Abstract
The “spotlight” column draws attention to selected articles in Environmental Engineering Science (EES), the official journal of the Association of Environmental Engineering and Science Professors (AEESP). Spotlight articles appear regularly in the journal as an editor's note, as well as in the AEESP newsletter. Through publication of high-quality peer-reviewed research, the EES journal helps AEESP achieve its mission of developing and disseminating knowledge in environmental engineering and science. In this entry, we shine the spotlight on selected articles from the December 2018 issue through the March 2019 issue of EES. Congratulations to all whose work is highlighted.
One approach to minimize the discharge of nutrients (nitrogen and phosphorus) into the aquatic system is to recover ammonium nitrogen and phosphate from wastewater treatment effluents for reuse. Ion exchange has been applied for such a purpose; however, the presence of micropollutants can limit their reuse potentials. Tong et al. (2018) evaluated the capability of biosolids-derived biochar for the adsorption of micropollutants as a pretreatment step, using triclosan, estradiol, and sulfamethoxazole as model micropollutants. Through batch and flow-through experiments, they demonstrated an effective removal of triclosan and estradiol by the biochar, and, to a lesser extent, sulfamethoxazole. It was in the presence of ammonium nitrogen and phosphate that the removal occurred, suggesting that the biochar sorption could be used as pretreatment before use of ion exchange resin for nutrient recovery.
In parts of the developing world, many people still do not have adequate access to clean drinking water. Because conventional water supply infrastructure is too expensive to build, point-of-use systems such as ceramic water filters are often used. Jackson et al. (2019) studied porous ceramic filters fabricated in a pot shape similar to commercial filter units, in which silver and copper were embedded in different ways to deactivate pathogens. Their results showed that the ceramic filter prepared by mixing AgNO3 with clay and sawdust, followed by firing in a kiln, had the best performance based on its ability for deactivation of Escherichia coli and minimal silver release to the treated water.
Membrane separation has been increasingly used not only for desalination but also for drinking water and wastewater treatment. There are many types of membrane and many system configurations, so selection of the best approach for a specific application is not always easy. Wang et al. (2019) conducted a life cycle assessment to analyze the energy consumption and environmental impacts of the catalytic ceramic membrane system, in comparison with the polymer-based hollow-fiber membrane filtration system. Their result suggested that ceramic membrane combined with ozonation was a promising technology; further improvement could be gained by lowering cost for ozone generation and transport, and development of better catalytic coating materials.
Membrane biofouling is one of the most challenging issues that hinders the application of membrane technologies for water treatment. The challenge could be addressed by the fabrication of membranes with antifouling surfaces. Fleming et al. (2019) modified the polysulfone surface by grafting polydopamine, which, when exposed to silver nitrate solution, would reduce silver cations to form zerovalent silver nanoparticles. The modified membrane with polydopamine and silver nanoparticles was found to have better performance and antifouling properties.