Effect of biochar combined with a biotrickling filter on deodorization, nitrogen retention, and microbial community succession during chicken manure composting

The high-nitrogen content and dense structure of poultry manure compost cause volatilization of N to ammonia (NH3). This study evaluated the combined application of biochar and biotrickling filtration (BTF) to remove of odor in chicken manure mixed straw compost (w/w, 2.5:1). Adding of 10% biochar reduced NH3, hydrogen sulfide (H2S), and total volatile organic compounds (TVOCs) contents by 20.04%, 16.18%, and 17.55% respectively, and decreased the N loss rate by 8.27%, compared with those observed in control. The organic matter content decreased by 28.11% and germination index reached 97.36% in the experimental group. Meanwhile, the N-cycling microorganisms such as Pusillimonas and Pseudomonas became more active, and the relative abundance of sulfur-cycling microorganisms Hydrogenispora decreased in the experimental group. Following BTF application, the NH3, H2S, and TVOCs removal rates reached 95%, 97%, and 53%, respectively.

Automated summary

The study demonstrated that the addition of biochar can significantly reduce the levels of ammonia, hydrogen sulfide, and volatile organic compounds in poultry manure compost, while also decreasing the nitrogen loss rate and promoting organic matter decomposition. The application of biochar can also improve the microbial composition and enhance the activity of certain nitrogen-cycling microorganisms.