Brominated trihalomethane (THM) specie is seventy-five percent of the four regulated total trihalomethane (TTHM) and has
significantly greater implications, especially DCBM, as drinking water contaminant than
chlorinated THM regarding human health. Of the four individual trihalomethanes, only high
DCBM exposure was associated with spontaneous abortion both alone and after adjustment for
the other THMs. This project explored the use of electrolysis with silver electrodes, coated Ti
electrodes (dimensionally stable anode) and a combination of both to remove bromide from California SWP at Palmdale
Water District Treatment Plant, California. Herbert Henry Dow used electrolysis coupled with air
stripping of brine that has high proportion of bromide to manufacture bromine. In surface
water treatment, bromide occurs at very low levels and may form very low levels of
hypobromous acid (HOBr), hypobromic acid (HBr) and hypobromite (OBr-) ions during
electrolysis especially if the energy provided is below the ionization energy for bromide. These
byproducts are difficult to remove by air or gas stripping and make bromine available to form TTHM downstream. With silver electrodes at ambient temperature, silver ions released from the
anode immediately bond directly with all halogens to various degrees depending on their
concentrations, current applied, contact time, and electrode spacing. Minimal amount of oxy-
halides are formed and power requirement is low. Varying current density and bromide
concentration, positioning the electrolytic cell before coagulation and after sedimentation, and
changing electrode combinations (Silver/Silver, DSA/DSA, and Silver/DSA as cathode/anode
respectively), bromide removal was achieved to varying degrees. This process in combination
with enhanced coagulation can be used to substantially extend the life of biologically active granular activated carbon (GAC)
filter and ensure compliance with the US Environmental Protection Agency Stage 2 DBPR, LRAA of 80µg/L TTHM. Includes 11 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 880 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 11/01/2005 |
