Simple, robust, and low-cost nitrate- and ammonium-selective electrodes were made using substrate prepared from household materials. We explored phosphonium-based ILs and poly (methyl methacrylate)/poly(decyl methacrylate)(MMA-DMA) copolymer as matrix materials alternative to classical PVC-based membranes. IL-based membranes showed suitability only for nitrate-selective electrode exhibiting linear concentration range between 5.0 × 10⁻⁶ and 2.5 × 10⁻³ M with a detection limit of 5.5 × 10⁻⁷ M. On the other hand, MMA-DMA—based membranes showed suitability for both ammonium- and nitrate-selective electrodes, and were successfully applied to detect NO₃⁻ and NH₄⁺ in water and soil samples. The proposed ISEs exhibited near-Nernstian potentiometric responses to NO₃⁻ and NH₄⁺ with the linear range concentration between 5.0 × 10⁻⁵ and 5.0 × 10⁻² M (LOD = 11.3 µM) and 5.0 × 10⁻⁶ and 1.0 × 10⁻³ M (LOD = 1.2 µM), respectively. The power of ISEs to detect NO₃⁻ and NH₄⁺ in water and soils was tested by comparison with traditional, portable colorimetric techniques. Procedures required for analysis by each technique from the perspective of a non-trained person (e.g., farmer) and the convenience of the use on the field are compared and contrasted.

Successfully addressing the complex global sanitation problem is a massive undertaking. Anaerobic digestion (AD), coupled with post-treatment, has been identified as a promising technology to contribute to meeting this goal. It offers multiple benefits to the end users, such as the potential inactivation of pathogenic microorganisms in waste and the recovery of resources, including renewable energy and nutrients. This feature article provides an overview of the most frequently applied AD systems for decentralized communities and low- and lower-middle-income countries with an emphasis on sanitation, including technologies for which pathogen inactivation was considered during the design. Challenges to AD use are then identified, such as experience, economics, knowledge/training of personnel and users, and stakeholder analysis. Finally, accelerators for AD implementation are noted, such as the inclusion of field studies in academic journals, analysis of emerging contaminants, the use of sanitation toolboxes and life cycle assessment in design, incorporation of artificial intelligence in monitoring, and expansion of undergraduate and graduate curricula focused on Water, Sanitation, and Hygiene (WASH).

An overview is given dealing with application of ion-selective electrodes (ISEs) in environmental analysis. ISEs are placed into the context of the trend of development of sensors for extensive and frequent monitoring. Discussed are the issues such as sensing platforms and their mass-production, improvement of precision, diagnostic of sensor?s functionality, and development of reference electrodes and several examples of real-life application of ISEs in environmental analysis are given. The main emphasis of this article is directed towards summarizing recent of authors? results during the past several years.