Ion exchange (IX) resins can reduce nitrate concentrations in groundwater to very low
levels; however, regeneration brines containing high nitrate concentrations pose a
disposal problem. This research investigated hydrogenotrophic (hydrogen utilizing)
biological reduction of nitrate in regenerant brines. Salt tolerant denitrifying batch
cultures were enriched from the denitrification stage of a wastewater treatment plant and
marine sediments from Cape Cod, Massachusetts and the Dead Sea. The cultures were
inoculated into nitrate nutrient media, with and without added NaCl, with hydrogen as the
sole electron donor. The salt tolerant cultures were able to denitrify 800 mg/L NO<sub>3</sub>-N in
the presence of 12.6 g/L NaCl to 200 mg/L NO<sub>3</sub>-N. The cultures were inoculated into two
different hollow fiber membrane bioreactors (HFMBs), one fed 50 mg/L NO<sub>3</sub>-N with no
added NaCl (non-brine) and the other fed 600 mg/L NO<sub>3</sub>-N with 12.5 g/L NaCl (brine).
The non-brine HFMB was able to consistently reduce nitrate to less than 8 mg/L at a
hydraulic residence time (HRT) of 5 hours when pH and biofouling were controlled. The
brine HFMB only achieved partial denitrification at an HRT of 53 hours. Current
research is focused on treatment of the brine in a batch HFMB. Includes 11 references, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 280 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 06/01/2006 |
