Volume 15, No. 6, November 2015, Pages 2397-2408 PDF(1.07 MB)
Design and Evaluation of the Field-Deployable Electrostatic Precipitator with Superhydrophobic Surface (FDEPSS) with High Concentration Rate
Taewon Han, Huajun Zhen, Donna E. Fennell, Gediminas Mainelis
Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, USA
- A field-deployable electrostatic bioaerosol sampler was developed and tested.
- The sampler achieved collection efficiency for bacteria as high as ~70%.
- Use of a 20 µL collecting water droplet resulted in 0.5 × 106 min–1 concentration rates.
- The sampler successfully measured total bioaerosol burden outdoors.
- The sampler can detect bioaerosol presence 40× faster than other tested samplers.
Here we report on further development of an electrostatics-based bioaerosol collector with high concentration rate. We developed a field-deployable version of the electrostatic precipitator with superhydrophobic surface (FDEPSS), which consists of two combined half-cylinder collection chambers and an integrated control box. The collector is made of a static dissipative material and each collection chamber features a 3.2 mm wide collection electrode. The round top part of each chamber contains eight carbon fiber ionizers arranged in two lines of four. The collected particles are removed by a 20 µL rolling water droplet. Sampler’s components were integrated into a control box.
The FDEPSS was tested with two bacterial species, Bacillus atropheus and Pseudomonas fluorescens bacteria, and one fungal spore, Penicillium chrysogenum for 10 and 60 min collection times and showed collection efficiency of ~70% at a sampling flow rate of 20 L min–1. The use of a collecting water droplet of 20 µL per collection chamber achieved sample concentration rates approaching 0.5 × 106 min–1. The FDEPSS was also tested against BioSampler (SKC Inc., Eighty Four, PA) and Button aerosol sampler (SKC Inc.) when sampling bioaerosols outdoors for 60 min. The samples were characterized based on the total airborne adenosine triphosphate (ATP) concentration, which was reported as relative luminescence units (RLU). The FDEPSS detected 5.1 × 105 RLU m–3, while the BioSampler and the Button sampler showed 4.1 × 105 RLU m–3 and 8.7 × 105 RLU m–3, respectively. Since ATP analysis can be performed with small sample volumes, and the FDEPSS captures particles into 20 µL of liquid, resulting in a high concentration rate, we show that this sampler can detect the presence of airborne microorganisms 40× faster than the BioSampler or Button aerosol sampler. This FDEPSS feature could be integrated into bioaerosol detection systems, especially where concentrations are low and time is critical.
Field-deployable bioaerosol sampler; Electrostatic collection; Concentration rate; Adenosine triphosphate (ATP); Bioaerosol detection system.