TESTING OF PEATS FOR REMOVAL OF ODORS FROM LIQUID SWINE MANURE

This paper reports on research designed to investigate the capacities of different kinds of peat to remove odor-causing compounds from liqui d swine manure (LSM). Two experiments were conducted. In experiment #1 , five different peat types (both wet and dry) representing a wide ran ge of properties were tested. Eight percent slurries (of peat/LSM) wer e measured for odor changes at 6, 24, and 96 hours using odor panel an d GC/FID analysis. Experiment #2 was designed to determine more precis ely the kinds of odor-causing compounds that were changing during trea tment. Two extremely different wet peat types were tested in 8 percent slurries after 24 hours of treatment. Odor changes were evaluated usi ng both an odor panel and GC/MS, head-space, solid-phase, microextract ion (HSM).The GC/FID and odor panel results indicated that wet peats w ere much more effective in removing odor-causing compounds from LSM th an were dry pests. Wet pests significantly reduced the LSM odor intens ity after 6 hours of treatment, and completely eliminated odors after the 24 hour treatment. The results from the GC/MS HSM method (experime nt #2) confirmed the results from experiment #1 and also, allowed us t o more precisely identify the specific odor-causing compounds being re duced and to distinguish specific changes in these compounds between p eat types. Of the 23 malodorous compounds identified in experiment #2, all showed significant reductions; however, one peat was better at re ducing 10 of these, while the wet North Carolina peat was better at re ducing 9 others. These results suggest that improvements in odor remov al efficiency and costs can be achieved by selection of specific peat types for a specific LSM site.