Ultrafiltration water reuse

Lucid Treatment Systems POU water reuse, ultrafiltration... 

Shao, E., Wei, J., Yo, A., Levy, R. (2009). Apphcahon of ultrafiltration and reverse osmosis for mine waste water reuse. In Water in mining conference, Perth, 15 — 17 September Available from http //www.nirosoft.com/files/CollahausiChileMiningEffluents(l).pdf. Accessed January 2014. 

Microfiltration and Ultrafiltration are the best available technology for water reuse. Two options are available conventional activated sludge followed by tertiary filtration and an integrated membrane bioreactor. Both provide effluent of high quality suitable for treatment by reverse osmosis. The cost of tertiary filtration can be lower than a membrane bioieactor if the water reclamation plant is designed for constant flow and is located at a different site. 

Lipe, K. M., Sabatini, D. A., Hasegawa, M. A., and Harwell, J. H., Micellar Enhanced Ultrafiltration and Air Stripping for Surfactant-Contaminant Separation and Surfactant Reuse Ground Water Monitoring Remediation, Winter, pp. 85-92. 

The ultrafiltration membrane is treated with glycerol and preservatives that need to be removed prior to use. Float the membrane, shiny side down, on water for a few hours. Rinse the membrane and insert it into the ultrafiltration apparatus with the shiny side up. The membrane can be stored in 20% ethanol and reused. 

In the synthesis of A-acetyllactosamin from lactose and A-acetylglucosamine with (3-galactosidase (289,290), the addition of 25 vol% of the water-miscible ionic liquid [MMIM][MeS04] to an aqueous system was found to effectively suppress the side reaction of secondary hydrolysis of the desired product. As a result, the product yield was increased from 30 to 60%. Product separation was improved, and the reuse of the enzymatic catalyst became possible. A kinetics investigation showed that the enzyme activity was not influenced by the presence of the ionic liquids. The enzyme was stable under the conditions employed, allowing its repeated use after filtration with a commercially available ultrafiltration membrane. 

During the semibatch experiments, vacuum filtration was applied at 4 d and 8 d after the start of saccharification, to remove the sugar product as filtrate. In selected semibatch experiments, ultrafiltration was applied to the vacuum filtrate to recover soluble enzymes. In other semibatch experiments, the vacuum filter cake was washed extensively with deionized water to remove any enzymes not bound to the solids. After filtration, pretreated corn stover slurry and 7 mL of solution (the ultrafiltration filtrate, or citrate buffer when ultrafiltration was not used) were added to the residual solids and bound enzymes, to replace the volume removed as filtrate during the ultrafiltration step. The additional substrate promotes further saccharification by reusing the cellulase enzymes. To promote further saccharification in a final set of semibatch experiments, additional cellulase at a specific activity of 5 FPU/g of fresh cellulose was added along with the fresh corn stover after vacuum filtration. 

The most common uses of RO are for desalination of seawater and brackish water for potable and industrial applications. However, as demand for fresh water grows, RO is being pressed into service for wastewater and reuse applications. These will require extensive pretreatment, sometimes involving other membrane technologies such as micro- or ultrafiltration, to minimize fouling of the RO membranes (see Chapter 16). 

Micro-, ultra-, and nano-filtration can separate smaller particles using media with defined porous sizes (i.e., 10 1—1 pm in microfiltration, 10 2—10 pm in ultrafiltration, and 10 3— 10 2 pm in nanofiltration). Residual colloidal and suspended solids can be removed by microfiltration. Selected salts, most organic compounds, bacteria, protozoan cysts, oocysts and viruses are removed by nanofiltration, so that the treated water will be disinfected. This advanced filtration is used for the treatment of effluents for indirect potable reuse applications such as groundwater injection, water softening, decoloriza-tion, or removal of micropollution. 

Some areas of application are the nuclear industry and the treatment of radioactive liquid wastes, with two main purposes reduction in the waste volume for further disposal, and reuse of decontaminated water. Pressure-driven membrane processes (microfiltration, ultrafiltration, nanofiltration, and reverse osmosis [RO]) are widely used for the treatment of radioactive waste. 

The Linpac linerboard mill has a two-stage tubular ultrafiltration system and VSEP filters as a kidney. The ultrafiltration systems (Koch membrane systems) treat the overflow from DAF clarifiers. TSS removal in the DAF units is improved significantly by pressurized ozone injection before the DAF. To reduce the concentrate (reject) volume from the UF system and to improve the reused water quality, a VSEP nanofiltration system has been installed to further concentrate the two stage UF concentrate [50]. 

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