ERIC Number: ED162836
Record Type: Non-Journal
Publication Date: 1978-Jan
Reference Count: N/A
Land Application of Wastes: An Educational Program. Phosphorus Considerations - Module 19, Objectives, and Script.
Clarkson, W. W.; And Others
The treatment of wastewater phosphorus via land application includes both chemical and biological mechanisms. Chemically, phosphorus reacts with iron, aluminum, and calcium compounds in the soil providing efficient removal over a wide range of pH values. Phosphorus is also absorbed by rooted plants which, upon harvest, constitute a further removal mechanism. The general principles of phosphorus interactions between soil and wastewater are illustrated, and the mass balance is derived for a typical loading rate and application season. Soil P movement and retention are discussed, with particular reference to the chemical environment necessary to produce movement of phosphorus among the three possible categories: dissolved, labile, and fixed. Crop uptake and surface runoff are examples of other mechanisms of phosphorus removal which are discussed in this module. Application of domestic sewage effluents at a rate of 2 inches/wk for 30 weeks results in annual phosphorus additions of approximately 140 lb P/acre. At this rate, many soils are capable of efficient phosphorus removal for periods ranging from 20 to 50 years or more. Rapid infiltration systems, with annual applications of 1500 lb P/acre or more, are generally less efficient in phosphorus removal but vary considerably depending on specific site characteristics. Results from existing land application systems are cited to illustrate the basic principles of phosphorus removal. (Author/BB)
Descriptors: Chemistry, Environment, Land Use, Learning Modules, Sanitation, Science Education, Soil Science, Waste Disposal, Wastes
Van Nostrand Reinhold, 450 West 33rd Street, New York, N.Y. 10001
Publication Type: Guides - General
Education Level: N/A
Sponsor: Corps of Engineers, Washington, DC.; Environmental Protection Agency, Washington, DC.
Authoring Institution: State Univ. of New York, Ithaca. Coll. of Agriculture and Life Sciences at Cornell Univ.