Abstract
In this study, Application of sequencing batch reactor (SBR) process for RO retentate treatment was performed. Efficiency of treatment by load and temperature variation was tested. The SBR process was operated two types as HRT per one cycle was 8 and 12 hours, respectively. Methanol was injected for an effective denitrificaion owing to low C/N ratio of the RO retentate. TN removal efficiency of the SBR process was relatively stable at the change of flow-rate and temperature. The optimum time cycle of SBR process was 2 cycle/day for TN removal, and in the case of 3 cycle/day, the effluent TN concentration was found under the effluent quality standard. In the result of assessment, the application of SBR process for RO retentate treatment was effective and could be utilized to design for the wastewater treatment plant. The specific nitrification rate (SNR) and specific denitrification rate (SDNR) were $0.043{\sim}0.066kg\;NH_3-N/kg\;MLVSS{\cdot}day$ and $0.096{\sim}0.287kg\;NH_3^--N/kg\;MLVSS{\cdot}day$, respectively. The derived kinetic could be applied for design to the aerobic and anoxic tank in the RO retentate treatment.
본 연구는 역삼투공정에서 발생하는 농축수의 생물학적 처리에 관한 것으로, SBR공정의 처리성능 및 부하변동과 온도변화에 따른 효율을 평가하였다. SBR공정의 cycle당 HRT가 각각 8시간과 12시간으로 2가지 형태로 공정운전이 이루어졌으며, RO농축수의 낮은 C/N비 때문에 효과적인 탈질을 위해 메탄올을 주입하였다. 유량과 온도의 변화에도 SBR공정의 질소제거 효율은 비교적 안정적인 것으로 나타났다. SBR공정의 최적 time cycle은 2 cycle/day이지만, 3 cycle/day 조건에서도 방류수 TN 농도가 수질기준 이하로 나타났다. 평가결과 RO 농축수 처리를 위한 SBR공정의 적용은 효과적이었으며, 폐수처리장 설계에 활용이 가능할 것이다. SNR과 SDNR은 각각 $0.043{\sim}0.066kg\;NH_3-N/kg\;MLVSS{\cdot}day$와 $0.096{\sim}0.287kg\;NH_3^--N/kg\;MLVSS{\cdot}day$로 나타났다. 도출된 동역학적인자는 RO농축수 처리에서 포기조와 무산소조 설계에 적용이 가능할 것이다.
