title: Assessment of sulfide production risk in soil during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification process.
abstract: This study aimed to determine the potential of sulfide generation during infiltration through soil of domestic wastewater treated by a sulfur-utilizing denitrification process. Three types of soil with different permeability rates (K s = 0.028, 0.0013, and 0.00015 cm/s) were investigated to evaluate the potential risk of sulfur generation during the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system. These soils were thoroughly characterized and tested to assess their capacity to be used as drainages for wastewaters. Experiments were conducted under two operating modes (saturated and unsaturated). Sulfate, sulfide, and chemical oxygen demand (COD) levels were determined over a period of 100 days. Despite the high concentration of sulfates (200 mg/L) under anaerobic conditions (ORP = -297 mV), no significant amount of sulfide was generated in the aqueous (<0.2 mg/L) or gaseous (<0.15 ppm) phases. Furthermore, the soil permeability did not have a noticeable effect on the infiltration of domestic wastewater treated by a sulfur-utilizing denitrification system due to low contents of organic matter (i.e., dissolved organic carbon, DOC). The autotrophic denitrification process used to treat the domestic wastewater allowed the reduction of the concentration of biochemical oxygen demand (BOD5) below 5 mg/L, of DOC below 7 mg/L, and of COD below 100 mg/L.
authors.affiliation: Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Université du Québec, 490 rue de la Couronne, Québec, QC, G1K 9A9, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Ghorbel
authors.affiliation: Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Université du Québec, 490 rue de la Couronne, Québec, QC, G1K 9A9, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Coudert
authors.affiliation: PREMIER TECH, 1 avenue Premier Campus Premier Tech, Rivière-du-Loup, QC, G5R 6C1, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Gilbert
authors.affiliation: Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Université du Québec, 490 rue de la Couronne, Québec, QC, G1K 9A9, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Mercier
authors.affiliation: Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Université du Québec, 490 rue de la Couronne, Québec, QC, G1K 9A9, Canada. blaisjf@ete.inrs.ca.
authors.forename: J F
authors.initials: JF
authors.lastname: Blais
mesh_terms: D052818:Autotrophic Processes; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D058440:Denitrification; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry*; D013431:Sulfates / Q000032:analysis / Q000737:chemistry; D013440:Sulfides / Q000032:analysis* / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D012987:Soil; D013431:Sulfates; D013440:Sulfides; D013455:Sulfur; D062065:Wastewater
keywords: Autotrophic denitrification; Domestic wastewater; Infiltration; Soil; Sulfide production