Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6354605 | Waste Management | 2015 | 7 Pages |
â¢Impact of compost O2, N, and moisture on organic pollutant removal investigated.â¢Decreased compost O2 level significantly reduces organic micro-pollutant removal.â¢Increased N level in the form of ammonium can reduce micro-pollutant removal.â¢Typical compost moisture contents do not affect micro-pollutant removal.â¢Bench-scale data from non-sterile compost well represent full-scale conditions.
Knowledge about the effects of oxygen concentration, nutrient availability and moisture content on removal of organic micro-pollutants during aerobic composting is at present very limited. Impact of oxygen concentration, readily available nitrogen content (NH4+, NO3â), and moisture content on biological transformation of 15 key organic micro-pollutants during composting, was therefore investigated using bench-scale degradation experiments based on non-sterile compost samples, collected at full-scale composting facilities. In addition, the adequacy of bench-scale composting experiments for representing full-scale composting conditions, was investigated using micro-pollutant concentration measurements from both bench- and full-scale composting experiments. Results showed that lack of oxygen generally prevented transformation of organic micro-pollutants. Increasing readily available nitrogen content from about 50Â mg N per 100Â g compost to about 140Â mg N per 100Â g compost actually reduced micro-pollutant transformation, while changes in compost moisture content from 50% to 20% by weight, only had minor influence on micro-pollutant transformation. First-order micro-pollutant degradation rates for 13 organic micro-pollutants were calculated using data from both full- and bench-scale experiments. First-order degradation coefficients for both types of experiments were similar and ranged from 0.02 to 0.03Â dâ1 on average, indicating that if a proper sampling strategy is employed, bench-scale experiments can be used to represent full-scale composting conditions.