남해 어장 준설토의 환경친화적 처리방안 연구

황응주,고문정 대구대학교 환경기술연구소 2005 미래환경기술 Vol.1 No.2

본 연구는 연안 어장의 수질 개선 및 양식 환경 개선을 위하여 준설퇴적물을 환경친화적으로 처리하는 방안을 모색하기 위한 실험으로써 준설퇴적물의 유기물 분별정량을 통한 최대 분해율 선정, 예비안정화 시험, 준설퇴적물 희석배율별 안정화 특성 평가 등을 수해하였다. 유기물 분별정량 결과 준설퇴적물의 유기물 분해율 30~40%를 안정화의 지표로 얻을 수 있었고 희석배율별로 측정한 TCOD, SCOD 역시 32%와 83%의 제거율을 보여 충분한 안정화가 진행된 것으로 나타났다. 또한 안정화 처리 전ㆍ후 준설퇴적물의 실제 안정성평가를 위해 발아시험을 실시해 본 결과 유기물의 안정화 처리를 거칠 경우 준설퇴적물의 식물 독성이 저감됨을 알 수 있었다. It was attempted to treat organic matter in the dredged sediments from costal mari-culture site eco-friendly. Carbohydrates in the dredged sediment were fractionated, and the potential of oxygen consumption was estimated. 30-40% of organic matter found to be maximum degradable content in a biological treatment. Easily degradable organic matter was removed in the aerobic batch test, and the sediment sample was gradually stabilized. 32% of TCOD and 83% of SCOD was removed in this experiment. TCOD removal of 32% was in the range of maximum degradable content for organic matter (30-40%). Seed germination test was conducted for the sediment samples before and after the biological stabilization, and it was found that phyto-toxicity was substantially reduced by the stabilization process.

ENHANCED HUMUS FORMATION IN A SUBSTRATE- CONTROLLED COMPOSTING REACTOR

황은주,김준수,전관수 대구대학교 환경기술연구소 2004 미래환경기술 Vol.1 No.1

A substrate-amended fed-batch composting of food waste was investigated and its effect on humus formation and cellulose decomposition were studied. Various substrates were added to the reactor in fed-batch mode while no additional feed was introduced into the other reactor for comparison. Active composting was prolonged by the amendment of substrate. Cellulose composition changed from initial value of 33.4% to 32.6% in conventional batch composting. Cellulose decreased to 30.2% in the substrate-amended, fed-batch composting. It decreased further to 24.2% when the amount of substrate amendment increased in the fed-batch composting. Humus formation was enhanced in the substrate-amended composting. Humic substances were produced more in the fed-batch composting (7.47% and 8.76%) as compared to conventional batch composting (7.12%). About 5% to 23% increase in humic substance was achieved in the fed-batch composting. It was confirmed that the substrate-amended, fed-batch composting improved the degradation of cellulose and the formation of humus.

Graphical Analysis and Determination of Optimum Mixing Ratio of Bulking Agent for Composting of Food Waste

황은주,이주헌 대구대학교 환경기술연구소 2004 미래환경기술 Vol.1 No.1

Composting of food waste was studied in a controlled batch reactor with the addition of cooked rice as a biodegradable carbon source to investigate the effect of carbon to nitrogen (C/N) ratio control on composting. And, composting of bulking agents such as sawdust and wheat straw were tested with the addition of ammonium sulfate as a nitrogen source. As expected, biodegradation of the food waste having low C/N ratio was improved to some extent when foreign carbon was added. But, bulking agents used in this study exerted themselves slightly biodegradable carbon potential, indicating that the estimation of the dose of additional carbon considering desirable C/N ratio was not reasonable when lignocellulosic bulking material was added to food waste. Also, as another parameter for the estimation of bulking agent addition, the optimum moisture contents at different mixing ratios of bulking agent were evaluated. As a result, it was found that the optimum moisture content increased with sawdust addition meaning the C/N ratio increment. At these points, it was suggested that 78g sawdust / 100g food waste be mixed to make C/N ratio to 25 and moisture content to 56% for effective composting of the food waste studied in this paper.

Effect of feed/seed ratio on the performance of aerobic digester

( Eung Ju Hwang ),( Xiao Zhang ),( Young Ok Lee ) 한국폐기물자원순환학회(구 한국폐기물학회) 2006 한국폐기물자원순환학회 추계학술발표논문집 Vol.2006 No.-

Effect of feed/seed ratio on the performance of aerobic digester

Eung Ju Hwang,Xiao Zhang,Young Ok Lee 한국폐기물자원순환학회 2006 한국폐기물자원순환학회 학술대회 Vol.2006 No.1

단세포군항체에 반응하는 사람세포거대바이러스(HCMV) 단백질에 대한 특이한 유전자 클로닝 및 이의 중합효소 연쇄 반응을 이용한 HCMV 조기검색에의 이용

황응수(Eung-Soo Hwang),황도영(Do-Young Hwang),박정규(Chung-Gyu Park),박재원(Jae-Won Park),임동균(Dong-Gyun Lim),서주영(Ju-Young Seoh),정현순(Hyun-Soon Jong),국윤호(Yoon-Hoh Kook),차창룡(Chang-Yong Cha) 大韓微生物學會 1994 大韓微生物學會誌 Vol.29 No.6

슬러지 호기성 소화공정에서의 유기물 분해 및 질산화 특성

황응주(Eung Ju Hwang) 大韓環境工學會 2009 대한환경공학회지 Vol.31 No.10

슬러지의 감량과 최종처분 기술 개발을 위해 실험실 규모 호기성 소화공정을 279일간 운전하였다. 혐기성 소화 슬러지를 원료로 40℃에서 120분간 알칼리 전처리하여 호기성 소화조에 유입시켰다. 유입 슬러지 성상과 HRT의 변화에 따라 소화효율의 변화가 있었으며 적정 HRT는 6일인 것으로 나타났다. 이때 NH₃-N, SCOD, TKN, TCOD, SS, VSS의 평균 제거율(소화조 유입 슬러지 기준)은 각각 97.4%, 81.7%, 68.7%, 61.4%, 50.6%, 47.0% 이었다. SS는 전처리와 호기성 소화를 통해 원료 슬러지(23,920 mg/L)의 73.9% 감량화가 가능하였다. 처리 슬러지는 약 350 mg/L의 SCOD를 포함하고 있어 액비로 활용하기에 무리가 없을 것으로 판단되었다. HRT를 5일 이상으로 유지할 경우 질산화 반응이 활성화되었으며 최대 658 mg/L의 유출 슬러지 질산성 질소 농도를 얻을 수 있었다. 암모니아성 질소 농도는 20 mg/L 내외로 크게 감소하였다. Continuous operation of aerobic sludge digestion reactor was attempted for 279 days. Anaerobic digester sludge, the target material of the experiment, was pretreated by sodium hydroxide at 40℃ for 120 minutes, and the pretreated sludge was fed to 5 L CSTR (continuous stirred tank reactor). Reactor performance was affected by properties of input sludge and HRT (hydraulic retention time). 6 days of HRT showed best and stable performance, and under this condition, removal rates of NH₃-N, SCOD, TKN, TCOD, SS, and VSS were 97.4%, 81.7%, 68.7%, 61.4%, 50.6%, and 47.0%, respectively. 73.9% of SS in anaerobic digester sludge was reduced by pretreatment and aerobic digestion. Effluent sludge had low soluble COD of 350 mg/L. This implied the sludge was stabilized and suitable for use as liquid fertilizer. Nitrification took place when HRT was higher than 4 days. NO₃-N concentration was as high as 658 mg/L while NH₃-N was as low as 20 mg/L.

제주 특별 심포지엄 : 제주도의 순환형 폐기물 관리 시스템 구축의 필요성 ; 그린시티 싱가포르의 폐기물관리 동향

황응주 ( Eung Ju Hwang ),( Jing Yuan Wang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2003 한국폐기물자원순환학회 심포지움 Vol.2003 No.2

생물공정 처리수의 PAC (Poly Aluminum Chloride) 응집에 의한 고효율 인 제거 특성

황응주(Eung Ju Hwang),천효창(Hyo Chang Cheon) 大韓環境工學會 2009 대한환경공학회지 Vol.31 No.8

2011년부터 시행될 2단계 수질 오염 총량제에 대비하여 고효율 인 제거 공정 개발이 필요하며 본 연구에서는 생물학적 처리와 화학적 응집처리를 조합한 공정이 대안으로 검토되었다. 2세대 응집제로서 최근 많이 사용되고 있는 PAC(poly aluminum chloride)를 이용하고 실제 하수종말처리장 A₂O 공정의 호기조 유출수를 시료로 하여 인 응집 특성 및 적정 조건, 효율 향상 방안 등에 대해 실험연구를 수행하였다. 먼저 적정 PAC 투입 농도는 부피기준으로 30 ppm, mol비로는 2.81 mol Al/mol P인 것으로 나타났다. 단순침전에서 17.2%에 불과하던 용존성 인의 제거율이 PAC 10 ppm 투입으로 30.3%까지 증가 하였으며, 20 ppm에서 30 ppm으로 PAC 투입량을 증가시킬 때 49.3%에서 88.4%로 제거율을 크게 향상시킬 수 있었다. 이때 총 인의 제거율은 92.4%, 유출수 총 인 농도는 0.3 mg/L로 총량제에 부합하는 방류수 수질을 달성할 수 있었다. 적정한 응집시간은 4분, 침전시간은 20분, 초기 pH는 7로 나타났고 원시료 (pH 7.0)는 별도의 pH 조절 없이 응집 가능한 것으로 판단되었다. pH 7 조건에서 용존성 인의 제거가 크게 향상되었으며, 추가적인 확인 연구가 필요하나, 이는 인의 경우 Al(OH)3에 의한 sweep floc formation이 주요 제거 기작임을 의미하였다. 2차침전조 유입부에 PAC를 투입하여 2차침전조를 응집침전조로 활용하는 방안과 별도의 응집침전조를 2차침전조 후단에 설치하여 PAC를 투입하는 방안을 비교한 결과 PAC 투입량 대비 인 제거효율 증진 관점에서 후자가 바람직한 것으로 조사되었다. 이때 처리수의 인 농도는 0.18 mg/L, 제거율은 95.4%로 향상시킬 수 있었다. 끝으로 응집 처리수를 반송할 경우 인 제거 효율을 높일 수 있었으며 적정 반송율은 0.3인 것으로 분석되었다. High-rate phosphorous removal by PAC (poly aluminum chloride) coagulation of A₂O effluent was investigate to meet the stringent requirement of wastewater discharge from municipal wastewater treatment plant. A series of jar tests were conducted to find optimum coagulation condition and to enhance removal efficiency. The optimum volumetric concentration of PAC was 30 ppm (2.81mol Al/mol P by mol ratio). Only 17.2% of soluble P was removed for 30 minutes` settling without PAC addition, while this increased to 30.3% by dosing 10ppm PAC. It even increased conspicuously from 49.3% to 88.4% by increasing PAC dose from 20 ppm to 30 ppm. 92.4% of total P was removed by 30 ppm PAC, and the effluent concentration (0.3 mg/L) was acceptable for discharge. The optimum value of coagulation time, settling time, and pH were 4minutes, 20 minutes, and 7.0, respectively. It was not necessary to control pH of raw sample whose pH was 7.0. Soluble P removal was remarkably enhanced at pH 7.0. This implied that sweep floc formation by Al(OH)3 was the main mechanism of coagulation for soluble P removal. Influent and effluent of secondary clarifier were tested for coagulation, and the effluent was better for high-rate P removal. It resulted in 0.18 mg/L of P and 95.4% of P removal by coagulation. It was favorable to recycle the treated water to coagulation tank and the optimum recycle ratio was 0.3.

Enhancing aerobic digestion efficiency by pretreatment of sewage sludge

황응주(Eung Ju Hwang),장효(Xiao Zhang),이영옥(Young Ok Lee) 대한환경공학회 2006 대한환경공학회 학술발표논문집 Vol.2006 No.12

In order to destroy the refractory structure of sewage sludge and to increase its solubilisation, the processes of various pretreatments have been carried out using alkaline treatment, ultrasonic treatment and different combination of these two methods: alkaline followed by ultrasonic, ultrasonic followed by alkaline, and the combining method in which ultrasonic treatment is applied to waste sludge dosed with alkaline. For sewage sludge with described pretreatment, the SCOD/TCOD ratio varied from 23% to 42%. And based on SCOD concentration and SCOD/TCOD ratio, the combination pretreatment was more effective than a single treatment, especially the combination of simultaneous alkaline and ultrasonic treatment. Sewage sludge pretreated using simultaneous ultrasonic and alkaline treatment could achieve a maximum SCOD/TCOD ratio of 42% and SCOD of 6700mg/l in only 2 hours. In the aerobic batch test, the performance of digester B was better than that of digester A. TSS and TCOD removal rates of sludge in digester B got to 66% and 79% at 40days of retention time, respectively. And after aerobic digestion, the contents of some heavy metals (Mo, As, Cr, Pb, Ti and Hg) were too low to be available, which suggested that it was feasible to apply the stabilized sludge to agriculture.