CAJ | 학술논문

甲基叔丁基醚(MTBE)是北美燃料市场最常用的汽油添加剂, 由于在土壤中的不吸附性和极高的水溶性,MTBE已成为一种蔓延性的地下水污染物.植物修复技术被认为是目前对MTBE污染治理最为有效的方法之一.蒸腾流浓度因子(TSCF)作为植物修复技术中十分重要的参数,其通常是用污染物的辛醇-水分配系数(KOW)直接评估的.由于不同植物其体内脂肪含量不同,所以如果仅用污染物的KOW值来计算其TSCF值,往往不能准确表达污染物在植物体内的传输行为.由于MTBE在植物体内不发生降解,植物挥发是MTBE植物修复技术中唯一的作用机理.本实验用一自行设计的植物反应器来测定MTBE在不同温度条件下的TSCF值.长出新根须和嫩叶的柳树(Salix alba)枝条在一容积500 mL的植物反应器中生长9～12 d(其中MTBE溶液500 mL,浓度4.81～6.60 mg/L)来观察柳树对MTBE 的吸收.MTBE 的去除率和柳树的蒸腾量之间的关系用来计算其TSCF值.在15 ℃,20 ℃和25 ℃条件下,MTBE的TSCF值分别为0.58,0.75 和 0.49.本实验结果表明,柳树对MTBE的吸收是一个被动的行为,并且MTBE在柳树体内随蒸腾流的传输也有一定的限度. 图2 表1 参11
갑기숙정기미(MTBE)시북미연료시장최상용적기유첨가제, 유우재토양중적불흡부성화겁고적수용성,MTBE이성위일충만연성적지하수오염물.식물수복기술피인위시목전대MTBE오염치리최위유효적방법지일.증등류농도인자(TSCF)작위식물수복기술중십분중요적삼수,기통상시용오염물적신순-수분배계수(KOW)직접평고적.유우불동식물기체내지방함량불동,소이여과부용오염물적KOW치래계산기TSCF치,왕왕불능준학표체오염물재식물체내적전수행위.유우MTBE재식물체내불발생강해,식물휘발시MTBE식물수복기술중유일적작용궤리.본실험용일자행설계적식물반응기래측정MTBE재불동온도조건하적TSCF치.장출신근수화눈협적류수(Salix alba)지조재일용적500 mL적식물반응기중생장9～12 d(기중MTBE용액500 mL,농도4.81～6.60 mg/L)래관찰류수대MTBE 적흡수.MTBE 적거제솔화류수적증등량지간적관계용래계산기TSCF치.재15 ℃,20 ℃화25 ℃조건하,MTBE적TSCF치분별위0.58,0.75 화 0.49.본실험결과표명,류수대MTBE적흡수시일개피동적행위,병차MTBE재류수체내수증등류적전수야유일정적한도. 도2 표1 삼11
This paper presents a numeric estimation of MTBE transpiration stream concentration factor (TSCF), an important parameter for the design of engineered MTBE phytoremediation systems, using the experimental data from plant uptake tests in a carefully designed bioreactor at 15～25 ℃. Pre-rooted willow (Salix alba) were kept in an Erlenmeyer flask of 500 mL with approximately 500 mL spiked aqueous solution for 9～12 d. MTBE concentrations were 4.81～6.60 mg/L. Samples were taken directly from the solution with a needle and injected to a purge and trap unit. Results from willow uptake tests indicated that the fraction of MTBE removed from the test systems strongly correlated with volume of water transpired in a temperature range of 15～25 ℃. The relationship between percent of mass reduction in aqueous solution and volume of water transpired was used to determine the observed TSCF value for MTBE. Due to the volatilization of MTBE involved in this test, the corrected TSCF values for MTBE were computed to be 0.58, 0.75 and 0.49 at 15 ℃, 20 ℃, and 25 ℃, respectively. These results indicated that the uptake of MTBE by willow was in a restricted passive manner and MTBE was unable to significantly transport through the transpiration stream of rooted vascular plants. Fig 2, Tab 1, Ref 11