title: Simultaneous nitrate and organic matter removal from salmon industry wastewater: the effect of C/N ratio, nitrate concentration and organic load rate on batch and continuous process.
abstract: Although simultaneous denitrification-anaerobic digestion has been studied extensively, the use of salmon effluents as organic matter source has received little attention. This study evaluated the effect of C/N ratio, nitrate concentration, and organic load rate (OLR) on simultaneous nitrate and organic matter removal using salmon effluents. The study was carried out in a batch reactor with suspended biomass at 37 °C and pH 7.5, and in continuous biofilm tubular reactors at 37 °C fed with a mixture of a synthetic substrate and a saline protein-rich salmon-plant effluent. The results of the batch and continuous experiments showed that nitrate abatement was greater than 95% at all the studied C/N ratios, without effect of the C/N ratio on NO(3)(-)-N transformation and ammonia production. An increase of nitrate concentration increased organic matter consumption as well as the hydrolytic rate. The organic matter reduction varied between 88% and 40% in the continuous process. For a continuous process, the increase of the OLR decreases the removal of organic matter.
authors.affiliation: Department of Chemical Engineering, University of Santiago of Chile, Santiago, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Huiliñir
authors.forename: S
authors.initials: S
authors.lastname: Hernández
authors.forename: E
authors.initials: E
authors.lastname: Aspé
authors.forename: M
authors.initials: M
authors.lastname: Roeckel
mesh_terms: D000818:Animals; D019149:Bioreactors; D002244:Carbon; D058440:Denitrification; D005398:Fisheries / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D009566:Nitrates / Q000032:analysis* / Q000737:chemistry; D009584:Nitrogen; D009589:Nitrogen Oxides / Q000378:metabolism; D011506:Proteins / Q000737:chemistry; D012474:Salmon; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D007220:Industrial Waste; D009566:Nitrates; D009589:Nitrogen Oxides; D011506:Proteins; D002244:Carbon; D009584:Nitrogen