Many of the City of San Diego's groundwater sources require desalination, due to
high salinity, before it can be used to supplement drinking water supply. One of the
City's potential groundwater desalination projects is located in an inland area, where
reverse osmosis (RO) concentrate disposal options are limited. This location, on the San
Pasqual Basin, also has high levels of silica that limit RO process recovery to 65-75%.
In order to increase the overall recovery of the desalination process, two innovative
technologies were tested in this study. A Vibratory Shear Enhanced Process (VSEP) and
a Bipolar Membrane Electrodialysis (BMED) system were used for RO brine
minimization and beneficial reuse, respectively. Studies with VSEP were performed at
the pilot scale. The VSEP system was tested with a range of flux (30-65 gfd) and
recovery (50-75 %). After pretreatment (acid and antiscalant) of RO concentrate, an
overall feed water recovery of more than 93 % was achieved by using VSEP for treating
primary RO concentrate. The product water quality from the VSEP was similar to the
primary RO. On average, two chemical cleanings/week were necessary for the VSEP. For
beneficial reuse, a bench-scale BMED system was used to generate acid and base from
RO concentrate. The BMED process was tested as a proof of concept technology for
treating RO brine. Dissociation of salt was accomplished by using a DC voltage between
two electrodes. BMED was effective in treating RO concentrate and producing acid and
base for beneficial reuse. Mixed acids and bases with concentrations up to 0.2 N were
produced using BMED for treating RO concentrate. Includes 11 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.2 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 16 |
| Published : | 11/01/2009 |
