Concentrate disposal

While the cost of membrane based desalination has decreased over time with improving process efficiency, the cost of concentration disposal has remained relatively constant. Furthermore, disposal cost is unlikely to decrease in the future due to the simplistic and low-tech nature of the equipment required for concentrate management, and the range of nontechnical factors and limitations that determine the feasibility for each option (Mickley 2009). 

Fig. 3.1 Relative capital costs of common methods for concentrate disposal with increasing concentrate flow rate. Adapted from Mickley (2009)...

Mauguin, G., Corsin, P. Concentrate and other waste disposals from SWRO plants characterization and reduction of their environmental impact. Desalination 182(1—3), 355—364(2005) Mickley, M. Membrane Concentrate Disposal Practices and Regulation, Desalination and Water Purification Research and Development Program Report No. 123 (Second Edition). U.S. Department of the Interior, Bureau of Reclamation, Denver (2006)... 

The last sections describe membrane application issues in water treatment. The processes have been compared in terms of their volume of application and recent ffowth. This is obviously linked to treatment cost, an issue which will also be addressed hriefy. Problems which have arisen in previous pilot plant orfull scale studies will he part of the fouling studies in this thesis, where effects can he investigated on a smaller scale. Issues of concentrate disposal or treatment and membrane integrity are not discussed in this review. The concluding remarks address research needs and plans for this project. 

NF was found to be a very good treatment for a groundwater high in sulphates, hardness, and sodium, although the concentrate disposal was a problem (Dard et al. (1995)). 

The cross-section surface shows a dense tangling-up of flat crystals inside the particle (Figure 15.2.3.7). Flat crystals are concentrically disposed at the periphery of the rounded particles, like a shell. The inside of the particle is a disordered arrangement of small flat crystals. Thus, the surface offered to evaporation is very important and this should lead to the easy escape of RS. 

Two concentrate disposal options are considered in this exercise. The first is bioremediation which provides on-site destruction of PAH contaminants. A projected cost estimate of 10-40 cents per gallon of groundwater contaminated with 100-2000 ppm of PAHs is appropriate for a full-scale bioremediation system. 

The costs per 1,000 gal is dependent on the flow rate, the duration of the project, whether concentrate disposal is being considered, and the cost of effluent treatment and disposal. These ranges are shown below and are based on a one year project. 

In addition to the concentrate discharge methods discussed above, other alternative concentrate disposal methods are deep-well injection, evaporation ponds, mechanical... 

Figure 3.19 Concentrate disposal device. (From Gasson and Allison, 2004.)...

As previously mentioned, the key SWRO project construction expenditures are associated with building the plant intake, the pretreatment system, procurement and installation of the plant pumps and piping, the SWRO membranes and pressure vessels, the energy recovery system, the water posttreatment facilities, and the concentrate disposal system. It is difficult to compare the investment and construction costs of existing desalination projects because projects may differ significantiy in one or more of the cost-related parameters listed above. Based on previous experience, however, it can be estimated, for example, that the seawater pretreatment costs are in the range of 6-8 US cents/m and the costs of water conditioning and boron and chloride removal are between 4 and 8 US cents/m. ... 

Safe Drinking Water Act (SDWA) (2005). What do I do with this stuff Options for inland membrane concentrate disposal. Safe Drinking Water Act Newsletter. Available http //hdrinc.com/assets/ documents/pubhcations/SDWA/august2005/membraneconcentratedisposal.pdf, accessed Mar. 25, 2006. 

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