Effects of adding bulking agents on the biodrying of kitchen waste and the odor emissions produced.

The effects of adding a bulking agent on the performance and odor emissions (ammonia and eight sulfur-containing odorous compounds) when biodrying kitchen waste were investigated. Three treatments were considered: the addition of either cornstalks (CS) or wood peat (WP) to kitchen waste as a bulking agent before biodrying, and a control treatment (CK). The water-removal rates for CK, CS, and WP treatments were 0.35, 0.56, and 0.43kg/kg, respectively. Addition of bulking agents to kitchen waste produced less leachate, higher moisture-removal rates, and lower consumption of volatile solids. The CS treatment had the highest biodrying index (4.07), and those for the WP and CK treatments were 3.67 and 1.97, respectively. Adding cornstalks or wood peat decreased NH3 emissions by 55.8% and 71.7%, respectively. Total sulfur losses were 3.6%-21.6% after 21days biodrying, and H2 S and Me2 SS were the main (>95%) sulfur compounds released. The smallest amounts of sulfur-containing odorous compounds were emitted when cornstalks were added, and adding cornstalks and wood peat decreased total sulfur losses by 50.6%-64.8%.