Integrated nanofiltration and upflow anaerobic sludge blanket treatment of textile wastewater for in-plant reuse.
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.
Gomes
Arlindo Canigo
AC
Department of Chemistry, University of Beira Interior, Covilhã, Portugal.
Gonçalves
Isolina Cabral
IC
de Pinho
Maria Norberta
MN
Porter
John Jefferson
JJ
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*
D004396:Coloring Agents; D007220:Industrial Waste; D012722:Sewage; D013431:Sulfates