Use of Peat for On-Site Wastewater Treatment: II. Field Studies1
- J. L. Brooks,
- C. A. Rock and
- R. A. Struchtemeyer2
Three full-size sphagnum (Sphagnum spp.) peat filter fields were monitored to determine the treatment levels after application of septic tank effluent (STE). Systems I and II were designed with a liner and had overboard discharges, whereas system III was constructed with a subsurface discharge. Gravity-feed, dosed-feed, and pressure distribution systems all provided excellent organic and 99% fecal coliform removal without additional disinfection.
The 5-day biochemical oxygen demand (BOD5) reduction exceeded 90% and chemical oxygen demand (COD) reduction exceeded 80% in all three systems. Total suspended solids (TSS) measured 16 and 9 mg/L in the effluent from systems I and II, respectively. Systems I and II showed 58 and 62% total P reduction, respectively, while a total P reduction of 96% was obtained in system III. Nitrate-N in the effluent from all three systems was < 4.5 mg/L, well below the recommended limit of 10 mg/L. The pH of the effluents ranged from 5.3 to 6.5 and color averaged 330 standard units. In Maine, or other areas where the natural waters tend to be both colored and slightly acidic, neither parameter would be problematic when using an overboard discharge. Effluent from the well-aerated fields contained dissolved O2 averages of 4.6 and 6.7 mg/L for systems I and II.
Annual variation in weather conditions, including prolonged cold, with and without snow cover, and extreme short-term precipitation, had no adverse effects on the performance of the peat filter fields. The use of sphagnum peat for on-site wastewater treatment seems to be an acceptable alternative for areas where conventional systems cannot be installed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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