잔류유분 함유 반출처리토 재활용을 위한 호밀 식재 식물상 토성회복 가능성

Abstract

The amount of TPH contaminated soil treated at off-site remediation facilities is ever increasing. For the recycle of thetreated-soil on farmlands, it is necessary to restore biological and physico-chemical soil characteristics and to removeresidual TPH in the soil by an economic polishing treatment method such as phytoremediation. In this study, a series ofexperiments was performed to select suitable plant species and to devise a proper planting method for the phytorestorationof TPH-treated soil. Rye (Secale cereale) was selected as test species through a germination test, among 5 otherplants. Five 7-day-old rye seedlings were planted in a plastic pot, 20 cm in height and 15 cm in diameter. The pot wasfilled with TPH-treated soil (residual TPH of 1,118 mg/kg) up to 15 cm, and upper 5 cm was filled with horticulture soil toprevent TPH toxic effects and to act as root growth zone. The planted pot was cultivated in a greenhouse for 38 days alongwith the control that rye planted in a normal soil and the blank with no plants. After 38 days, the above-ground biomass ofrye in the TPH-treated soil was 30.6% less than that in the control, however, the photosynthetic activity of the leafremained equal on both treatments. Soil DHA (dehydrogenase activity) increased 186 times in the rye treatment comparedto 10.8 times in the blank. The gross TPH removal (%) in the planted soil and the blank soil was 34.5% and 18.4%,respectively, resulting in 16.1% increase of net TPH removal. Promotion of microbial activity by root exudate, increase insoil permeability and air ventilation as well as direct uptake and degradation by planted rye may have contributed to thehigher TPH removal rate. Therefore, planting rye on the TPH-treated soil with the root growth zone method showed boththe potential of restoring biological soil properties and the possibility of residual TPH removal that may allow the recycleof the treated soil to farmlands.