustrates the benefits of reactor staging and the yet un-exploited potentials of high-rate AnWT.


1982 ◽  
Vol 17 (1) ◽  
pp. 63-74 ◽  
Author(s):  
R.C. Landine ◽  
G.J. Brown ◽  
A.A. Cocci ◽  
T. Viraraghavan

Abstract A laboratory bench-scale study using a unified anaerobic fermenter-filter system (referred to as a BVF-HAF system) was conducted at room temperature over an 8 month period on potato processing wastewater for the purpose of verifying a proposed full-scale design concept. In addition to two-stage anaerobic treatment, the first stage anaerobic effluent (BVF effluent) was subjected to aerobic polishing in a simulated facultative aerated lagoon with a retention of 4 days. The basic design conditions entailed treatment of a clarified potato wastewater with a COD of 7600 mg/L and a retention of 4 d in the BVF (loading 1.71 kg/m3.d). After over-coming an upset condition believed due to toxicity of the vacuum filtrate feed, the model performed well achieving 78.9% COD removal in the BVF plus 5 3.4% in the HAF for a combined total of 90.2%. When the BVF effluent was aerated the combined BVF - aerated lagoon removal reached 94.8%.


Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Zehua Huang ◽  
Renren Wu ◽  
XiaoHui Yi ◽  
Hongbin Liu ◽  
Jiannan Cai ◽  
...  

The anaerobic treatment process is a complicated multivariable system that is nonlinear and time varying. Moreover, biogas production rates are an important indicator for reflecting operational performance of the anaerobic treatment system. In this work, a novel model fuzzy wavelet neural network based on the genetic algorithm (GA-FWNN) that combines the advantages of the genetic algorithm, fuzzy logic, neural network, and wavelet transform was established for prediction of effluent quality and biogas production rates in a full-scale anaerobic wastewater treatment process. Moreover, the dataset was preprocessed via a self-adapted fuzzy c-means clustering before training the network and a hybrid algorithm for acquiring the optimal parameters of the multiscale GA-FWNN for improving the network precision. The analysis results indicate that the FWNN with the optimal algorithm had a high speed of convergence and good quality of prediction, and the FWNN model was more advantageous than the traditional intelligent coupling models (NN, WNN, and FNN) in prediction accuracy and robustness. The determination coefficients R2 of the FWNN models for predicting both the effluent quality and biogas production rates were over 0.95. The proposed model can be used for analyzing both biogas (methane) production rates and effluent quality over the operational time period, which plays an important role in saving energy and eliminating pollutant discharge in the wastewater treatment system.


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.


2018 ◽  
Vol 77 (11) ◽  
pp. 2589-2597 ◽  
Author(s):  
Christel Kampman ◽  
Laura Piai ◽  
Hardy Temmink ◽  
Tim L. G. Hendrickx ◽  
Grietje Zeeman ◽  
...  

Abstract Chemical energy can be recovered from municipal wastewater as biogas through anaerobic treatment. Effluent from direct anaerobic wastewater treatment at low temperatures, however, still contains ammonium and considerable amounts of dissolved methane. After nitritation, methane can be used as electron donor for denitrification by the anaerobic bacterium ‘Candidatus Methylomirabilis oxyfera’. It was shown that in the presence of 0.7% O2, denitrifying methanotrophic activity slightly increased and returned to its original level after oxygen had been removed. At 1.1% O2, methane consumption rate increased 118%, nitrite consumption rate increased 58%. After removal of oxygen, methane consumption rate fully recovered, and nitrite consumption rate returned to 88%. Therefore, traces of oxygen that bacteria are likely to be exposed to in wastewater treatment are not expected to negatively affect the denitrifying methanotrophic process. 2.0% O2 inhibited denitrifying activity. Nitrite consumption rate decreased 60% and did not recover after removal of oxygen. No clear effect on methane consumption was observed. Further studies should evaluate if intermittent addition of oxygen results in increased growth rates of the slow-growing ‘Candidatus Methylomirabilis oxyfera’.


1999 ◽  
Vol 40 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Pavel Jeníček ◽  
Michal Dohányos ◽  
Jana Zábranská

One of the most recent and progressive reactor principles used in anaerobic wastewater treatment technology is a vertical compartmentalization, which is used in the USSB (Upflow Staged Sludge Bed) reactor. Thanks to its specific design and features the operation of such a reactor can be very flexible. Examples are given showing tested alternatives of operation with combined wastewater and sludge treatment. A high treatment efficiency and a very low specific sludge production was achieved with the operation of a technological system consisting of a USSB reactor and an aerobic biofilm reactor. In the USSB reactor wastewater and surplus sludge treatment can not only be combined but also anaerobic pretreatment and biological denitrification.


1991 ◽  
Vol 24 (8) ◽  
pp. 61-78 ◽  
Author(s):  
S. R. Harper ◽  
M. T. Suidan

A discussion of principles guiding the experimental elucidation of microbial growth and substrate utilization kinetics, and the development of mathematical models for anaerobic wastewater treatment systems, is presented. Recent developments in the areas of anaerobic treatment microbiology (including biomass characterization), biochemical mechanisms, microbial growth dyamics, reactor hydrodynamics, and mathematical modeling approaches are presented and explored.


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