While speaking at the Wastewater Treatment Challenges program for the Poultry and Egg Industry at the 2018 International Production & Processing Expo, Dr. Clifford Lange, associate professor of civil engineering at Auburn University, began his presentation on the “Effects of Quaternary Ammonia on Wastewater Operations” by describing the properties of quaternary ammonium compounds (QACs) and their major uses, including biocides, fabric softeners, hair conditioners, antistatic agents, corrosion inhibitors, leather softening, pigment dispersants, sewage flocculants and preservatives to increase the shelf life of many products.
Lange observed that QACs are almost ubiquitous in poultry protein and fat wastewater and solids streams. However, not all QACs are equally inhibitory. Those used for sanitation are generally the more inhibitory species, thus there is little room for choosing less inhibitory QACs.
Lange remarked that QAC blockers may protect wastewater treatment processes at the poultry plant but will increase the QAC loading of the solids sent to rendering; and processing the solids can re-solubilize the QACs, making them more inhibitory. The age of the microorganisms in the wastewater treatment plant will also affect how QACs accumulate in the biomass. Thus, higher microbial ages can increase biomass load and inhibition. Further, wastewater biomass is generally more effected by sudden increases in QACs, and gradual addition of high QAC waste streams can reduce inhibition. Optimizing pH, alkalinity, trace nutrients and redox state can also reduce the severity of QAC inhibition.
Dr. Spyros Pavlostathis, professor of environmental engineering at the School of Civil and Environmental Engineering at the Georgia Institute of Technology, reviewed a research project being funded by USPOULTRY’s research program on the fate and effect of peracetic acid (PAA) solutions in poultry processing treatment systems. Pavlostathis noted that PAA decay is significantly affected by pH, salts and transition metals; and PAA transformation is irreversible. PAA carryover to the biological treatment process is also possible. However, the effect of PAA on biological treatment processes and its actual cause are still largely unknown.
During his food safety chemical update, Juanfra DeVillena, director of quality assurance and food safety for Wayne Farms LLC, commented that peracetic acid is a highly effective antimicrobial primarily used in the food industry and healthcare systems. He provided a history on interventions and USDA micro requirements as well as discussed poultry processing plant antimicrobial interventions in detail.