In Korea, the chemical oxygen demand(CODsed) in freshwater sediments has been measured by the potassium permanganate method used for marine sediment because of the absence of authorized analytical method. However, this method has not been fully verified for the freshwater sediment. Therefore, the use or modification of the potassium permanganate method or the development of the new CODsed analytical method may be necessary. In this study, two modified CODsed analytical methods such as the modified potassium permanganate method for CODMn and the modified closed reflux method using potassium dichromate for CODCr were compared. In the preliminary experiment to estimate the capability of the two oxidants for glucose oxidation, CODMn and CODCr were about 70% and 100% of theoretical oxygen demand(ThOD), respectively, indicating that CODCr was very close to the ThOD. The effective titration ranges in CODMn and CODCr were 3.2 to 7.5 mL and 1.0 to 5.0 mL for glucose, 4.3 to 7.5 mL and 1.4 to 4.3 mL for lake sediment, and 2.5 to 5.8 mL and 3.6 to 4.5 mL for river sediment, respectively, within 10% errors. For estimating CODsed recovery(%) in glucose-spiked sediment after aging for 1 day, the mass balances of the CODMn and CODCr among glucose, sediments and glucose-spiked sediments were compared. The recoveries of CODMn and CODCr were 78% and 78% in glucose-spiked river sediments, 91% and 86% in glucose-spiked lake sediments, 97% and 104% in glucose-spiked sand, and 134% and 107% in glucose-spiked clay, respectively. In conclusion, both methods have high confidence levels in terms of analytical methodology but show significant different CODsed concentrations due to difference in the oxidation powers of the oxidants.

The environmental behaviors of polycyclic aromatic hydrocarbons (PAHs) are mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation (SER) systems, surfactant plays a critical role in remediation. In this study, sorptive behaviors and partitioning of naphthalene in soils in the presence of surfactants were investigated. Silica and kaolin with low organic carbon contents and a natural soil with relatively higher organic carbon content were used as model sorbents. A nonionic surfactant, Triton X-100, was used to enhance dissolution of naphthalene. Sorption kinetics of naphthalene onto silica, kaolin and natural soil were investigated and analyzed using several kinetic models. The two compartment first-order kinetic model (TCFOKM) was fitted better than the other models. From the results of TCFOKM, the fast sorption coefficient of naphthalene (k1) was in the order of silica > kaolin > natural soil, whereas the slow sorbing fraction (k2) was in the reverse order. Sorption isotherms of naphthalene were linear with organic carbon content (foc) in soils, while those of Triton X-100 were nonlinear and correlated with CEC and BET surface area. Sorption of Triton X-100 was higher than that of naphthalene in all soils. The effectiveness of a SER system depends on the distribution coefficient (KD) of naphthalene between mobile and immobile phases. In surfactant-sorbed soils, naphthalene was adsorbed onto the soil surface and also partitioned onto the sorbed surfactant. The partition coefficient (KD) of naphthalene increased with surfactant concentration. However, the KD decreased as the surfactant concentration increased above CMC in all soils. This indicates that naphthalene was partitioned competitively onto both sorbed surfactants (immobile phase) and micelles (mobile phase). For the mineral soils such as silica and kaolin, naphthalene removal by mobile phase would be better than that by immobile phase because the distribution of naphthalene onto the micelles (Kmic) increased with the nonionic surfactant concentration (Triton X-100). For the natural soil with relatively higher organic carbon content, however, the naphthalene removal by immobile phase would be better than that by mobile phase, because a high amount of Triton X-100 could be sorbed onto the natural soil and the sorbed surfactant also could sorb the relatively higher amount of naphthalene.

Lab-scale Electrodialysis(ED) system with different membranes combined with before or after pyroma process were carried out to remove nitrate from two pickling acid wastewater containing high concentrations of NO3-(≈150,000 mg/L) and F-(≈160,000 mg/L) and some heavy metals(Fe, Ti, and Cr). The ED system before Pyroma process(Sample A) was not successful in NO3- removal due to cation membrane fouling by the heavy metals, whereas, in the ED system after Pyroma process(Sample B), about 98% of nitrate was removed because of relatively low NO3- concentration (about 30,000 mg/L) and no heavy metals. Mono-selective membranes(CIMS/ACS) in ED system have no selectivity for nitrate compared to divalent-selective membranes(CMX/AMX). The operation time for nitrate removal time decreased with increasing the applied voltage from 10V to 15V with no difference in the nitrate removal rate between both voltages. Nitrate adsorption of a strong-base anion exchange resin of Cl- type was also conducted. The Freundlich model(R2 > 0.996) was fitted better than Langmuir model(R2 > 0.984) to the adsorption data. The maximum adsorption capacity (Q0) was 492 mg/g for Sample A and 111 mg/g for Sample B due to the difference in initial nitrate concentrations between the two wastewater samples. In the regeneration of ion exchange resins, the nitrate removal rate in the pickling acid wastewater decreased as the adsorption step was repeated because certain amount of adsorbed NO3- remained in the resins in spite of several desorption steps for regeneration. In conclusion, the optimum system configuration to treat pickling acid wastewater from stainless-steel industry is the multi-processes of the Pyroma-Electrodialysis-Ion exchange.

This study was conducted to remove organics and nutrients using 2 stage intermittent aeration reactor. First reactor, using suspended microbial growth in intermittent aeration instead of anaerobic reactor in the typical BNR process, used minimum carbon source to release P, and it was possible to reduce ammonia loading going to second reactor. In the second reactor, using moving media intermittent aeration, it was effective to reduce nitrate in non-aeration time by attached microorganisms having long retention time. In aeration time, nitrification and P uptake were taken place simultaneously. From the experiment, two major results were as follows. First, the removal of organics was more than 90%, and optimum aeration/non-aeration time ratio for organic removal was corresponded with aeration/non-aeration time ratio for nitrogen removal. Second, in the first reactor, optimum aeration/non-aeration time ratio was 15/75 (min.) because it was necessary to maintain 75 min. of non-aeration time to suppress of impediment of return nitrate and to lead release of phosphate. In the second reactor, optimum aeration/non-aeration time ratio was 45/90 (min.).

자연발효에 의해 다시마를 첨가하여 제조한 전통고추장에 대한 일반성분을 분석한 결과, 기존 고추장에 비해 대부분의 무기물 함량이 증가하였다. MNNG에 대한 항돌연변이 효과(200 /plate)에서 S. typhimurium TA100 균주에 대해 다시마 분말을 5% 첨가한 고추장이 다른 첨가 농도보다 높은 87.2%의 억제효과를 나타내었다. 4NQO에서는 5%의 다시마 분말 첨가 고추장이 S. typhimurium TA98 균주와 TA100 균주

번데기동충하초(Cordyceps militaris(L. ex fr.) Link)의 수소전자공여능 및 항돌연변이원성을 살펴본 결과 부탄을 분획물과 에틸 아세테이트 분획물에서 수소전자공여능이 다른 시료에 비해 2배 이상 높게 나타났다. 항돌연변이원성 실험결과에서는 직접변이원인 MNNG, 4NQO 그리고 간접변이원인 B()P, Trp-P-1에 대해서 유의성 있는 돌연변이 억제효과를 보였다. MNNG(0.4 /plate)의 경우 S. typhimuriu