Fate of organic micropollutants during brackish water desalination for drinking water production in decentralized capacitive electrodialysis.

Capacitive electrodialysis (CED) is an emerging and promising desalination technology for decentralized drinking water production. Brackish water, often used as a drinking water source, may contain organic micropollutants (OMPs), thus raising environmental and health concerns. This study investigated the transport of OMPs in a fully-functional decentralized CED system for drinking water production under realistic operational conditions. Eighteen environmentally-relevant OMPs (20 µg L-1) with different physicochemical properties (charge, size, hydrophobicity) were selected and added to the feed water. The removal of OMPs was significantly lower than that of salts (∼94%), mainly due to their lower electrical mobility and higher steric hindrance. The removal of negatively-charged OMPs reached 50% and was generally higher than that of positively-charged OMPs (31%), whereas non-charged OMPs were barely transported. Marginal adsorption of OMPs was found under moderate water recovery (50%), in contrast to significant adsorption of charged OMPs under high water recovery (80%). The five-month operation demonstrated that the CED system could reliably produce water with low salt ions and TOC concentrations, meeting the respective WHO requirements. The specific energy consumption of the CED stack under 80% water recovery was 0.54 kWh m-3, which is competitive to state-of-the-art RO, ED, and emerging MCDI in brackish water desalination. Under this condition, the total OPEX was 2.43 € m-3, of which the cost of membrane replacement contributed significantly. Although the CED system proved to be a robust, highly adaptive, and fully automated technology for decentralized drinking water production, it was not highly efficient in removing OMPs, especially non-charged OMPs.

Protocol for Multi-Stage Treatment of Temporomandibular Joint Ankylosis in Children and Adolescents.

Treatment of temporomandibular ankylosis is challenging and frequently leads to re-ankylosis, relapse, dangerous complications and, in turn, the need for multiple operations. In this article, we present a protocol for the treatment of ankylosis of the temporomandibular joints that assumes earlier intervention with the assistance of 3D virtual surgical planning (3DVSP) and custom biomaterials for better and safer surgical outcomes. Thirty-three patients were treated due to either uni- or bilateral temporomandibular ankylosis. Twenty individuals received temporomandibular prosthesis, whereas seventeen required simultaneous 3D virtual surgical/planned orthognathic surgery as the final correction of the malocclusion. All patients exhibited statistically significant improvements in mouth opening (from 1.21 ± 0.74 cm to 3.77 ± 0.46 cm) and increased physiological functioning of the mandible. Gap arthroplasty and aggressive rehabilitation prior to temporomandibular prosthesis (TMJP) placement were preferred over costochondral autografts. The use of 3DVSP and custom biomaterials enables more precise, efficient and safe procedures to be performed in the paediatric and adolescent population requiring treatment for temporomandibular ankylosis.

Non-steady diffusion and adsorption of organic micropollutants in ion-exchange membranes: effect of the membrane thickness.

There is no efficient wastewater treatment solution for removing organic micropollutants (OMPs), which, therefore, are continuously introduced to the Earth's surface waters. This creates a severe risk to aquatic ecosystems and human health. In emerging water treatment processes based on ion-exchange membranes (IEM), transport of OMPs through membranes remains unknown. We performed a comprehensive investigation of the OMP transport through a single IEM under non-steady-state conditions. For the first time, positron annihilation lifetime spectroscopy was used to study differences in the free volume element radius between anion- and cation-exchange membranes, and between their thicknesses. The dynamic diffusion-adsorption model was used to calculate the adsorption and diffusion coefficients of OMPs. Remarkably, diffusion coefficients increased with the membrane thickness, where its surface resistance was more evident in thinner membranes. Presented results will contribute to the improved design of next-generation IEMs with higher selectivity toward multiple types of organic compounds.