AEESP Journal Spotlight: Mid 2018

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 2017 issue through the March 2018 issue of EES. Congratulations to all whose work is highlighted.

The design of wastewater treatment plant (WWTP) networks can be complicated by the existence of uncertainties and the multiscale nature of the planning process. Liang et al. (2017) presents a multiscale two-stage mixed integer stochastic (MSTMIS) model for optimal design of WWTP networks under uncertainty. The model was tested on a WWTP network in a metropolitan area. The proposed MSTMIS model simultaneously addresses the challenges posed by uncertainty and multiscale nature and, thus, provides the decision-makers more confidence in making economic decisions related to WWTP network design.

Values of air pollution index (API) are evaluated by the maximum value of five pollutants: sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, and suspended particulate matter (PM10) at a particular hour. Ahmed et al. (2018) explored the exceedance of API values and its dominants, using peaks-over-threshold method in three urban areas in Peninsular Malaysia for the period of January 2005 to December 2014. Results obtained showed that PM-10 and ozone are the pollutants that dominate elevated API values.

While the formation of calcium carbonate (CaCO₃) has long been a concern in potable water, Richards et al. assert that it is re-emerging as an important issue due to climate change, higher set-point temperatures in hot water systems, use of scaling and corrosion inhibitors, and self-repair of pipeline leaks. Actions to increase the lifespan of distribution systems through reduced corrosion (i.e., adding corrosion inhibitors) may inadvertently worsen leaks and pipe lifespans, due to interference with natural self-repair from CaCO₃ precipitation. These changes in practice, coupled with knowledge gaps over CaCO₃ formation in water systems.

Zinc oxide (ZnO) nanoparticles (NPs), which are widely used in cosmetics, sunscreen lotions, medicines, and as antibacterial agents, were evaluated by Chul et al. (2018) for their effect on bacterial bioluminescence and gene mutation, seed germination, and algal growth. Under exposure conditions, the toxicity of ZnO NPs increased on seed germination, but decreased on algal growth and gene mutation. No significant differences were observed in bacterial bioluminescence over the range of particle sizes tested. These findings show that a toxicity evaluation of NPs needs to consider the different effects with respect to particle sizes and tested organisms.