Environmental science and engineering graduate student Erin Neil is working on an independent study with civil and environmental engineering professors Dr. Tzahi Cath and Dr. Pei Xu on developing cost-effective and environmentally sound technologies to increase the quality of water from water waste.
“We are trying to use waste streams from one water treatment process to treat another stream that might be used beneficially,” Cath said.
Neil is comparing the removal efficiencies of different types of sludge and evaluating the potential for microbiological contaminants to leach from the sludge to the treated water. The group has collected samples from Golden Drinking Water Treatment Plant, El Paso Water Utilities and other drinking water treatment plants. Neil uses the EPA Membrane Filtration Method to test fluid samples for microbiological contamination.
“We have seen promising adsorption results and expect to better understand the feasibility of re-using this water,” Neil said.
The project is part of a large effort with The National Science Foundation Engineering Research Center Program, ReNUWit Engineering Research Center. It is part of a collaborative study among Mines, New Mexico State University and the industrial partner, El Paso Water Utilities.
The researchers use sludge from drinking water treatment plants to treat reverse osmosis (RO) waste. RO waste is made of concentrated brine, which contains minerals, organics and metals that are rejected by the RO membranes. Treating this concentrate could provide additional water supplies to the public, and reduce the environmental impacts from discharging concentrate laden with salt and toxic heavy metals.
“Treatment of reverse osmosis concentrate can convert the waste stream to additional water for beneficial use, such as irrigation, that is otherwise scarce in arid climates,” Xu said. “Removal of toxic contaminants from RO concentrate will allow beneficial use of the water and protection of environment.”
Although several disposal methods are available, they can be associated with high processing costs, constrained by permitting, environmental impacts and other limitations.
“It can be a challenge with respect to regulations that surround deep well injection,” Neil said. “It can be expensive to dispose of that concentrate.”
Kathleen Morton, Communications Coordinator / 303-273-3088 / KMorton@mines.edu
Karen Gilbert, Director of Public Relations / 303-273-3541 / KGilbert@mines.edu