title: Enhancing denitrification using a carbon supplement generated from the wet oxidation of waste activated sludge.
abstract: This study compared the effect of four pure carbon supplements on biological denitrification to a liquor derived as a by-product from the wet oxidation (WO) of waste activated sludge. Sequencing batch reactors were used to acclimate sludge biomass, which was used in batch assays. Acetate, WO liquor and ethanol-supplementation generated the fastest denitrification rates. Acetate and WO liquor were efficiently utilised by all acclimated biomass types, while poor rates were achieved with methanol and formate. When comparing an inoculum from an ethanol-supplemented and non-supplemented wastewater treatment plant (WWTP), the ethanol-acclimated sludge obtained superior denitrification rates when supplemented with ethanol. Similarly high nitrate removal rates were achieved with both sludge types with acetate and WO liquor supplementation, indicating that WO liquors could achieve excellent rates of nitrate removal. The performance of the WO liquor was attributed to the variety of organic carbon substrates (particularly acetic acid) present within the liquor.
authors.affiliation: Green Processing Unit, Sustainable Design, Scion, Private Bag 3020, Rotorua 3046, New Zealand. PJStrong@gmail.com
authors.forename: P J
authors.initials: PJ
authors.lastname: Strong
authors.forename: B
authors.initials: B
authors.lastname: McDonald
authors.forename: D J
authors.initials: DJ
authors.lastname: Gapes
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000494:pharmacology*; D058440:Denitrification / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry*; D018508:Water Purification
chemical_list: D012722:Sewage; D014867:Water; D002244:Carbon