Two Knoxville-based startups are tackling the challenges of waste and sustainability, one household at a time. KnoxFill, founded by Dr. Michaela Barnett, is the city’s only refillery, and provides household and food products, ranging from shampoo and laundry detergent to coffee and tea. Vitriform3D, a 3D printer technology focused on using glass waste and converting it into architectural building products, was founded by Alex Stiles, PhD., and Dustin Gilmer, PhD.