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This article in JEQ

  1. Vol. 40 No. 1, p. 1-12
    Received: May 27, 2010

    * Corresponding author(s): jim.ippolito@ars.usda.gov


Drinking Water Treatment Residuals: A Review of Recent Uses

  1. J. A. Ippolito *a,
  2. K. A. Barbarickb and
  3. H. A. Elliottc
  1. a J.A. Ippolito, USDA-ARS NWISRL, Kimberly, ID, 83341
    b Dep. of Soil and Crop Sciences, Colorado State Univ., Fort Collins, CO, 80523-1170
    c Agricultural and Biological Engineering Dep., Pennsylvania State Univ., University Park, PA, 16802. Assigned to Associate Editor Kenneth Sajwan


Coagulants such as alum [Al2(SO4)3•14H2O], FeCl3, or Fe2(SO4)3 are commonly used to remove particulate and dissolved constituents from water supplies in the production of drinking water. The resulting waste product, called water-treatment residuals (WTR), contains precipitated Al and Fe oxyhydroxides, resulting in a strong affinity for anionic species. Recent research has focused on using WTR as cost-effective materials to reduce soluble phosphorus (P) in soils, runoff, and land-applied organic wastes (manures and biosolids). Studies show P adsorption by WTR to be fast and nearly irreversible, suggesting long-term stable immobilization of WTR-bound P. Because excessive WTR application can induce P deficiency in crops, effective application rates and methods remain an area of intense research. Removal of other potential environmental contaminants [ClO4 , Se(+IV and +VI), As(+III and +V), and Hg] by WTR has been documented, suggesting potential use of WTR in environmental remediation. Although the creation of Al plant toxicity and enhanced Al leaching are concerns expressed by researchers, these effects are minimal at circumneutral soil pH conditions. Radioactivity, trace element levels, and enhanced Mn leaching have also been cited as potential problems in WTR usage as a soil supplement. However, these issues can be managed so as not to limit the beneficial use of WTR in controlling off-site P losses to sensitive water bodies or reducing soil-extractable P concentrations.

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Copyright © 2011. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyAmerican Society of Agronomy, Crop Science Society of America, and Soil Science Society of America