title: Integrated nanofiltration and upflow anaerobic sludge blanket treatment of textile wastewater for in-plant reuse.
abstract: The filtration characteristics of simulated dyeing effluents containing Acid Orange 7, sodium sulfate, and a pH buffer made of acetic acid and sodium acetate is described using a commercially available nanofiltration membrane. The original membrane filtration properties were characterized with deionized water to provide a baseline of membrane performance. At high volumetric concentration of the test solutions, greater than 98% rejection of dye and sodium sulfate were obtained. Rejection of buffering chemicals was approximately 50% in all experiments, giving a permeate water not suitable for reuse in most dyeing operations. The final composite concentrate had a chemical oxygen demand (COD) value > 2000 mg/L. No problems were encountered with anaerobic treatment of the concentrate obtained from the dyeing wastewater. Adjusting the sulfate concentration to give COD-to-sulfate ratios to 2.9, 5.4, and 18.2 in the reactor feed had no significant alterations in the performance of the upflow anaerobic sludge blanket reactor.
authors.affiliation: Department of Chemistry, University of Beira Interior, Covilhã, Portugal.
authors.forename: Arlindo Canigo
authors.initials: AC
authors.lastname: Gomes
authors.forename: Isolina Cabral
authors.initials: IC
authors.lastname: Gonçalves
authors.forename: Maria Norberta
authors.initials: MN
authors.lastname: de Pinho
authors.forename: John Jefferson
authors.initials: JJ
authors.lastname: Porter
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D004396:Coloring Agents / Q000302:isolation & purification / Q000378:metabolism; D003247:Conservation of Natural Resources / Q000379:methods*; D007220:Industrial Waste / Q000032:analysis; D008851:Micropore Filters; D008954:Models, Biological; D049329:Nanostructures; D012722:Sewage / Q000737:chemistry; D013431:Sulfates / Q000494:pharmacology; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism; D013783:Textile Industry / Q000379:methods*; D013997:Time Factors; D014462:Ultrafiltration; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D012722:Sewage; D013431:Sulfates