Fluorescence-based evidence for adsorptive binding of pyrene to effluent dissolved organic matter

Using fluorescence intensity measurements, pyrene interactions with different types of effluent dissolved organic matter (EDOM) originated from treated municipal wastewater are examined. Multiple observations show that fluorescence intensity of pyrene–EDOM solutions is non-linearly related to pyrene concentration, with distinct concave-up dependence. Testing the effect of pyrene concentration on fluorescence intensity of pyrene–EDOM solutions provides a tool to examine whether binding of an organic compound to EDOM follows linear or non-linear isotherm. Possible coupling between static and dynamic quenching effects was addressed while analyzing fluorescence data. Limited number of EDOM binding sites results in a non-linear binding isotherm such that the concept of pyrene “partitioning” between aqueous phase and “bulky” EDOM organic phase is hardly relevant. Maximal EDOM capacity for pyrene binding is estimated approximately as 0.1% w w⁻¹. Examination of the differences between the total fluorescence intensity of pyrene–EDOM solution and the fluorescence intensities of separated constituents (pyrene and EDOM) was used to illustrate the accumulation of pyrene–EDOM complexes and saturation of some EDOM binding sites. Strong interactions between pyrene and EDOM binding sites may result in pyrene distribution coefficients differing at least by a factor 3.5–7 at varying pyrene concentrations.     

Bringing flood resilience into practice: the FREEMAN project

The recent shift in flood risk management concedes that floods cannot be prevented but the impacts on and vulnerability of the risk prone communities can be reduced. Beyond mere structural defence, an integrated risk management approach deploys a diversified set of measures that moderate the economic and social drivers of risk and improve risk governance. In this context, the concept of resilience gains on importance despite the many challenges that obstruct its implementation in management practice. This paper contributes to tackling these challenges and elaborates on opportunities and bottlenecks to bring resilience into practice based on a review of the flood risk management in three case studies in Europe: Flanders (Belgium), Niedersachsen (Germany) and Calabria (Italy). The paper summarizes insights gained on three components of resilience being – institutional interplay, flood management tools and risk communication. The work that has lead to this paper is done under the FREEMAN project (flood resilience enhancement and management), funded under the 2nd CRUE ERA-Net Funding Initiative.