본 연구는 배수지에서 저수조를 포함한 대수용가의 수도꼭지에 이르는 구간에서 탁도와 잔류염소 농도의 시간적⋅공간적 변화를 분석하였다. 모니터링은 배수지, 중블록 유입 지점, 대수용가 유입 지점, 저수조 유출 지점, 수도꼭지 등 5개 지점에서 수행되었으며, 유량, 잔류염소, 탁도, pH, 전기전도도, 온도를 측정하였다. 연구 결과, 수돗물 이동 경로를 따라 잔류염소 농도는 점차 감소하고 탁도는 증가하는 경향을 보였다. 특히, 비업무시간대에는 수돗물 정체로 인한 수질 저하가 확인되었다. 또한, 저수조의 건전성을 평가하기 위해 반응계수를 산출한 결과, 시간에 따른 저수조 내부 건전성 저하와 수질 악화 가능성이 확인되었다. 본 연구는 수돗물의 이동 거리, 사용 시간대, 유량 변화 및 공급 방식에 따라 수질이 달라질 수 있음을 보여주며, 저수조에 의존하는 지역에서는 안전한 수돗물 공급을 위해 지속적인 모니터링과 관리가 필요함을 시사한다.

본 연구에서는 하수처리 과정에서 분리된 항생제 내성균(Antibiotic Resistant Bacteria, ARB)을 제거하기 위해 박테리오파지와 차아염소산 나트륨(NaClO)을 결합한 병용 처리 기술을 응용하였다. ARB를 감염시키는 용균성 박테리오파지는 폐수 샘플에서 성공적으로 분리되었다. 이러한 박테리오파지와 NaClO를 순차적으로 적용한 결과, 5시간 이내에 ARB를 상당히 감소시킬 수 있었다. 환경 안정성 평가에서는 분리된 박테리오파지가 온도, pH, 독성 물질에 대한 노출 등 다양한 조건에서도 효과를 유지하는 것으로 나타냈다. 또한, 실험실 규모의 반응기 실험을 통해 단독 염소 소독과 비교했을 때, 결합 처리가 ARB를 효과적으로 억제하는 것을 확인할 수 있었다. 박테리오파지와 차아염소산 병용 처리는 유기물, 질소(N), 인(P)과 같은 영양소 제거 효율에 영향을 미치지 않았다. 이러한 결과는 박테리오파지를 기반으로 한 생물학적 제어법과 기존의 소독 방식을 결합하여 폐수 처리 공정(Wastewater treatment plant, WWTP)에서 효과적인 항생제 내성 박테리아 제어 방안을 제시할 가능성을 시사한다.

In treatment processes of drinking water, the use of disinfectants is essential for eliminating microorganisms and pathogenic viruses. Chlorine dioxide (ClO2) is one of the most promising disinfectants. To ensure its effective application in drinking water treatment, it is crucial to investigate the stability and reactivity of ClO2 in drinking water treatment environments. Therefore, we examined the effects of various environmental factors such as temperature, light type, fluorescence intensity, and water quality on its stability. We also examined its reactivity with activated carbon and other inorganic compounds such as coagulants and hypochlorous acid. Findings revealed that ClO2 stability was influenced by several environmental factors. Typically, ClO2 is highly volatile. However, the rate of its volatility is independent of its concentration. As temperature and fluorescent light intensity increased, the concentration of ClO2 showed a rapid decline. Additionally, the presence of activated carbon significantly reduced ClO2 levels. In contrast, the reactivity of ClO2 with coagulants and hypochlorous acid was negligible. These findings provide essential insights for optimizing the use of ClO2 in drinking water treatment facilities.

This study aimed to investigate the effect of Liriope platyphylla and organic acids on enteric methane mitigation in goats using an open-circuit simplified respiration chamber system. Methane recovery was evaluated by injecting 3% standard methane gas for 30 min at 3 L/min. The percentage of methane recovery from the four chambers was 99±5.4%. Following the recovery test, an animal experiment was conducted using eight castrated Boer goats (body weight 46.6±7.77 kg) using a 2×2 crossover design. Experimental diets were as follows: 1) Control (CON), commercial concentrate and tall fescue, and 2) Treatment (MIX), concentrate supplemented with L. platyphylla and organic acids and tall fescue. Goats were offered feed at 2% of body weight (dry matter basis) in equal portions twice daily at 8:00 and 15:30. The goats were adapted to the feed and methane chamber for 10 and 3 days, respectively. Methane emission was measured one day per goat using tunable diode laser absorption spectroscopy, and temperature and airflow measurements were used to estimate methane emissions. Dry matter intake (DMI), body weight, and methane emission were measured during each period. Methane production with CON and MIX was 24.48 and 22.68 g/d, respectively, and 26.81 and 24.83 g/kg DMI, respectively. Although the differences were not significant, the use of supplements resulted in a numerical reduction in methane in MIX compared with CON. Collaboration with experts in other areas, including various engineering departments, is imperative to measure methane emissions using a chamber system accurately.

This study was conducted to evaluate in vitro antioxidant activity of goat meat hot water extracts and the changes in apoptosis-related protein expression levels in the cancer cells treated with these extracts. Goat meat hot water extracts were prepared using different cuts of goat meat, including foreleg, hindleg, loin, and rib. Among these extracts, the foreleg and hindleg extracts displayed higher (P<0.05) ABTS radical scavenging activity than the other two extracts. Protein expression levels of BAX, p53, and p21 were not different in the cells treated with the extracts from different cuts, regardless of the cell type. Only p53 expression in HT-29 cells was elevated (P<0.05) after loin extract treatment. These results suggest that antioxidant activity and apoptosis-related effects of goat meat hot water extract varied with cut of meat under in vitro conditions. Because all data was obtained from the in vitro experiment, the ability to generalize conclusions is limited. Additional in vivo studies are necessary.

This study aimed to investigate the effects of Centella asiatica powder on the quality characteristics and storage stability of goat meat Tteokgalbi. The goat meat Tteokgalbi samples were prepared with four different quantities (0, 0.5, 1, and 1.5%) of Centella asiatica powder. The moisture content of the samples containing Centella asiatica powder was significantly lower than that of the control (p<0.05). The protein content of the samples containing Centella asiatica powder was significantly higher than that of the control (p<0.05). As the proportion of Centella asiatica powder increased, the pH, L*, and a* values of the uncooked and cooked samples decreased (p<0.05). The water holding capacity and the cooking yield of the uncooked and cooked samples were higher in the samples containing Centella asiatica powder than in the control (p<0.05). Also, with the increasing amounts of the Centella asiatica powder, the thiobarbituric acid reactive substance (TBARS) levels decreased. The 1-1.5% Centella asiatica powder group showed lower levels of volatile basic nitrogen (VBN) than the other groups as per the assay (p<0.05). The results indicate that Centella asiatica powder could enhance the quality characteristics and storage stability of goat meat Tteokgabi.

본 연구는 집단급식소에서 제공되는 빈도수가 높은 비 가열 및 가열조리 엽경채류에 사용되는 차아염소산나트륨 수에 대하여 미생물적 안전성을 평가하고자 수행되었다. 비병원성 대장균과 장출혈성 대장균의 칵테일(E. coli O157:H7)을 엽경채류(초기 균수 7-8 log CFU/g)에 인위적 으로 오염시킨 후 차아염소산나트륨을 5분간 침지 후 흐 르는 물에 3번 씻어서 생균수를 측정하였다. 실험 결과 초 기 오염물질에 비해 살균효과가 1-2 log CFU/g 저감화하 여 대조군에 대해 유의적인 차이가 있었다(P<0.05). 잎채 소의 특성에 따라 약간의 차이가 있었는데 표면적이 클수 록, 덜 거칠고 잎이 부드러울수록 살균효과가 높았다. 200 mg/kg으로 처리하였을 때 100 mg/kg에 비해 0.1-0.3 log CFU/g만큼 효과가 더 감소하였으나 농도 증가에 따 른 유의적 차이는 없었다(P>0.05). 그러므로 학교급식위생 관리지침에서 제시한 기준 이상으로 차아염소산나트륨 농 도를 높이는 것은 불필요하다고 판단된다. 그러나 잎채소 는 일반적으로 미생물의 초기 오염도가 높기 때문에 차아 염소산나트륨 처리만으로는 안전한 수준의 저감을 달성하 기 어려워 생물학적 위험이 잔존한다. 따라서 여름철에 가 열하지 않은 잎채소의 대체 조리방법을 개발하는 것이 안 전성에 보다 효과적인 것으로 판단된다.

본 연구는 장미 ‘Bubble Gum’의 절화수명을 연장시키기 위하여 미산성 차아염소산수(Slightly acidic hypochlorous water, HOCl, pH 6.26)의 처리효과와 절화수명 연장제로써 의 가능성을 구명하고자 수행되었다. 침지처리는 30μL･L-1의 미산성 차아염소산수를 0분, 0.5분, 1분, 3분, 5분간 침지처 리 후 수돗물(Tap water, control)에 꽂아 두었다. 대조구의 절화수명은 8.7일인데 비해 5분 침치처리 시 10.8일로 대조 구보다 2.1일 수명을 연장시켰다. 상대생체중은 모든 처리구 에서 2일까지 증가하였고, 수분흡수율은 모든 처리구에서 6일 까지 증가하다가 감소하는 추세를 보였다. 화색 변화율인 ΔE 값은 3분(5.25), 5분(6.48), 30초(6.65), 1분(6.79) 침지처리 에서 대조구보다 낮았으며, 상대 화폭 증가율은 5분 침지 처 리구가 145%로 화폭의 증가율이 가장 컸고, 엽록소함량은 처 리 간 차이가 없었다. 결론적으로 절화장미 ‘Bubble Gum’의 절화수명은 미산성 차아염소산수의 5분 침지 처리가 효과적 으로 연장시켰다.

The effect of permanganate oxidation was investigated as water treatment strategy with a focus on comparing the reaction characteristics of NaOCl and sodium permanganate (NaMnO4) in algae (Monoraphidium sp., Micractinium inermum, Microcystis aeruginosa)-contained water. Flow cytometry explained that chlorine exposure easily damaged algae cells. Damaged algae cells release intracellular organic matter, which increases the concentration of organic matter in the water, which is higher than by NaMnO4. The oxidation reaction resulted in the release of toxin (microcystin-LR, MC-LR) in water, and the reaction of algal organic matter with NaOCl resulted in trihalomethanes (THMs) concentration increase. The oxidation results by NaMnO4 significantly improved the concentration reduction of THMs and MC-LR. Therefore, this study suggests that NaMnO4 is effective as a pre-oxidant for reducing algae damage and byproducts in water treatment process.

To improve the shelf-life of Centella asiatica, Centella asiatica was treated with gel packs containing slow-released chlorine dioxide (ClO2) gas at 3-5 ppm for 20 days at 4℃. The weight loss rate, as well as the changes in pH, color, and texture of the treated samples, were investigated. The weight of the control and ClO2 gas-treated samples was decreased during the storage period. The change in weight of the control was slightly faster than that of the samples treated with 3 and 4 ppm ClO2 gas. The pH of the control and the ClO2 gas treated samples were decreased during the storage period and there was no significant difference between the control and ClO2 gas treated samples. Concerning color (lightness, redness, and yellowness) changes of Centella asiatica during the storage period, there was no significant difference between the control and ClO2 gas treated samples. The change in shear force in the leaf and stem of Centella asiatica during the storage period was slightly lower in the 4 ppm ClO2 gas treated samples (in the leaf) compared to the control and 3 and 4 ppm ClO2 gas treated samples (in the stem) compared to the control and 5 ppm ClO2 gas treated sample.

본 연구에서는 병원균인 Bacillus cereus, Staphylococcus aureus, Salmonella Typhimurium 그리고 Escherichia coli O157:H7을 이산화염소수와 전해수에 0분, 2분, 4분, 6분, 8분 및 10분간 반응시켜 이산화염소수와 전해수의 살균 효과를 확인하고, 그람 양성균(B. cereus, S. aureus)과 그 람 음성균(S. Typhimurium, E. coli O157:H7)의 민감성 비 교를 실시하였다. B. cereus, S. aureus, S. Typhimurium 그 리고 E. coli O157:H7의 이산화염소수에서의 D값은 1.85±0.64, 2.06±0.85, 2.26±0.89 그리고 2.59±0.40분으로 나 타났고 전해수의 경우 각각 2.13±0.32, 1.64±0.64, 1.71±0.32 그리고 1.86±0.36분으로 나타났다. 각 용액에 처리한 10분 간 모든 균주에서 꾸준한 감소 추세를 나타내었으며 각 용액에서 각 균주의 D값은 서로 유의적인 차이는 보이지 않았다 (P>0.05). 이산화염소수와 전해수의 살균력을 비교 한 결과 D값은 유의적인 차이가 나타나지 않았으나, pH 와 유효염소농도 모두 이산화염소가 전해수보다 낮은 값 을 보였다. 살균·소독을 실시할 대상의 pH에 대한 민감성 과 같은 특성을 고려하여 최적의 살균제를 선택하고, 최 적의 농도를 결정하여 식품 산업에 적용하기 위한 자료로 활용될 것으로 기대된다.

The nutrient balances originated from livestock manure in Korea has not being include minor livestock species (e.g., horse, deer, and goat) since their manure excretion unit (MEU), nutrient excretion unit (NEU), and nutrient loading coefficient (NLC) are not known yet. In the present research work, the primary focus had laid therefore on securing domestic MEU for the specified minor livestock species which provides the basis for the computation of NEU and NLC. Moreover, the nutrient potential and economic value of composted manure from minor livestock was assessed on the basis of contents in the inorganic fertilizers such as Urea, (46% N) and Fused superphosphate (20% phosphorus pentoxide). The obtained MEU was found to be 10.52±5.48, 4.07±1.69, and 0.843±0.1 kg/head/day for horse, deer, and goat, respectively. In addition, the measured NLCs of horse, deer, and goat were [N, 0.7; P, 0.9], [N, 0.7; P, 0.6] (Both deer and goat were the same.), respectively. Consequently, the horse, deer, and goat manure have a potential of 3,840.1 ton N/year and 9,390.2 ton P/year as an inorganic fertilizer of urea and fused superphosphate. These findings may facilitate the development of more accurate nutrient budget taking into account both major and minor livestock and improve the manure management measures for land application.

In this study, a model to optimize residual chlorine concentrations in a water supply system was developed using a multi-objective genetic algorithm. Moreover, to quantify the effects of optimized residual chlorine concentration management and to consider customer service requirements, this study developed indices to quantify the spatial and temporal distributions of residual chlorine concentration. Based on the results, the most economical operational method to manage booster chlorination was derived, which would supply water that satisfies the service level required by consumers, as well as the cost-effectiveness and operation requirements relevant to the service providers. A simulation model was then created based on an actual water supply system (i.e., the Multi-regional Water Supply W in Korea). Simulated optimizations were successful, evidencing that it is possible to meet the residual chlorine concentration demanded by consumers at a low cost.

알칼리 금속 이온과 염소 이온이 포함된 용액으로부터 이온교환수지를 이용한 이온 제거에 대한 연구를 진행하였다. 양이온인 금속이온(Na+와 K+)의 제거에는 양이온교환수지를, 음이온인 염소 이온(Cl-)의 제거에는 음이온교환수지를 사용하였다. 용액 A (Na+를 36,633 ppm, Cl-를 57,921 ppm 함유)의 경우, Na+ 이온과 Cl- 이온은 20분 이내에 99% 이상 제거되었다. 용액 B (K+를 1,638 ppm 함유)의 경우, K+ 이온은 3분 이내에 99% 이상 제거되었다.

This study was conducted to determine the maintenance energy requirements of growing goats in order to establish an appropriate energy benefit system, to reduce feed costs and improve livestock productivity of goat farmers, and to present basic data for detailed specifications afterwards. This experiment was conducted as a group specification test for a total of 3 months, with 32 goats of three months age and conducted by four treatments with different energy levels (T1: NRC+0%, T2: NRC+10%, T3: NRC+20%, and T4: NRC+ 30%). The average daily gain was the highest in the treated with NRC + 10% of the energy level of the experimental diet, and the feed conversion ratio was in the range of 6.3 g to 7.3 g in the group feeding experiment. Although there was no significant difference in digestibility between treatments, the digestibility of dry matter, crude protein, and crude fat was higher in T2 treated with NRC + 10% than the other treatments. Through the regression equation of the values of MEI and ADG obtained through the experiment (Y=0.5439X+ 111.51, R2=0.712), the maintenance energy requirement of the goat in the growing period was estimated to be 111.51 kcal/kgBW0.75.

Chlorination and UV illumination are being widely applied to inactivate a number of pathogenic microbials in the environment. Here, we evaluated the inactivation efficiency of individual and combined treatments of chlorination and UV under various aqueous conditions. UV dosage was required higher in waste water than in phosphate buffer to achieve the similar disinfecting efficiency. Free chlorine generated by electrolysis of waste water was abundant enough to inactivate microbials. Based on these, hybrid system composed of sequential treatment of electrolysis-mediated chlorination and UV treatment was developed under waste water conditions. Compared to individual treatments, hybrid system inactivated bacteria (i.e., E. coli and S. typhimurium) and viruses (i.e., MS-2 bacteriophage, rotavirus, and norovirus) more efficiently. The hybrid system also mitigated the photo re-pair of UV-driven DNA damages of target bacteria. The combined results suggested the hybrid system would achieve high inactivation efficiency and safety on various pathogenic microbials in wastewater.