Ability of soil amendments to reduce metal bioavailability on zinc and lead mine tailings

Abstract

A cooperative greenhouse study was conducted in 4 institutes to test the ability of soil amendments to reduce metal availability in situ. Soil for the study was collected from historic Zn and Pb mine tailings in Jasper County, MO. Total concentrations of Ca, K and P in the tailings were each less than 200 mg kg-1. The soil was highly contaminated with total Cd, Pb and Zn concentrations equal to 102 mg kg-1, 4060 mg kg-1 and 19900 mg kg-1. Common amendments added to the soils by all cooperators included lime and lime + phosphorus. Additional amendments included municipal biosolids, red mud, water treatment residuals and berengite. The control soil was phytotoxic with no plant growth. Phosphorus addition increased yield and reduced metal solubility (as measured by soil solution and mild salt extracts) over both control and lime amended soils. Highest yields in 3 of the groups resulted from P addition. At the U WA, highest yields were achieved with addition of biosolids + water treatment residuals. Results indicate that it is possible to reduce metal availability and restore a vegetative cover to severely contaminated sites using soil amendments.