Evaluation of full-scale biofilter with rockwool mixture treating ammonia gas from livestock manure composting

NH3 removal by a full-scale biofilter with rockwool packing materials was studied by measuring the gases and potential nitrification and denitrification activities of those materials in order to improve the biofiltration technology used in livestock farms. The rockwool biofilter was a durable and effective system for removing NH3, which was varied with the turning of manure composts. Furthermore, NH3 could be treated in the absence of an extra increase in two greenhouse gases, N2O and CH4. Potential nitrification and denitrification activities of the packing materials were estimated to be 8.2–12.2 mg N, and 1.42–4.69 mg N/100 g dry samples per day, respectively. The results suggested that potential nitrification and denitrification activities would increase within the biofilter where substrates, NH3 or NO3−, have accumulated as a result of its operation. However, since percolate water contained high concentrations of NH4+ and NO3−, further improvement is required by reducing nitrogenous compounds within both the biofilter and percolate water.