A two-stage process is proposed that is based on the biological production of H2S from organic waste and its subsequent overall conversion to H2 via an exothermic reaction. The current study examined the first step of this process, namely, the design and operation of a packed bed bioreactor with high volumetric H2S production (mol/m3.d) and its comparison to analogous methanogenic technology. A novel method of inoculum design was developed by evaluating the kinetics and immobilization potential of Desulfovibrio desulfuricans (ATCC 7757) and a sulfate reducing bacteria (SRB) consortium. The consortium’s kinetics, as measured by the specific rate of sulfate reduction (1.2 g SO42-/g CDW.h), were approximately twice as fast as those of D. desulfuricans. The pure strain however exhibited superior immobilization potential. Studies revealed that a mixed inoculum containing 96 % D. desulfuricans and 4 % consortium facilitated the rapid immobilization of a highly active SRB biomass and contributed to improved bioreactor performance. Diatomaceous earth (DE) pellets, porous glass beads, polyurethane foam, and bone char were evaluated as potential carrier materials for SRB immobilization. The DE pellets immobilized the most biomass, were well suited for use at the industrial scale, and were thus employed in all continuous flow bioreactor experiments. Using the designed inoculum and DE pellets, a 615 mL bioreactor achieved a volumetric productivity of 493 mol H2S/m3.d (at D = 1.6 h-1) and a dissolved sulfide concentration of 9.9 mM. This occurred after 8 d of operation and represents a tenfold reduction in the required start-up period compared to similar bioreactors in the literature. An N2 strip gas was later used to remove the dissolved sulfide to the gas phase and enhance sulfate conversion. Shifting the medium pH from 7 to 6 increased the fraction of strippable sulfide and improved the strip gas composition from 3.6 to 5.8 mol % H2S. The strip gas to liquid feed ratio (G/L, m3/m3) was investigated in the range of 0-14 and was found to be a suitable basis for scale-up indicating that productivities of up to 830 mol/m3.d were readily achievable. This represents a considerable improvement over current methanogenic bioreactor productivities. / Thesis (Master, Chemical Engineering) -- Queen's University, 2007-09-23 16:44:22.443

Berlin, Techn. Univ., Diss., 2003. / Computerdatei im Fernzugriff.

Berlin, Techn. Univ., Diss., 2003. / Computerdatei im Fernzugriff.

Duisburg, Essen, Universiẗat, Diss., 2004.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 160-168). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 160-168). Also available on the Internet.

This study aimed to investigate the feasibility of using several genetic techniques for identification of sulphate-reducing bacteria. A group of eight type strains (seven of which were <I>Desolfovibrio</I>) were used as test group for every method except RSGP, for which an established set of oil field isolates was used. Ribotyping involves restriction fragment length polymorphism (RFLP) analysis of ribosomal RNA (rRNA) operons. Hybridisation of <I>Eco </I>RI-digested genomic DNA to a PCR-amplified (500 bp) rRNA gene product resulted in generation of discriminatory RFLP patterns for all but two of the eight test strains. Restriction digestion of PCR-amplified (1400 bp) rRNA gene products (PCR-robotyping) allowed differentiation between all eight strains for two of the seven enzymes tested. Random amplified polymorphic DNA (RAPD) analysis allows PCR-generation of distinct sets ("fingerprints") of amplification products from genomic DNA templates. Nine oligonucleotide decamers were tested as primers, two of which were found to generate discriminatory profiles for each of the eight type strains. Hybridisation of 32P-labelled RAPD products against genomic DNA from eleven sulphate-reducing strains was found to result in specific hybridisation of probes to their complementary genomic DNA. Reversal of the hybridisation procedure, using 32P-labelled genomic DNA against immobilised RAPD probes, was found to allow analysis of mixed genomic DNA samples in a single step. This reverse method is very similar in principle to RSGP, which allows analysis of mixed genomic DNA preparations by hybridisation against a master filter of genomic DNAs from a series of environmental bacterial standards. This study developed a method to allow quantitation of RSGP hybridisation signals, and went on to analyse biofilm samples from various locations in Western Canadian oil fields, resulting in identification of 21% (average) of each mixed DNA sample.

Berlin, Techn. Univ., Diss., 2001. / Computerdatei im Fernzugriff.

Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed June 29, 2006). Vita. Includes bibliographical references.