Review on Photocatalytic Applications for Deodorization in Livestock and Poultry Farms

Odor emissions from intensive livestock and poultry farming operations pose significant environmental and health concerns. Photocatalysis, an advanced oxidation process (AOP), has shown great promise for mitigating odorous gasses in livestock and poultry farming due to its efficiency, environmental friendliness, and mild operating conditions. This review summarizes the principles and performance of photocatalytic deodorization in livestock and poultry farming and evaluates the advancements in photocatalytic deodorization from lab- to field-scale. Photocatalytic systems demonstrate removal efficiencies of up to 98% for ammonia (NH 3 ), 89.9% for hydrogen sulfide (H 2 S), 99% for volatile organic compounds (VOCs), and 17.2% for particulate matter (PM). However, reduced efficacy occurs in practical applications due to humidity, dust, and pollutant complexity. Key knowledge gaps, such as insufficient field-scale experiments and limited studies on complex pollutants, hinder further improvements in photocatalytic deodorization. Therefore, this review highlights strategies to enhance photocatalytic systems under farming conditions, including an improved photocatalyst design, reactor optimization, and combined technologies. By bridging the gap between lab-scale studies and field-scale applications, this work provides a foundation for developing sustainable and effective odor control solutions for livestock and poultry farming.