• Environmental Engineering Research
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• 제24권2호
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• pp.309-317
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• 2019

This study evaluated the kinetics of acrylamide (AM) biodegradation by mixed culture bacteria and Enterobacter aerogenes (E. aerogenes) in sequencing batch reactor (SBR) systems with AQUASIM and linear regression. The zero-order, first-order, and Monod kinetic models were used to evaluate the kinetic parameters of both autotrophic and heterotrophic nitrifications and both AM and chemical oxygen demand (COD) removals at different AM concentrations of 100, 200, 300, and 400 mg AM/L. The results revealed that both autotrophic and heterotrophic nitrifications and both AM and COD removals followed the Monod kinetics. High AM loadings resulted in the transformation of Monod kinetics to the first-order reaction for AM and COD removals as the results of the compositions of mixed substrates and the inhibition of the free ammonia nitrogen (FAN). The kinetic parameters indicated that E. aerogenes degraded AM and COD at higher rates than mixed culture bacteria. The FAN from the AM biodegradation increased both heterotrophic and autotrophic nitrification rates at the AM concentrations of 100-300 mg AM/L. At higher AM concentrations, the FAN accumulated in the SBR system inhibited the autotrophic nitrification of mixed culture bacteria. The accumulation of intracellular polyphosphate caused the heterotrophic nitrification of E. aerogenes to follow the first-order approximation.

• 미생물학회지
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• 제40권1호
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• pp.29-36
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• 2004

논 토양에서 acrylamide의 분해능이 탁월한 세균 Pseudomonas JK-7를 분리하여 acrylamide의 생분해에 영향을 미치는 물리화학적 요인을 조사하였다. 초기 실험에서 acrylamide를 유일 탄소원과 질소원으로 하여 호기적 조건에서 생장할 수 있는 세균 JK-7을 논의 토양표본에서 분리하였다. BIOLOG system을 이용한 생리학적 분석으로 Pseudomonas속(genus)임을 확인하였고, 이 세균을 Pseudomonas sp. JK-7로 명명하였다. 분리 균주 JK-7은 50 mM acrylamide를 배양 72시간 이내에 완전히 분해하였다. 배양기간 중에 acrylamide 분해 중간대사 물질로서 acrylic acid가 나타나는 것을 HPLC를 통해 확인하였으며, 배양초기에 배양액에 존재하지 않았던 ammonia가 배양기간 중에 관찰되었다. 배양초기 pH는 7.0이었으나 acrylamide가 완전히 분해된 후 배양액의 최종 pH는 8.7이었다. Acrylamide 분해와 JK-7의 생장에 대한 pH의 영향을 조사한 결과, PH 5, pH 7 그리고 pH 9에서 생장과 분해가 이루어졌으나, pH3과 pH11에서는 거의 관찰되지 않았다. 부가 탄소원의 존재하에서 JK-7에 의한 acrylamide분해에서 glucose, fructose, citrate 또는 succinate를 각각 첨가하여 조사한 결과, 부가 탄소원이 없을 때보다 acrylamide분해와 JK-7의 생장은 가속화되었다. 또한 부가질소원 첨가에 따른 영향조사 실험에서, yeast extract는 acrylamide분해와 JK-7의 생장을 촉진시켰다. 그러나 다른 질소원인 $(NH_{4})_{2}SO_{4}$, $NH_4Cl$ 그리고urea는 생장과 분해에 본질적으로 큰 영향을 미치지 않았다. 금속이온에 대한 영향으로 배지내에 $ZnSO_{4}$를 첨가하였을 때 분해와 생장이 진행되었으나, $AgNO_{3}$, $CuSO_{4}$ 또는 $HgCl_{2}$를 첨가하였을 때 acrylamide분해와 JK-7의 생장이 이루어지지 않았다.

• Advances in materials Research
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• 제2권1호
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• pp.15-36
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• 2013

Incorporation of polar functional moieties into polyethylene (PE) film has been achieved by graft copolymerization of polar monomers such as methacrylic acid (MAAc) and acrylamide (AAm) on to PE film, preirradiated with ${\gamma}$-rays from $^{60}Co$ source, using benzoyl peroxide (BPO) as initiator in aqueous medium. Percentage of grafting of MAAc and AAm was determined as a function of irradiation dose, monomer and initiator concentration, temperature, reaction time and amount of water. Maximum percentage of grafting of MAAc (1453%) and AAm (21.28%) was obtained at [MAAc] = $235.3{\times}10^{-2}$ mol/L, [AAm] = $23.4{\times}10^{-2}$ mol/L, [BPO] = $5.5{\times}10^{-2}$ mol/L and $16.5{\times}10^{-2}$ mol/L at $80^{\circ}C$, $90^{\circ}C$ in 180 min and 90 min respectively. The grafted PE films were characterized by FTIR, Thermogravimetric analysis (TGA) Scanning Electron Micrography (SEM) and X-ray diffraction methods. Some selective properties of grafted films such as swelling behavior, ion and metal uptake have been carried out. The biodegradation studies of the grafted PE films have also been investigated. The grafted films developed superior swelling behavior with maximum swelling (480%) in water as compared to pristine PE (13.55%), better thermal stability and ion and metal uptake studies showed promising results that can be effectively used for desalination of brackish water and separation of metals from the industrial effluents.