Field Investigations of Overland Flow Treatment of Municipal Lagoon Effluent

摘要

Overland flow to provide advanced treatment of municipal lagoon effluent was studied in a field environment near Utica, Miss. The field studies were conducted on slopes constructed at 2, 4, and 8 percent and seeded with a mixture of four grass species. Wastewater from a facultative lagoon was applied to the surface in measured amounts, and surface runoff was collected and metered at the end of each plot. The effectiveness of overland flow to renovate municipal wastewater with respect to biochemical oxygen demand (BOD5), total suspended solids (TSS), nutrients, fecal coliforms, and heavy metals was studied over approximately a 3-year period. Samples of surface runoff and subflow were analyzed for several operational conditions with variable depths of wastewater application, period, and frequency of application per week. The roles played by soil, soil temperature, vegetative cover, and management in wastewater renovation by overland flow were also investigated. Because of interest in cost recovery from land treatment systems through marketing of the vegetative cover for animal feed, results of dry matter yield of grass for the various operational conditions were determined. Several specialized studies within the broader research goals were conducted to answer questions related to algae reduction, enhanced phosphorus removal by alum addition, characterization of stormwater runoff from overland flow systems, fecal coliform reduction, and nitrogen losses through volatilization of ammonia.