M.M. Durán

Universidad de Sevilla, Sevilla, Andalusia, Spain

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Publications (9)1.85 Total impact

  • R. Borja, E. Sánchez, M. M. Durán
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    ABSTRACT: Addition of zeolite counteracted to some extent the inhibitory effect of ammonia during thermophilic anaerobic digestion of cattle manure. In continuously‐fed reactor experiments, addition of zeolite delayed the onset of the inhibition and aided process recovery after initial inhibition. The effect was observed mainly when the ammonia concentration was increased gradually, indicating that the major effect of zeolite was not through a direct antagonistic effect towards ammonia but through an increased process resistance to toxic compounds. In batch experiments zeolite had a similar stimulatory effect leading to a decreased lag phase and increased methane production rate in ammonia inhibited reactors.
    Journal of Environmental Science and Health Part A-toxic/hazardous Substances & Environmental Engineering - J ENVIRON SCI HEALTH A. 01/1996; 31(2):479-500.
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    ABSTRACT: Three materials of different structure, sepiolite, saponite and bentonite, assayed as supports for the microorganisms effecting anaerobic digestion, were found to behave differently towards cheese whey wastewater from a kinetic point of view. Assuming the overall anaerobic digestion process to conform to first-order kinetics, the apparent kinetic constant for the digester including sepiolite as support was 2.44 days−1, while that of the digester using the saponite and bentonite support was 2.20 days−1 and 0.70 days−1, respectively. Thus, the support used to immobilize the microorganisms that mediate the process had a marked influence on the constant. This was found significant at 95% confidence level. The yield coefficients, Yp/s, were 0.336, 0.329 and 0.311 litres CH4 STP/g COD for the sepiolite, saponite and bentonite supports, respectively.
    Resources, Conservation and Recycling. 06/1994;
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    ABSTRACT: A study of the kinetics of the anaerobic digestion of brewery wastewater was carried out using a 1-litre, continuous-flow, completely-mixed, bioreactor operating at 35°C and containing a saponite-immobilized biomass at a concentration of 6·2 g volatile suspended solids (VSS)/litre. The bioreactor worked satisfactorily in a range of hydraulic retention times from 1·2 to 10 days and eliminated more than 95% of the initial chemical oxygen demand (COD) in all instances.Guiot's kinetic model was used to determine the macroenergetic parameters of the system, and showed it to have a yield coefficient for the biomass (Y) of 0·080 g VSS/g COD and a specific rate of substrate uptake for cell maintenance (m) of 0·045 g COD/g VSS day.The experimental results showed the rate of substrate uptake (Rs; g COD/g VSS day), correlated with the concentration of biodegradable substrate (Sb; g COD/litre), through an equation of the Michaelis-Menten type.
    Process Biochemistry. 01/1994;
  • R Borja, A Martín, M.M Durán, J Barrios
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    ABSTRACT: The kinetics of the anaerobic treatment of dairy wastewater has been studied. The material consists basically of washing and rinsing waters produced in the delivery and packaging of the milk and from tanks, pumps or spill (chemical oxygen demand=1.5 gl1). The bioreactors contained suspensions of micronized clays (sepiolite, saponite and bentonite) of different chemical compositions on which the micro-organisms responsible for the process adhered.Assuming that the overall anaerobic digestion process conforms to first-order kinetics, experimental data pairs [namely volumetric yield of methane (G) and time (t)] fitted the equation: G=Gm·[1−exp(−K0·t)]. The apparent kinetic constant, K0, was determined in each of the situations studied and its mean value was 1.32 day−1 (sepiolite), 1.00 day−1 (saponite) and 0.37 day−1 (bentonite). Thus, the support used to immobilize the microorganisms that mediate the process had a marked influence on the aforesaid constant. This was significant at 95% confidence level. The yield coefficient of methane, Yp, was 342 ml CH4·g−1COD. The average elimination of COD was 90.4%.
    Applied Clay Science. 01/1993;
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    ABSTRACT: The kinetics of anaerobic treatment of wastewater (consisting of whey plus wash water with a COD of 30 g/1) from a cheese factory was investigated using bioreactors which contained suspension of micronized clays (Sepiolite, Saponite and Bentonite), to which the anaerobic microorganisms adhered. On the assumption that the overall process conforms to first-order kinetics, experimental data pairs (namely the methane volume yielded (G) and time (t)) fitted the equation: Gm = Gm · [I − exp(-K0 · t)]. The apparent kinetic constants, K0, were determined under various conditions. The mean values were 2.5 days−1 (Sepiolite), 1.9 days−1 (Saponite), 0.8 days−1 (Bentonite) and 0.5 days−1 (Control). The yield coefficients of methane, Yp, were around 350 ml CH4 STP/g COD. The elimination of COD exceeded 82% in all cases.
    Biomass & Bioenergy - BIOMASS BIOENERG. 01/1993; 4(1):15-22.
  • R. Borja, A. Martín, M. Luque, M.M. Durán
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    ABSTRACT: A kinetic study was made of the anaerobic purification or biomethanation of wine distillery wastewaters (‘vinasses’), using bioreactors containing various suspended clayey supports (sepiolite, bentonite and saponite), on to which the microorganisms effecting the purification were immobilised. Assuming that the overall anaerobic fermentation process conforms to first-order kinetics, experimental data pairs, namely the methane volume yielded (G) and the time (t), fitted the following equation: G = Gm × (1 − exp (K0 × t)). The specific rate constant, K0, was determined in each of the situations studied. The support used has a marked influence on the kinetic constant of the process; the saponite support yielding significantly the highest values. On the other hand, the specific rate constant decreased over the chemical oxygen demand (COD) range studied (1·0–8·1 g/litre) when the volume of wastewater added or substrate concentration was increased; this showed an inhibition phenomenon. Also, the mean rate biogas production and the methanogenic activity decreased irrespective of the support used. The yield coefficient, YP, was 0·32 litres CH4 STP/g COD.
    Process Biochemistry. 01/1993;
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    ABSTRACT: Removal of most of the phenolic compounds (88.5%) present in molasses by an aerobic pretreatment with Geotrichum candidum considerably increased the kinetics of anaerobic digestion of this wastewater. Inhibition phenomena were not observed in the range of COD studied (2.3–12.9 g/l). The yield coefficient of methane was 51 % higher than for untreated molasses.
    Biotechnology Letters 01/1993; 15(3):311-316. · 1.85 Impact Factor
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    ABSTRACT: Wine-distillery wastewater has a high organic pollutant load (40 g COD/litre) which includes various phenolic compounds, the major ones being gallic acid, p-coumaric acid and gentisic acid. This feature makes it difficult to treat this wastewater anaerobically without a prior dilution of the wastewater. Partial removal of some of the organic matter and phenolic compounds by aerobic pretreatment with Geotrichum candidum is described in this study. This method provides a partially purified effluent that is more rapidly anaerobically degraded than the original wine-distillery wastewater for the same COD-loading level. The anaerobic bioreactor contained a suspension of micronized clay (saponite) to which the microorganisms responsible for the process adhered. Assuming that the overall anaerobic digestion process follows first-order kinetics, the specific rate constant, K0, was obtained under various conditions. In contrast to the anaerobic digestion of unmodified wine-distillery wastewater, the kinetic constants of the anaerobic digestion of aerobically pretreated wine-distillery wastewater were virtually constant over the COD range used (1·0–6·7 g/litre).
    Bioresource Technology. 01/1993;
  • R BORJA, M DURAN, A MARTIN
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    ABSTRACT: Three materials of different composition, sepiolite, saponite and bentonite, assayed as supports for the micro-organisms effecting anaerobic fermentation, were found to behave differently towards slaughterhouse wastewater from a kinetic point of view. Assuming the overall anaerobic digestion process to conform to first-order kinetics, the apparent kinetic constant for the digester including bentonite as support was 1·28 per day, while that of the digesters using the sepiolite and saponite were 0·83 and 0·56 per day, respectively. Thus, the support used to immobilize the micro-organisms that mediate the process had a marked influence on the constant. This was found to be significant at 95% confidence level. The yield coefficient, Yp, was 343, 334 and 349 ml CH4 STP per g COD added for the sepiolite, saponite and bentonite, respectively.
    Bioresource Technology - BIORESOURCE TECHNOL. 01/1993; 44(1):57-60.

Publication Stats

111 Citations
1.85 Total Impact Points

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Institutions

  • 1993
    • Universidad de Sevilla
      • Departamento de Ingeniería Química
      Sevilla, Andalusia, Spain