Removal of As(V) and Cr(VI) by enhanced sand filtration
- Stevens Institute of Technology, Hoboken, NJ (United States)
In this study, an iron injection-sand filtration process for selective removal of arsenate (As(V)) and chromate (Cr(VI)) was investigated. The process involved treatment of packed-bed sand columns using small amount of iron solution during filtration. The advantage of this technique was the continues formation of high adsorptive iron hydroxide in the column. The saturated columns could be regenerated by backwash at neutral pH. No chemicals were needed for the regeneration of the saturated sand columns. The filtration process was more effective than iron coagulation treatment for As(V) removal. Moreover, existing conventional sand filters can be modified to the iron injection filters. Pilot filtration results demonstrated that As(V) could be removed from 2,000 ppb down to less than 5 ppb using two treated sand columns in series. When influent As(V) concentration was 20 ppb, one treated column could filter 700 pore volumes (700 L) of the water with effluent As(V) concentration less than 1 ppb in one filtration run. However, the process was not effective in treating waste water containing As(V) concentrations {ge}10,000 ppb.
- OSTI ID:
- 210486
- Report Number(s):
- CONF-9509139--
- Country of Publication:
- United States
- Language:
- English
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