Effluents filtration, membranes

Jonsson, A.-S. Jonsson, C. Teppler, M. Tomani, P. Wannstrom, S. Treatment of paper coating color effluents by membrane filtration. Desalination 1996, 105, 263-276. 

For serum replacement (6), the latex is confined in a cell with a uniform-pore-size Nuclepore filtration membrane. Distilled, deionized water is pumped through the latex until the conductance of the effluent stream is about the same as that of the distilled, deionized water. This serum replacement removes the adsorbed emulsifier and solute electrolyte quantitatively and allows recovery of the serum in a form suitable for further analysis however, it does not+replace the Na+ and K counterions of the surface groups with Vl ions. To do this, dilute hydrochloric acid (ca. 10 N) is pumped through the latex, followed by distilled, deionized water to remove the excess acid. The latex is then titrated conductometrically to determine the surface charge. 

Ultrafiltration — This process has been successful with mixtures difficult to separate, such as oily machining wastes and oily wastewater. A pressure-driven filtration membrane separates multicomponent solutes from solvents, according to molecular size, shape and chemical bonding. Substances below a preselected molecular size are driven through the membrane by hydraulic pressure, while larger molecules, such as oil droplets, are held back. Effluent oil concentration depends on influent concentration, but properly operated ultrafiltration units can produce oilfree water (less than 0.1 ppm for all practical purposes). 

Jbnsson A-S, Jbnsson C, Teppler M, Tomani P, and Wannstrbm S. Treatment of coating colour effluents by membrane filtration. Desalination 1996 105 263-276. 

Ekengren O, Eihpsson S, and Bjurhem J.-E. Treatment of bleach plant effluents by membrane filtration. Environ. Conf, Boston, MA, March 28-31, 1993, 403 11. 

Chabot B, Krishnagopalan GA, and Abubakr S. Flexographic newspaper deinking Treatment of wash filtrate effluent by membrane technology. J. Pulp Pap. Sci 1999 25(10) 337-343. 

The key part of the reactor is a nanofiltration membrane unit (a), which allows the permeation of small molecules but not macromolecules such as enzymes. In operation, the reactor is initially charged with d-LDH and FDH before the start of the reaction. An aqueous mixture, which consists of 6, ammonium formate, and a catalytic amount of NAD, is then continuously fed into the reactor by a peristaltic pump (b). After passing a check valve (c), the substrate solution is mixed with enzymes inside the reactor by a circulation pump (d). The product is collected continuously as an effluent from the filtration membrane unit. In this fashion, both enzymes are retained inside the reactor by the membrane leading to high turnover. 

In a membrane bioreactor (MBR), biomass is separated from cleaned groimdwater by special membranes [26,55,89]. hi general, high pressure is used for effluent filtration. 

AN, 0-Carboxy methyl chitosan/cellulose acetate blend nano filtration membrane was prepared in acetone solvent. It had been tested to separate chromium and copper fiom effluent treatment. The highest rejection was observed to be 83.40% and 72.60%, respectively (Alka et al., 2010). A chitosan/cellulose acetate/polyethylene glycol ultra filtration membrane was prepared with DMF as solvent. It was focused to be efficient in removing chromium from artificial and tannery effluent wastewater. The highest rejection rate was responding (Sudha et al., 2008).Cross-linked chitosan/polyvinyl alcohol blend beads were prepared and studied for the adsorption capacity of Cd from wastewater. The maximum adsorption of Cd(II) ions was foimd to be 73.75% at pH 6 (Kumar et al., 2009). 

The costs to treat sewage to indirect potable reuse standards are only a fraction of the costs to desalinate seawater. When total fife-cycle costs are considered, the cost of treating secondary effluent by membrane filtration and RO is 0.28US /m, as compared to 0.62US /m for seawater desalination. 

Membrane bioreactors are an option for municipal wastewater treatment when high effluent water quality is required, for example, bathing water quality, or when the receiving water body is very sensitive or when the water is to be treated for reuse. As mentioned before (see Section 9.2.5.1), the effluent quality is superior to that of secondary sedimentation. To attain a similar effluent quality by conventional treatment, effluent filtration and disinfection would be required in addition. This needs to be taken into account when comparing the cost of MBR and conventional activated sludge treatment. 

Manttari, M., J. Nuortila-Jokinen and M. Nystrom, Evaluation of Nanofiltration Membrane for Filtration of Paper Mill Total Effluent , Filtration Separation 34, 275-280 (1997). 

Filter Selection. A variety of product- and process-related factors govern filter selection. Considerations include the characteristics of the fluid to be filtered, ie, its chemical composition and compatibiHty with the filtration system (inclusive of the membrane, filter hardware, piping, etc), the level of bioburden present, specifications on effluent quaHty, the volume of product to be filtered, flow rate, and temperature. 

Methods to Detect and Quantitate Viral Agents in Fluids. In order to assess the effectiveness of membrane filtration the abihty to quantitate the amount of vims present pre- and post-filtration is critical. There are a number of techniques used. The method of choice for filter challenge studies is the plaque assay which utilizes the formation of plaques, localized areas in the cell monolayer where cell death caused by viral infection in the cell has occurred on the cell monolayer. Each plaque represents the presence of a single infectious vims. Vims quantity in a sample can be determined by serial dilution until the number of plaques can be accurately counted. The effectiveness of viral removal may be determined, as in the case of bacterial removal, by comparing the vims concentration in the input suspension to the concentration of vims in the effluent. 

Effluent pretreatment is necessary when RO is used as tertiary treatment in order to prevent membranes filters form being blocked or abraded. UF offers a powerful tool for the reduction of fouling potential of RO/NF membranes [57]. A typical pretreatment consist of a MF allowing the removal of the large suspended solids form the WWTP effluent followed by UF unit which removes thoroughly suspended solids, colloidal material, bacteria, viruses and organic compounds from the filtrated water. The UF product is sent to the RO unit where dissolved salts are removed. 

Kim SL, Chen JP, Ting YP (2002) Study on feed pre-treatment for membrane filtration of secondary effluent. Sep Purif Technol 29 171-179... 

Manttari M, Nystron M (2007) Membrane filtration for tertiary treatment of biologically treated effluents from the pulp and paper industry. Water Sci Technol 55(6) 99-107... 

Recently, membrane filtration has become popular for treating industrial effluent. Membrane filtration includes microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse... 

Membrane filtration processes have been successfully applied to the field of environmental engineering for air pollution control,34 potable water purification,22-24 groundwater decontamination,35,36 industrial effluent treatment,37 hazardous leachate treatment,35,36 and site remediation,36 mainly because membrane filtration can remove heavy metals and organics. 

Recently, Wang100 introduced a membrane sequencing batch reactor (membrane-SBR) process for groundwater decontamination, water purification, and industrial effluent treatment. A membrane-SBR is similar to conventional SBR except that membrane filtration is used (instead of sedimentation) for the separation of mixed liquor suspended solids (MLSS) from the mixed liquor. 

Vourch et al49 studied the applicability of the RO process for the dairy industry wastewater. The treated wastewater total organic carbon (TOC) was <7 mg/L. It was found that in order to treat a flow of 100 m3/d, 540 m2 of the RO unit is required with 95% water recovery. Dead-end NF and RO were studied for the treatment of dairy wastewater.50 Permeate COD, monovalent ion rejection, and multivalent ion rejection for the dead-end NF were reported as 173-1095 mg/L, 50-84%, and 92.4-99.9%, respectively. When it comes to the dead-end RO membranes, the values for permeate COD, monovalent ion removal, and multivalent ion removal were 45-120 mg/L, >93.8%, and 99.6%, respectively. Membrane filtration technology can be better utilized as a tertiary treatment technology and the resultant effluent quality will be high. There can be situations where the treated effluents can be reused (especially if RO is used for the treatment). 

The main techniques that have been used to dispose of industrial effluents include chemical precipitation, ion exchange, electrochemical processes, and adsorption onto various adsorbents and/or membrane filtration. Although all of these techniques are capable of removing heavy metals to some extent, adsorption by solid substrates is preferred because of its high efficiency, easy handling and cost as well as the availability of adsorbent. 

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