Horizontal Packed Bed Fume Scrubber

This is a cross-flow design with scrubbing liquid flowing vertically downwards while the gas passes horizontally through the packing section. A Monroe Horizontal Packed Bed Scrubber is used when limited headroom is an issue at a customer’s facility or when low profile is desired for roof-top applications. Multiple stages can be easily provided in one housing with separate sumps and pumps if required.

The cross-flow design is less susceptible to fouling for airstreams that may contain solid particulate. Air flow capacity for a single shop fabricated tower can be up to 75,000 CFM.

Chromic Acid Fume Scrubber — Multiple Stage Design

Emissions from chrome plating and chromic acid anodizing operations produce hexavalent chrome mist that cannot be effectively removed in a conventional packed tower scrubber. A modified type of horizontal scrubbing unit using specialized mesh filter pads with periodic flushing is required to meet regulatory guidelines for this contaminant. PVC construction is typical.

Typical Chrome Applications

• Anodizing chrome
• Chrome etching
• Chrome manufacturing
• Chrome stripping
• Hard chrome plating

Multi-Stage Air Scrubbing Systems

Multiple scrubbing stages with different scrubbing solutions can be achieved by providing multiple scrubbing towers in series. These configurations can provide the highest removal efficiencies as well as multiple gas constituent removal. The diagram below includes three towers in series that could be used for H2S and ammonia removal.

Additional components that may be necessary to properly treat a given air stream can include:

• Quench Towers
• Venturi Scrubbers with clarification tanks (for particulate removal)
• Carbon Adsorbers
• Fiberglass filters
• And many others

Learn more about Monroe’s capabilities with Multi-Stage Scrubbing Systems

Bioscrubber

A Bioscrubber uses living microbes to consume pollutants from an air stream. This technology will efficiently remove gasses that cause odors at wastewater treatment plants such as H2S, dimethyl sulfide (C2H6S), carbonyl sulfide (COS), and methanethiol (CH4S). Bioscrubbers can effectively remove aldehydes, organic acids, nitrous oxide (N2O), sulfur dioxide (SO2), and a range of water-soluble VOCs.

Advantages of biological air pollution control:

• Often less expensive: the pollutants in the air stream feed and sustain the microorganisms that consume them. Avoids the expense of continually adding scrubbing chemicals.
• The process is green. It does not produce NOX or CO like combustors do. Chemicals requiring disposal are not generally produced. The products of a bioreaction in which microbes consume hydrocarbons are mainly CO2 and water.

Monroe Environmental experts will analyze your application to determine if a biological solution is appropriate. Extremes of hot and cold will limit the effectiveness of microbes. Most microbes thrive in a moist environment that is around neutral pH, near 7. Monroe will analyze the variables of temperature, moisture, pH, nutrient mix, and residence time to achieve conditions that will support a microbial population that will efficiently consume and remove the air pollutants that occur in a particular application.

Monroe Environmental will custom-design a biological scrubber for each application and manufacture it in-house. Units may range from a simple bio-filter tank with drain to a complete electronically controlled biological scrubbing system employing blower, liquid pumps, media with supporting structure, and a sump with nutrient addition and pH control to treat water that is distributed to the biological film living on the media.