December 2010, Vol. 22, No.12
Tracking pharmaceutical and personal-care product uptake in soybeans
Pharmaceuticals and personal-care products (PPCPs), often found in biosolids and effluents from wastewater treatment plants, make their way into terrestrial and aquatic environments from the land application of biosolids and use of reclaimed wastewater. University of Toledo (Ohio) scientists studied the uptake of some of these chemicals by soybeans. They looked at the pharmaceuticals carbamazepine, diphenhydramine, and fluoxetine, as well as the PPCPs triclosan and triclocarban.
“[The] majority of other plant-uptake studies look at veterinary pharmaceuticals originated from animal-feeding operations,” said Chenxi Wu, lead scientist of the study. “This study also considered the most important pathways for PPCPs entering the terrestrial environment. Others either use hydroponic systems or use spiked soil to test the concept.”
Scientists analyzed the plant tissues and soils of plants that were grown for 60 and 110 days under two treatments, the first simulating biosolids application and the second simulating wastewater irrigation. Carbamazepine, triclosan, and triclocarban concentrated in root tissues and translocated into aboveground parts, including beans, while accumulation and translocation for diphenhydramine and fluoxetine were limited.
Results showed that the amount of uptake differed by treatment. Biosolids application resulted in higher plant concentrations, which is likely the result of higher loading, according to the abstract of a report on the study published in Environmental Science and Technology. But the compounds introduced by irrigation seemed to be more available for uptake and translocation, the abstract says. Data from the different harvests suggest that uptake from soil to root and translocation from root to leaf may be rate-limited for triclosan and triclocarban, and that the plants may metabolize some of the carbamazepine, the abstract says.
The toxic effect of PPCPs at low levels should be researched, because not much is known about it, and if chemicals cause adverse effects to consumers or plants, “better management practices should be used to reduce the risks,” Wu said.
If precautionary steps are found to be needed, limiting biosolids application rates can allow time for the chemicals to dissipate. Additionally, application of biosolids and reclaimed wastewater can be restricted to those crops that have low PPCP-uptake potential. Advanced techniques that remove PPCPs from effluent and biosolids also could be applied to substances used on plants with higher uptake potential, Wu explained.
GreenBox uses wastewater to produce hydrogen energy
Ohio University (Athens) professor Gerardine Botte invented technology that cleans commercial and agricultural wastewater and produces hydrogen energy. The GreenBox, a new invention that produces energy by converting the ammonia and urea in wastewater to hydrogen, nitrogen, and pure water, is now being developed commercially by the new company E3 Technologies LLC (Athens, Ohio), according to a university news release.
The company recently licensed a suite of electrochemical devices and technologies developed by Botte to sell commercially. E3 Technologies, a new part of the university’s business incubator, the Innovation Center, will help take this invention from the laboratory to the marketplace, explained Rathindra Bose, vice president for research at Ohio University.
Botte, founder and chief technology officer of the company, explained that the technology could assist with the disposal of ammonia. The U.S. Environmental Protection Agency classifies ammonia as a toxin that affects surface and underground water and air quality. Ammonia is found in wastewater from agricultural, industrial, and municipal sources, the news release says.
The GreenBox uses a patented low-energy electrolysis process to create an electrochemical reaction that oxidizes urea and turns it into carbon dioxide, which is then sequestered in the electrolyte material in the machine while producing hydrogen energy. The synergistic technology reduces emissions and offers a free, clean source of hydrogen energy, the release says.
The GreenBox could aid farmers with the disposal of animal waste and help commercial customers reduce operational costs. A farmer with 2000 hogs might use a GreenBox that runs on 5 kW to treat ammonia waste, Botte said in the release. And a commercial building with 300 employees would need a unit that only requires 1 kW to operate, reducing operational costs for eliminating ammonia from wastewater by 60%, she explained.
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