%0 Research Notes %T Use of peat-soil for biological purification of ethylene contaminated air %A Elsgaard, Lars %D 2000 %J Suo - Mires and peat %V 51 %N 3 %U http://suo.fi/article/9802 %X The gaseous plant hormone and air pollutant ethylene (C2H4) has a strong effect on plant physiological processes, such as ripening and senescence, and its removal is often required from contaminated air.This study tested the efficiency of indigenous microor ganisms in horticultural peat-soil to purify C2H4 contaminated air under biofilter condi tions.Peat-soil, acclimated to C2H4 removal, was placed in a biofilter (687 cm3) and subjected to an air flow (73 mL min–1 ) with ~117 ppm C2H4 (ppm, parts per million; equivalent to µL L–1 ).C2H4 was removed to a lowest level of 0.034 ppm after operation of the biofilter for 12 days at 26°C. This corresponded to a C2H4 removal efficiency of >99.9%and a specific C2H4 removal rate of 6.4 µg C2H4 g–1 dry wt soil h–1 (wt, weight). However, this efficient C2H4 removal was only transient (4 days), and during day 16 to 21, the C2H4 removal efficiency decreased to 51%. In contrast to this result, it was previously found that, under comparable biofilter conditions, cultivated ethylene-oxidizing bacteria were able to survive and efficiently remove C2H4 for at least 75 days. Thus, prolonged and efficient purification of highly C2H4 contaminated air by horticultural peat-soil under biofilter conditions apparently depended on bacterial inoculation.