During the dismantling of nuclear facilities, a large quantity of radioactive concrete is generated and chelating agents are required for the decontamination process. However, disposing of environmentally persistent chelated wastes without eliminating the chelating agents might increase the rate of radionuclide migration. This paper reports a rapid and straightforward ion chromatography method for the quantification of citric acid (CA), a commonly used chelating agent. The findings demonstrate acceptable recovery yields, linearities, and reproducibilities of the simulated samples, confirming the validity of the proposed method. The selectivity of the proposed method was confirmed by effectively separating CA from gluconic acid, a common constituent in concretes. The limits of detection and quantification of the method were 0.679 and 2.059 mg·L−1, respectively, while the recovery yield, indicative of the consistency between theoretical and experimental concentrations, was 85%. The method was also employed for the quantification of CA in a real concrete sample. These results highlight the potential of this approach for CA detection in radioactive concrete waste, as well as in other types of nuclear wastes.

Complexing agents used at various nuclear facilities exist in low- and intermediate level radioactive wastes deposited in the repository site. In addition these will be generated through the degradation of the wastes such as cellulose materials. The presence of chelating agents may possibly affect the safety of the wastes repository by promoting the migration of radionuclides into geosphere. Thus, under Nuclear Safety and Security Commission’s Notice No. 2021-16, the contents of chelating agents in radioactive wastes are required to be determined for the secured disposal. UV-Vis method based on an enzymatic reaction was proved to be in adequate to analyze citric acid in radioactive wastes with complex matrix, especially for concrete. A rapid automated method using ion chromatography (IC) for analysis of citric aicd in concrete samples is developed. This automated method enables a sample solution to measure without pretreatment and a target substance to separate from other concrete admixtures. Also, the developed method here, for radioactive concrete wastes was successfully applied to real samples with lowering a limit of quantification value.

Pollution of agricultural soil by alkaline salts, such as Na2CO3, is a critical and long-lasting problem in cultivable land. The aim of the study was to examine the putative role of citric acid (CA) in alleviating Na2CO3-stress in alfalfa. In this study, Na2CO3 significantly induced leaf chlorosis, inhibited plant growth and photosynthesis related parameters, increased hydrogen peroxide (H2O2) and reduced major antioxidant enzymes (SOD ,CAD, APX) in alfalfa. However, the presence of CA these negative effects of Na2CO3-stress largely recovered. Interestingly, expression of antioxidant and ion transporter genes (Fe-SOD, CAT, APX, DHAR and NHX1) involved in Reactive oxygen species (ROS) homeostasis and oxidative stress tolerance in alfalfa. These findings suggest that CA-mediated Na2CO3 stress alleviation is an ecofriendly approach that would be useful to local farmer for alfalfa and other forage crop cultivation in alkaline soils.

와사비 페이스트의 저장성 향상을 위하여 구연산을 농도별로 첨가하고 저장기간에 따른 이화학적 및 미생물학적 특성, 가스발생량 및 ally isothiocyanate 함량 변화를 측정하였다. 와사비 페이스트의 pH는 구연산 첨가량에 따 라 감소하였으며, CA 0.4%처리구에서 4.34±0.01로 가장 낮게 나타났다. 저장기간 동안 와사비 페이스트의 pH는 4.01-5.19사이로 나타났다. 총산의 함량은 저장 7일까지 유의적인 차이가 나타나지 않았으며 저장 14일 이후 감소하였다. 와사비 페이스트의 가용성 고형분 함량은 구연산 첨가량에 따라 증가하였으며, 저장기간에 따른 유의적 차이를 보이지 않고 저장 28일 후 25.60-29.50 oBrix로 나타났다. 저장기간에 따른 와사비 페이스트의 L값은 감소하였으며, a값과 b값은 증가하는 경향을 나타내다. 일반세균 수는 저장기간이 경과함에 따라 감소하는 경향을 나타냈으며, 저장 초기에 2.56±0.09~4.87±0.17 log CFU/g에서 저 장 21일 후 CA 0.30%와 CA 0.40% 처리구에서 일반세균이 검출되지 않았다. 효모의 경우 일반세균의 경우와 마찬가지로 저장기간에 따라 감소하는 경향을 나타내었으며, CA 0.30%와 CA 0.40%의 경우 저장 초기부터 28일까지 검출되지 않았다. 이로써 와사비 페이스트에 구연산 0.30% 이상 첨가하면 미생물의 생장이 억제되는 것을 확인할 수 있었다. 가스발생량은 21일 저장 후 가스 발생량의 증가폭이 가장 크게 나타났으며, 저장 28일 후 19.55-19.80 mL/ tube로 나타났으며, 구연산 처리농도에 따른 유의성은 나타나지 않았다. Allyl isothiocyanate 함량은 구연산 처리 농도 와 저장기간에 따라 감소하였으며, CA 0.40% 처리구에서 저장 초기와 28일 후 각각 45.62±12.78 mg/100 g와 29.72±0.58 mg/100 g로 가장 낮게 측정되었다. 연구 결과 와사비 페이스트에 구연산 0.30%를 첨가하여 제조 시 저장성 향상 효과를 얻을 수 있으며, 이를 통하여 와사비 페이스트의 상온유통 시 유통기한 연장 효과를 얻을 수 있을 것으로 생각된다.

The purpose of this study is to develop a method to cultivate lactic acid bacteria (LAB) as a by-product in the fermentation of kimchi through the use of Chinese cabbage leaves. A method to reduce the initial number of microorganisms using citric acid and ethanol to wash cabbage leaves was investigated. In this experiment, Chinese cabbage leaves were washed using a mixture of 3% citric acid and 7% ethanol and the washed cabbage leaves were juiced and used as a sample. The total microorganisms of kimchi cabbage juice (KCJ) was reduced from log 6.53 CFU/g to log 3.69 CFU/g by washing with citric acid and ethanol, and lactic acid bacteria from log 4.40 CFU/g to log 2.01 CFU/g. The salinity of KCJ was appropriate for the growth of lactic acid bacteria but the pH was too low. The yield of washing, juice extraction, and total were 80.82%, 79.32%, and 64.11%, respectively. KCJ made by washing with citric acid and ethanol was good for the culture broth of lactic acid bacteria.

A citric acid functionalized graphene oxide nanocomposite was successfully synthesized and the structure and morphology of the nanocatalyst were comprehensively characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, X-ray diffraction patterns, atomic force microscopy images, scanning electron microscopy images, transmission electron microscopy images, and thermogravimetric analysis. The application of this nanocatalyst was exemplified in an important condensation reaction to give imidazole derivatives in high yields and short reaction times at room temperature. The catalyst shows high catalytic activity and could be reused after simple work up and easy purification for at least six cycles without significant loss of activity, which indicates efficient immobilizing of citrate groups on the surface of graphene oxide sheets.

Highly pathogenic avian influenza virus (HPAIV) damages vital organs and tissues, frequently leading to death in birds, and causes serious economic losses in the poultry industry. In addition, HPAIV can infect humans and other mammals, often with fatal outcomes. In this study, the virucidal efficacy of Clean-Zone®, which contains citric acid, malic acid and phosphoric acid, against avian influenza virus (AIV, H9N2) was investigated. Virucidal efficacy was determined by examining the viability of AIV after contact with the disinfectant in the allantoic membrane of chicken embryos. The disinfectant and AIV were reacted under hard water (HW) and organic matter suspension (OM) condition. AIV was inactivated with 200- and 50-fold dilutions of the disinfectant under HW and OM conditions, respectively. As the disinfectant, Clean-Zone®, has a virucidal efficacy against AIV, it can be used to prevent the spread of animal viral diseases.

2025년 세계 국가의 20%, 전세계 인구의 38%가 물 부족에 시달릴 것이라는 예측에 따라 향후 물 부족 문제는 전 세계적인 관심사가 되고 있다. 따라서 지구 물 자원의 97.5%를 차지하고 있는 해수로부터 음용수, 공업용수를 생산하는 정삼투에 대한 관심이 점차 증가하고 있다. 정삼투 시스템의 경우 가압 조건이 필요하지 않으므로 에너지 비용을 저감할 수 있고, 막 오염 및 파쇄 현상이 역삼투 시스템에 비해 발생하지 않는다는 장점이 있다. 이에 사용되는 유도 용질 의 경우 높은 친수성을 가져야 하며, 농도 대비 높은 삼투압을 보여야 한다. 또한 유도용액 후처리 공정에서의 분리가 용이하여야 한다. 본 연구에서는 정삼투 시스템의 유도용질로 Citric acid 금속염을 사용하여 성능평가를 수행하였다.

Quality characteristics such as texture and sensory properties of garaetteok(Korean rice cake)made with organic rice flour treated withcitric acid were investigated. Compared to rice flour without addition of citric acid,rice flour treated with citric acid showed a significantly lower viscosity and viscoelasticity level as the concentration of citric acid increased. Hardness of garaetteokmade with citric acid showed a similar trend in viscoelasticity changes, whereas cohesiveness was not significantly affected by the pretreatment of citric acid.Garaetteok of 0.5% citric acid pretreatment showed the highest scores in hardness, springiness, chewiness and overall acceptability.However,flavor and taste of garaetteokof citric acid pretreatment were lower than those of the control.

살모넬라증과 부루셀라증은 가축 및 사람에 심각한 피해를 유발하는 질병으로, 축산업과 식품산업에 많은 경제적 손실을 초래하고 있다. 본 연구에서는, 자몽종자추출물, 구연산, 사과산 그리고 염화벤잘코늄을 주성분으로 하는 스프레이형 소독제의 Salmonella Typhimurium과 Brucella ovis에 대한 효력시험을 수행하였다. 살균효력시험은 배지희석법에 따라 수행하였으며, 스프레이형 소독제와 시험 세균들을 처리조건에 따라 경수와 유기물로 희석하여 반응을 시켰다. 유기물 조건에서, Salmonella Typhimurium과 Brucella ovis에 대한 스프레이형 소독제의 살균력은 경수조건에서의 살균력과 비교하여 낮게 나타났는데, 이는 유기물들에 의한 소독제의 살균 유효성분에 대한 저해작용에 따른 것으로 사료된다. 스프레이형 소독제는 Salmonella Typhimurium과 Brucella ovis와 같은 인수공통전염병 유발 병원균들에 대해 살균효과를 나타내어, 살모넬라증과 브루셀라증과 같은 세균성 질병의 확산을 제어하는데 효과적으로 이용될 수 있을 것으로 사료된다.

Porcine epidemic diarrhea virus (PEDV) causes porcine epidemic diarrhea (PED) and a considerable economic loss in the swine industry. In this study, the virucidal efficacy of a disinfectant composed of citric acid, benzalkonium chloride and phosphoric acid against PEDV was investigated. Virucidal efficacy was assessed as the infectivity of PEDV toward Vero cells after exposure of the virus to the disinfectant. PEDV was exposed to the disinfectant in the presence of either hard water (HW) or an organic matter suspension (OM). In HW condition, PEDV was inactivated by 600-fold dilutions of the disinfectant. In the presence of OM, the disinfectant showed virucidal activity after a 200-fold dilution. As the disinfectant possesses virucidal activity against PEDV, it should be an effective reagent to use to limit the spread of animal viral diseases.

수처리 분리막에서 poly(vinyl alcohol) (PVA)는 물질 고유의 친수성과 높은 화학적, 열적, 그리고 물리적 특성으로 인해 많이 사용되고 있다. 그러나 PVA를 이용한 막의 경우 제거율이 RO막에 미치지 못한다. Citric acid를 이용해 crosslinking을 시도하면 막에 charge가 부여되고, 이것은 막에서 donnan효과를 통해 rejection의 향상을 가져올 것이라 기대 된다. 본 연구에서는 poly(vinyl alcohol)-g-polyethylene oxide (PVA-g-PEO) copolymer를 citic acid를 이용해 crosslinking을 하여 복합막을 제조하였다. Crosslinking 정도와 charge density에 의한 막 특성의 변화와 그에 따른 투과도와 제거율에 대해 연구하였다.

This test was performed to evaluate the acute oral toxicity and skin irritation of Lamia-Kill®, disinfectant,containing 20% benzalkonium chloride and 10% citric acid. In acute oral toxicity, Lamia-Kill® was orally administered at dose levels of 2,000, 1,000, 500, 250 and 0 mg/kg body weight. After single oral administration to both sexes of SD rats, the rats were observed for 14 days. In primary skin irritation test, New Zealand white rabbits were dermally treated with Lamia-Kill® for 24 hr and observed for 3 days. All rats treated with Lamia-Kill® were induced no toxic signs in mortalities, clinical findings, body weights and gross findings. Also, the disinfectant did not induce any adverse reactions such as erythema and edema on intact skin sites for the most part rabbits, but on abraded skin sites, some rabbits showed very slight erythema on 24 hr after topical application. With the results of this study,Lamia-Kill® have no effect on acute toxicity and side effect in SD rats and was classified as a practically non-irritating material based on the score 0.50 of primary irritation index.

본 연구는 돈분슬러지에 함유되어 있는 구리와 아연을 제거하여 합리적인 돈분슬러지 자원화비료 생산법을 연구하였고, 돈분슬러지 자원화비료를 시비 후 사일리지 옥수수의 생육특성과 사료가치를 조사하여 돈분슬러지 자원화비료의 효용성을 평가하였다. 돈분슬러지의 화학적 특성으로 질소와 인산의 함량은 각각 4.4와 6.29%였으며, 구리와 아연의 함량은 각각 805와 이었다. 구연산을 유기산 용액으로 제조하여 돈분슬러지의 구리와 아연 제거율은 유기산용액의 혼합비율이

여러 크기의 이중실관 생물 반응기에서의 Aspergillus niger(KCTC 1232)를 이용한 구연산 생산 실험을 수행하였다. 초종 세포농도는 세포 성장구간 기준으로 300g/l에 달하였다. 공기와 산소의 공급 조건하에서의 단위 용적당의 생산성은 각각 0.63, 0.02g/l.h였고 이는 회분식 발효에 대해 10, 16배 증가한 결과이다. 공급배지의 초기 pH는 구연산의 생산에 중요한 요소이며 pH가 낮을수록 높은 구연산 생산수율을 얻을 수 있었다. Scale-up의 가능성을 알아보기 위해 반응기 unit와 배지의 공급속도를 변화시킨 결과 반응기 unit와 배지 공급속도의 증가는 기질의 높은 소비속도로 인해 생산성의 증가를 가져왔다.