title: Post-treatment of anaerobic reactor effluent using coagulation/oxidation followed by double filtration.
abstract: This study evaluates the efficacy of a sanitary sewage treatment system, proposing post-treatment of the effluent generated by the upflow anaerobic sludge blanket UASB reactor, through a Fenton coagulation/oxidation ((ferric chloride (FC) or ferrous sulfate (FS) and peracetic acid (PAA)), followed by a double filtration system, composed of a gravel ascending drainage filter and a sand descending filter. Following the assessment of treatability, the system efficiency was evaluated using physicochemical and microbiological parameters. In all treatments performed in the pilot unit, total suspended solids (TSS) were completely removed, leading to a decrease in turbidity greater than 90% and close to 100% removal of total phosphorous. In the FC and PAA combination, the effluent was oxygenated prior to filtration, enabling a more significant removal of biochemical oxygen demand (BOD), which characterizes aerobic degradation even in a quick sand filter. The treatments carried out in the presence of the PAA oxidizing agent showed a more significant bleaching of the effluent. Concerning the microbiological parameters, the simultaneous use of PAA and FC contributed to the partial inactivation of the assessed microorganisms. A 65% recovery of the effluent was obtained with the proposed treatment system, considering the volume employed in filter backwashing.
authors.affiliation: Department of Environmental Chemistry, Tocantins Federal University, 77402-970, Gurupi, Tocantins, Brazil. grasielesoares@gmail.com.
authors.forename: Grasiele Soares
authors.initials: GS
authors.lastname: Cavallini
authors.affiliation: Master's Program on Sanitary and Environmental Engineering, Department of Environmental Engineering, Centro-Oeste State University, Irati, Parana, Brazil.
authors.forename: Carlos Magno
authors.initials: CM
authors.lastname: de Sousa Vidal
authors.affiliation: Master's Program on Sanitary and Environmental Engineering, Department of Environmental Engineering, Centro-Oeste State University, Irati, Parana, Brazil.
authors.forename: Jeanette Beber
authors.initials: JB
authors.lastname: de Souza
authors.affiliation: DoctoralProgram in Chemistry, Ponta Grossa StateUniversity, Ponta Grossa, Paraná, Brazil.
authors.forename: Sandro Xavier
authors.initials: SX
authors.lastname: de Campos
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D005374:Filtration; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D012722:Sewage; D010758:Phosphorus; D010100:Oxygen
keywords: Coagulation/oxidation; Double filtration; Peracetic acid and iron ions; Wastewater reuse