Assessing contaminant mobilization from waste materials: application of Bayesian parameter estimation to batch extraction tests at varying liquid-to-solid ratios.
We investigated the release of chloride, sulfate, sodium, copper, chromium, and dissolved organic carbon from a demolition waste material and a municipal waste incineration product Batch leaching tests at the liquid-to-solid ratios (L/S ratios) 1, 2, 5, 10, and 50 L kg(-1) were carried out and the parameters of a mass balance-partitioning model were estimated from measured concentrations in the extracts by applying a Bayesian approach using a Markov Chain Monte Carlo sampler. We assessed the uncertainty of the model parameters, the desorption isotherms, and the model-predicted concentrations, respectively. Both the excellent fit to the experimental data and a comparison between the model-predicted and independently measured concentrations at the L/S ratios of 0.25 and 0.5 L kg(-1) showed the applicability of the model for almost all studied substances and both materials. Since experimental difficulties impede extraction tests at L/S ratios representative of field soil-water contents, the predictability of concentrations in this range is of great practical relevance for risk assessments. We conclude that batch extraction tests at varying L/S ratios provide, at moderate experimental cost, a powerful complement to established test designs like column leaching or single batch extraction tests.
Iden
Sascha C
SC
Institut für Geoökologie, Technische UniversitätCarolo-Wilhelmina zu Braunschweig, Germany. s.iden@tu-bs.de
Delay
Markus
M
Frimmel
Fritz H
FH
Durner
Wolfgang
W
D001499:Bayes Theorem; D004785:Environmental Pollutants / Q000032:analysis*; D053834:Explosive Agents; D017745:Incineration; D008962:Models, Theoretical; D012037:Refuse Disposal
D004785:Environmental Pollutants; D053834:Explosive Agents