Current Projects

Efficiency of small contaminant removal by Reverse Osmosis

Vittorio Albergamo (Uva)

Supervisors: Michiel Kraak, Pim de Voogt (UvA), Walter van der Meer (UT)

Duration: 2014-2018
Funded by Water Company Oasen

The nature of organic contaminants present in raw waters is constantly changing, reflecting changes in societal use of chemicals on the one hand and climatological change on the other. Chemicalisation of modern society and recent innovations is leading towards an increased use of hydrophilic chemicals that, in turn, results in higher loads of such chemicals in aqueous environments. As a consequence, the drinking water companies may face stronger demands on removal processes as the hydrophilic compounds inherently are more difficult to remove.

While other methods of water treatment such as activated carbon filtration and advanced oxidation remove selected groups of contaminants only, the majority of organic compounds present in raw water used for producing drinking water can be removed efficiently with Reverse Osmosis (RO). Reversed osmosis is a powerful advanced treatment technique that does not create impurities or unwanted transformation products because of the lack of chemical reactions in the process applied. Reversed osmosis will in general remove ionic impurities almost completely, and polar and neutral organic compounds will be removed if their molecular size is larger than approximately 20 nm or ~120Da. Reversed osmosis has been proposed as a treatment technique that can be used stand alone to produce impeccable drinking water without any additional purification steps needed.

The main objectives of the present Ph.D. project are i.) to verify if RO is the most effective and efficient means of removing existing and newly emerging organic microcontaminants; (ii) to identify emerging organic contaminants that are not effectively removed by RO and to assess their potential threat for human and ecosystem health. To that end the following working objectives have been identified: a.) to identify trends in concentrations and identities of organic microcontaminants in source waters; (b) to assess the extent of removal from water of new emerging contaminants, in particular small polar molecules, by RO; c.) to assess the toxicity, including the mixture toxicity, of the effluents of optimized RO treatments; d) to relate removal rates to compound properties and RO characteristics

The project is a collaboration between the Dutch water company Oasen, KWR Watercycle Research Institute and IBED-UvA, and funded by Oasen. The duration of the project is from September 2014 to August 2018.