Emission of biocides from treated materials test procedures for water and air

Abstract

Methods for the determination of biocide emissions from treated materials into water and air were developed and tested in order to support a comparative ecological assessment of biocidal products. Leaching tests, experiments with simulated rain, extraction cleaning of carpets and emission chamber tests were performed with a series of treated materials. The experiments focused on the effect of changes in the procedure as well as characteristics of the specimens and demonstrate the suitability of the proposed methods for biocides of different product types. It was demonstrated that emissions of biocides into water can be compared on the basis of leaching tests in which the emission kinetics of the active ingredients are recorded. However, the water volume per surface area and the timetable for water changes have to be defined in such tests. Functions of flux rates related to time can be well described for inorganic compounds, whereas modelling of the data is more complicated for organic substances. Emission chamber tests using 20-litre and 23-litre glass exsiccators, originally developed to study volatile organic compounds, were successfully adapted for the investigation of the emission of biocides from treated materials which are usually semi volatile organic compounds. However test parameters and the method of analysis have to be adapted to the substances to be determined. Generally, it was found that the emission curves for the semi volatile organic compounds investigated differ from those of volatile organic compounds.

Influence of leaching medium and drying time between successive leaching periods on the emission of chromium, copper, and boron from treated wood

“…Soil water was obtained by passing deionized water at a flow of 27 ml/h through a soil column of 5.9-cm internal diameter and 8.5-cm length during 24 h. The characteristics of leaching solutions are shown in Table 1. Based on a recent literature survey [32], the pH values of these leaching media (between pH 5.86 and 7.23) were not considered to affect the emission rate of metals.…”

Biocides used in building materials and their leaching behavior to sewer systems

“…Diuron, terbutryn and carbendazim used in paints and plaster of facades were detected in effluents of waste water treatment plants (WWTPs) (Gerecke et al, 2002). Nevertheless, most information on the leaching of biocides from facades and plastic roofs is based on laboratory studies (Cadmus and Brophy, 1982;Lindner, 1997;Schoknecht et al, 2003). Elution of mecoprop from bitumen roofs and its transfer to surface water has been reported almost ten years ago (Bucheli et al, 1998).…”

Polyacrylate–water partitioning of biocidal compounds: Enhancing the understanding of biocide partitioning between render and water

“…Hence, the total content of biocides in render and exterior paints ranges from 5 to 10 g kg À1 (Burkhardt et al, 2011). Laboratory studies on constantly soaked material, dipping experiments with alternating wet and dry cycles, or forced rain experiments showed that the biocides leach out of the render material in considerable fractions (Schoknecht et al, 2003;Burkhardt et al, 2007;Schoknecht et al, 2009;Burkhardt et al, 2011Burkhardt et al, , 2012Wangler et al, 2012). The leaching process of biocides from render is assumed to be a multistep process: (1) removal from the surface layer which is itself (2) in equilibrium with the deeper layers of the render, from which (3) the surface layer is constantly refilled.…”