Suchergebnisse

The role of microbial diversity in microbial electrosynthesis
Bacteria are often painted as the enemy of humanity. Before the discovery of antibiotics, a wound getting infected was frequently a death sentence. Even with modern medicine, infections such as C. difficile and infectious diseases such as tuberculosis continue to kill many people globally. Crop blights and diseases among livestock cause extensive monetary losses and threaten food security in affected areas. With all of these reasons to distrust bacteria, it may come as a surprise that certain microbes are immensely beneficial to humanity. Unfortunately, they rarely get to enjoy the limelight. Our gut microbiomes help us digest complex molecules in our food, and many of the antibiotics we discovered were invented by microbes facing competition from their neighbors. We have leveraged microbes to process sewage and waste for centuries and to ferment food for millennia.

This article presents guidelines for orientation and mobility instructors and traffic engineers to assess the need for adaptive devices to make crosswalks at signalized intersections accessible to pedestrians with visual impairments. The discussions of audible and tactile pedestrian devices, along with the case examples, distinguish when each device should be implemented to resolve specific problems.

AbstractRemoval of per‐ and polyfluoroalkyl substances (PFAS) from water sources is of significant interest as many states have established limits. Three granular activated carbons (GACs) and a clay‐based adsorbent, Fluoro‐sorb® 200 (FS200), were tested using rapid small scale column tests (RSSCTs) to compare relative performance of the media for PFAS removal. FS200 effluent was below detection for all PFAS except PFHxA at 300,000 bed volumes (BVs). The three GACs performed similarly except for PFBS and PFHxA. FS200 showed higher BVs to breakthrough, required a significantly shorter empty bed contact time, and had higher hydraulic loading rate, translating into a smaller footprint than GAC. This work provides important contributions to the water treatment literature, including RSSCT evaluation of FS200 media and media life comparison of GAC and FS200 in drinking water matrices with low PFAS and organic carbon concentrations.Article Impact StatementUtilities needing PFAS treatment will benefit from the testing methodology and results.