Interactions of the sulfur and nitrogen cycles: microbiology and process technology

Abstract

Microorganisms play a key role in the biogeochemical cycling of numerous elements. This is particularly the case for the elements of living biomass such as carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus. When studying these cycles, the interactions between the different elements are of utmost importance. This chapter describes the interactions between the sulfur and nitrogen cycles, with particular attention paid to processes allowing nitrogen removal from polluted environments using sulfur cycle conversions. 13.1.1 The nitrogen cycle The nitrogen cycle largely depends on microbial activities (Figure 13.1). Gaseous N 2 from the air is reduced in soil or water to ammonium by bacterial nitrogen fixationstep (1) in Figure 13.1. These bacteria possess the Nif genes that code for a specialized enzyme, nitrogenase, which catalyzes this N 2 reduction under well-defined conditions. In soil, it is present in free-living microorganisms such as Azotobacter sp. and Klebsiella sp. or in symbiotic bacteria such as Rhizobium sp. growing in association with plants. Nitrogen fixation also occurs in aquatic habitats by Cyanobacteria. Ammonium thus formed is incorporated into organic

Autotrophic Denitrification of Nitrate Rich Wastewater in Fluidized Bed Reactors Using Pyrite and Elemental Sulfur as Electron Donors

“…It is likely that the formation and precipitation of other minerals (e.g. CaSO 4 -Section 4.2) acted as a physical barrier and limited electron transfer (Chazal et al, 2020). The period IX-A is the only one in which the N-NO − 3 concentration in SR effluent exceeded the Usepa (2020) drinking water regulations (10 mg N-NO − 3 /L).…”

“…Thiobacillus sp. are known to exploit reduced sulfur compounds as electron donors (Huang et al, 2020;Chazal et al, 2020;Zhang et al, 2022) and Sulfurovum sp. are also frequently found in autotrophic denitrification literature (Li et al, 2022;Xu et al, 2016).…”

Cinética de bactérias Anammox aderidas a biofilmes

“…Deste modo, a sua disponibilidade na biota se deve à ciclagem ambiental das formas disponíveis destes elementos, as quais são extremamente dependentes de processos biológicos (CHAZAL & LENS, 2000). Sendo assim, em relação a sua microbiologia, o ciclo do nitrogênio é formado por reações catabólicas, sendo elas: Fixação, Nitrificação parcial e total e Desnitrificação (JETTEN et al, 2009).…”