The perchlorate anion (ClO4-) has been found in potentially harmful concentrations innumerous water sources. Because perchlorate is not removed by conventional watertreatment processes, new treatment processes are needed. Biological perchlorate reductionis a promising alternative. The authors investigated a hydrogen-oxidizing hollow-fibermembrane-biofilm reactor system for perchlorate removal. Hydrogen is an ideal electrondonor for biological drinking water treatment because it presents no toxicity, is inexpensive,and is unlikely to persist as a source of biological instability in distributions systems. Thereactor delivers hydrogen in an efficient and safe manner. Results showed that biologicalperchlorate reduction takes place concurrently with nitrate reduction, no specializedinoculation is required, and perchlorate can be removed to below the preliminary regulatorystandards with no chemical addition other than hydrogen gas. The optimal pH is 8, and theaccumulation of intermediates is unlikely. Full denitrification and pH control may be requiredfor excellent perchlorate removal. Includes 76 references, tables, figures.
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Edition: Vol. 94 - No. 11 Published: 11/01/2002 Number of Pages: 12File Size: 1 file , 250 KB