title: Evaluation of the impact of lime softening waste disposal in natural environments.
abstract: Drinking water treatment residues (WTR), generated from the lime softening processes, are commonly reused or disposed of in a number of applications; these include use as a soil amendment or a subsurface fill. Recently questions were posed by the Florida regulatory community on whether lime WTR that contained a small percentage of other treatment additives could appropriately be characterized as lime WTR, in terms of total element content and leachability. A study was done using a broad range of leaching tests, including a framework of tests recently adopted by the United States-Environmental Protection Agency (EPA) and tests that were modified to account for scenario specific conditions, such as the presence of natural organic matter (NOM). The results of these additional leaching tests demonstrated that certain applications, including disposal in a water body with NOM or in placement anaerobic environment, did result in increased leaching of elements such as Fe, and that a site specific assessment should be conducted prior to using WTR in these types of applications. This study illustrates the importance of leaching test selection when attempting to provide an estimation of release in practice. Although leaching tests are just one component in a beneficial use assessment and other factors including aquifer and soil properties play a significant role in the outcome, leaching tests should be tailored to most appropriately represent the scenario or reuse application being evaluated.
authors.affiliation: Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA.
authors.forename: Nawaf I
authors.initials: NI
authors.lastname: Blaisi
authors.affiliation: Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA.
authors.forename: Justin
authors.initials: J
authors.lastname: Roessler
authors.affiliation: Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA.
authors.forename: Weizhi
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA. Electronic address: ttown@ufl.edu.
authors.forename: Timothy
authors.initials: T
authors.lastname: Townsend
authors.affiliation: National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA.
authors.forename: Souhail R
authors.initials: SR
authors.lastname: Al-Abed
mesh_terms: D000693:Anaerobiosis; D017610:Calcium Compounds / Q000737:chemistry; D060766:Drinking Water; D004777:Environment; D005431:Florida; D006863:Hydrogen-Ion Concentration; D010087:Oxides / Q000737:chemistry; D018570:Risk Assessment; D018508:Water Purification / Q000379:methods*
chemical_list: D017610:Calcium Compounds; D060766:Drinking Water; D010087:Oxides; C016538:lime
keywords: Beneficial use; Leaching; Lime; Redox; Sludge