Investigating Graywater Filtration Efficacy of Pacific Northwest Pumice and Scoria
Loading...
Date
2022
Authors
Price, Margery
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
Graywater is non-sewage wastewater from washing machines, bathing, and cleaning. It can be recycled if particles of shampoo, soap, and other contaminants can be removed, usually by filtration through a medium such as gravel or sand. Such graywater recycling methods are becoming increasingly important as water crises worsen worldwide and fresh water becomes scarcer. This project aims at testing the potential of pumice and scoria (porous volcanic rocks) from Oregon volcanoes as efficient filters for graywater recycling. After characterizing the physical properties of the rock samples (size, shape, porosity), we carried out week-long experiments in which graywater interacts with different size fractions of the two types of rock to identify the best graywater filter. We find that, among the samples tested, 1-2-mm pumice particles are the most effective filtration media amongst those tested. Immersion of graywater in these samples results in the neutralization of the graywater pH to a value of 6.8 and a >75% decrease in turbidity after seven days. The interaction of the rock particles with the graywater also leads to an increase in Total Dissolved Solids (TDS). More work needs to be done analyzing the complex chemical and physical interactions between the rocks and the graywater.
Description
Keywords
Graywater, Wastewater, Pumice, Scoria, Filtration