Control Measures for Secondary Sources at Sample Wastewater Co. The secondary sources identified at the Sample Wastewater Co. are the rotary screen and the aeration basin. Table 4 lists control measures that are currently in use or have been developed to mitigate this type of odour source. The odour sources or source groups and the associated control measures, as well as potential alternative control measures, are provided in Table 4. Table 4 – Potential Odour Control Measures for Sample Wastewater Co. Secondary Sources Odour Source Control Measure Applicability All Secondary Sources Engineering Controls: Emission Capture Improve emission capture with an engineered enclosure or cover for specific process units or operational areas. All Secondary Sources Stack Optimization Effective stack design will improve dispersion to reduce off-site effects with vertical, unimpeded discharge at optimal stack height and velocity. Combining multiple exhausts to one common stack possible to allow for stack optimization or to implement one odour treatment system for the combined exhaust flows. All Secondary Sources Oxidizing Scrubber Wet scrubbers that use an oxidizing agent such as hydrogen peroxide, bleach, or others, as the scrubbing solution. Oxidizing agents may be problematic for wastewater treatment. All Secondary Sources Thermal Treatment Thermal oxidation is highly effective at removing odorous VOCs and H2S. Odorous exhaust flow may be directed to the site boiler combustion chamber for incineration, or to a thermal oxidizer. All Secondary Sources Biofilter / Biological Treatment Process exhausts are directed to a conditioning system and biofilter where microorganisms biologically degrade the organic compounds. Trickling filter or use of aeration basin as a bioscrubber are alternatives to conventional biofilters. All Secondary Sources Carbon Adsorption Activated carbon effective on low VOC concentration streams.
All Primary and Secondary Sources Carbon Adsorption Technically Feasible The installation of a carbon adsorption unit will be evaluated should additional measures be needed to control odours. Carbon adsorption would only be useful for smaller, unsaturated flows. All Primary and Secondary Sources Ozonation Technically Not Feasible Ozonation is an emerging technology and there is limited documentation on demonstrated control efficiency or applicability on VOC and odour destruction. All Primary and Secondary Sources Non-Thermal Plasma (NTP) Technically Not Feasible NTP is an emerging technology and there is limited documentation on demonstrated control efficiency or applicability on VOC and odour destruction. It is also not suitable for exhaust gases with high moisture content. DAF Process Optimization: Optimize Bubble Size Technically Feasible – previously implemented The DAF system has been optimized, and monitoring is conducted to identify changes in operating parameters that may require adjustments to maintain bubble size. DAF Process Optimization: Optimize Flocculation/Coagulation Chemistry Technically Feasible – previously implemented The flocculation and coagulation chemical addition to the DAF system has been optimized and is automated. Rotary Screen BREF BAT Specific to Wastewater Treatment: Temperature Technically Feasible The facility would conduct a review of the processes to identify opportunities to remove heat and thereby reduce the temperature of the wastewater requiring treatment.