하수처리장 유출수의 수질 예측은 수질 사고의 사전 대응 및 처리장의 안정적인 운영을 위해 필수적인 요소이다. 최근 머신러닝을 활용한 예측 모델링에서 예측 성능 향상과 과적합 방지를 위해 다양한 교차 검증법과 하이퍼파라미터 최적화 기법이 활용되고 있으나, 하수처리장 데이터는 시간적 의존성과 급격한 변동성이 내재되어 있어 과적합에 취약하고 안정적인 모델 구축에 어려움이 따른다. 본 연구에서는 이러한 데이터 특성을 효과적으로 반영할 수 있는 최적의 모델링 파이프라인을 구축하고자 하였으며, XGBoost 모델을 기반으로 유출수 내 총질소 농도를 예측하였다. 예측 성능 평가 지표로는 평균 제곱근 오차(Root Mean Square Error, RMSE), 결정계수(coefficient of determination, R2), RMSE 오차 개선율(the rate of improvement on RMSE, RIRRMSE) 그리고 계산 시간을 사용하였다. 기본적인 Hold-out 방식의 성능을 기준으로 K-fold, 시계열 교차 검증(Time Series Cross Validation, TSCV), 블록 시계열 교차 검증(Blocked Time Series Cross Validation, BTSCV) 기법의 예측 성능을 분석한 결과, BTSCV는 인접한 데이터만을 고려하는 방식으로 시간적 의존성과 급변 특성을 효과적으로 반영하여 가장 높은 RIR(36.37%)을 기록하였다. 또한, 하이퍼파라미터 최적화(그리드 서치와 베이지안 최적화) 기법과의 다양한 교차 검증법의 조합을 통해 모델 성능과 과적합 방지 효과를 분석한 결과, BTSCV와 베이지안 최적화의 결합은 짧은 계산 시간(364.64초)과 함께 가장 높은 RIR(64.93%)을 보였으며, 훈련 및 평가 데이터 간 성능 차이도 최소화되어 일반화된 예측 모델로서의 효과성이 입증되었다. 따라서 본 연구는 하수처리장 시계열 데이터의 특성에 적합한 BTSCV와 베이지안 최적화 기법을 결합한 모델링 파이프라인 전략을 제안하며, 향후 실시간 수질 모니터링 및 하수처리장 운영 효율성 제고에 기여할 수 있을 것으로 기대된다.

The aim of this study was to determine the quality characteristics of bread with 2%, 4%, 6%, and 8% cuttlefish ink added. The pH of the dough decreased as the addition percentage increased, and the addition of 8% was the lowest. The pH of the bread and the fermentation expansion power of the dough decreased as the addition percentage increased. Moisture and ash content were positively correlated with the addition percentage, and the crude protein and crude ash content were negatively correlated. As the addition percentage increased, the color of the bread became darker, and the bread volume decreased. The inside and outside color of the bread also decreased as the addition percentage increased. The volume and specific volume of bread decreased as the addition percentage increased. The amino acid analysis indicated glutamic acid was the largest, free amino acid analysis pointed out aspartic acid the highest. The springiness, cohesiveness, gumminess, brittleness, and hardness of the bread were positively correlated with the addition percentage. Overall, it seems possible to develop bakery items using cuttlefish ink as a functional ingredient.

고치벌과의 송충살이고치벌아과에 속하는 Aleiodes conina Quicke and Butcher, 2012를 국내 최초로 보고한다. 본 종에 대한 진단, 분포 및 삽화를 제공한다.

Conventional wastewater treatment plants (WWTPs) do not fully remove micropollutants. Enhanced treatment of sewage effluents is being considered or implemented in some countries to minimize the discharge of problematic micropollutants from WWTPs. Representative enhanced sewage treatment technologies for micropollutant removal were reviewed, including their current status of research and development. Advanced oxidation processes (AOPs) such as ozonation and UV/H2O2 and adsorption processes using powdered (PAC) and granular activated carbon (GAC) were mainly discussed with focusing on process principles for the micropollutant removal, effect of process operation and water matrix factors, and technical and economic feasibility. Pilot- and full-scale studies have shown that ozonation, PAC, and GAC can achieve significant elimination of various micropollutants at economically feasible costs(0.16-0.29 €/m3). Considering the current status of domestic WWTPs, ozonation and PAC were found to be the most feasible options for the enhanced sewage effluent treatment. Although ozonation and PAC are all mature technologies, a range of technical aspects should be considered for their successful application, such as energy consumption, CO2 emission, byproduct or waste generation, and ease of system construction/operation/maintenance. More feasibility studies considering domestic wastewater characteristics and WWTP conditions are required to apply ozonation or PAC/GAC adsorption process to enhance sewage effluent treatment in Korea.

The purpose of this study was to investigate the quality characteristics of bread made with 1%, 3%, 5%, and 7% of Bigeumdo Seomcho powder (Spinacia oleracea L.). The pH of dough and bread decreased as the amount of addition increased; 7% indicated the lowest. The moisture level correlated negatively with the powder addition, but the difference was not statistically meaningful (p<0.05). As the amount of addition was increased, the intensity of color increased but the volume decreased. The brightness and redness of the bread decreased as the amount of addition increased. The volume, specific volume, and baking loss rate correlated negatively with the powder addition. Regarding springiness, cohesiveness, and gumminess, the experiment group was higher than the control group and they lowered as the addition amount increased. The brittleness showed positive correlation with the addition amount. Out of the amino acids of bread, glutamic acid showed the highest value as the amount of addition was increased. Overall, it is possible to produce bakery bread using functional ingredients.

Due to the large-scale production and use of synthetic chemicals in industralized countries, various chemicals are found in the aquatic environment, which are often termed as micropollutants. Effluents of municipal wastewater treatment plants (WWTPs) have been identified as one of the major sources of these micropollutants. In this article, the current status of occurrence and removal of micropollutants in WWTPs and their management policies and options in domestic and foregin countries were critically reviewed. A large number of pharmaceuticals, personal care products, and industrial chemicals are found in WWTPs’ influent, and are only partially removed by current biological wastewater treatment processes. As a result, some micropollutants are present in WWTPs’ effluents, which can negatively affect receiving water quality or drinking water source. To better understand and assess the potential risk of micropollutants, a systematic monitoring framework including advanced analytical tools such as high resolution mass spectrometry and bioanalytical methods is needed. Some Western European countries are taking proactive approach to controlling the micropollutants by upgrading WWTP with enahnced effluent treatment processes. While this enahnced WWTP effluent treatment appears to be a viable option for controlling micropollutant, its implementation requires careful consideration of the technical, economical, political, and cultural issues of all stakeholders.

The objective of this study was to investigate quality characteristics of sourdough bread with fermented Zante currants juice. The sweetness of fermented Zante currants starter increased while its pH value decreased as time passed. The pH values were negatively correlated to the added amount of starter with the lowest pH being recorded at 70% addition. Similarly, bread’s moisture was inversely correlated to the added amount of starter with the highest moisture content being recorded at 10% addition. For bread’s height, excluding the control, 70% addition turned out to be the highest, and the height decreased as the added amount increased. The oven-spring was similar between the control and 70% addition. For the volume, except the control, 70% addition turned out to be the largest. The larger the specific volume was, the higher the volume of bread got. The brightness, redness, and yellowness were decreased as the added amount was increased. For the texture, the control had the highest elasticity and cohesiveness, and they increased as the added amount of starter increased. The hardness had a negative correlation with the added amount, and 70% addition yielded the same result as the control. The adhesiveness appeared only in 10% addition.

본 연구는 섬초 분말 1%, 3%, 5%, 7% 첨가비율에 따른 식빵의 품질 특성을 연구하였다. 반죽의 pH는 첨가량이 증가할수록 낮아졌으며, 7% 첨가에서 낮게 나타났다. 반죽의 발효 팽창력은 1차 발효와 2차 발효에서 첨가량이 증가할수록 낮아졌으며, 첨가량에 따라 반죽의 발효시간이 지날수록 감소하는 것으로 나타났다. 식빵의 수분함량은 첨가량이 증가할수록 낮아졌으며, 식빵의 부피는 1% 첨가> 3% 첨가> 5% 첨가> 7% 첨가 순으로 나타났다. 비용적은 첨가량이 증가할수록 제품의 부피는 낮게 나타났으며, 비용적이 낮을수록 부피는 감소하였다. 내부색도는 첨가량이 증가할수록 명도, 적색도는 감소하였으며, 황색도는 증가하는 걸로 나타났다. 총 구성아미노산 함량은 첨가량이 증가할수록 높게 나타났으며, glutamic acid가 높게 나타났다. 총 유리아미노산 함량은 첨가량이 증가할수록 높게 나타났으며, 5% 첨가와 7% 첨가에서 cystine이 가장 높게 나타났다. 식빵의 조직감은 대조구에 비하여 탄력성과 응집성이 낮게 나타났으며, 씹힘성, 부서짐성, 경도는 대조구에 비하여 높게 나타났다. 부착성은 7% 첨가에서 나타났다.

Large amounts of oily wastewater discharged from various industrial operations (petroleum refining, machinery industries and chemical industries) cause serious pollution in the aquatic environment. Although dissolved air flotation (DAF) separating oil pollutants using microbubbles represents current practice, bubble size cannot be selectively controlled, and lots of power is required to generate microbubbles. Therefore, to investigate performance of the DAF process, this study examined the distribution of different sizes of microbubbles resulting from changes in physical shear force via modifying shapes of a slit-nozzle without an additional power supply. Three types of slit-nozzles (different angle, shape and length of the slit-nozzle) were used to analyze the distribution of bubble size. At a slit angle of 60°, shear force was 4.29 times higher than a conventional slit, and particle size distribution (PSD) in the range between 2 and 20 μm more than doubled. Treatment efficiency of synthetic oily wastewater through the coagulation-DAF process achieved 90% removal of COD by injecting FeCl3 and PACl of 250 mg/L and 100 mg/L, respectively, and the same performance resulted using FeCl3 of 200 mg/L and PACl of 80 mg/L employing a slit-nozzle angle of 60°. This study shows that a coagulation-DAF process using a modified slit-nozzle can improve the pre-treatment of oily wastewater.

장어의 과산화 억제를 위해 월계수잎, 총백, 헛개열매, 녹차를 시판 소주(30°)를 용매로 하여 추출한 것을 시료로 사용하였다. 장어 250 g에 5 g의 주정 추출물을 장어 전체에 고루 바른 후 35℃ 15시간 열풍건조한 후 실험에 사용하였다. 주정 추출물의 항산화 활성은 DPPH 소거 활성 실험, 반건조 장어의 산가, 과산화물가, 리놀레산 및 장어유 과산화 지연반응을 통해 확인하였다. DPPH 소거 활성이 가장 높았던 것은 녹차 추출물이었으며, 다음으로 활성이 높았던 것은 월계수잎, 헛개열매 추출물이었다(p<0.05). 21일 동안 냉장보관한 장어의 산가 측정에서 헛개열매 추출물로 처리한 경우, 산가가 가장 낮았으며, 다음으로 녹차 추출물로 처리한 경우의 산가가 낮았다. 유리지방산 생성 억제 효과와 유사하게 헛개열매, 녹차 추출물이 장어의 열풍건조 동안 초기 과산화물 생성을 억제하고, 냉장보관 21일 동안 반건조 장어의 과산화물의 생성을 억제하는 것으로 나타났다. 4종의 주정 추출물들은 반응 20일 동안 리놀레산의 과산화를 억제하는 효과가 있는 것으로 나타났다. 반응 20일 동안 장어유의 과산화를 지연시킨 효과가 높았던 것은 헛개열매와 녹차 추출물이었으며, 다른 추출물에 비해 상대적으로 장기간 안정적으로 장어유의 과산화를 억제하는 것으로 판단되었다. 본 연구의 결과를 종합해 볼 때, 장어의 건조 전 전처리에 헛개열매와 녹차 주정(30° 소주)추출물을 적용하는 것은 장어의 건조 및 반건조 장어의 냉장보관 중의 과산화를 지연시키는데 효과가 있는 것으로 판단되었다.

The quality characteristics of bread with black rice flour were investigated to find the most preferred ratio of black rice flour. Its moisture, ash content, crude protein, crude fat, amino acids, and texture were analyzed. A sensory evaluation was also performed. The moisture and crude fat of bread with black rice flour were decreased in proportion to the added amount of black rice flour, but the crude protein and ash content were increased. The volume of bread decreased as the added amount of black rice flour increased. The pH value of bread increased in proportion to the added amount of black rice flour. The value of brightness and yellowness of the dough were the highest in the control. The added amount of black rice flour was negatively correlated with the brightness and the yellowness of the dough, but was positively correlated with the redness. Total free amino acids were found, and the dough with 5% black rice flour contained the highest amount, followed by 3%, 2%, and 1%. When evaluating the storage days, the springiness and cohesiveness of bread with black rice flour they decreased with time, but the chewiness and brittleness increased. Regarding the taste, preference was given to the bread with 2% black rice flour, which had the lowest rejection rate and was not affected by time in any meaningful sense. The bread with 2% black rice flour won the highest scores in the overall preference measurement.

The quality properties of bread with Lentinula edodes powder were investigated to find the most adequate ratio of the Lentinula edodes powder. The protein and crude fat were increased in proportion to the added quantity of Lentinula edodes powder. The amount of ash was found the most in the bread with 1% Lentinula edodes powder. It was confirmed that the volume of bread with Lentinula edodes powder decreased as the amount of the Lentinula edodes powder increased. The brightness was the highest in the control and was inversely proportional to the added amount of Lentinula edodes powder. The yellowness and redness of the dough were proportional to the added amount of Lentinula edodes powder. Total amino acids and free amino acids were found. The dough with 3% Lentinula edodes powder contained the highest amounts of both, followed by 2%, and 1%. When evaluating the length of storage, the bread’s springiness and cohesiveness decreased. Regarding the taste, preference was given to the bread with 2% Lentinula edodes powder, which had the lowest value of bad odors and odd texture in the sensory test.