earticle

영어

The objective of this study is development of HIS (hybrid-type inclined settler) system for treatment of untreated 2Q wastewater during storm event. Instead of coagulation and flocculation reactor, HIS system was used hydrocyclone for coagulation. HIS system is consisted of hydrocyclone with chitosan coagulant and inclined storage tank. Three type chitosan (manufacture P, K, D) were used to determine the optimum type coagulant for treatment of storm runoff. As the results of Jar test (rapid mixing 1 min, slow mixing 3 min, settling 10 min), the best type chitosan was D chitosan and the optimum dosage of 11 mg/L for road side sediments was analysed. Because of the effectiveness of chitosan in removing turbidity was independent on pH, the operation of HIS system would be simple. The synthesized storm runoff was made with water and addition of under 200 μm stream sediments. The operated range of inclined settler retention time was 1.17-4.17 min and surface loading rate was 170.7-609.5 m3/m2/day. Results indicate that the range of removal efficiency of turbidity and SS were 71.2-89.1% (mean 82.8%) and 83.2-99.2% (mean 93.5%), respectively. As a results of micro particle size treatment, average particle size in foul flow was greater than that in inflow, which means that coagulation by chitosan makes floc well in hydrocyclone. HIS system would have possibility for replace coagulation and flocculation reactor to treat untreated 2Q of sewer overflows.

한국어

본 연구는 강우 시 하수처리장에서 단순 침전하여 방류되는 2Q를 기존의 응집조, 응결조를 대체할 수 있는 시설로 hydrocyclone 를 이용하여 고속 응집·응결하여 침전하는 하이브리드형 경사판 침전지(HIS, hybrid-type inclined settler) 시스템의 적용 가능성 을 분석함에 있다. 응집제로는 3곳의 제조회사에서 제조한 chitosan을 주입하여 응집교반실험(응집 1분, 응결 3분, 침전 10분)하여 잔류탁도를 분석한 결과 D사에서 제조한 chitosan이 잔류농도가 가장 낮게 나타났고, chitosan 최적 주입농도는 11 mg/L으로 분 석되었다. 하천 및 도로변에 퇴적된 미세 토양입자를 채취하여 200 μm 이하 입자들을 수돗물로 희석하여 강우 유출수 모의 시료 로 사용하였다. HIS 시스템의 경사판 침전지의 체류시간 1.17-4.17 min, 수면적 부하율 170.7-609.5 m3/m2/day 범위의 운전조건에 서 200 μm 이하 도로변 퇴적물질 미세입자를 대상으로 처리효과를 분석한 결과, 탁도 처리효율 범위는 71.2-89.1%(평균 82.8%), SS는 83.2-99.2%(평균 93.5%)로 분석되었다. Hydrocyclone 하부배출수의 평균입경은 유입수 입경보다 증가하는데 이는 chitosan 에 의한 응집이 hydrocyclone에서 플럭을 형성하는 것으로 분석되었다. 강우 시 하수처리장으로 유입되어 미처리되는 2Q를 화학 적으로 처리 시 hydrocyclone은 응집조, 응결조를 대체할 수 있는 방안으로 판단된다.