DPWE robuustheid: toepassen van bioassays

Watermonsters van innamepunten (zg. bronnen) én drinkwater zijn onderzocht met een combinatie van bioassays en chemische analyses. Met name in de bronnen lieten de chemische analyses een breed spectrum organische microverontreinigingen zien en de bioassays een spectrum aan biologische activiteit.Figuur 13 uit het rapport toontverschillen tussen de geïntegreerde respons van de toegepaste CALUX bioassays (weergegeven door gesommeerde bioassay punten) en de gesommeerde analytische concentraties. Deze verschillen worden verklaard door het feit dat de zoetstoffen, complexvormers en metformine -die in relatief grote hoeveelheden worden aangetoond met de chemische analyses- geen biologische activiteit vertonen en dus geen responsgeven in de bioassays. Hieruit blijkteentoegevoegde waarde van bioassays: chemische stoffen die biologisch niet relevant zijn, worden ook niet opgepikt

Removal of polar organic micropollutants by pilot-scale reverse osmosis drinking water treatment

The robustness of reverse osmosis (RO) against polar organic micropollutants (MPs) was investigated in pilot-scale drinking water treatment. Experiments were carried in hypoxic conditions to treat a raw anaerobic riverbank filtrate spiked with a mixture of thirty model compounds. The chemicals were selected from scientific literature data based on their relevance for the quality of freshwater systems, RO permeate and drinking water. MPs passage and the influence of permeate flux were evaluated with a typical low-pressure RO membrane and quantified by liquid chromatography coupled to high-resolution mass spectrometry. A strong inverse correlation between size and passage of neutral hydrophilic compounds was observed. This correlation was weaker for moderately hydrophobic MPs. Anionic MPs displayed nearly no passage due to electrostatic repulsion with the negatively charged membrane surface, whereas breakthrough of small cationic MPs could be observed. The passage figures observed for the investigated set of MPs ranged from less than 1%-25%. Statistical analysis was performed to evaluate the relationship between physicochemical properties and passage. The effects of permeate flux were more pronounced for small neutral MPs, which displayed a higher passage after a pressure drop

DPWE robuustheid: toepassen van bioassays

Watermonsters van innamepunten (zg. bronnen) én drinkwater zijn onderzocht met een combinatie van bioassays en chemische analyses. Met name in de bronnen lieten de chemische analyses een breed spectrum organische microverontreinigingen zien en de bioassays een spectrum aan biologische activiteit.Figuur 13 uit het rapport toontverschillen tussen de geïntegreerde respons van de toegepaste CALUX bioassays (weergegeven door gesommeerde bioassay punten) en de gesommeerde analytische concentraties. Deze verschillen worden verklaard door het feit dat de zoetstoffen, complexvormers en metformine -die in relatief grote hoeveelheden worden aangetoond met de chemische analyses- geen biologische activiteit vertonen en dus geen responsgeven in de bioassays. Hieruit blijkteentoegevoegde waarde van bioassays: chemische stoffen die biologisch niet relevant zijn, worden ook niet opgepikt

Assembly of polyelectrolyte-containing block copolymers in aqueous media

\u3cp\u3eIn this review we present an overview of the developments of (self-)assembly of linear block copolymers containing one or more polyelectrolyte blocks in aqueous solution. Different micellar structures and phase behaviour are described. The role of inter- and intramolecular complex coacervation is emphasised. Recent developments in applications of assembly of polyelectrolyte-containing copolymers are presented.\u3c/p\u3

Comparison of complex coacervate core micelles from two diblock copolymers or a single diblock copolymer with a polyelectrolyte

\u3cp\u3eWith light scattering titrations, we show that complex coacervate core micelles (C3Ms) form from a diblock copolymer with a polyelectrolyte block and either an oppositely charged polyelectrolyte, a diblock copolymer with an oppositely charged polyelectrolyte or a mixture of the two. The effect of added salt and pH on both types of C3Ms is investigated. The hydrodynamic radius of mixed C3Ms can be controlled by varying the percentage of oppositely charged polyelectrolyte or diblock copolymer. A simple core-shell model is used to interpret the results from light scattering, giving the same trends as the experiments for both the hydrodynamic radii and the relative scattering intensities. Temperature has only a small effect on the C3Ms. Isothermal titration calorimetry shows that the complexation is mainly driven by Coulombic attraction and by the entropy gain due to counterion release.\u3c/p\u3

Carbon footprint of drinking water over treatment plant life span (2025–2075) is probably dominated by construction phase

Drinking water companies must limit their effects on climate change. Therefore, in this study, we conducted a hybrid life cycle assessment (LCA) for a new drinking water treatment plant (DWTP) to be built in 2025 and expected to be operational until 2075. We focused on obtaining a nearly complete carbon footprint (CF), including both construction (activities and materials) and operation phases. We compared three DWTP concepts: (i) conventional treatment followed by granular activated carbon (GAC) and ultrafiltration; (ii) conventional treatment followed by reverse osmosis; and (iii) capillary nanofiltration followed by GAC. As the DWTP is to be built in The Netherlands, we considered the current plans of the European Union for reducing CFs using two future scenarios (reductions of 80% and 100% in 2050). We found that the CF of the construction over the lifetime of the DWTP accounts for 20–70% of the total (excluding beneficial effects), depending mainly on the electricity used (Dutch mix, solar, or wind) and the future scenario. This means that the construction phase should be investigated in detail to obtain a complete and accurate estimate of the total CF of drinking water production for new DWTPs

Carbon footprint of drinking water softening as determined by life cycle assessment

In the Netherlands, central softening of drinking water is widely applied for reasons of public health, client comfort, economic and environmental benefits. Currently, the detrimental contributions of softening, in particular the use of chemicals and energy, are taken into account in the carbon footprint of the Dutch drinking water companies. The beneficial contributions have, however, until now not been included in the carbon footprint. Here, we present an attributional life cycle assessment (LCA) for the softening of drinking water, including effects at the household level and several sensitivity analyses. Five central softening methods were included (pellet reactor (PR), water storage reservoir (WSR), reverse osmosis (RO), nanofiltration (NF) and ion exchange (IEX)). Domestic softening by IEX is represented as well. Central softening, except RO, is shown to reduce the carbon footprint when effects at the household level are included. The main detrimental contributions are caused by the consumption of chemicals and energy in the softening process. The main beneficial contributions of softened water with respect to the carbon footprint are at the household level. Decreases in water hardness result in reduced scaling and give rise to a prolonged lifespan of appliances in which water is heated, reduced energy use of those appliances and less required cleaning agents. For PR and WSR a new beneficial effect was identified; carbon capture in the crystallized calcite and dissolution of CO2 into the softened water. We show that for the Dutch water companies Evides and Waternet approximately 20% and 60%, respectively, of their total carbon footprint is compensated by the net carbon benefit of softening. The net total carbon footprint of drinking water softening in the Netherlands is estimated to be −0.11 Mtonne CO2 eq./yr.Complex Fluid Processin

Removal of polar organic micropollutants by pilot-scale reverse osmosis drinking water treatment

The robustness of reverse osmosis (RO) against polar organic micropollutants (MPs) was investigated in pilot-scale drinking water treatment. Experiments were carried in hypoxic conditions to treat a raw anaerobic riverbank filtrate spiked with a mixture of thirty model compounds. The chemicals were selected from scientific literature data based on their relevance for the quality of freshwater systems, RO permeate and drinking water. MPs passage and the influence of permeate flux were evaluated with a typical low-pressure RO membrane and quantified by liquid chromatography coupled to high-resolution mass spectrometry. A strong inverse correlation between size and passage of neutral hydrophilic compounds was observed. This correlation was weaker for moderately hydrophobic MPs. Anionic MPs displayed nearly no passage due to electrostatic repulsion with the negatively charged membrane surface, whereas breakthrough of small cationic MPs could be observed. The passage figures observed for the investigated set of MPs ranged from less than 1%–25%. Statistical analysis was performed to evaluate the relationship between physicochemical properties and passage. The effects of permeate flux were more pronounced for small neutral MPs, which displayed a higher passage after a pressure drop.</p