Comparative study on the removal efficiency of hydrogen sulfide (H₂S) using three different packings

Area of Science:

• Environmental Science
• Microbiology
• Chemical Engineering

Background:

• Hydrogen sulfide (H2S) is a common air pollutant requiring efficient removal methods.
• Biofiltration offers a sustainable approach for H2S remediation.
• Optimizing packing materials is crucial for enhancing biofilter performance.

Purpose of the Study:

• To evaluate the H2S removal efficiency of different biofilter packing materials.
• To investigate the impact of packing composition and environmental factors on H2S removal.
• To identify optimal conditions for H2S biodegradation in biofilters.

Main Methods:

• Development of a polyvinyl chloride (PVC) pipe biofilter system.
• Testing three distinct packing materials (A, B, C) with varying compositions (activated carbon, sawdust, wormcast, perlite, pig manure compost).
• Monitoring H2S removal rates, contribution rates of packing layers, filler height effects, humidity, pH, and microbial populations (bacteria and fungi) over time.

Main Results:

• Packing B achieved the highest H2S removal efficiency at 92.96%.
• Packing material contribution was highest at the bottom layer and decreased upwards; top layers outperformed middle layers.
• Optimal humidity for H2S removal was 50-65%; pH decreased in packing A but remained stable in B and C.
• Bacterial and fungal populations increased over time, with distinct distribution patterns in packing B and C.

Conclusions:

• Packing B, composed of wormcast, sawdust, and activated carbon, is the most effective material for H2S removal in biofilters.
• Wormcast-containing packings offer combined physical absorption and biological removal with good sustainability and efficiency.
• Environmental factors and microbial nutrient content significantly influence biofilter performance.
• Wormcast is a cost-effective and efficient material for future biofilter applications.