Behavior of TiO2 and CeO2 Nanoparticles and Polystyrene Nanoplastics in Bottled Mineral, Drinking and Lake Geneva Waters. Impact of Water Hardness and Natural Organic Matter on Nanoparticle Surface Properties and Aggregation

Abstract

Intensive use of engineered nanoparticles (NPs) in daily products ineluctably results in their release into aquatic systems and consequently into drinking water resources. Therefore, understanding NPs behavior in various waters from naturel to mineral waters is crucial for risk assessment evaluation and the efficient removal of NPs during the drinking water treatment process. In this study, the impact of relevant physicochemical parameters, such as pH, water hardness, and presence of natural organic matter (NOM) on the surface charge properties and aggregation abilities of both NPs and nanoplastic particles is investigated. TiO2, CeO2, and Polystyrene (PS) nanoplastics are selected, owing to their large number applications and contrasting characteristics at environmental pH. Experiments are performed in different water samples, including, ultrapure water, three bottled mineral waters, Lake Geneva, and drinking water produced from Lake Geneva. Our findings demonstrate that both water hardness and negatively charged natural organic matter concentrations, which were measured via dissolved organic carbon determination, are playing important roles. At environmental pH, when negatively charged nanoparticles are considered, specific cation adsorption is promoting aggregation so long as NOM concentration is limited. On the other hand, NOM adsorption is expected to be a key process in NPs destabilization when positively charged PS nanoplastics are considered.

Synthesis and characterization of CeO2/Bi2O3/gC3N4 ternary Z‐scheme nanocomposite

“…An increase in zeta potential at lower pH values is commonly observed for different interfaces. A similar observation for CeO 2 catalyst was already reported 37 . Meanwhile, as pH increases, there is an increase in negative charge on the surface due to increased dissociation of the surface OH groups 38 .…”

Antimicrobial Properties of the Polyaniline Composites against Pseudomonas aeruginosa and Klebsiella pneumoniae

“…The overall negative charge of two Gram-negative cell walls is attributed to the presence of considerable carboxylic external groups located in bacterial walls. The zeta potential of TiO 2 nanoparticles is 31 ± 0.5 mV at pH 3.0 and approaches 0 at pH = 5.8 ± 0.1 [55]. The surface of the CuO nanoparticles is positively charged between pH 2 and 6 (44.2 ± 1.1 and 36.2 ± 0.9 mV), and approaches neutral at elevated pH 10 [56].…”

Measurement of CeO2 Nanoparticles in Natural Waters Using a High Sensitivity, Single Particle ICP-MS

“…Nonetheless, for the majority of detected NP, similar particle size distributions were determined in the St. Lawrence River (mean diameter ~19 nm; Figure 4), as were observed in the Meuse and IJssel Rivers in the Netherlands (14-21 nm, mean 19 nm) [27]). Such a narrow distribution of NP in such geographically different samples suggests either a similar source for the NP or similar removal processes such as agglomeration leading to removal of the larger particles [28,29].…”