Pilot-Scale Biofilter Performance for Methyl Mercaptan and Dimethyl Sulfide Removal from Pulp Mill Odors

Abstract

The emission of reduced sulfur compounds from pulp and paper industries represents a major environmental challenge due to their strong odor intensity and potential impact on air quality. This study evaluates the performance of a pilot-scale biofilter for the removal of methyl mercaptan and dimethyl sulfide from pulp mill odor emissions under continuous operating conditions. The biofiltration system was designed to enhance biological degradation through optimized airflow distribution, moisture control, and microbial activity within the packing medium. Experimental investigations were conducted to assess the influence of inlet pollutant concentration, empty bed residence time, temperature, and humidity on the removal efficiency of sulfur-containing compounds. Results demonstrated that the pilot-scale biofilter achieved high removal efficiencies for both methyl mercaptan and dimethyl sulfide, with stable long-term operation and minimal secondary pollution. The biodegradation process was strongly influenced by operational parameters, particularly moisture content and residence time, which significantly affected microbial performance and mass transfer characteristics. Kinetic analysis indicated effective adaptation of microbial communities to fluctuating pollutant loads, contributing to consistent odor reduction and enhanced process reliability. The study further revealed that biofiltration provides an environmentally sustainable and cost-effective alternative to conventional physicochemical treatment methods for industrial odor control. The findings confirm the suitability of pilot-scale biofilters for large-scale implementation in pulp mills, supporting cleaner production practices and improved environmental management in industrial air pollution control systems.