Page 285 - Materials Chemistry, Second Edition

268 Practical Design Calculations for Groundwater and Soil Remediation

2. A pilot-scale test to determine the removal efficiency and the
reaction rate constant is always recommended for AOPs.

Example 6.23: Sizing the Reactor for an Advanced Oxidation Process

UV/ozone treatment is selected to remove TCE from an extracted ground-
water stream (Q = 100 gpm, TCE concentration = 400 ppb). A pilot study was
conducted and found the electrical energy per order to be 6 kWh/1,000 gal/
log of TCE reduction for this type of groundwater. What would be the daily
energy requirement to reduce TCE concentration from 400 ppb to 16 ppb?

Solution:
(a) The reduction from 400 to 16 is equal to log(400/16) = 1.4 logs

(b) The total volume of water treated per day
= (100 gal/min) × (1,440 min/day) = 144,000 gal

(c) Daily energy required = (1.4 logs) × (6 kWh/1,000 gal/log reduc-
tion) × (144,000 gal)
= 1,210 kWh

Discussion:
If the cost of electricity is $0.15/kWh, the energy cost will be $181.5/day.

References
1. Javandel, I., and Chin-Fu Tsang. 1986. Capture-zone type curves: A tool for
aquifer cleanup. Groundwater 24 (5): 616–25.
2. Metcalf & Eddy, Inc. 1991. Wastewater engineering. 3rd ed. New York:
McGraw-Hill.
3. USEPA. 2004. How to evaluate alternative cleanup technologies for under-
ground storage sites. EPA/510/R-04/002. Washington, DC: Office of Solid
Waste and Emergency Response, US EPA.
4. USEPA. 1991. Site characterization for subsurface remediation.
EPA/625/R-91/026. Washington, DC: Office of Research and Development, US
EPA.
5. Johnson, R.L., P.C. Johnson, D.B. McWhorter, R.E. Hinchee, and I. Goodman.
1993. An overview of in situ air sparging. Ground Water Monitoring Review,
Fall:127–35.
6. Peters, M.S., and K.D. Timmerhaus. 1991. Plant design and economics for chemical
engineers. 4th ed. New York: McGraw-Hill.