ADVANCED MEMBRANE DESALINATION TECHNOLOGY FOR NAVAJO NATION GROUNDWATER REMEDIATION

A significant shortage of fresh water is a big challenge throughout the Navajo Nation. Currently, more than 30% of homes lack access to safe and drinkable water. Livestock in the Navajo Nation mainly rely on windmill-pumped groundwater in which naturally elevated arsenic and uranium pose a serious threat to the animals’ well-being. The possibility of residual arsenic and uranium in the animal meat and dairy products is an additional risk to humans. To address these challenges, we developed an innovative desalination technology for water remediation using cross-linked polyvinylidene fluoride (CPVDF) hollow-fiber membranes. Laboratory results show salt rejection of >99.9% and > 30 kg/(m2·h) water flux in desalination of brine and groundwater samples from the Navajo Nation. Further, there was no arsenic or uranium detected in the recovered product water. The high specific surface area (>1,000 m2/m3) of the hollow fiber membrane reduces the footprint of the technology and allows the technology to be easily integrated within a portable skid-mounted system that can be installed at any windmill wellhead for the production of high-quality (TDS<150 mg/L) water free of toxic metals. A team from Navajo Technical University (NTU) and New Mexico Tech (NMT) proposes the NTU-NMT Navajo Nation Water Purification Project (N4WPP) to install these units at remote locations within the Navajo Nation in partnership with Navajo Nation chapter houses. The research involved the collection of water quality samples from local water wells within the Navajo Nation. The wells of interest are those that have the lowest quality water, to effectively test the filtration system. Once wells of interest are identified, the filtration system will be put into place and will be tested for water quality by the students at NTU. The regular data collection will help determine if the filtration system is effective and producing clean water. The overall goal of this project is to reach water quality healthy enough for livestock consumption, as well as human consumption.