Contents Notes |
Hyperfiltration (HF) is a membrane separation technique widely used in desalination of natural water and in some industrial separation applications. Because energy, process chemicals, and water are discharged from industrial processes in large quantities, recycle has been studied with the objectives of energy and material conservation and pollution abatement. The results of several research projects with formed-in-place membranes are the background for the current project, which is the joining of an HF system with an operating caustic scour and preparation range in an integrated textile dye and finishing plant. The effluent treated by HF is a 3 to 10 weight percent caustic (NaOH) solution. The caustic percentage and the amounts and types of contaminants in the effluent depend on the style and weight of fabric being processed. HF membranes formed on porous sintered-steel tubular supports are used to remove contaminants from a hot (95ÀC) caustic scour solution and render it reusable for scouring. For this demonstration over 15 million m of approximately 1.5 m wide fabric was scoured using over 3 million L of recycled caustic solution. The initial prototype unit was replaced with an improved design, using 316L stainless steel porous material to achieve the necessary corrosion resistance. The report describes the applicable textile process, the reuse scenario, and the HF unit and its operation. |