Redesigning Point-of-use Treatment from the Perspectives of Water Quality Tradeoffs and Human Behavior

About This Grant

Many homes in the U.S. use carbon-based point-of-use filters to purify drinking water —whether in the refrigerator, under the sink, or attached to the faucet. These filters are common in cities with lead problems, in rural areas with private wells, and among people who prefer not to drink tap water. While these filters are popular, scientists still do not fully understand how they affect water quality over time. In some cases, the filters may even make water quality worse by increasing the concentrations of contaminants like nitrite to unsafe levels. This research aims to understand how the design and use of the filters can impact the quality of household water. Outcomes of this research can be used to improve the safety of filtered water. The researchers will work closely with local community members to communicate results to the public. Activated carbon block (ACB) point-of-use (POU) filters exist in almost every U.S. home, yet fundamental knowledge regarding ACB POU filter water quality tradeoffs, filter nitrification, microbial colonization, use patterns, and long-term operation is still lacking. ACB POU filters are installed in urban neighborhoods in response to high lead levels, in rural areas to treat private wells impacted by regulated and emerging pollutants, and as a personal choice to avoid tap water. However, consumers do not expect water quality to worsen after installing ACB POU filters, let alone suspect high nitrite concentrations. The goal of this research is to redesign ACB POU filters by investigating the motivations to install, water quality tradeoffs created, and patterns of use once a filter is in place. The project will: (1) advance the knowledge of water quality tradeoffs by investigating ACB POU filter microbial colonization, nitrite production mechanisms, and the impacts on target contaminant treatment efficiency; and (2) develop a mechanistic understanding of ACB POU filter component and operational status impacts on microbial colonization and filtrate quality using technical and human behavior inputs. The research includes developing a novel flow pathway approach, normalized by surface area, to reduce experimental space and influent water volume requirements. This scale of investigation of POU filter components and operation could transform filter research and inform certification methods. The project has a strong focus on increasing scientific communication by disseminating results to relevant policy groups, industry collaborators, utility partners, professional associations, and to community groups within the Tampa Bay Area to ensure research communication to the broadest possible audience. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.