Microbiology of Anaerobic Digestion

1986 ◽  
Vol 18 (12) ◽  
pp. 1-14 ◽  
Author(s):  
R F. V. Novaes

This paper presents a general overview of studies conducted with microorganisms involved in the anaerobic digestion process, and also some ways of applying these studies as fundamental tools in the understanding, improvement and control of the anaerobic treatment of residuals.

2019 ◽  
Vol 1 (2-2) ◽  
Author(s):  
M. Fatma Syahirah ◽  
R. Nazaitulshila

High volumes of sludge discharge from the aquaculture industry have relatively high pollutant content that may lead to severe local environmental problems. Anaerobic digestion is one of the technologies for sludge treatment that might be an efficient method to reduce salty aquaculture sludge production load. However, hydrolysis solubility is becoming a limitation step during the anaerobic digestion process when the occurrence of intermediate accumulation resulted from the conversion of non-soluble biopolymers to soluble organic compounds. Thus, pretreatment is required to increase the solubilization of pollutant parameters from aquaculture sludge before it is further treated in the anaerobic treatment. Therefore, this study focuses on the production of biocatalytic enzyme from the fermentation of pre-consumer supermarket waste such as pineapple dregs to increase the solubility of aquaculture sludge. The fermentation of the pineapples waste was produced via a three-month fermentation of the mixture of molasses, pineapple dregs and water, with the ratio of 1:3:10 in a tight plastic container. Apart from that, analyses showed that the enzyme possessed lipase, amylase and protease activity. The sludge solubilization pretreatment was performed at different pH values, with treatment time for 120 hours and the solubilization was evaluated by determination of Chemical Oxygen Demand (COD) and Total Ammonia Nitrogen (TAN) solubilization; the solubilization of COD and TAN increased by 80% and 50%, respectively. This finding showed that the pineapple enzyme has the capability to solubilize organic compound, which has the potential to improve hydrolysis in further anaerobic digestion process.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 239-248 ◽  
Author(s):  
Sung Ryong Ha ◽  
Dwang Ho Lee ◽  
Sang Eun Lee

Laboratory scale experiments were conducted to develop a mathematical model for the anaerobic digestion of a mixture of night soil and septic tank sludge. The optimum mixing ratio by volume between night soil and septic tank sludge was found to be 7:3. Due to the high solids content in the influent waste, mixed-liquor volatile suspended solids (MLVSS) was not considered to be a proper parameter for biomass concentration, therefore, the active biomass concentration was estimated based on deoxyribonucleic acid (DNA) concentration in the reactor. The weight ratio between acidogenic bacteria and methanogenic bacteria in the mixed culture of a well-operated anaerobic digester was approximately 3:2. The proposed model indicates that the amount of volatile acid produced and the gas production rate can be expressed as a function of hydraulic residence time (HRT). The kinetic constants of the two phases of the anaerobic digestion process were determined, and a computer was used to simulate results using the proposed model for the various operating parameters, such as BOD5 and volatile acid concentrations in effluent, biomass concentrations and gas production rates. These were consistent with the experimental data.


2020 ◽  
Vol 53 (2) ◽  
pp. 16840-16845
Author(s):  
Camilo Garcia-Tenorio ◽  
Mihaela Sbarciog ◽  
Eduardo Mojica-Nava ◽  
Alain Vande Wouwer

Chemosphere ◽  
2021 ◽  
pp. 130449
Author(s):  
Yiwei Liu ◽  
Xiang Li ◽  
Shaohua Wu ◽  
Zhao Tan ◽  
Chunping Yang

Author(s):  
Miguel Casallas-Ojeda ◽  
Sully Meneses-Bejarano ◽  
Ronald Urueña-Argote ◽  
Luis Fernando Marmolejo-Rebellón ◽  
Patricia Torres-Lozada

2005 ◽  
Vol 52 (1-2) ◽  
pp. 419-426 ◽  
Author(s):  
C.A. Aceves-Lara ◽  
E. Aguilar-Garnica ◽  
V. Alcaraz-González ◽  
O. González-Reynoso ◽  
J.P. Steyer ◽  
...  

In this work, an optimization method is implemented in an anaerobic digestion model to estimate its kinetic parameters and yield coefficients. This method combines the use of advanced state estimation schemes and powerful nonlinear programming techniques to yield fast and accurate estimates of the aforementioned parameters. In this method, we first implement an asymptotic observer to provide estimates of the non-measured variables (such as biomass concentration) and good guesses for the initial conditions of the parameter estimation algorithm. These results are then used by the successive quadratic programming (SQP) technique to calculate the kinetic parameters and yield coefficients of the anaerobic digestion process. The model, provided with the estimated parameters, is tested with experimental data from a pilot-scale fixed bed reactor treating raw industrial wine distillery wastewater. It is shown that SQP reaches a fast and accurate estimation of the kinetic parameters despite highly noise corrupted experimental data and time varying inputs variables. A statistical analysis is also performed to validate the combined estimation method. Finally, a comparison between the proposed method and the traditional Marquardt technique shows that both yield similar results; however, the calculation time of the traditional technique is considerable higher than that of the proposed method.


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