Kinetic and stoichiometric characterization of anoxic sulfideoxidation by SO-NR mixed cultures from anoxic biotrickling filters.

Monitoring the biological activity in biotrickling filters is difficult since it implies estimating biomass concentration and its growth yield, which can hardly be measured in immobilized biomass systems. In this study, the characterization of a sulfide-oxidizing nitrate-reducing biomass obtained from an anoxic biotrickling filter was performed through the application of respirometric and titrimetric techniques. Previously, the biomass was maintained in a continuous stirred tank reactor under steady-state conditions resulting in a growth yield of 0.328±0.045 g VSS/g S. To properly assess biological activity in respirometric tests, abiotic assays were conducted to characterize the stripping of CO2 and sulfide. The global mass transfer coefficient for both processes was estimated. Subsequently, different respirometric tests were performed: (1) to solve the stoichiometry related to the autotrophic denitrification of sulfide using either nitrate or nitrite as electron acceptors, (2) to evaluate the inhibition caused by nitrite and sulfide on sulfide oxidation, and (3) to propose, calibrate, and validate a kinetic model considering both electron acceptors in the overall anoxic biodesulfurization process. The kinetic model considered a Haldane-type equation to describe sulfide and nitrite inhibitions, a non-competitive inhibition to reflect the effect of sulfide on the elemental sulfur oxidation besides single-step denitrification since no nitrite was produced during the biological assays

The psychic life of fragments: splitting from Ferenczi to Klein

The present paper starts from the reflection that there is a curious “phenomenological gap” in psychoanalysis when it comes to processes of splitting and to describing the “life” of psychic fragments resulting from processes of splitting. In simpler terms, we are often in a position to lack a precise understanding of what is being split and how the splitting occurs. I argue that although Melanie Klein’s work is often engaged when talking of splitting (particularly through discussions on identification, projection and projective identification), there are some important phenomenological opacities in her construction. I show that by orchestrating a dialogue between Melanie Klein and Sándor Ferenczi, we arrive at a fuller and more substantive conception of psychic splitting and of the psychic life of fragments which are the result of splitting. This is even more meaningful because there are some unacknowledged genealogical connections between Ferenczian concepts and Kleinian concepts, which I here explore. While with Klein we remain in the domain of “good” and “bad” objects—polarised objects which are constantly split and projected—with Ferenczi we are able to also give an account of complicated forms of imitation producing psychic fragments and with a “dark” side of identification, which he calls “identification with the aggressor”. While attempting to take steps toward imagining a dialogue between Klein and Ferenczi, I note a certain silent “Ferenczian turn” in a late text by Melanie Klein, “On the Development of Mental Functioning”, written in 1958. In particular, I reflect on her reference to some “terrifying figures” of the psyche, which cannot be accounted for simply as the persecutory parts of the super-ego but are instead more adequately read as more enigmatic and more primitive psychic fragments, resulting from processes of splitting

CATALYTIC AND NON-CATALYTIC PYROLYSIS OF BIOLOGICALLY TREATED MANURE

SSCI-VIDE+CARE+DLGInternational audienceThe utilization of manure for waste-to-bioenergy conversion processes may be a sustainable development choice rather than its traditional use as a fertilizer. Furthermore, the valorization of manure via thermochemical conversion routes and their integration with biological processes can provide an additional pathway in the utilization of residual biomass. On the other hand, the use of metal oxides might enhance the performance of thermochemical processes such as pyrolysis by either cracking the heavy hydrocarbon chains which turns into the production of a higher quality fuel or increasing the H-2 production by promoting secondary reactions as steam reforming or water-gas shift. The derivate thermogravimetric (DTG) profiles of manure samples could be divided into four general stages: dehydration, devolatilization, char transformation and inorganic matter decomposition. For samples Pre and Dig R, the maximum DTG peaks were obtained at the same temperature. The first peak was lower for sample Dig R due to the removal of organic matter during the anaerobic digestion. On the other hand, the fourth step was not observed for sample Swine, which could be attributed to its low inorganic components (ash) content. The catalysts used in the catalytic pyrolysis process were: CaO, MgO and ZnO. The addition of these oxides modified the corresponding DTG profiles especially for sample Pre. These effects could be also observed in the mass spectra (MS) profile of the samples leading to a higher production of H2, especially at high temperatures which could be attributed to the enhancement of secondary reactions that usually take place at temperatures higher than 500 degrees C

CATALYTIC AND NON-CATALYTIC PYROLYSIS OF BIOLOGICALLY TREATED MANURE

SSCI-VIDE+CARE+DLGInternational audienceThe utilization of manure for waste-to-bioenergy conversion processes may be a sustainable development choice rather than its traditional use as a fertilizer. Furthermore, the valorization of manure via thermochemical conversion routes and their integration with biological processes can provide an additional pathway in the utilization of residual biomass. On the other hand, the use of metal oxides might enhance the performance of thermochemical processes such as pyrolysis by either cracking the heavy hydrocarbon chains which turns into the production of a higher quality fuel or increasing the H-2 production by promoting secondary reactions as steam reforming or water-gas shift. The derivate thermogravimetric (DTG) profiles of manure samples could be divided into four general stages: dehydration, devolatilization, char transformation and inorganic matter decomposition. For samples Pre and Dig R, the maximum DTG peaks were obtained at the same temperature. The first peak was lower for sample Dig R due to the removal of organic matter during the anaerobic digestion. On the other hand, the fourth step was not observed for sample Swine, which could be attributed to its low inorganic components (ash) content. The catalysts used in the catalytic pyrolysis process were: CaO, MgO and ZnO. The addition of these oxides modified the corresponding DTG profiles especially for sample Pre. These effects could be also observed in the mass spectra (MS) profile of the samples leading to a higher production of H2, especially at high temperatures which could be attributed to the enhancement of secondary reactions that usually take place at temperatures higher than 500 degrees C