title: Fate of H2S during the cultivation of Chlorella sp. deployed for biogas upgrading.
abstract: The H2S may play a key role in the sulfur cycle among the biogas production by the anaerobic digestion of wastes and the biogas upgrading by a microalgae based technology. The biogas is upgraded by contacting with slightly alkaline aqueous microalgae culture, then CO2and H2S are absorbed. The dissolved H2S could limit or inhibit the microalgae growth. This paper evaluated the role of dissolved H2S and other sulfured byproducts under prevailing biogas upgrading conditions using a microalgal technology. At initial stages of batch cultivation the growth of Chlorella sp. was presumably inhibited by dissolved H2S. After 2 days, the sulfides were oxidized mainly by oxic chemical reactions to sulfate, which was later rapidly assimilated by Chlorella sp., allowing high growing rates. The fate of H2S during the microalgae cultivation at pH > 8.5 was assessed by a mathematical model where the pentasulfide, thiosulfate and sulfite were firstly produced and converted finally to sulfate for posterior assimilation.
authors.affiliation: Institute of Process Engineering in Life Sciences, Section III Bioprocess Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany; Institute of Engineering, Universidad Nacional Autónoma de México (UNAM), Circuito Escolar, Ciudad Universitaria, 04510, Mexico City, Mexico. Electronic address: agonzalezs@iingen.unam.mx.
authors.forename: Armando
authors.initials: A
authors.lastname: González-Sánchez
authors.affiliation: Institute of Process Engineering in Life Sciences, Section III Bioprocess Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Posten
mesh_terms: D056804:Biofuels; D002245:Carbon Dioxide; D002708:Chlorella; D058086:Microalgae; D013455:Sulfur
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide; D013455:Sulfur
keywords: Biogas upgrading; Chemical oxidation; Chlorella sp.; H(2)S; Modelling; Sulfate assimilation