Hydrogen Sulfide Removal Column
Accumulation of hydrogen sulfide (H2S) in Anaerobic Microbiology Chambers can result in damage to electronics and decreased catalyst lifetime. The Coy Hydrogen Sulfide Removal Column (HSRC) provides maintenance-free, high capacity removal of undesirable hydrogen sulfide (H2S) by recirculating the Chamber atmosphere through the Column.
The HSRC’s unique layering of H2S removal media acts via a combination of adsorption and chemisorption. Having two media maintains performance under a broad range of operating conditions since the mechanism-of-action/performance of individual media depends on a complex set of variables. An integral airflow system, combined with the column design, ensures required air flow conditions to take advantage of the high H2S removal capacity with single-pass H2S clearance.
- Provides a high H2S removal capacity
- Removes other volatile byproducts of microbial metabolism
- Functions over a wide range of environmental conditions
- Requires no maintenance for months
- Includes indicator to signal when media change is needed
- Can operated vertically or horizontally with optional cradle
These posters presented at scientific meetings provided examples of results from utilizing the columns in anaerobic chambers growing C difficile or mixed cultures of fecal material in bioreactors.
Hydrogen Sulfide Removal in Anaerobic Chambers
The hydrogen sulfide removal column (HSRC) functions by recirculating the anaerobic chamber atmosphere through layers of defined media at a controlled rate. This facilitates chemical interactions that leave the output free of H2S, based on an H2S-specific sensitive color-change indicator. Various media were examined. Other important considerations were also addressed in the design and application of the HSRC, including temperature, humidity, use in a contained environment, detection of H2S, function in an anaerobic atmosphere, byproducts of reaction with H2S, disposal of spent media, H2S capacity, chamber atmosphere circulation, and overall HSRC flow characteristics to optimize performance. The HSRC was run continuously without any maintenance under constant exposure to H2S for a 6-month period and had remaining capacity based on H2S indicators at the outlet. Inside the chamber, H2S levels reached as high as ~10ppm during growth of C. difficile without the HSRC. Within 10 minutes, the HSRC could lower this to a level undetectable with sensitive lead acetate indicators.
One challenge encountered when working with organisms in anaerobic chambers is management of hydrogen sulfide. H2S poisons palladium catalysts, damages expensive electronics, and can also lead to sulfuric acid corrosion. Existing H2S management approaches, such as bubbling the atmosphere through a silver sulfate solution, can be inefficient, lack capacity, be difficult to use, and/or lack indication of when H2S removal capacity is reached. Therefore, we developed a convenient hydrogen sulfide removal column (HSRC) that removes H2S by recirculating the chamber atmosphere through removal media at a controlled rate and coupled this column with a simple, sensitive H2S indicator at the column outlet to indicate the column’s effectiveness and H2S binding capacity. We initially deployed the HSRC in a chamber used for cultivating large volumes of Clostridium difficile. We then deployed the HSRC in chambers used for cultivating human fecal microbial communities and developed a version of the column for use in applications such as this were there are significant additional volatile metabolites in addition to H2S.