Effects of mix ratio, moisture content and aeration rate on sulfur odor emissions during pig manure composting. (October 2016)

• Record Type: Journal Article
• Authors: Zang, Bing; Li, Shuyan; Michel, Frederick; Li, Guoxue; Luo, Yuan; Zhang, Difang; Li, Yangyang
• Is Part Of: Waste management. Volume 56(2016)
• Page Start: 498
• Page End: 505
• Publication Date: 2016-10
• Subjects: Compost -- Sulfur odor -- Pig manure -- Dimethyl sulfide -- Dimethyl disulfide -- Aerated static pile; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.06.026
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: 8 odorous sulfur compounds were measured frequently. Sulfur odors were mainly emitted during the first two weeks. Dimethyl sulfide and dimethyl disulfide were the main emitted sulfur compounds. More dimethyl-sulfide and dimethyl-disulfide emitted after each turning. Less manure, lower moisture and higher aeration led to lower sulfur gas emissions. Abstract: Sulfur compounds in swine manure can cause odor emissions during composting if conditions are not conducive to their rapid oxidation and degradation. In this study, the effects of controllable composting process variables on sulfur odor emissions were investigated. These included pig manure to corn stalk mix ratio (0.7:1, 1.5:1 and 2.2:1 dw basis), initial moisture content (60%, 65%, 70% and 75%) and aeration rate (1.0, 2.0, 3.0 and 4.0 m 3 m −3 h −1 ). The compounds measured were carbonyl sulfide, carbon disulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, diethyl sulfide, dimethyl sulfide (Me2 S) and dimethyl disulfide (Me2 SS). The results showed that total sulfur losses ranged from 3.9% to 18.3% after 26 days of composting. Me2 S and Me2 SS were the primary (>59.61%) sulfur compounds released during this period. After turning, emission rates of both Me2 S and Me2 SS increased. Emissions of the other six sulfur compounds were low and inconsistent during composting. Within the compost, feedstock mix ratio significantly influenced the concentration of Me2 SS, while aeration rate significantly affected Me2 S concentration (p < 0.05). Moisture content did not have a significant effect on the concentrations of either of these two compounds. Concentrations of sulfur odor compounds were the lowest at the highest aeration rate. Therefore, high aeration rates during the thermophilic phase, especially after turning, are recommended to minimize sulfur odors produced during swine manure composting.