earticle

영어

This study is aimed to investigate the effect of chlorine dioxide treatment for the removal of dissolved manganeses in raw water and the effect of chlorine treatment and coagulation during purification. The purpose of this study is to remove Mn(II) below 0.05 mg/ L as Mn(II) because Mn(II) occur aesthetic influences of the tap water and the clogging of the filter in purification. This study compared dissolved manganeses removal efficiency depending on the reaction time, the molar ratio of chlorine dioxide to manganese, pH, temperature to determine the optimal conditions for the oxidation of dissolved manganeses and chlorine dioxide. When the initial concentration of Mn(II) was 0.282 mg/L and the molar ratio of chlorine dioxide to Mn(II) was 2, the removal efficiency of Mn(II) was 89.6%. At this time the concentration of Mn(II) was 0.035 mg/L which was lower than 0.05 mg/L of water quality standard in Republic of Korea. The removal efficiency of Mn(II) was 75.3% when initial conditions were 0.449 mg/L of initial Mn(II) concentration, at pH 6.9 and molar ratio was 3. Mn(II) removal efficiency was 89.3% when initial conditions were 0.449 mg/L of initial Mn(II) concentration, at pH 8.9 and molar ratio was 3. These results indicate that pH adjustment is necessary at high Mn(II) concentration. As the temperature was 25.7oC, 15.6oC and 4oC, the concentrations of Mn(II) was 0.028 mg/L, 0.036 mg/L, 0.041 mg/ L. These removal efficiencies were 91.1%, 87.4% and 85.0% respectively. Even at lowest temperature, Mn(II) concentration was removed effectively below 0.05 mg/L. The removal efficiency of manganese in the presence of residual chlorine by pretreatment chlorination process was 92.1% in the presence of 0.2 mg / L as Cl - and 92.7% in the presence of 0.08 mg/L as Cl -, There was little difference in efficiency. In addition, the production of manganese dioxide by manganese and chlorine dioxide increased the turbidity of water. As a result, the coagulation efficiency was not significantly influenced by adding chlorine dioxide.

한국어

원수 중 존재하는 용존 망간을 제거하기 위한 이산화염소로 산화처리 시 최적 조건 도출 및 정수처리 중 전염소처리 및 응집과정 에서 영향을 알아보고자 하였다. 본 연구는 수돗물의 심미적인 영향을 끼치며 정수처리에서 막 폐색 문제를 일으키는 용존 망간을 먹 는 물 수질기준인 0.05 mg/L as Mn(II) 이하까지 제거하는 것을 목표로 하였다. 망간과 이산화염소의 산화반응에 있어 영향을 끼칠 수 있는 반응시간, 망간에 대한 이산화염소 몰비, pH, 온도에 따른 망간 제거효율을 비교하였다. Mn(II)는 이산화염소와는 1분 이내 로 반응하였으며, 0.282 mg/L as Mn(II)일 때 Mn(II)에 대한 이산화염소 몰비가 2일 경우 89.6%의 Mn(II)제거율을 보이며, 먹는 물 수질기준인 0.05 mg/L 이하인 0.035 mg/L as Mn(II)까지 제거되었다. 0.449 mg/L as Mn(II)일 때 망간에 대한 이산화염소의 몰비가 3일 경우 pH 6.9, pH 8.9일 때 각각 75.3%, 89.3%의 Mn(II)제거율을 보였으며, Mn(II)이 고농도로 유입 시 pH 조정이 필요할 것으 로 나타내었다. 수온이 25.7oC, 15.6oC, 4.4oC일 때 0.028, 0.036, 0.041 mg/L까지 제거되었으며 제거율은 각각 91.1%, 87.4%, 85.0% 로 낮은 온도에서도 0.05 mg/L 이하까지 제거되었다. 정수처리 전단 전염소 공정에 의한 잔류염소 존재 시 망간제거 효율 비교한 결 과, 0.2 mg/L as Cl- 로 존재 시 92.1%의 제거율로 0.08 mg/L as Cl- 존재 시 92.7%의 제거율과 비교하였을 때 효율차이는 거의 없 었다. 또한, 망간과 이산화염소 반응에 의한 이산화망간 생성으로 수질의 탁도가 증가하여 이산화염소 투입에 따른 응집효율 실험 결 과, 응집효율에 큰 영향을 보이지 않았다.