Nicoleta Schiopu

Biocide leaching from CBA treated wood — A mechanistic interpretation

Treated wood is frequently used for construction. However, there is a need to ensure that biocides used for the treatment are not a threat for people or environment. The paper focused on Pinus sylvestris treated with copper-boron-azole (CBA), containing tebuconazole as organic biocide and monoethanolamine (Mea). This study investigates chemical mechanisms of fixation and mobilisation involved in the leaching process of the used inorganic and organic biocides in CBA. A pH dependent leaching test was performed, followed by a set of complementary analysis methods in order to identify and quantify the species released from wood. The main findings of this study are: - Organic compounds are released from untreated and treated wood; the quantity of released total organic carbon, carboxylic and phenolic functions increasing with the pH. - Nitrogen containing compounds, i.e. mainly Mea and its reaction products with extractives, are released in important quantities from CBA treated wood, especially at low pH. - The release of copper is the result of competitive reactions: fixation via complexation reactions and complexation with extractives in the liquid phase. The specific pH dependency of Cu leaching is explained by the competition of ligands for protonation and complexation. - Tebuconazole is released to a lesser extent relative to its initial content. Its fixation on solid wood structure seems to be influenced by pH, suggesting interactions with \OH groups on wood. Boron release appears to be pH independent and very high. This confirms its weak fixation on wood and also no or weak interaction with the extractives.

Assessment of Dangerous Substances Release from Construction Products to Environment

In 2005 the European Commission mandate CEN to prepare test methods with which construction products can be tested with respect to the potential release of dangerous substances to water, soil and to indoor air. A horizontal approach is considered the best route for such test development. Horizontal approach means that it is product independent and consists of the development of a test method applicable for different products used in a certain scenario. This action will satisfy the needs resulting from Essential Requirement n° 3, on Hygiene, Health and Environment, as specified in the Construction Products Directive. In this context, the aim of the work presented here is to study the release mechanisms and the parameters which could influence the leaching of pollutants from construction products towards soil and water, in order to provide information for the development of a horizontal test. The research has been carried out on monolith products, based on three types of matrices: concrete, wood and metal (zinc). For the concrete products, one of the choice criteria was the presence of trace metals (e.g. chromium VI); the wood products are pertinent candidates for our study because of the preservation treatment, which by definition is toxic for some form of life (biocidal substances are used for the treatment); as for the zinc based products, research on contributions of the different sources of urban run-off pollution, showed a very high concentration of zinc (up to 6 mg/L in a catchment in Paris) in roof run-off. Also, this source represents a very high percentage among other urban run-off pollution sources (92% from roof vs. 8% from yard and street run-off).

A Proposition to Extend CityGML and ADE Energy Standards for Exchanging Information for LCA Simulation at Urban Scale

Environmental performances assessment of urban projects is essential to meet the current challenges of urban sustainable development. In recent years, Life Cycle Assessment (LCA) has been applied to urban scale to assess complex systems such as districts, urban facilities and territories. Yet, application of LCA to large scale is challenging in terms of data modelling. To overcome this challenge, integration of Building Information Model (BIM) to LCA could reduce efforts during the data acquisition, as well as allowing the feedback of LCA results into BIM. To ensure interoperability e.g. with energy simulation tools, digital mock-up using an open information standard must be preferred. To answer this need, the Open Geospatial Consortium (OGC) developed the open standard CityGML which is an XML-based data model that defines classes and relations for 3D object in cities (e.g. buildings, roads, water bodies etc.). This format also provides for domain-specific extension to other objects or attributes using Application Domain Extensions (ADE). To date, LCA data requirements have not been fully integrated into the CityGML format nor its ADE. The aim of this paper is to propose extension of CityGML and Energy-ADE standards for exchanging information for LCA simulation at urban scale. The scope of the study is limited to the integration of information necessary for LCA of buildings’ construction and renovation. First, data requirements are listed and then compared to CityGML and Energy-ADE structures to identify missing information. Finally, propositions and recommendations are presented to fully integrate information needed for LCA at urban scale into CityGML and Energy-ADE. This paper paves the way for further integration of LCA models with CityGML.