• 한국환경과학회지
• /
• 제24권12호
• /
• pp.1551-1558
• /
• 2015

In Korea, many drinking water treatment plants (DWTPs) have introduced and are going to introduce biological activated carbon (BAC) process to treated dissolved organic matter (DOM) in water which are difficult to control by conventional water treatment processes. Even though more decade have passed since introduced BAC in Korea, most of BAC operating method was followed to the modified sand filter operating manuals. In case of BAC backwashing, many DWTPs set the periods of backwashing about 3~5 days. In this study, we have collected data to set the proper BAC backwashing periods from both pilot-plant and real DWTPs. We had measured heterotrophic plate count (HPC), turbidity, water temperature, dissolved organic carbon (DOC) and headloss from just after backwashing to the next backwashing time for two years. Considering water quality factors, the BAC run time from backwashing to the next backwashing could extend more 30 days without water quality deterioration if the head loss do not reach the limited level which depends on each BAC facilities' condition. It means the BAC treated water could be saved in the proportion of extended the backwashing period to the existing backwashing period.

• 한국물환경학회지
• /
• 제37권6호
• /
• pp.433-441
• /
• 2021

The aim of this study was to optimize the ozonation and ceramic membrane integrated process for greywater reclamation. The integrated process is a repeated sequential process of filtration and backwash with the same ceramic membrane. Also, this study used ozone and oxygen gas for the backwashing process to compare backwashing efficiency. The study results revealed that the optimum filtration and backwash time for the process was 10 minutes each when comparing the filtrate flow and membrane recovery rate. The integrated process was operated at three different operating conditions with i) 10 minutes for filtration and 10 minutes for ozonation, ii) 10 minutes for filtration and 10 minute for oxygen aeration, and iii) continuous filtration without any aeration for synthetic greywater. The integrated process with ozone backwashing could produce 0.55 L/min of filtrate with an average of 18.42% permeability recovery, while the oxygen backwashing produced 0.47 L/min and 6.26%, respectively. And without any backwashing, the integrated process could produce 0.29 L/min. This shows that the ozone backwash process is capable of periodically recovering from membrane fouling. The resistance of the fouled membrane was approximately 34.4% for the process with ozone backwashing, whereas the resistance was restored by 10.8% for the process with oxygen backwashing. Despite the periodical ozone backwashing and chemical cleaning, irreversible fouling gradually increased approximately 3 to 4%. Approximately 97.6% and 15% turbidity and TOC were removed by ceramic membrane filtration, respectively. Therefore, the integrated process with ozonation and ceramic membrane filtration is a potential greywater treatment process.

• 멤브레인
• /
• 제24권5호
• /
• pp.393-399
• /
• 2014

본 연구에서는 디스크 링 형태에 패터닝된 박막을 적층시킨 모듈의 분리특성을 규명하고자 투과실험을 수행하였다. 먼저, 본 연구에서 자체 제작한 5가지 형태의 디스크 필터의 순수 투과도를 측정하였으며 그 값은 0.25 내지 $2.24L/m^2{\cdot}hr{\cdot}bar$이었다. 0.1 wt% 카올린 수용액을 투과시키면 순수 투과율이 가장 높은 모듈의 투과유속이 가장 높았고, 순수 투과율이 가장 낮았던 모듈의 카올린 투과유속이 가장 낮게 나타났다. 그러나 모든 모듈의 카올린 투과유속이 순수 투과율에 비례하지는 않았다. 또한 0.1 wt% 수용액으로 장시간 운전하기 위하여 디스크 필터 모듈 1에 주기적으로 역세척을 실시하였으며 가장 효율적인 운전조건은 투과시간 8분, 역세척 2분 주기임을 확인하였다.