In this study, air scouring cleaning was selected and applied among 5 small blocks (S1~S5) in domestic S cities to analyze the cleaning effect of particles causing discoloration. In order to identify the cleaning effect, 10 locations were selected as water quality investigation point, such as the stagnant or water mains ends. Removal of solids, variation of particle components, weight and concentration were analyzed. And the level of the cleanness of the surface inside water mains using endoscope was investigated. As a result of analysis, the solids discharged after cleaning were mainly sand and gravel, pieces related to pipe materials, and corrosion products. As a result of analyzing the concentrated particles of the filter before and after cleaning, it was found that the change in discoloration on the filter was large. In addition, as a result of comparing the weight and the concentration of the particles, it was found that the particles causing discoloration were significantly removed after cleaning. From the results of the endoscopy, it was confirmed that most of the precipitated and accumulated dark yellow discoloration matters inside water mains were removed through cleaning. Therefore, it seems that the particles causing discoloration in water decreased after cleaning. Therefore, it is expected that, if properly cleaning was applied, matters that cause discoloration can be removed from the water mains, and customer's complaints can also be reduced through water quality improvement.

Optimal processes to remove chromaticity at E water treatment plant(WTP) mainly caused by algae of E lake in Jeju island were investigated based on lab-tests of chlorine and ozone oxidation. 42.9% of chromaticity of filtered water was removed by chlorine oxidation under pH 7.0∼8.0, dose of 1.0 mg/L with contact time of 30∼60 min. On the other hand, chromaticity removal was 71.4% when post-ozone dose of 0.9∼1.9 mg/L and pH 9.0, while it was increased to 86.7% under post-ozone dose of 3.1∼7.3 mg/L and pH 9.0. However, there was no significant chromaticity removal efficiency increase when ozone doses were higher than 5.0 mg/L regardless of feeding point(i.e., pre-ozonation and post-ozonation) and pHs(i.e., 7.0 and 9.0.) under the experimental conditions. Based on the results, chlorine oxidation using existing chlorination facilities at the WTP is recommended for lower chromaticity while ozone oxidation is recommended for higher chromaticity by installing new ozone feeding facilities.

This study were performed to control color and satisfy discharge permission standard of effluents operating a small dyeing factory based on a fiber. The color removal efficiency was very high when the injection site of Sodium Hypochlorite(NaOCl) was more discharge site of second sedimentation tank than of first sedimentation tank. Although NaOCl usages was reduced from 1.0 ㎥/day to 0.8 ㎥/day, the removal efficiency of BOD, COD and SS were similar. At the time, the optimal Hydraulic Retention Time(HRT) was calculated to twenty five minute after NaOCl injection until effluent discharged finally. After controlling NaOCl usages and HRT, the effluent quality of BOD, COD, SS, Color and Chloroform were 8.6 mg/L, 24.7 mg/L, 43.3 mg/L, 191.2 degree and 0.346 mg/L, respectively, so that was satisfied to discharge permission standard.

참외를 껍질째 먹기 위하여 착과 5일후부터 과실에 배, 사과, 포도봉지를 씌워 재배한 결과, 봉지내의 온도는 외기온에 비하여 주간에는 낮고 야간에는 높았으며 습도는 주간에는 높고 야간에는 낮았다. 무처리구에 비하여 봉지재배로 과장은 짧고 과폭은 좁고 과육두께는 얇고 과중은 가벼운 경향이었으나 처리간 차이는 없었다. 과육 및 태좌부의 당도는 봉지재배 처리구에서 낮은 경향이었으나 처리간 차이는 없었다. 그러나 과실의 당도는 봉지제거 직후 보다는 봉지제거 5일후 조사에서 높아지는 것을 알 수 있었다. 봉지재배로 과피의 경도 및 색도가 낮았다. 이와 같이 봉지재배로 과피의 경도가 낮아 껍질째 먹기는 쉬워졌으나 과피의 색도 및 당도가 낮아 금후 보완이 필요한 것으로 생각된다.

Water quality has been deteriorated by the increasing amount of industrial waste water that is due to the better standard of living. In order to lessen the polluted water and substantially reutilize it at factories, a new method is needed. The plasma generator, which uses discharge current below 1,500 voltage and processes at extremely low temperature, has more strong oxidization than current method and an advantage of miniaturizing the apparatus in dealing with waster water by producing carrier gas at room temperature. This study were measured on the 3 kinds of waster water to the plasma generator for 120 minutes. As results, COD was almost decreased and removed in 15 minutes. The results suggest that the plasma generator can be used reduce COD and removal of color for various waster water, which can be reutilized as industrial water, It would be of benefit to the country like Korea in which qualified water is deficient.

본 연구는 음식물류 폐기물 처리장에서 발생하는 부산물의 활성화 공정을 통해 제조된 친환경 활성탄의 공업분석, 요오드 흡착 성능, 메틸렌블루 등의 특성을 평가하고, 그로 인한 탁도 및 색도 제거능력을 연구하여 활성탄의 대체물질로서의 재활용 가능성을 평가하고자 한다. 실험에 사용된 실험재료는 B시 F사의 음식물류 폐기물 처리시설에서 발생하는 음식물류 폐기물 처리장 부산물을 함수율 10% 미만으로 건조한 후, 분쇄기로 100 mesh 이하로 하여 사용하였다. 연구에 사용한 실험 장치는 최고온도 1,200℃까지 유지 가능한 고온전기로를 사용하였고, 600℃ 90분의 친환경 활성탄 시료의 요오드 흡착 성능이 가장 높게 나타났으며, 한국 활성탄소공업협동조합 수처리용 분말활성탄 기준인 950mg/g 이상의 기준과 비교하였을 경우는 600℃ 90분의 975.11mg/g 및 700℃ 60분의 950.92mg/g이 기준에 만족하는 것으로 나타났다. 메틸렌블루 탈색력 역시, 요오드 흡착성능 분석과 마찬가지로 600℃ 90분의 친환경 활성탄 시료의 메틸렌블루 탈색력이 가장 뛰어나게 나타났다. 또한 대부분의 활성화 온도에서의 메틸렌블루 탈색력이 요오드 흡착 성능과 비슷한 양상을 나타냄을 알 수 있었다. 이와 같이, 본 연구에서는 음식물류 폐기물 처리장 부산물을 이용하여 제조된 친환경 활성탄의 활성탄 대체물질로서 재활용이 충분히 가능할 것으로 판단했다.