title: Metal and nanoparticle occurrence in biosolid-amended soils.
abstract: Metals can accumulate in soils amended with biosolids in which metals have been concentrated during wastewater treatment. The goal of this study is to inspect agricultural sites with long-term biosolid application for a suite of regulated and unregulated metals, including some potentially present as commonly used engineered nanomaterials (ENMs). Sampling occurred in fields at a municipal and a privately operated biosolid recycling facilities in Texas. Depth profiles of various metals were developed for control soils without biosolid amendment and soils with different rates of biosolid application (6.6 to 74 dry tons per hectare per year) over 5 to 25 years. Regulated metals of known toxicity, including chromium, copper, cadmium, lead, and zinc, had higher concentrations in the upper layer of biosolid-amended soils (top 0-30 cm or 0-15 cm) than in control soils. The depth profiles of unregulated metals (antimony, hafnium, molybdenum, niobium, gold, silver, tantalum, tin, tungsten, and zirconium) indicate higher concentrations in the 0-30 cm soil increment than in the 70-100 cm soil increment, indicating low vertical mobility after entering the soils. Titanium-containing particles between 50 nm and 250 nm in diameter were identified in soil by transmission electron microscopy (TEM) coupled with energy dispersive x-ray spectroscopy (EDX) analysis. In conjunction with other studies, this research shows the potential for nanomaterials used in society that enter the sewer system to be removed at municipal biological wastewater treatment plants and accumulate in agricultural fields. The metal concentrations observed herein could be used as representative exposure levels for eco-toxicological studies in these soils.
authors.affiliation: School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States. Electronic address: yu.yang.2@asu.edu.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Westerhoff
authors.affiliation: College of Technology and Innovation, Arizona State University at the Polytechnic Campus, Mesa, AZ 85212, United States.
authors.forename: Kiril
authors.initials: K
authors.lastname: Hristovski
authors.affiliation: USDA - Agricultural Research Service, University of Nebraska-Lincoln, East Campus, Lincoln, NE 68583-0937, United States.
authors.forename: Virginia L
authors.initials: VL
authors.lastname: Jin
authors.affiliation: USDA - Natural Resources Conservation Service, Grassland, Soil, and Water Research Laboratory, Temple, TX 76502, United States.
authors.forename: Mari-Vaughn V
authors.initials: MV
authors.lastname: Johnson
authors.affiliation: USDA - Agricultural Research Service, Grassland, Soil, and Water Research Laboratory, Temple, TX 76502, United States.
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Arnold
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation; D008670:Metals / Q000032:analysis*; D053758:Nanoparticles / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D008670:Metals; D012987:Soil; D012989:Soil Pollutants
keywords: Metal profile; Nanomaterials; Soil; Titanium