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 + , NO3
), 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 fullscale
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 50 mg N per 100 g compost to about 140 mg N per 100 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 0.03 d1
on average, indicating that if a proper sampling strategy is employed, bench-scale experiments can be
used to represent full-scale composting conditions