Iranian Journal of

Background and Objectives: Emission of volatile organic compounds and unpleasant smell are the important characteristics of the rendering plant, causing disturbance for the workers and nearby residents. In order to prevent the spread of air pollutants and to provide favorable environment, application of treatment technologies is essential. Materials and Methods: In this study, in order to select suitable collector and ventilation system for rendering plant, air sampling was performed via NIOSH sampling methods (1501, 1300, 1600, and 2002). Totally, 24 air samples were collected from the ambient air, air pollution source, and worker’s breathing zone using two sorbent, activated charcoal and silica gel and were analyzed using GC-MS. Then, the local ventilation system was designed based on the qualification and quantitation analysis of air samples. The stairmand high efficiency cyclone and thermal oxidizer were designed for dust control and gas cleaning respectively. Results: In total, 41 chemical pollutants in exhaust air from rendering plant were identified these compounds included hydrocarbons, aldehydes, ketones, alcohols, ethers, halogenated compounds, sulfur compounds, nitrogen compounds, and acids. The results of ventilation system designing showed that the system with airflow of 5725 m³/h and a cyclone with the diameter of 1 m and the height of 4 m could remove 50% of particles with 9.45-micron diameter. Gaseous pollutants were removed using thermal oxidation via the consumption of 96 m³/h fuel gas flow. The chamber volume was 6.67 m³. The daily fuel costs were estimated 310000 RLS. Conclusion: Application of local exhaust ventilation system and integrated collectors for control of air pollutants in rendering plant can remove large amounts of particulate and gaseous pollutants. Control of these pollutants can cause loss of smell nuisance and environmental pollution and improving the health and welfare of workers and neighboring residents of such industries.