waste not

Houston researchers harness dialysis for new wastewater treatment process

Rice University's Menachem Elimelech and Yuanmiaoliang “Selina” Chen published a study in Nature Water on mimicking dialysis from the medical field to treat wastewater. Photo by Gustavo Raskosky/Rice University

By employing medical field technology dialysis, researchers at Rice University and the Guangdong University of Technology in China uncovered a new way to treat high-salinity organic wastewater.

In the medical field, dialysis uses a machine called a dialyzer to filter waste and excess fluid from the blood. In a study published in Nature Water, Rice’s team found that mimicking dialysis can separate salts from organic substances with minimal dilution of the wastewater, addressing some of the limitations of previous methods.

The researchers say this has the potential to lower costs, recover valuable resources across a range of industrial sectors and reduce environmental impacts.

“Traditional methods often demand a lot of energy and require repeated dilutions,” Yuanmiaoliang “Selina” Chen, a co-first author and postdoctoral associate in Elimelech’s lab at Rice, said in a news release. “Dialysis eliminates many of these pain points, reducing water consumption and operational overheads.”

Various industries generate high-salinity organic wastewater, including petrochemical, pharmaceutical and textile manufacturing. The wastewater’s high salt and organic content can present challenges for existing treatment processes. Biological and advanced oxidation treatments become less effective with higher salinity levels. Thermal methods are considered “energy intensive” and susceptible to corrosion.

Ultimately, the researchers found that dialysis effectively removed salt from water without requiring large amounts of fresh water. This process allows salts to move into the dialysate stream while keeping most organic compounds in the original solution. Because dialysis relies on diffusion instead of pressure, salts and organics cross the membrane at different speeds, making the separation method more efficient.

“Dialysis was astonishingly effective in separating the salts from the organics in our trials,” Menachem Elimelech, a corresponding author on the study and professor of civil and environmental engineering and chemical and biomolecular engineering at Rice, said in a news release. “It’s an exciting discovery with the potential to redefine how we handle some of our most intractable wastewater challenges.”

Trending News

A View From HETI

Houston had two big strikes against it on WalletHub's Greenest Cities in America report. Photo via Getty Images.

Houstonians may be feeling blue about a new ranking of the greenest cities in the U.S.

Among the country’s 100 largest cities based on population, Houston ranks 99th across 28 key indicators of “green” living in a new study from personal finance website WalletHub. The only city with a lower ranking is Glendale, Arizona. Last year, Houston landed at No. 98 on the WalletHub list.

“‘Green’ living means a choice to engage in cleaner, more sustainable habits in order to preserve the planet as much as possible,” WalletHub says.

Among the study’s ranking factors are the amount of greenhouse gas emissions per capita, the number of “smart energy” policies, and the presence of “green job” programs.

In the study, Houston received an overall score of 35.64 out of 100. WalletHub put its findings into four buckets, with Houston ranked 100th in the environment and transportation categories, 56th in the lifestyle and policy category, and 52nd in the energy sources category.

In the environment category, Houston has two big strikes against it. The metro area ranks among the 10 worst places for ozone pollution (No. 7) and year-round particle pollution (No. 8), according to the American Lung Association’s 2025 list of the most polluted cities.

In the WalletHub study, San Jose, California, earns the honor of being the country’s greenest city. It’s followed by Washington, D.C.; Oakland, California; Irvine, California; and San Francisco.

“There are plenty of things that individuals can do to adopt a green lifestyle, from recycling to sharing rides to installing solar panels on their homes,” WalletHub analyst Chip Lupo said in the report. “However, living in one of the greenest cities can make it even easier to care for the environment, due to sustainable laws and policies, access to locally grown produce, and infrastructure that allows residents to use vehicles less often. The greenest cities also are better for your health due to superior air and water quality.”

Trending News