Effluent treatment reverse osmosis

Options 8 and 9. Other Effluent Treatments. Reverse osmosis is a physical process by which the majority of the effluent water is cleansed of polluting ions. However, a highly polluted reject-water stream also is produced. This reject stream is normally sent to evaporation ponds for further concentration and ultimate disposal of the pollutant solids. Ion exchange is a physiochemical process that similarly produces a pure-water stream and a lower volume stream of concentrated waste that must be evaporated. Both processes are more expensive than is Option 7, have the same general drawbacks, and have the additional problem of disposing their concentrated waste streams. 

Lin, K.L., Min Lin, C. Shieh, M.C. (1987) Treatment of uranium containing effluents with reverse osmosis process. Desalination, 61, 125-136. 

Industrial Wastes. Closely related to seawater concentration is the simultaneous concentration of industrial effluents and recycle of recovered water (see Wastes, industrial). These appHcations are expected to increase as environmental restrictions increase. Examples are the concentration of blowdown from cooling towers in power plants concentration of reverse osmosis blowdown and the processing of metal treatment wastes (11) (see... 

Indian Ion Exchange and Chemical Industries - Produces reverse osmosis and demineralization systems, base exchange softeners, clarifiers and filters, degassers and de-aerators, filtration and micro filtration systems, effluent treatment plant...http //www.indianionexchange.com. ... 

Beier S, Koster S, Veltmann K, Schroder HFr, Pinnekamp J (2010) Treatment of hospital wastewater effluent by nanofiltration and reverse osmosis. Water Sci Technol 61 1691-1698... 

Advanced wastewater treatment techniques, for example oxidation processes, can achieve up to 100% removal for diclofenac [52,53], Reverse osmosis, activated carbon and ozonation have been shown to significantly reduce or eliminate antibiotics from wastewater effluents [32], The efficiency of two tertiary treatments, chlorination and UV disinfection, was compared and chlorination led to lower quantities of antibiotics [54],... 

Heavy metals such as copper, zinc, lead, nickel, silver, arsenic, selenium, cadmium and chromium may originate from many sources within a rehnery and may, in specihc cases, require end-of-pipe treatment. Some agencies have set discharge limits that are beyond the capability of common metals removal processes such as lime precipitahon and clarihcation to achieve. Other treatment processes such as iron coprecipitation and adsorption, ion exchange, and reverse osmosis may be required to achieve these low effluent concentrations [52]. 

Koyuncu et al. [56] presented pilot-scale studies on the treatment of pulp and paper mill effluents using two-stage membrane filtrations, ultrafiltration and reverse osmosis [56]. The combination of UF and RO resulted in very high removals of COD, color, and conductivity from the effluents. At the end of a single pass with seawater membrane, the initial COD, color and conductivity values were reduced to 10-20 mg/L, 0-100 PCCU (platinum cobalt color units) and 200-300 ps/cm, respectively. Nearly complete color removals were achieved in the RO experiments with seawater membranes. 

Now that we have determined what processes the facility will be used for, we can finalize utility requirements. The following utilities are required for our solid-dose facility heating, ventilation, and air conditioning (HVAC), hot and cold water, steam, electrical service, compressed air, vacuum systems, dust collection, chillers, effluent stream, and purified water. For the more specialized processes or special material handling, we may need specialized gases and breathing air. Purified water is one of the more difficult utilities to maintain the quality of. From a source of potable water, a series of treatments must be performed to control microbiological quality. Typical treatment options include carbon filters, reverse osmosis, and UV radiation. 

A conventional wastewater treatment system with an average flow rate of 160,000 gpd produces effluent suitable for NPDES discharge. Metal hydroxide sludges are dewatered in a 15 cu. ft filter press producing more than one half ton of filter cake per day. The filter cake is further dewatered in a 7 cu. ft, batch-type sludge dryer. Based upon recommendations by their consultant, the firm also uses the sludge dryer to dehydrate nickel strip solutions. Two reverse osmosis systems are used for partial nickel recovery. Trivalent chromium is recovered by drag-out control and evaporation. 

End of Pipe" Treatment - It is possible to use reverse osmosis and ultrafiltration to concentrate or "dewater" mixed effluent streams in order to reduce the hydraulic loading to down stream treatment processes. Typically, at least 90% of the feed volume can be purified and often returned to the process, with the salts concentrated in the remaining 10%. 

Figure Eleven (11) illustrates a total printed circuit effluent treatment system utilizing reverse osmosis to recover purified water from mixed rinses and the airscrubber. Bath dumps and reverse osmosis concentrate are chemically treated, producing a sludge for landfilling and effluent suitable for discharge.

Membrane technologies can also be used in other parts of this total treatment system microfiltration could be substituted for the clarifier (see Figure 9), and reverse osmosis could purify the clarified effluent for re-use. 

Alternative water-treatment technologies have recently been developed and applied for the treatment of mine-site effluents. Biologically mediated systems that reduce sulfate and promote the precipitation of insoluble metal sulfides have been developed for treatment of mine-waste streams. Reverse-osmosis systems have been applied for treatment of mine-waste effluents, or for polishing the effluent from facilities that use lime treatment. 

Membrane technology may become essential if zero-discharge mills become a requirement or legislation on water use becomes very restrictive. The type of membrane fractionation required varies according to the use that is to be made of the treated water. This issue is addressed in Chapter 35, which describes the apphcation of membrane processes in the pulp and paper industry for treatment of the effluent generated. Chapter 36 focuses on the apphcation of membrane bioreactors in wastewater treatment. Chapter 37 describes the apphcations of hollow fiber contactors in membrane-assisted solvent extraction for the recovery of metallic pollutants. The apphcations of membrane contactors in the treatment of gaseous waste streams are presented in Chapter 38. Chapter 39 deals with an important development in the strip dispersion technique for actinide recovery/metal separation. Chapter 40 focuses on electrically enhanced membrane separation and catalysis. Chapter 41 contains important case studies on the treatment of effluent in the leather industry. The case studies cover the work carried out at pilot plant level with membrane bioreactors and reverse osmosis. Development in nanofiltration and a case study on the recovery of impurity-free sodium thiocyanate in the acrylic industry are described in Chapter 42. 

For radioactive effluent treatment, the relevant membrane processes are microfiltration, ulfrafiltration (UF), reverse osmosis, electrodialysis, diffusion, and Donnan dialysis and liquid membrane processes and they can be used either alone or in conjunction with any of the conventional processes. The actual process selected would depend on the physical, physicochemical, and radiochemical nature of the effluents. The basic factors which help in the design of an appropriate system are permeate quality, decontamination, and VRFs, disposal methods available for secondary wastes generated, and the permeate. 

Radioactive waste treatment applications have been reported [3-9] for the laundry wastes from nuclear power plants and mixed laboratory wastes. Another interesting application of reverse osmosis process is in decontamination of boric acid wastes from pressurized heavy water reactors (PHWRs), which allows for the recovery of boric acid, by using the fact that the latter is relatively undissociated and hence wdl pass with water through the membrane while most of the radioactivity is retained [10]. Reverse osmosis was evaluated for treating fuel storage pool water, and for low-level liquid effluents from reprocessing plants. 

The treatment of ADUF by reverse osmosis [13] was found to be useful in concentrating activity in small volume while making a larger volume of the decontaminated effluent for direct disposal after required dilution. Porous cellulose acetate membranes were used in plate module configurations. The concentration of ammonium nitrate in the permeate stream is not very different from that of the contaminated retentate. With the addition of flocculating aids, the decontamination factors in the range of 1000 with VRFs in the range of 100 were achieved. 

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