Simulation of the biocide distribution in soil using PELMO coupled with COMLEAM

Area of Science:

• Environmental Science
• Ecotoxicology
• Soil Science

Background:

• Biocides in building materials pose environmental risks due to leaching into aquatic and soil environments.
• Predicting the transport, transformation, and ecotoxicity of continuously released, diluted biocides in soil presents significant challenges.

Purpose of the Study:

• To develop and validate an integrated modeling approach for predicting biocide behavior and environmental risks in soil.
• To assess the impact of leaching simulations, absorption, and degradation kinetics on biocide distribution predictions.

Main Methods:

• Combined the COMLEAM model (facade leaching) with the FOCUS PELMO pesticide model for soil distribution prediction.
• Simulated concentrations of 1,2-benzisothiazol-3(2H)-one (BIT), 2-n-octyl-4-isothiazolinone-3-one, and terbutryn in soil over 600 days.
• Evaluated the influence of varying leaching, absorption, and degradation parameters on model outcomes.

Main Results:

• The integrated model effectively simulates biocide behavior in soil.
• Predictions showed a tendency to overestimate risks for short-acting biocides like BIT but offered precise predictions for long-acting preservatives.
• Biocide concentration variance was minimal in upper soil layers, increasing with depth.

Conclusions:

• The integrated COMLEAM-PELMO approach offers a cost-effective method for predicting environmental risks of biocides in soil.
• This modeling approach aids in formulating effective management strategies for soil contamination.
• Incorporating experimentally determined soil-specific degradation and absorption values enhances prediction accuracy.