Mitigating Odors from Agricultural Facilities: a Review of Literature concerning Biofilters

This article reviews literature on biofilter research both in laboratories and at confined livestock facilities. The purpose is to give an up‐to‐date review of biofilters used to mitigate of odors and volatile organic compounds (VOCs) from agricultural facilities using biofilters. More specifically the article addresses: 1) Factors concerned in design and operation of biofilters such as media property, empty bed residence time, media moisture measurement and control, microbial ecology, construction, and operation cost; and 2) Biofilter performance such as odor/VOC reduction efficiency (RE), and air pressure drop. Lab‐scale, pilot‐scale, and full‐scale biofilter studies were reviewed. Biofilter design and odor/VOC REs were summarized in tables for easy reference and for a perspective on the current state of the art. The relationship between the biofilter configuration/operation factors and biofiter performance was discussed. This literature study indicates: 1) Biofilters can be used as an effective technology for reducing odor/VOC emissions from animal facilities (RE up to 99% for odor and up to 86% for 16 odorous VOCs reported); 2) The three most important factors effecting biofilter performance are packing media, media moisture content, and empty bed residence time; 3) Removal efficiency, air pressure drop, and construction/operation cost are three parameters of concern when a biofilter is installed and operated; and 4) Further studies such as developing precise media moisture measurement and control technologies, bacterial structure, and long time full‐scale biofilter tests are needed to better understand the biofiltration process and improve biofilter applications for agriculture.