Treatment and disposal of concentrate from nanofiltration (NF) and reverse
osmosis (RO) membrane filtration processes is an important issue facing utilities in areas
of scarce water supply. Feasible disposal options for membrane concentrate are
ultimately site specific and depend on the concentrate's quantity and quality. It has been
proposed that removal of trace pollutants such as arsenic from membrane concentrate
may increase the number of disposal options or even allow for concentrate reuse.
This paper presents results of an on-going study exploring chemical treatment of
membrane concentrate, with emphasis on coagulation using iron chloride followed by
solid-liquid separation. Simplified concentrate solutions at ionic strengths representative
of NF/RO concentrate (0.2 and 0.7 M) were prepared in the lab using specific ratios of
major ions (e.g. sodium, bicarbonate, etc.). Removal of arsenic from these simulated
concentrates was determined experimentally using small volume jar test procedures.
Solids formed during treatment were separated from solution using 0.2 micron pore size
filters. Removal of arsenic as functions of background matrix, natural organic matter (NOM) source, and
coagulant dose are presented. Includes 3 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 240 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 8 |
| Published : | 11/01/2007 |
