Removal of hydrogen sulfide and ammonia from gas mixtures by co-immobilized cells using a new configuration of two biotrickling filters

The simultaneous removal of H₂S and NH₃ was investigated using two biotrickling filters packed with polyurethane foam cubes. One biotrickling filter was inoculated with Thiobacillus thioparus ATCC 23645 for the removal of H₂S (BTT) and the other filter with Nitrosomonas europaea ATCC 19718 for the removal of NH₃ (BNE). Three different configurations were studied by modification of the gas line and recirculation medium line. The best results were obtained with the BNE biotrickling filter after the co-immobilization of the two bacteria. A removal efficiency of 100% for 230 ppmv of NH₃ and 129 ppmv of H₂S was reached at an EBRT of 60 seconds. The results obtained show that it is possible to co-immobilize both microorganisms using the same recirculation medium and remove successfully H₂S and NH₃ from a gas mixture.