유용 참나무 선발을 목적으로 도입된 루브라참나무는 1972 년 원산지로부터 도입하여 적응성 검정 결과 생장과 재질이 우수하고 적응력이 뛰어나, 1991년 추가로 23개 산지를 도입 하여 각 산지별 75본씩 소규모 산지시험을 하였다. 그 결과 New York와 Vermont주 루브라참나무의 수고생장이 우수하 였고, Minnesota주와 Virginia의 생장이 불량하였다. 직경생장에서도 수고생장과 유사한 결과가 나왔으며, 특히 수고생장 이 불량한 Minnesota주와 Virginia주는 직경생장도 불량 하 였고, 직경생장이 우수한 지역인 Illinois주와 Vermont주의 수고 생장은 상위 그룹에 속하였다. 수종별 생장에서 루브라 참나무는 상수리나무보다 약 30% 생장이 우수하고, 알바참 나무와는 약 300% 생장이 우수하였다. 특히 재적생장에서 루 브라참나무는 상수리나무보다 약 3배가량 재적생장량이 좋았 다. 수간의 형태적 특징에 따른, 통직성 조사시 가장 우수한 산지는 캐나다의 Qubec주의 Beloeill 산지였고, 가장 불량한 산지는 Wisconsin주의 Sauk Country 산지로 나타났다. 특히, 가장 우수한 Qubec주의 Beloeill 산지는 우리나라 향토 수종 인 상수리나무(Control) 보다 생장에서 약 3.5배 우량한 특징 을 보였다. Beloeill 산지는 다른 산지들에 비해 수간이 통직 하고 우량하여 우리나라의 기후 풍토에 잘 적응하는 것으로 판단된다. 또한, 생장과 통직성 조사시 우수한 산지는 북위 43～46°에 분포하는 미국의 New York주와 캐나다 Qubec주 의 루브라참나무가 우수한 것으로 나타났다. 따라서 루브라참 나무는 국내 수종인 상수리나무보다 생장이 우수하고, 로버참 나무와 알바참나무보다 적응력이 뛰어나 유망해 보여 도입수 종으로서 산지자원화에 기여할 수 있을 것으로 판단된다.

The main objectives of this research are to investigate characteristics of ozone solubility due to low solubility of conventional bubbles-ozone generators, evaluate the treatment characteristics of reclaiming textile wastewater for industrial water by means of micro/nano bubbles-dissolved ozone flotation(MNB-DOF) process. The textile wastewater used in this research was obtained from final effluent of the textile wastewater in B city. There is a 400L reactor which consists of a micro-nano bubble system and a ozone generator for experiments. As a result of generating micro-nano bubbles (below 0.5 ㎛) by using of MNB-DOF process, it improved ozone solubility due to higher ozone transfer rates. Consequently, the shorter ozonation time clearly indicates the lower power costs. The reported results clearly indicated that MNB-DOF process can be effectively and inexpensively. Results of the experiments through MNB-DOF process in this study satisfy all reclaiming standards as industrial water: pH 6.5～8.5, SS 10 mg/L or below, BOD_5 6 mg/L or below, turbidity 10 NTU or below, Coliforms 1,000/100 mL or below. Therefore there is a possibility of the reclaiming of the textile wastewater as industrial water.

The objectives of this research are to evaluate and compare the oxygen transfer coefficients(KLa) in both a general bubbles reactor and a micro-nano bubbles reactor for effective operation in sewage treatment plants, and to understand the effect on microbial kinetic parameters of biomass growth for optimal biological treatment in sewage treatment plants when the micro-nano bubbles reactor is applied. Oxygen transfer coefficients(KLa) of tap water and effluent of primary clarifier were determined. The oxygen transfer coefficients of the tap water for the general bubbles reactor and micro-nano bubbles reactor were found to be 0.28 hr -1 and 2.50 hr -1 , respectively. The oxygen transfer coefficients of the effluent of the primary clarifier for the general bubbles reactor and micro-nano bubbles reactor were found be to 0.15 hr -1 and 0.91 hr -1 , respectively. In order to figure out kinetic parameters of biomass growth for the general bubbles reactor and micro-nano bubbles reactor, oxygen uptake rates(OURs) in the saturated effluent of the primary clarifier were measured with the general bubbles reactor and micro-nano bubbles reactor. The OURs of in the saturated effluent of the primary clarifier with the general bubbles reactor and micro-nano bubbles reactor were 0.0294 mg O2/L․hr and 0.0465 mg O2/L․hr, respectively. The higher micro-nano bubbles reactor's oxygen transfer coefficient increases the OURs. In addition, the maximum readily biodegradable substrate utilization rates(Kms) for the general bubbles reactor and micro-nano bubbles reactor were 3.41 mg COD utilized/mg active VSS․day and 7.07 mg COD utilized/mg active VSS․day, respectively. The maximum specific biomass growth rates for heterotrophic biomass(μmax) were calculated by both values of yield for heterotrophic biomass(YH) and the maximum readily biodegradable substrate utilization rates(Kms). The values of μmax for the general bubbles reactor and micro-nano bubbles reactor were 1.62 day -1 and 3.36 day -1 , respectively. The reported results show that the micro-nano bubbles reactor increased air-liquid contact area. This method could remove dissolved organic matters and nutrients efficiently and effectively.