Optimizing of phosphorus dosage in autotrophic denitrification of Thiobacillus denitrificans in batch reactors

Abstract

Thiobacillus denitrificans is widely distributed microorganism, which is not toxic and pathogenic. It belongs to group of chemolithoautotrophic and facultative anaerobic bacteria. It can obtain energy by the oxidation of elemental sulfur and certain other sulfur-containing inorganic compounds while electrons are released. Under anoxic conditions, nitrate and nitrite ions are reduced by these electrons. It is environmentally important – Th. denitrificans can be used in processes of alternative methods of removing nitrates from such contaminated water. In this work, we focused on the optimal dosage of phosphorus to the reactor, which is one of the key factors affecting growth of bacteria cells and which does not lead to secondary contamination of treated water. All experiments were done in batch reactors and the elemental sulfur was used as electron donor.