TGP Project 3.11_Study Report on Nanomaterial removal from wastewater

The purpose of this study report is to assess the feasibility of complementary methods to currently existing ones and to address specific unknown factors such as the relevance of measuring an equilibrium isotherm while reducing the cost and time burdens associated with performing tests such as those described by OECD 303A The TG will address removal of emerging chemicals eg nanomaterials from wastewater by interaction with activated sludge andor wastewater additives such as flocculants and coagulants typically encountered in the clarifying stages of wastewater treatment Originally the project intended to develop a new Test Guideline for removal of nanomaterials from wastewater treatment plants The lead country decided to abandon efforts in that direction and stopped the projectrelated activities including testing of robustness and reproducibility of the methodology As a risk mitigation measure and in order to better understand whether the lack of a standardized OECD Test Guideline in this area was perceived as a critical gap in the regulatory toolbox the OECD Secretariat organized a webinar in June 2022 with key experts recognized internationally see deliverable D11 Conclusions were generally supportive of research efforts in developing computational models to assess to removaldistributiondissipation of various types of nanomaterials in different media including wastewater treatment plants rather than developing experimental methods that are costly difficult to implement and suffer from a lack of reproducibility