STARTUP AND OPERATING CONSIDERATIONS FOR ODOR CONTROL SCRUBBERS

Wet chemical scrubbers have been one of the most common odor control technologies used in the municipal wastewater industry. Thousands of systems have been installed throughout the world and their performance characteristics on various odors have been well documented and reported in a number of forums. Typically, wet chemical scrubbing has been shown to be highly effective on sulfide-based odors, which are routinely found in municipal wastewater treatment systems. However, the use of wet chemical scrubbing often produces significant operating and maintenance challenges for the municipalities and agencies that depend on them. This paper will discuss start-up and operating considerations for wet chemical scrubbers. Significant points that will be discussed include:Principles of odor control using wet chemical scrubbing.How odor types influence system and chemical selection.Major components of wet chemical scrubbers and what is their purpose.Common operating and control variables, what they indicate, and why they are important.Scrubber performance expectations.How to recognize symptoms of poor or improper performance.Procedures used to maintain wet chemical scrubbing systems.All wet scrubbers achieve contaminant removal by absorption of an undesirable gas phase component by a liquid solution, selected to have high absorptive capacity of the gas being absorbed. The technical aspects of gas/liquid absorption systems are relatively well understood by the engineering community. However, the application of these principles in real-world designs often produces a host of unintended consequences that affect the operation and maintenance requirements of the system. The paper will address common operating problems such as:Reliable ORP and pH control and what happens when these control parameters are poor.Scaling tendencies in wet scrubbers.“Contact” limited performance versus “Chemical” limited performance.Control system parameters and what they reveal about system operation.