Ultrafiltration paper industry

Many application studies have been conducted on the use of ultrafiltration and reverse osmosis to process "black liquors" in the paper industry. Inorganic membranes have the... 

Manttari M and Nystrbm M. Ultrafiltration and nanofiltration in the pulp and paper industry using cross-rotational (CR) filters. Wat. Sci. Techn. 2004 50(3) 229-238. 

Vieira M, Tavares CR, Bergamasco R, and Petrus JCC. Application of ultrafiltration-complexation process for metal removal from pulp and paper industry wastewater. J. Membr. Sci. 2001 194 273-276. 

J. Nuortila-Jokinen, T. Uusluoto and M. Nystrom, Removal of disturbing substances by ultrafiltration of make-up waters in the pulp and paper industry. Paper Timber, 76 (1994) 256-261. 

Ultrafiltration and Hyperfiltration in the Pulp and Paper Industry for By-Product Recovery and Energy Savings... 

While reverse osmosis and ultrafiltration were being established in several applications, there was a lack of available membranes with cutoffs between 400 and 4000 g/mol. Increasing interest in NF membranes developed in the last decade. An extensive review on principles and applications of nanofiltration has been published recently [38]. Nanofiltration is important for water softening [39] and removal of organic contaminants. In the food industry, nanofiltration can be applied for concentration and demineralization of whey, concentration of sugar and juice. Nanofiltration also finds application in the pulp and paper industry, in the concentration of textile dye effluents and in landfill leachate treatment. The improvement of solvent stabihty of available NF membranes opens a wide range of potential applications in the chemical and pharmaceutical industry as weU as in metal and acid recovery. 

Typical applications of ultrafiltration processes are the treatment of electroplating rinse water, the treatment of cheese whey, and the treatment of waste-water from the pulp and paper industry. 

Ullrafiltration processes have proved successful for the treatment of effluents, the treatment of black liquor, bleaching effluents and paper machine wash waters. They have also found use in the treatment of Kraft process effluents and there is increasing use of ultrafiltration to recover lignosulphonate and alkali lignin from the spent Uquors to produce other products. Reverse osmosis is used in the pulp and paper industry for concentration of sulphate liquor, using plate and frame modules and cellulose acetate membranes. Reverse osmosis is also used in the treatment of bleach effluents after various pretreatment stages. 

The large number of papers necessitated publishing the symposium in two volumes. Volume I describes the desalination and salt-rejecting hyperfiltration membranes. Volume II covers hyper- and ultrafiltration membrane utilization in the following areas food, medicine, pulp, paper, and textile industries, oily waste stream purification, and in the separation of gases, polymers, organic solutes, and biopolymers. 

This paper covers mainly the industrial and medical applications of electrodialysis, ultrafiltration and microfiltration rather than those of reverse osmosis, which have been covered by many authors elsewhere. 

The range of industrial applications to liquid filtration is very broad. Water purification is one of the most important applications in liquid filtration. The processes of water purification include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), depending on the size of the undesired particles/molecules to be removed. Some examples of industrial applications including fuel filters, water filters, carbon filter, and wet/dry filters are being widely used in the production of textile, cosmetics, food and beverage, electronic components, papers, ship builders, and oil and gas wells. 

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