The purpose of this study was to evaluate the effect of high-salinity wastewater on the microbial activity of Aerobic Granule Sludge (AGS). Laboratory-scale experiments were performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen removal efficiency, sludge precipitability, and microbial activity were evaluated under various salinity injection. The COD removal efficiency was found to decrease gradually to 3.0% salinity injection, and it tended to recover slightly from 4.0%. The specific nitrification rate was 0.043 0.139 mg NH4 +-N/mg MLVSS·day. The specific denitrification rate was 0.069 0.108 mg NO3 --N/mg MLVSS·day. The sludge volume index (SVI30) ultimately decreased to 46 mL/g. The specific oxygen uptake rate decreased from an initial value 120.3 to a final value 70.7 mg O2/g MLVSS·hr. Therefore, salinity injection affects the activity of AGS, causing degradation of the COD and nitrogen removal efficiency. It can be used as an indicator to objectively determine the effect of salinity on microbial activity.

석탄과 철광석은 산업발달의 시작부터 현재까지 지속적으로 사용되고 있다. 이에 따라 수반된 석탄 및 철광석 정제산업의 발달은 석탄철광폐수의 양적 증가를 초래하여 그 처리가 많은 관심 속에 활발하게 연구되고 있다. 석탄철광폐수는 페놀, 시안과 같은 독성 물질 뿐 만 아니라 혐기성미생물과 경쟁관계에 있는 황산염환원균활성증가를 초래하는 SO42-를 고농도로 함유한다. 이 석탄철광폐수의 처리법으로는 물리적, 화학적, 생물학적 처리가 다양하게 연구되어왔는데, 고농도의 폐수처리에 익히 알려진 혐기성미생물을 이용한 석탄철광폐수의 처리는 경제성과 재생에너지 측면에서 최근 큰 관심을 받고 있다. 하지만 폐수에 함유된 페놀, 시안, 등과 같은 독성물질이 생물학적 처리에 심각한 저해를 초래할 수 있어 문제로 지적되고 있으나 그 독성에 대한 현재까지의 연구는 미진한 형편이다. 이에 본 연구는 입상 혐기성미생물이 석탄철광폐수 소화 시 받게 되는 급성독성에 대하여 실험적 고찰을 진행하고 그 적응 방안을 연구하였다. 석탄철광폐수는 석탄철광정제의 완료시점에 실폐수 샘플을 채취하여 사용하였다. 폐수특성 분석결과 pH 7, 페놀 589±23 mg/L, 시안 49 mg/L, 암모니아성질소 39±9 mg/L, SO4-2는 735 mg/L이며 화학적 산소요구량은 3.9 g/L으로 나타났다. 석탄철광폐수에 대한 물벼룩 급성독성시험 결과 TU가 28로 매우 높게 측정되었다. 이 폐수에 UASB의 입상슬러지를 이용하여 혐기성소화를 수행하였다. 약 20일간 유기물 부하 0.6 g COD/L/day에서 초기 적응을 수행하였고, 혐기성소화조의 정상상태에서 COD 제거율은 98%, 메탄수율은 약 80 mL CH4/g COD로 나타났다. 이 혐기성소화조가 석탄철광폐수 유기물부하 0.76 g COD/L/day에 노출 되었을 경우 미생물의 활성을 모니터링한 결과, 폐수유입 즉시 메탄가스발생이 80% 이상 감소되는 강한 독성이 감지되었으며 COD 제거효율은 점차 감소하여 약 20일 후 10%로 낮아졌다. 유출수 내 페놀은 약 210 mg/L로 제거율 60%을 나타났지만 시안은 106 mg/L로 분해되지 않고 축적되어 유입 대비 2배가량 증가하였다. SO4-2 는 2000 mg/L로 급격하게 농도가 증가한 후 약 20일 후 1000 mg/L 이하로 감소하였다. 이로보아 석탄철광폐수 내 시안과 황화합물로 인하여 혐기성미생물 내의 메탄균의 저해가 이루어짐을 짐작할 수 있다. VFA 분석결과는 산발효균과 메탄발효균의 공생관계가 파괴되었음을 보여주었다. 더불어 높은 SO4-2 농도는 황산염환원균과의 경쟁이 유도될 수 있는 농도로 밝혀졌다. 이러한 석탄철광폐수의 급성독성은 고농도의 독성물질 제거를 위한 전처리 혹은 혐기성미생물의 적응기간이 필요함을 나타내었으며, 후자를 선택하여 약 30일 간 단계적인 미생물의 독성적응절차를 거친 결과 급성독성을 극복하고 유기물 및 페놀 분해가 점진적으로 가능함을 확인 하였다.

At the time of the end of 2013, public sewage treatment facilities running nationwide facility capacity to over the 500 m³/day is 569 places at 25,085,810 m³/day, less than 500 m³/day facility capacity to 3,205 places is 244,592 m³/day. This is increased by about 2% annually in sewer diffusion rate 78.8% from 2003 to 2013 increased to 92.1%, but due to factors such as an increase in population. Also, every year changes in the inflow rate and the inflow sewage of concentration of sewage treatment facilities, has increased continuously. The concentration of organic matter in the sewage thus generated, which is removed by sewage treatment process, the most important process in the second process is a biological process. Most biological processes, maintaining DO, pH, and the environment of operation by a temperature sensor. But if you have these sensors to the original, there is a disadvantage that it is impossible to monitor the state of the microorganisms directly. And, therefore, in this study, we tried to study the possibility by direct measurement method the state of the microorganisms of activated sludge was used intermittently investigation and deviation capture of NADH of the light source of the biological reaction tank. In this study, measured is installed a detector capable deviation capture detection by a light source is irradiated to the fluorescence due to the reaction of NADH in microorganisms in light source unit and 460 nm which can be intermittently irradiated with UV at 340 nm, and devices, profile is made to be composed of a passage for receiving the fluorescence emitted microorganisms by irradiation with UV light microorganisms size diameter 200 mm, length 740 mm. Biological reactor of interest, and the activated sludge biological reaction tank of Gyeonggi A City sewage treatment plant to the subject, measurement points, was carried out in the total of four locations. The sensor was calibrated in the same conditions as zero state laboratory, this time when the NAD based on the water 0.2 m point current (A) is 50 mA, 100 mA, 200 mA, respectively 26, 48, 84.5 has been measured in the (intensity value). This is according to the increase in current value. Intensity also proportionally increased, is determined as indicating a direct electrical reception may show the ease of measurement. Also, salvaged and re-invasion enemy repeatedly re-dipping after, shows the Intensity value of 84.1 at 200 mA, it was found that the reproducibility is good. The results were tested using an actual immersion light measuring device using the intermittent investigation and variance capture method from bioreactor wastewater treatment plants in operation, changes in the value of the change in star Intensity of current, as the load is high, higher and the current value increases, the proportional is increased it is determined that the reproducibility is good, and those entering least a light source and the detection consumable parts rain due to the previous year and maintain than investigation and detection methods continuous light source.

Waste activated sludge (WAS) and food waste (FW) are available year round at low cost and have the potential to promote synergism in anaerobic digestion (AD). The goal of this study was to clarify the synergism in co-digestion of WAS and FW. A slight amount of FW at various ratios was added to WAS as an auxiliary substrate, and anaerobic batch tests were performed under mesophilic conditions. By adding FW, total CH₄ produced was increased, where most of them were come from WAS, clearly suggesting synergism. Also, lag period was shortened and CH₄ production rate was increased by FW addition. It was hypothesized that enhanced performance was owing to the facilitated hydrolysis of WAS by FW addition, which was revealed by the increased activities of hydrolytic α-amylase and protease.

The objectives of this study have been carried out to investigate the solubilization of municipal sewage sludge by single and dual frequency ultrasonic pretreatment, and the methane production characteristics of pretreated sewage sludge by specific methanogenic activity test for sewage sludge reduction. The waste activated sludge was collected from thickened tank of Suyoung sewage treatment plant in Busan city, and its concentration was adjusted to 1.0% total solids. Ultrasonic frequency was varied 15, 20, 15+20 kHz, and acoustic density was used a maximum 176W/L. The dual frequency ultrasonic pretreatment was found to be more effective than single frequency ultrasonic in the solubilization rate and methane production. The SCODCr/TCODCr rate were 15.2%, 13.9%, 17.0% with single frequency of 15 kHz, 20 kHz, dual frequency of 15+20 kHz, respectively. The application of dual frequency ultrasound for sewage sludge pretreatment can be interest for sewage treatment plants having problems in sludge treatment and disposal.