Lakhwinder S. Hundal1, Kang Xia2, Albert E. Cox1, Kuldip Kumar1, Thomas C. Granato1, Louis Kollias1, Richard Lanyon1, and Kevin Armbrust2. (1) MWRD, 6001 W Pershing Rd, R&D Dept, Section 123, Cicero, IL 60804-4112, (2) Mississippi State Chemical Lab, P.O. Box CR, Mississippi State, MS 39762
Farmland application of biosolids is the most sensible and cost-effective option for many municipalities and it provides significant savings in fertilizer costs to the farmers. However, concerns continue to be raised by the public and in the news media about the safety of this practice because biosolids may contain traces of several organic (pharmaceuticals and personal care products) contaminants that enter the wastewater stream via domestic and industrial wastewater. During the wastewater treatment process, the hydrophobic organic contaminants partition into biosolids due to their high affinity for organic carbon. Although detectable levels of 4-NP and PBDEs have been reported in biosolids, the information about their concentrations in soil after long-term land application of biosolids is scarce. The concentrations of 4-NP and PBDEs were evaluated in soil samples from our long-term plots that have been receiving annual applications of biosolids since 1973. At the end of 2002, the cumulative biosolids loadings were 0 (control), 504, 1008, and 2016 Mg dry biosolids per hectare in the plots receiving annual biosolids applications at the rate of 0, 16.8, 33.6, and 67.2 Mg dry biosolids per hectare. Detailed analysis of 4-NP and PBDEs levels in soil will be presented and the effect of long-term biosolids application on 4-NP and PBDEs levels in soil will be discussed.