Research Terms
Civil Engineering Environmental Sciences Environmental Chemistry Environmental Engineering Waste Management Environmental Monitoring Environmental Planning Environmental Pollution Water Pollution Environmental Quality Water Quality
Keywords
Algae Biofuel Feedstock Generation Biofilm Biological Wastewater Treatment Chlorine/Chloramine Disinfection Confocal Laser Scanning Microscopy Electrocoagulation Environmental Electrochemistry In Situ Water Quality Monitoring Microsensor Nitrification Nutrient Removal Process Oil-In-Water Emulsion Separation Pahs Monitoring Sensor Phosphate Monitoring Sensor
Industries
Association of Environmental Engineering and Science Professors, Member; 2009 - present
American Water Works Association, Member; 2008 - present
Water Environmental Federation , Member; 2008 - present
Biofilm formation in drinking water distribution systems has been associated with water quality degradation and may result in non-compliance with existing regulations. United States water utilities report biofilm survival and regrowth despite disinfectant presence, and systems that use chloramines to comply with disinfection by-product regulations will release ammonia which serves as a growth substrate for ammonia-oxidizing bacteria (AOB). If unchecked, these AOB can accelerate chloramine loss, leading to disinfectant depletion. Once this occurs, utilities have very few options available to correct the situation and often switch to free chlorine for a period of time to remove the growth substrate (ammonia) and inactivate biofilm. Currently, the only method to assess effectiveness of the switch to free chlorine is to measure free chlorine concentrations in the bulk fluid, but this may be unrepresentative of the free chlorine concentration in the biofilm. Biofilm is considered more resistant than suspended cultures, and thus it is important to understand the dynamics of biofilm activity and viability related to disinfectant biofilm penetration. Previous research has shown by direct measurement that monochloramine penetrates faster and farther into biofilm compared to free chlorine which exhibits limited biofilm penetration. The current research seeks to provide a better understanding of free chlorine application to nitrifying biofilm by monitoring free chlorine penetration over an extended period of time and assessing activity and viability through the entire biofilm depth to the substratum.
Subject Areas:
Keywords:
Audience:
Adults
Duration:
1 hour or less
Fee:
Expenses Only
Researchers at the University of Central Florida have developed an inexpensive, reliable sensor that can rapidly and simultaneously detect traces of multiple heavy metals in water. With its unique biopolymer-metal composite thin film, the device provides improved sensitivity for identifying toxins in situ, including mercury, cadmium, arsenic, chromium, thallium, lead and zinc.
As part of the technology development, the researchers also invented a novel fabrication process to produce the new composite film. Manufacturers can use the process to reduce costs significantly. With existing fabrication methods, an electrode (microsensor) can cost hundreds of dollars. In contrast, the UCF method provides an electrode with an estimated cost of less than $1. As an example, the technology offers the capability to develop an instrument that easily connects to a kitchen faucet to monitor heavy metal ions in drinking water.
Technical Details
The invention comprises a sensing device and a method for fabricating the device. A key aspect of the technology is a novel and simple electrodeposition method in which a metal ion and a polysaccharide form an integrated biopolymer-metal composite film. The process is more cost-effective than photolithography or physical deposition. It produces an electrode suitable for use aquatically to monitor the concentration of heavy metal ions or for in situ analysis of leachate heavy metal ions in water. Examples of metal ions used to make the composite film are iron (Fe), copper (Cu), or bismuth (Bi). Polysaccharide examples include chitosan or chitin.
In one example application, the researchers created two biopolymer-metal composite film-based sensors: one made of Bi-chitosan and another made of Fe-chitosan. Using the sensors with square-wave anodic stripping voltammetry (SWASV), the researchers simultaneously analyzed concentrations of heavy metals in real mining wastewater. They used the Bi-based composite film sensor to detect cadmium (Cd2+) and lead (Pb2+), and the Fe-based composite to detect arsenic (As3+). The detection limits observed in parts per billion (ppb) were 0.5 of Cd, 1 of Pb, and 3.75 of As.
Partnering Opportunity
The research team is looking for partners to develop the technology further for commercialization.
Stage of Development
Prototype available.
