Evaluation of autotrophic and heterotrophic processes in biofilm reactors used for removal of sulphide, nitrate and COD

Biological removal of nitrate by an oil reservoir culture capable of autotrophic and heterotrophic activities: Kinetic evaluation and modeling of heterotrophic process

“…Specifically, Thiomicrospira denitrificans CVO, the main microbial component of Coleville enrichment, could tolerate and oxidize sulphide at concentrations as high as 18 mM and is capable of both autotrophic and heterotrophic activities [34]. Process of autotrophic denitrification by Coleville enrichment has been studied in our earlier work [32,33]. Results have indicated that in the presence of sufficient nitrate, sulphide is the preferred electron donor and oxidation of acetate occurs only after oxidation of sulphide to sulphur and complete exhaustion of sulphide.…”

“…The procedure for the enrichment and maintenance of this culture has been described elsewhere [33]. Coleville Synthetic Brine (CSB) containing per liter: 7.0 g NaCl, 0.68 g MgSO 4 ·7H 2 O, 0.24 g CaCl 2 ·2H 2 O, 0.02 g NH 4 Cl, 0.027 KH 2 PO 4 , 0.68 NaCH 3 COO·3H 2 O, 1.0 g KNO 3 , 1.9 g NaHCO 3 , 6.06 g Tris Base and 0.5 mL trace element solution was used as medium [33]. COD to nitrate ratio in the CSB medium was maintained at 2 mM O 2 (mM NO 3 ) −1 to ensure that acetate was in excess of the theoretical level required for complete reduction of nitrate to N 2 (1.25 mM O 2 /mM NO 3 ).…”

“…Results have indicated that in the presence of sufficient nitrate, sulphide is the preferred electron donor and oxidation of acetate occurs only after oxidation of sulphide to sulphur and complete exhaustion of sulphide. In the absence of sulphide, sulphur and acetate are oxidized simultaneously and oxidation of acetate proceeds much faster than that of sulphur [32,33].…”

“…Autotrophic denitrification has attracted much attention in recent years due to its beneficial applications in desulphurization of sour gases, biogas, and sulphide laden waters, as well as its critical role in the in situ removal of H 2 S from the oil reservoirs subjected to water flooding [8]. Various aspects of autotrophic denitrification thus have been investigated extensively [20][21][22][23][24][25][26][27][28][29][30][31][32][33] Coleville enrichment is a mixed microbial culture originated from the produced water of a Canadian oil reservoir and possesses superior characteristics as far as biodesulphurization is concerned [23,32,33]. Specifically, Thiomicrospira denitrificans CVO, the main microbial component of Coleville enrichment, could tolerate and oxidize sulphide at concentrations as high as 18 mM and is capable of both autotrophic and heterotrophic activities [34].…”

Hydrogen sulfide elimination from natural gas by native isolated bacteria from hot-spring

“…H 2 S is one of the dangerous sulfur compounds which must be removed from fossil fuel prior to utilize [1,2].. Combustion of H 2 S in fossil fuel makes sulfur-oxides (SOx) components.…”