Analysis of Odor Nuisance Emitted by a Rendering Plant Processing Animal By-products, Which is Located in the Center of a Several-thousand Population Village

Abstract

The constantly growing need for livestock production for food purposes generates huge amounts of animal by-products unfit for human consumption. Therefore, the number of rendering plants that facilitate the recovery of animal waste in the form of fat and protein flour constantly grows. Odors emitted from rendering processes can significantly impact air quality, causing nuisance for humans, especially when the plant is close to residential areas. This research focuses on the concentration of odour emission from thermal rendering operations determined by dynamic olfactometry and removal efficiency in the 3-stage water scrubber used in the investigated plant. Among the 6 process air stream emitters investigated, 3 presented the major odorous contributions according to their high odorant concentrations. The elimination of odour nuisance by a 3-stage water scrubber revealed a low removal efficiency of less than 55%. Such an outcome suggested inappropriate conditions such as alkaline pH and low odorant solubility in water. Thus, other removal methods need to be implemented to achieve satisfactory results.