Aplicação de bactérias do ciclo do enxofre no tratamento de efluentes e recuperação de enxofre elementar

Abstract

Rapid urban growth combined with expansion of different industrial sectors, agriculture and mining lead to numerous cases of pollution and environmental degradation. Research is being conducted to find solutions more economical and ecologically correct for the decontamination of industrial and domestic wastewater. The biological cycle of sulfur is attracting great interest from the scientific community, especially because of the discovery of many micro-organisms capable of reducing pollution caused by sulfur and promote the elemental sulfur recovery. These organisms are found in the seabed in water column of lakes and rivers, in sediments and other environments characterized by extreme conditions of salinity, pH and temperature. Bacteria could play an instrumental role in the oxidative reactions such as reductive in the sulfur cycle. The biogeochemical sulfur cycle include numerous essential processes, the reactions that occur in this cycle include the sulfide (H2S) and elemental sulfur (S) oxidation to sulfate (SO4-2), sulfate and elemental sulfur reduction, sulfur disproportanation to H2S, organic sulfur compounds oxidation and reduction, and desulfurylation. The treatment of wastewater containing sulfur compounds is particularly difficult to perform. Several studies have been conducted on the metabolic properties, phylogeny and ecological behavior of bacteria involved in the biological sulfur cycle. This work highlights the biological sulfur cycle and some applications of these bacteria in the treatment of industrial and domestic effluents for sulfur and H2S removal and elemental sulfur recovery.