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Author (up) Da Silva, C.; Astals, S.; Peces, M.; Campos, J.L.; Guerrero, L. pdf  doi
openurl 
  Title Biochemical methane potential (BMP) tests: Reducing test time by early parameter estimation Type
  Year 2018 Publication Waste Management Abbreviated Journal Waste Manage.  
  Volume 71 Issue Pages 19-24  
  Keywords Anaerobic digestion; Batch test; Biomethane potential; Kinetics; Modelling; Sensitivity functions  
  Abstract Biochemical methane potential (BMP) test is a key analytical technique to assess the implementation and optimisation of anaerobic biotechnologies. However, this technique is characterised by long testing times (from 20 to > 100 days), which is not suitable for waste utilities, consulting companies or plants operators whose decision-making processes cannot be held for such a long time. This study develops a statistically robust mathematical strategy using sensitivity functions for early prediction of BMP first-order model parameters, i.e. methane yield (B-0) and kinetic constant rate (k). The minimum testing time for early parameter estimation showed a potential correlation with the k value, where (i) slowly biodegradable substrates (k <= 0.1 d(-1)) have a minimum testing times of >= 15 days, (ii) moderately biodegradable substrates (0.1 < k < 0.2 d(-1)) have a minimum testing times between 8 and 15 days, and (iii) rapidly biodegradable substrates (k > 0.2 d(-1)) have testing times lower than 7 days. (C) 2017 Elsevier Ltd. All rights reserved.  
  Address [Da Silva, C.; Guerrero, L.] Univ Tecn Federico Santa Maria, Chem & Environm Engn Dept, Av Espana 1680,Casilla 110, Valparaiso 2340000, Chile, Email: cristopher.dasilva@usm.cl  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0956-053x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000423248500004 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 821  
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Author (up) Da Silva, C.; Peces, M.; Faundez, M.; Hansen, H.; Campos, J.L.; Dosta, J.; Astals, S. doi  openurl
  Title Gamma distribution function to understand anaerobic digestion kinetics: Kinetic constants are not constant Type
  Year 2022 Publication Chemosphere Abbreviated Journal Chemosphere  
  Volume 306 Issue Pages 135579  
  Keywords Anaerobic digestion; Anaerobic co -digestion; Modelling; Statistical analysis; Gamma distribution; First -order kinetics  
  Abstract The Gamma model is a novel approach to characterise the complex degradation dynamics taking place during anaerobic digestion. This three parameters model results from combining the first-order kinetic model and the Gamma distribution function. In contrast to conventional models, where the kinetic constant is considered invariant, the Gamma model allows analysing the variability of the kinetic constant using a probability density function. The kinetic constant of mono-digestion and co-digestion batch tests of different wastes were modelled using the Gamma model and two common first-order models: one-step one-fraction model and one-step twofraction model. The Gamma distribution function approximates three distinct probability density functions, i.e. exponential, log-normal, and delta Dirac. Specifically, (i) cattle paunch and pig manure approximated a lognormal distribution; (ii) cattle manure and microalgae approximated an exponential distribution, and (iii) primary sludge and cellulose approximated a delta Dirac distribution. The Gamma model was able to characterise two distinct waste activated sludge, one approximated to a log-normal distribution and the other to an exponential distribution. The same cellulose was tested with two different inocula; in both tests, the Gamma distribution function approximated a delta Dirac function but with a different kinetic value. The potential and consistency of Gamma model were also evident when analysing pig manure and microalgae co-digestion batch tests since (i) the mean k of the co-digestion tests were within the values of the mono-digestion tests, and (ii) the profile of the density function transitioned from log-normal to exponential distribution as the percentage of microalgae in the mixture increased.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0045-6535 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000830674400001 Approved  
  Call Number UAI @ alexi.delcanto @ Serial 1620  
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Author (up) del Rio, A.V.; Campos, J.L.; Da Silva, C.; Pedrouso, A.; Mosquera-Corral, A. pdf  doi
openurl 
  Title Determination of the intrinsic kinetic parameters of ammonia-oxidizing and nitrite-oxidizing bacteria in granular and flocculent sludge Type
  Year 2019 Publication Separation And Purification Technology Abbreviated Journal Sep. Purif. Technol.  
  Volume 213 Issue Pages 571-577  
  Keywords Ammonia oxidizing bacteria; Flocs; Granules; Kinetics; Monod; Nitrite oxidizing bacteria  
  Abstract The different oxygen affinities of ammonia-oxidizing (AOB) and nitrite-oxidizing bacteria (NOB) are often used to define the operational strategy to achieve partial nitritation (PN) required before the anammox (AMX) process. For this purpose, apparent kinetic parameters are mainly used in the case of granular sludge, which can lead to errors when defining the operational conditions to obtain only nitritation (avoiding nitratation). In the present study, a mathematical methodology is proposed to determine the intrinsic kinetic parameters of AOB and NOB in granular sludge based on data obtained by respirometric assays. Additionally, the oxygen affinity constant (K-O2) and maximum specific rate (r(max)) of flocculent and granular sludge sample, produced under mainstream and sidestream conditions were determined at various temperatures (15, 20 and 30 degrees C). The results show that for granules, the intrinsic K-O2 and r(max) values were lower and higher, respectively, than the apparent values. Furthermore, the K-O2 values for flocs and granules at all of the tested temperatures were lower for NOB than for AOB. The values obtained for the kinetic parameters indicated that it is impossible to maintain partial nitritation by only controlling the dissolved oxygen concentration.  
  Address [del Rio, Angeles Val; Pedrouso, Alba; Mosquera-Corral, Anuska] Univ Santiago de Compostela, Dept Chem Engn, Sch Engn, E-15705 Santiago De Compostela, Spain, Email: mangeles.val@usc.es;  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1383-5866 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000457657200054 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 977  
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