REGIONAL MASS FLUX BALANCING FOR CONTROLLING GENTLE SOIL REMEDIATION OPERATIONS

Extraction of heavy metals by accumulating plants is a method which is currently in development for the ''gentle'' remediation of contaminat ed agricultural soils (phytoremediation, see [2]). Areal contaminant m ass flux balances are basic criteria for the design of such remediatio ns and their control. A framework for the integration of contaminant b alances relating the field scale of remediation with the regional scal e of soil monitoring networks is provided by the recently developed me thod PROTERRA [3]. The objective of the study presented in this paper was to test the suitability of PROTERRA for planning and monitoring ge ntle soil remediations. For this purpose we applied the PROTERRA metho d to the contaminated agricultural land in and around Dornach, Switzer land, to assess copper flux balances. The calculations showed that atm ospheric deposition and the application of pesticides and manure are i mportant pathways for the inputs of copper. The copper export with a s pecial maize cultivar accumulating heavy metals would be about three t imes higher than the average metal export with crops. A moderate incre ase of sewage sludge application would lead to a substantial increase of the copper input. Decisions to remediate the soil should take the u ncertainty of mass flux balances both on field scale as well as on reg ional scale into account. Therefore, an important need of further deve lopment of the PROTERRA method is the integration of uncertainty analy sis on both scales.