Intermittent sand filtration for wastewater treatment in rural areas of the Middle East--a pilot study

Water Sci Technol. 2003;48(11-12):147-52.

Abstract

This paper concentrates on Intermittent Sand Filtration (ISF) as a polishing stage for effluent from a facultative pond. During the three-year research program, the system operated with an influent flow-rate of 500-1,000 L/day and an average BOD concentration of 200-400 hydraulic and BOD loadings of 110-200 L/m2/day and 20-40 gBOD/m2/day, respectively. Flow to the ISF was applied intermittently with a different number of doses in each run. In addition, the effects of the frequency and the duration of rest periods (no feeding) were studied. Removal of 90-95% of BOD and 75-90% of COD and TSS was achieved consistently throughout the study period. Elevated levels of nitrification were observed with 95-100% removal of NH3. The ISF performed best when fed with 5-10 doses/day. Reducing the daily number of doses to 3/day at the same hydraulic loading rate resulted in a 20-30% reduction in removal efficiency. The 2-4 week rest period had no effect on the biological activity in the subsequent run. However, rest periods of more than 30 days were found to negatively affect removal efficiency.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Facility Design and Construction
  • Filtration
  • Middle East
  • Oxygen / metabolism
  • Silicon Dioxide
  • Waste Disposal, Fluid / methods*
  • Water Purification / methods*

Substances

  • Silicon Dioxide
  • Oxygen