포트 재배에 의한 화약물질 오염토양 정화용 내오염성 식물 선정

Abstract

Nine plant species were selected through vegetation survey at three military shooting ranges at northern Gyeonggi Province. Plants were germinated in normal soil and three seedlings were transplanted to a bottom sealed pot containing sandy loam soils contaminated with either RDX (291 mg/kg) or TNT (207 mg/kg). Planted, blank (without plant), and control (without explosive compound) pots were grown in triplicate at a green house for 134 days. During cultivation, transplanted plants exhibited chlorosis and necrosis in flower and leaf by explosive toxicity and stress. Only three plants, Wild soybean, Amur silver grass, Reed canary grass, survived in TNT treated pot, while seven plant species except for field penny cress and jimson weed, thrived in RDX treated pot. Appreciable amount of TNT (61.6~241.2 mg/g-D.W.) was detected only in plant roots. Up to 763.3 mg/g-D.W. along with 4-amino-2,6-dinitrotoluene, an intermediate of TNT, accumulated in the root of wild soybean. In addition, azoxy compounds, abiotic intermediates of TNT, were detected in TNT treated soils. RDX absorbed average 1,839.95 mg/kg in shoot and 204.83 mg/kg in root. Most of TNT in plant was accumulated in underground part whereas RDX was localized in aerial part. Material balance calculation showed that more than 95% of the initial TNT was removed in the planted pots whereas only 60% was removed in the blank pot. The amount of RDX removed from soil was in the order of Amur Silver Grass (51%) > Chickweed (43%) > Evening primrose (38%). Based on the results of pot cultures, Amur silver grass and Reed canary grass are selected as tolerant remedial plants for explosive toxicity.