발전폐수 처리 및 재이용수 생산 방법과 검증에 관한 연구

Abstract

본 연구는 발전폐수를 효과적으로 처리함과 동시에 용수를 생산할 수 있는 기술을 제안하고 검증하기 위해 응집조, 침지형 UF조, RO로 구성된 24 ㎥/d 규모의 파일럿 플랜트를 약 6개월간 운영하였다. 발전소 내 자체폐수처리장을 거친 최종방류수와 공정폐수(응집처리, 응집미처리)를 대상으로 재이용수의 공업용수 수질기준 만족 여부를 실험하였다. 실험결과 유입원수 대비 생산수의 전기전도도 처리효율은 방류수 99.0%, 응집처리 폐수(pH 조절+응집처리) 98.8%, 응집미처리 폐수(pH 조절) 99.0%로 분석되었으며, 그 외 Pb, As, Cd, Hg, Cr, cyanide, PCE(Tetrachloroethylene), TCE(Trichloroethylene), phenol은 검출되지 않았다. 최종방류수 및 응집처리폐수의 막 압력은 10bar 이하로 안정적인 운전이 가능했으나 응집미처리 폐수의 경우 10 bar를 초과하여 막 세정주기가 잦아지는 경향을 확인하였다. 처리수질의 경우 TOC, T-N, T-P 농도는 방류수 허용기준(Ⅲ지역)을 만족했으며, 시설가동 시 회수율 관리를 통해 안정적인 폐수처리 및 재이용수 생산이 가능함을 확인하였다.

Abstract This study proposed and verified a technology that can effectively treat wastewater generated from a power plant and simultaneously reuse it as industrial water. A pilot plant with a scale of 24 m3/d and consisting of a coagulation tank, submerged UF (Ultra Filtration) tank, and RO (Reverse Osmosis) was operated for about six months as a case study. It was tested if the reused water satisfies the industrial water quality standards for the final effluent and process wastewater (coagulated and non-coagulated). Here, the final effluent and process wastewater had passed through the power plant's wastewater treatment plant. The experiment result shows that the electrical conductivity treatment efficiency of reused water compared to that of the inflow water was 99.0% for effluent, 98.8% for wastewater with pH adjustment and coagulation, and 99.0% for wastewater with only pH adjustment. Components such as Pb, As, Cd, Hg, Cr, cyanide, PCE (Tetrachlorethylene), TCE (Trichlorethylene), and phenol were not detected during the test. The membrane pressure of the final effluent and wastewater with pH adjustment and coagulation was 10 bar or less, which allowed a stable operation. However, in the case of wastewater with only pH adjustment, it exceeded 10 bar. So, the frequency of membrane cleaning cycles was increased. The TOC, T-N, and T-P concentrations satisfied the effluent standards (region Ⅲ), and it was confirmed that stable wastewater treatment and industrial water production were possible through recovery rate management during facility operation.