title: Removal of the organic content from a bleached kraft pulp mill effluent by a treatment with silica-alginate-fungi biocomposites.
abstract: This study attempts a treatment strategy of a bleached kraft pulp mill effluent with Rhizopus oryzae or Pleurotus sajor caju encapsulated on silica-alginate (biocomposite of silica-alginate-fungi, with the purpose of reducing its potential impact in the environment. Active (alive) or inactive (death by sterilization) Rhizopus oryzae or Pleurotus sajor caju was encapsulated in alginate beads. Five beads containing active and inactive fungus were placed in a mold and filled with silica hydrogel (biocomposites). The biocomposites were added to batch reactors containing the bleached kraft pulp mill effluent. The treatment of bleached kraft pulp mill effluent by active and inactive biocomposites was performed throughout 29 days at 28°C. The efficiency of treatment was evaluated by measuring the removal of organic compounds, chemical oxygen demand and the relative absorbance ratio over time. Both fungi species showed potential for removal of organic compounds, colour and chemical oxygen demand. Maximum values of reduction in terms of colour (56%), chemical oxygen demand (65%) and organic compounds (72-79%) were attained after 29 days of treatment of bleached kraft pulp mill effluent by active Rhizopus oryzae biocomposites. The immobilization of fungi, the need for low fungal biomass, and the possibility of reutlization of the biocomposites clearly demonstrate the industrial and environmental interest in bleached kraft pulp mill effluent treatment by silica-alginate-fungi biocomposites.
authors.affiliation: ISEIT/Viseu, Instituto Piaget, Estrada do Alto do Gaio, Galifonge, Lordosa, Viseu, Portugal.
authors.forename: Katia
authors.initials: K
authors.lastname: Duarte
authors.forename: Celine I L
authors.initials: CI
authors.lastname: Justino
authors.forename: Ruth
authors.initials: R
authors.lastname: Pereira
authors.forename: Teresa S L
authors.initials: TS
authors.lastname: Panteleitchouk
authors.forename: Ana C
authors.initials: AC
authors.lastname: Freitas
authors.forename: Teresa A P
authors.initials: TA
authors.lastname: Rocha-Santos
authors.forename: Armando C
authors.initials: AC
authors.lastname: Duarte
mesh_terms: D000464:Alginates / Q000737:chemistry; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D008401:Gas Chromatography-Mass Spectrometry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007220:Industrial Waste; D009930:Organic Chemicals / Q000378:metabolism*; D020076:Pleurotus / Q000378:metabolism*; D012233:Rhizopus / Q000378:metabolism*; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction; D013053:Spectrophotometry; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D007220:Industrial Waste; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D020723:Glucuronic Acid