Canadian researchers are trying to figure out the best methods to treat wastewater so that it can be reused — and they are using goldfish to help them provide the answers.
As clean water sources are in shorter supply throughout the world, municipalities are looking for ways to recycle wastewater for uses beyond industrial processing, perhaps for irrigation or even drinking water. Recycling of wastewater is becoming more common, and is already in use in California and Singapore.
University of Alberta’s aquatic research center is studying what effect chemicals — from pesticides to pharmaceuticals — found in wastewater have on goldfish, reports Dave Cooper in the Edmonton Journal. In essence, the researchers are using the goldfish like lab mice or canaries in a coal mine.
Like many cities, Edmonton, Alberta, has wastewater that contains trace amounts of herbicides, such as 2,4-D, and analgesics, stimulants, and prescribed pharmaceuticals, such as estrogen. Goldfish in tanks at the research center filled with the wastewater allows the researchers to see what long-term effects develop. “Yes, fish can live in this water, but can they really live over time?,” asks Mike Belosevic, distinguished biological sciences professor at the university.
The research found that membrane ultra-filtration does not remove all of these chemicals from the wastewater. Fish living in that water for months showed a significant decline in health and ability to fight disease. However, adding activated carbon filtration helps. Using ultraviolet radiation and hydrogen peroxide produced the best early results at removing the chemicals.
Belosevic hopes to eventually find out which doses of ultraviolet and hydrogen peroxide are needed to inactivate or remove the trace chemical pollutants. These chemicals may cause lower sperm production in humans and an increase in the incidence of certain cancers (breast, prostate, testicular) because they may affect human endocrine systems.
Source: “Fish researcher hopes to make a splash with waste water tests,” Edmonton Journal, 5/23/12
Image by Humanfeather, used under its Creative Commons license.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.