PVA removal in textile waste water treatment prior to RO to prevent clogging

Published on by in Technology

In Textile Sector, specially in Terry Towel & Bath Robe Industry; they use Zero Twist Threat for Weaving of Towel Fabric which is being done by wraping the thread on PVA Noddle. This PVA noddle is afterwards dissolved in the water and discharged into the wastewater. If we go for wastewater treatment and then recycling of this wastewater, then this PVA clogs the RO Membranes permanently. Anyone knows the process of how to remove this PVA from the wastewater prior to RO?

The quantity of this PVA enriched water is not so high i.e. 100 m3/day. The 100 m3/day water contains 600 kgs of PVA, 1500 liters of H2O2, and 400 kgs of Caustic (NaOH). If this water when mixed with other wastewater from textile then reaches after wastewater treatment to recycling unit, will it clog the RO membranes? We will have 3 stage RO for recovery 85% of Water out of it.

Taxonomy

6 Answers

  3. A bit late to answer this but a good contact would be Dr. Henry A. Boyter Jr. Director of CESTAB Center for Environmentally Sustainable Textile and Apparel Businesses see: http://waterandwastewaterforum.com/guest-authors/textile-wastewater-treatment-issues/

  4. The resulting effluent is usually high in color. A complimentary treatment process is needed to remove color and if possible residual impurities. The textile industry has been condemned to be the world’s worst environment polluters. A study was conducted on “Color/Dye Removal from a Textile Industry Effluent. Effluent Using Activated Carbon” In this study removal by adsorption of various acidic, reactive and direct dyes on two different samples of Granular Activated Carbon was observed in Static Batch Method as well as Continuous Flow Process.The steps of Process are


    Physical Chemical Biological Sedimentation Neutralization Stabilization Filtration Reduction Aerated Lagoons Floatation Oxidation Trickling Filters Foam Fractionation Catalysis Activated Sludge Coagulation Ion Exchange Anaerobic Digestion Reverse Osmosis Electrolysis Fungal Treatment Solvent Extraction - Flocculation Ionization Radiation - - etc

    It is important to remove the various pollutants from the waste waters before their final disposal. By reducing all forms of waste water industries can cut on costs and improve profits. It has been suggested that most companies can save 20% - 50% expenditure on water and effluent treatment charges by reducing their water use. After identifying where the potential water savings can be made the next step is to introduce appropriate water saving measures like re-use of water. This consists of rinsing the product in a series of tanks each using progressively cleaner water [8]. The rinse water is reused by moving it progressively from last rinse tank towards first. Wash water may also be suitable for re use elsewhere on the site such as for floor washing, rinsing containers etc

    With newer varieties of modern textiles, synthetic dyes and textile finishes entering the market air and water pollution are bound to go on increasing unless strictures are implemented and positive steps taken.

    regards,

    Prem Baboo

  5. Mills discharge millions of gallons of this effluent as hazardous toxic waste, full of color and organic chemicals from dyeing and finishing salts. Presence of sulphur, naphthol, vat dyes, nitrates, acetic acid, soaps, chromium compounds and heavy metals like copper, arsenic, lead, cadmium, mercury, nickel, and cobalt and certain auxiliary chemicals all collectively make the effluent highly toxic. Other harmful chemicals present in the water may be formaldehyde based dye fixing agents, hydro carbon based softeners and non bio degradable dyeing chemicals. The mill effluent is also often of a high temperature and pH, both of which are extremely damaging.  Good Question you have raised Mansoor.

  6. Hello Mansoor,

    Several studies have been done and are freely accessible on the Internet. One of them is: "An efficient biotreatment process for polyvinyl alcohol containing textile wastewater" - link for this study is http://www.iwaponline.com/wpt/008/0049/0080049.pdf (2013). For your convenience, i attached the downloaded pdf.

    2 Comments

    1. Dear Isabelle,
      Thank you for the detailed research paper you have shared. I have gone through it, though I heard about all the three process Biological Degradation, UF and Evaporation but was looking something which someone practical or commercial application of such PVA enriched (small quantity) wastewater before going to main biological treatment section.
      Dear Ingavar,Your idea is right if we might be able to coagulate PVA with some compound to make floccs and removed by settling or flotation.
      I found Biological or Chemical Coagulation could be a better way to treat, lets have some practical.

    2. I have also seen several studies on PVA removal. I do not have any experience in this particular application of waste water treatment, but it seems given the low volume one might consider adding some additional compound that could react with the PVA so that it will be caught by the RO but not clogging it? I have not seen this particular avenue discussed on the net.