The effects of temperature, initial Pb^2+, concentration and initial sludge concentration on the initial Pb^2+ removal rate and maximal Pb^2+ removal amounts in activated sludge, respectively, were investigated. The removal of Pb^2+ in activated sludge was proved to be temperature-dependent process. The initial Pb^2+ removal rate increased from 187.5 to 261.4 ㎎ Pb^2+/g sludge dry weight·min, in response to the promoted temperature from 10℃ to 60℃, while the maximal Pb^2+ removal amount (78.5 ㎎ Pb^2+/g sludge dry weight) occurred at 30℃. As the initial Pb^2+, concentration increased from 36 to 228 ㎎ Pb^2+/L at the constant temperature of 30℃ and initial sludge concentration of 1.5 g sludge dry weight/L, the time to reach an equilibrium state was almost independent of the initial Pb^2+ concentration and the equilibrium Pb^2+ removal amount was increased from 41.9 to 73.6 ㎎ Pb^2+/g sludge dry weight. On the contrary, the equilbrium Pb^2+ removal amount was decreased from 87.7 to 65.3 ㎎ Pb^2+/g sludge dry weight as the increase of initial sludge concentration from 0.22 to 1.76 g sludge dry weight/L.

본 연구에서는 (1) 운동과 이론에 기초한 강우, 유출 특성을 파악하고, (2) 강우 및 유수에 의해서 발생하는 침식, 퇴적량을 산정하는 모형을 연구하며, (3) 유사량 산정식, 유역의 불할 수 등이 하상변동 예측에 미치는 영향을 분석하고, (4) 평창강 유역에서 하도자료, 강우, 유츨량, 유사량 등을 실측하여 모형의 적용성을 검증하였다. 운동파 방정식을 평창강 유역에 적용하여 유출해석을 실시한 결과, 첨두 유량의 발생시간은 다소 빠르게 계산되었으나 전

To perform a long-term ambient sampling study at a residential site, an air sampler was constructed to collect 24-hour integrated air samples suitable for the volatile organic compounds (VOCs) analysis. It includes an esthetically acceptance due to proximity to homes, as well as providing the required sampling specifications. The VOCs sampler accomodates four 5/8 stainless steel(SS) traps packed with adsorbent(Tenax) and is capable of four flow rates in the range of 5 to 50 cc/min. Sintered metal filters(10 micrometer) were directly connected to the inlet of the trap adapters. Additional specifications include: 1) constructed of organically inert materials. 2) weatherproof, 3) battery operated, 4) collecting of VOCs at a breathing zone level, , and 5) quiet operation with micro diaphragm pumps wrapped by the sponge. The pump/battery system was separated from the sampling shelter. Sound levels measured for this system were below permissible sound levels (NJDEP) at a residential site. The sampler has been successfully operated at both ground level in a residential area and on the roof of a one story elementary school.