Effect of natural zeolite (clinoptilolite) on ammonia emissions of leftover food rice hulls composting at the initial stage of the thermophilic process
This study investigated ammonia reduction by natural zeolite (clinoptilolite) on leftover food rice hulls composting in seven enclosures containing composting fermenters. Amounts of 1.6% 3.1% 13.7% 21.8% 31.5% and 47.2% of clinoptilolite were added to six portions of the feedstock mixture on a dry mass basis, respectively, and 0% of clinoptilolite as a control. The ammonia emission pattern in the thermophilic stage of composting with the presence of clinoptilolite was investigated dependently of the process temperature. The addition of 31.5~47.2% clinoptilolite to leftover food composting was the optimum dose for the reduction of ammonia emission in leftover food composting. It was demonstrated that clinoptilolite acted as an adsorbent in the composting of leftover food in granular form.