Use case
BioOx Reactor reports up to 80-90% destruction of colony-forming viruses and bacterial pathogens
Medical Facilities, Research Centers, Clinics
Category 5: Viruses, mold and other pathogens
These contaminants are generated by high pressure, temperature, and friction. Oil and metal UF particles are generated by steel and other metal processors. Powders such as pharmaceuticals, food flavorings, additives, perfumes, paints; and particles which can cause cross-contamination are generated in manufacturing plants and in packaging plants which package different products such as drugs, paints, and flavorings for which contamination is prohibitive.
Jones and coworkers (2) are especially concerned about chronic exposure to ultrafine particles such as oil droplets and metals. They point out that chronic leakage of UFs into the air can lead to occupant exposure to health risks.
Treatment of UFs, oil droplets and fine metallic particles by Bioreactors
A gun manufacturer had concerns about UFs affecting the indoor air quality (IAQ) at their plant. Indoor air at the rifle barrel reaming work stations, generating UFs, was treated with a system of bioreactors. The system consisted of five large bioreactor units placed in the vicinity of the work stations, and two medium-sized units placed outside the area to capture any fugitive emissions. Run time was about 130 days. The team consisted of an engineer from the manufacturer, a PhD scientist from our partner company in this project, U-Earth, and an independent 3rd party analytical laboratory.
The data have been published by Zanni and others and are presented briefly and in modified form below. The baseline air quality measurements, while within regulator limits, were mainly due to fine and ultrafine oil particles, along with the metallic dust associated with the precision reaming of rifle barrels. Synthetic oils containing various additives were exposed to high temperatures and pressures in the reaming process, creating particulate emissions of oil, metals, and trace VOCs. Fine and UF metals and VOCs were also measured.
As shown in the table below, indoor air oil and UF metal abatement rates varied from station to station. Oils were digested, but captured non-digestible metals from total particulates are reported here. Metals and oils were generated at the workstations and entered the air as UFs in the precision reaming of rifles. Metallic fine particles generated over 130 days of continuous, real-time operation, were collected from the bioreactor units, analyzed, and weighed. The metal particles suspended in the air were both fine and ultrafine.
Table 1:
Capture and destruction rates of ultrafine particles, oil droplets, and metal powders in air. Oils from oil droplets, additives, and oil from oil-coated metals were destroyed and rendered non-toxic by biological oxidation. Clean metal particles dropped to the bottom of the bioreactors and were collected for sampling. Organic contaminants were oxidized to carbon dioxide and water, leaving only the non-digestible metals in the bottom residue. The units did not require cleaning during the 130-day operation. Data from four reaming workstations are reported here. Workers reported greatly improved air quality.
| Work Station Bioreactor Unit | Clean Metals Recovered (% of Total Particles) |
|---|---|
| A25 | 81% |
| A32 | 44% |
| A12 | 33% |
| A47 | 62% |
Baseline VOCs generated with the oil and metals from the rifle bore reaming ranged from 0.5 to 0.9 and were reduced to non-detectable levels (< 0.1 ppm)
Several observations are made from the results shown in Table 2 below. First, about 884 grams of iron were captured from the air, along with 2.7 grams of chromium and 1.6 grams of nickel. These are very large numbers of fine and ultrafine particle numbers, and scrubbing them out of air offers a great deal of relief to workers. Secondly, the approximate locations of the major sources of contamination can be identified, for example, locations 3 and 5 are hot spots. Further, it may be possible to identify the type of metal being ground by friction by studying its unique ‘fingerprint’ ratio of chromium, nickel, and iron ratios.
| Bioreactor Unit Size and Location | Chromium (g) | Nickel (g) | Iron (g) |
|---|---|---|---|
| Large 1 | 0.0765 | 0.0450 | 11.48 |
| Large 2 | 0.4590 | 0.2295 | 76.50 |
