SRP, ASU launch research grant to support renewable energy


August 16, 2012

Salt River Project (SRP) and the Conservation and Renewable Energy Collaboratory (CREC) at ASU’s College of Technology and Innovation (CTI) have partnered to award grant funding for research and professional development initiatives in the areas of renewable energy and conservation.

This year the SRP-CREC grant selected three research projects for funding. The projects cover areas of emphasis that were outlined as priorities in sustainability and renewable energy. Download Full Image

“The research environment at CTI is defined by the real-world challenges our industry partners face,” said Mitzi Montoya, vice provost and dean of CTI. “The SRP-CREC grant program provides a platform for applied research through our faculty and facilities.”

In addition to its partnership with CREC, SRP has engaged with CTI on the college’s iProjects program. iProjects pair senior-level students with industry mentors to find solutions to real-world problems. Last year a student team worked with SRP employees to develop a microgrid system that will make solar and other alternative energy sources more reliable. This year a group of undergraduate students are investigating the potential use of algae to remove carbon dioxide from coal-fired power plant emissions.

“We are excited about this new research agreement with CTI. It builds on our longstanding research partnership with ASU, and will allow us to address important issues affecting SRP and our customers in areas where CTI’s faculty have significant expertise,” said John Sullivan, SRP’s associate general manager and chief resources executive. “This year’s projects involve innovative research in the long-term performance of solar photovoltaic systems, the efficiency of solar hot water heating systems, and the performance of batteries in arid climates.”

Solar hot water system testing and evaluation program at ASU Polytechnic
Researcher: Brad Rogers

The use of solar-assisted hot water systems has the potential to significantly reduce residential use of electricity. However, accurate data on the performance of installed units is elusive, as are data on the reliability and failure rates of the systems. A solar hot water testing facility has been developed by ASU through SRP’s support to address this issue. Two commercial systems installed at ASU’s Polytechnic campus are automatically controlled to simulate water usage of a family of four and measure process variables. The endurance test will characterize and compare the energy of the solar-assisted system to a control system.

Performance degradation and reliability evaluation of SRP’s Solar Photovaltaic Systems
Govindasamy Tamizhmani

Photovoltaic (PV) system installations continue to rise, making measuring and predicting their performance, reliability and availability more important to installers, integrators, investors and owners. Monitoring and analyzing the performance degradation and reliability of existing PV systems is essential to predicting the same for future systems. The ASU Photovoltaic Reliability Laboratory at the Polytechnic campus will evaluate the performance, reliability and availability of several solar PV power systems that SRP owns or maintains.

Reliability and performance evaluation of batteries in hot/dry climate
Arunachala Mada Kannan, Xihong Peng, Scott Pollat

State-of-charge (SoC) and state-of-health (SoH) determination is an increasingly important issue in battery technology in terms of both extending battery life and displaying the usable charge to the user before recharging and replacing. An accurate determination of SoC enables the user to manage the battery to its optimal potential. At elevated temperatures states of extremely high or low SoC can lead to irreversible damage in the battery. The main focus of this research is to develop and optimize methods to determine SoC and SoH for various types of batteries at high temperatures.

Antimicrobials from personal care products found in rivers, lakes


August 16, 2012

In our zest for cleanliness, have we permanently muddied our nation’s waters?   



A science team from Arizona State University, in collaboration with federal partners, has completed the first statewide analysis of freshwater bodies in Minnesota, finding widespread evidence of the presence of active ingredients of personal care products in Minnesota lakes, streams and rivers. 
 
 Benny Pycke, holding a riverbed sample Download Full Image

These products are a billion dollar industry and can be found in antimicrobial soaps, disinfectants, and sanitizers to scrub our hands and clean countertops. Hundreds of antimicrobial products are sold in the United States, many marketed with efficacy claims that remain elusive due to the short duration of the average consumer’s handwashing practices. The fate of these products can be traced from home use to sewers to wastewater treatment plants to eventually, downstream bodies of water.  
 


The research team focused on two active ingredients found prominently in anti-bacterial soaps – triclosan and triclocarban – which have come under scrutiny by the EPA and FDA due to their environmental and human health concerns. These compounds persist for decades in the environment, and both triclocarban and triclosan are among the top 10 pharmaceuticals and personal care products most frequently found in the environment and in U.S. drinking water resources.

“This study underscores the extent to which additives of antimicrobial consumer products are polluting freshwater environments in the U.S.; it also shows natural degradation processes to be too slow to counter the continuous environmental release of these endocrine disrupting chemicals,” said Rolf Halden, director of Environmental Security at the Biodesign Institute and professor in the Ira A. Fulton School of Sustainable Engineering and the Built Environment.

Halden’s research focuses on the interconnectedness of the water cycle and human health, with special emphasis on the role of manmade products and human lifestyle choices on environmental quality.

In a previous study, Halden’s team found significant concentrations of harmful soap-related chemicals dating back to the 1950s in sediments of Jamaica Bay and Chesapeake Bay, into which New York City and Baltimore discharge their treated domestic wastewater, respectively.

Upon their use, triclosan and triclocarban are absorbed through the skin and hence contaminate human blood, urine and even breast milk. Ultimately, these chemicals together with the pharmaceuticals we use end up in our sewage and surface waters. In 2002, the USGS published a landmark study that showed 80 percent of 139 streams sampled from across 30 U.S. states were found to contain measurable levels of organic wastewater contaminants. The human health risks associated with these personal care product chemicals are still not fully understood despite them being used for decades.

In the ASU study, river, creek and lakebed sediment samples from 12 locations upstream and downstream of wastewater treatment plants were analyzed for the presence of antimicrobial compounds.

For Halden’s team, which consisted of postdoctoral researcher Benny Pycke and environmental engineering graduate student and first author Arjun Venkatesan, the results showed that overall concentrations of triclocarban were three- to 58-times higher than those of the more frequently monitored triclosan.

“We were able to detect these two compounds both upstream and downstream of suspected input sources, and the levels of the antimicrobial soap ingredient triclocarban were usually higher compared to triclosan,” said Venkatesan. “Although triclosan is used in a larger number of formulations and personal care products, we found triclocarban to be more abundant in freshwater environments.”

The team also found degradation products of TCC but transformation of this antimicrobial is known to be very slow in natural environments.

“Also, we expected to find these compounds mostly downstream of wastewater treatment plants; but when we consistently found detectable levels upstream and downstream, we realized that there are probably multiple sources contributing to the contamination of these sites, potentially including additional wastewater treatment plants further upstream and runoff from sites where antimicrobial-laden sewage sludge had been applied,” Venkatesan said.

“Every site is essentially downstream of something,” added Pycke. A site in the immediate vicinity of a wastewater treatment plant near Duluth (St. Louis Bay at Lake Superior) had the greatest concentration of triclocarban and its lower chlorinated derivatives, and the Duluth site and Shagawa Lake site had concentrations three times higher than river and creek sediments. There was a strong correlation between the level of contamination with wastewater treatment plant discharge, stream flow and the population density of the surrounding region.

“As the name suggests, these antimicrobial compounds (triclosan and triclocarban) are incompatible with biological wastewater treatment infrastructure paid for with tax dollars,” said Halden. “Municipalities in Minnesota and across the U.S. work hard using state-of-the-art equipment to keep our freshwater environments clean but they cannot control what consumers, misled by aggressive marketing, discharge into 
the sewage collection system.”

Wherever antimicrobial personal care products are in use, water and sediment have been contaminated, a situation that certainly is not unique to the state of Minnesota.

“Regulatory agencies are aware of the overuse of antimicrobials, but no state or federal restrictions have been implemented yet for either triclosan or triclocarban,” said Halden. “Aside from ecological concerns, widespread environmental occurrence of antimicrobials also is a potential public health concern because unwarranted use of antimicrobials can promote drug resistance of human pathogens.”

Halden’s research is developing engineering solutions to clean up environments impacted by antimicrobial compounds. However, he emphasizes that the best solution right now in combating this pollution is for consumers to limit their use of antimicrobial personal care products that, ironically, provide no measurable health benefits to the average consumer, as determined by an expert panel convened by the Food and Drug Administration in 2005.

For this project, ASU was supported by funding from the National Institute of Environmental Health Sciences.

Note: In addition to Halden’s appointment as director of Environmental Security at ASU’s Biodesign Institute, he holds the title of professor in the School of Sustainable Engineering and the Built Environment, at the Ira. A. Fulton Schools of Engineering, ASU, and adjunct associate professor of Environmental Health Sciences, at the Johns Hopkins Bloomberg School of Public Health.

Joe Caspermeyer

Managing editor, Biodesign Institute

480-258-8972