Algae gets enlisted to make wastewater safer
Endocrine disrupting chemicals, or EDCs, are mostly man-made compounds found in substances such as pesticides, food additives and personal care products. Unfortunately, they're also linked to some serious health issues. It appears that algae, however, could be used for removing them from wastewater.
Once they're in the environment, EDCs can enter the body via ingestion of food, dust and water; through inhalation of gases and airborne particles; and via skin contact. They then interfere with hormonal functions, potentially resulting in reproductive disorders, certain cancers, neurodevelopmental delays in children, and a variety of other hormone-related problems.
Trace amounts of the chemicals have been found in treated wastewater, which is why a team from Las Vegas' Desert Research Institute set about developing a better method of removing them. Led by Drs. Xuelian Bai and Kumud Acharya, the scientists looked to a common freshwater algae known as Nannochloris.
Over the course of a seven-day experiment, the algae was grown in treated wastewater effluent samples collected from the Clark County Water Reclamation District. In the case of samples that had already been treated using an ultrafiltration technique, the algae removed about 60 percent of three common EDCs – 17β-estradiol, 17α-ethinylestradiol and salicylic acid. It should be noted that in samples which had been treated using ozonation (ozone infusion), however, the algae didn't grow well and therefore had little effect.
That limitation aside, it is now hoped that the algae could ultimately be used in artificial ponds or constructed wetlands, for helping to address what the scientists say is definitely a problem.
"Most wastewater treatment plants are not designed to remove these unregulated contaminants in lower concentrations, but we know they may cause health effects to aquatic species and even humans, in large concentrations," says Bai. "This is concerning in places where wastewater is recycled for use in agriculture or released back into drinking water sources."
A paper on the research was recently published in the journal Environmental Pollution.
Source: Desert Research Institute