Professor Rolf D. Vogt, University of Oslo, Norway.

Title: “Climate change and NOM in aquatic environment”

Prof. Vogt is a biogeochemist studying the processes governing mobilization, transport, fate and effect of compounds in the environment. His work is interdisciplinary and international, cooperating with scientists from other disciplines within natural sciences as well as humanities and social sciences, in especially China, Africa and Europe.
The main research focus of Prof. Vogt is on the dissolved natural organic matter (DOM), how changes in environmental pressures influence its mobility and transport, and what effect this has on the physicochemical properties of freshwaters.
Ongoing and recent research projects are on regional pressures governing DOM quantity and quality, DOM and mercury, as well as size-fractionation and photo-oxidation of DOM.

Professor David A. Reckhow, University of Massachusetts Amherst, U.S.A.

Title: “Methods for near real-time monitoring and analysis of DBP precursors and NOM properties”

With tightening regulations on disinfection byproducts (DBPs) as well as anticipated climate changes, the water industry is in need of better monitoring tools.  While there are commercially available sensors and instruments that can partly address this need, there is little direct comparative data and critical analysis to help managers decide on the best approach.  This work will provide guidance for near real time management of natural organic matter (NOM) properties and DBP precursors.

Professor Marc F. BENEDETTI, Institut de Physique du Globe de Paris, Sorbonne Paris Cité, France.

Title: “Trace elements and organic matter interactions: Future Challenges”  

Prof. Marc Benedetti is the initiator of and a major contributor to research carried out to address the mechanisms regulating the formation of complexes between trace elements and natural organic colloids. His research has resulted in new approaches synthesizing and combining potentiometric techniques and new ion exchange approaches (Donnan effect). The studies carried out by him have provided a conceptual framework to decipher how major physicochemical parameters affect the binding of trace elements to organic ligands. These studies also contribute for our general understanding of how different elements compete to binding macromolecules and how the later control the fate of radionuclides or iron in the environment. Prof. Benedetti has published in this field 70 original publications in high impact factor journals between 2005 and 2018,

OM is found in soils and sediments at concentrations of 0.1-10% by weight. OM binds a variety of trace elements and typically contains 2-10 equiv kg-1 of ionizable groups.  The binding of protons and metal ions to OM is important for the speciation, transport, and toxicity of many trace metals, but it has proven difficult to find equations that describe this binding over a wide range of conditions. The direct measurement of their speciation in natural matrices is challenging since the analytical methods used should be sensitive for low concentration, and highly specific to the element and compartment of interest. In order to circumvent these potential analytical limitations, various speciation models are developed and included in software assuming a thermodynamic equilibrium.  However in natural systems, individual metals exist as components in mixtures with organic and inorganic substances and/or particulate matter. While the concepts encompassing mixture fates and modelling have been around for decades, only recently have new approaches been expanded to consider metal mixture scenarios to understand the fate and the availability of trace elements.  Although current environmental regulations rarely requires an assessment of chemicals mixtures, research on these mixtures in the environment are essential for future regulatory demands and vital for ensuring adequate environmental protection. Interpretation of speciation and bioavailability results from metal mixtures can be very complex and demanding, due to the existence of several chemical interactions between the various media constituents that can affect metal speciation, culminating in different transformed metal-containing products.

Associate Professor Kathleen Murphy, Chalmers University of Technology, Division of Water Environment Technology.

Title: “New data analytical approaches reveal ubiquitous signals in fluorescent DOM”

Dissolved organic matter (DOM) in aquatic environments forms a vast reservoir of carbon present as a complex super-mixture of compounds. An efficient approach to tracking the production and removal of specific DOM fractions is needed across disciplines, for purposes that range from improving global carbon budgets to optimizing water treatment in engineered systems. Although widely used to study DOM, fluorescence spectroscopy has yet to deliver specific fractions with known spectral properties and predictable distributions. This talk will discuss recent developments in analysing fluorescence datasets whereby parallel factor analysis is used to decompose individual samples instead of multi-sample datasets. Applied to contrasting samples from lakes, rivers, and the oceans, our results indicate that most measured fluorescence is explained by ubiquitous signals with nearly stable optical properties and predictable photodegradation behaviour over environmental pH gradients. A next step is to decide how to incorporate these findings into future studies to improve the overall interpretation of DOM fluorescence and increase its utility for studying DOM biochemistry and detecting changes to DOM quantity and quality in water treatment systems.

Professor Sadahiko Ito, Kyoto University, Japan.

Prof. Ito’s research interests include:

  1. Re-establishing water supply system in a depopulation society
  2. Indirect water reuse system using soil aquifer treatment
  3. Advanced water treatment process for reducing chlorinous odor
  4. Quantitative microbial risk assessment of drinking water
  5. Communication method for increasing willingness to pay to water tariff

Title: “Impacts of Changes in Source Water Conditions on Water Treatment and the Countermeasures”

The contents of the project of “Study on Establishing Water Treatment Technologies Corresponding to Change (A-Batons)” launched by Japan Water Research Center (JWRC) in 2015 are shown. A result of a nationwide questionnaire survey on troubles and problems on water treatment arised from changes in natural and social conditions revealed various kinds of changes in source waters and their impacts. “Guidebook of Implementing Countermeasures against Water Treatment Problems due to Changes in Natural Conditions” published by JWRC has summarized countermeasures including temporary measures and permanent measures.