• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1996년도 추계 학술발표회
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• pp.53-58
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• 1996

The Chitin Thiocarbonate-Fe(II)-H2O2 redox initiator system was investigated for the graft copolymerization of acrylonitrile(AN) and acrylic acid(AA) monomers onto chitin powder. The reactions with vinyl monomers onto chitin were carried out under various the graft copolymerization conditions to elucidate the polymerization behavior in terms of graft yield. Reactions of chitin-acrylonitrile graft copolymer with hydroxyl amine hydrochloride and those with sodium hydroxide were conducted in order to obtain chitin-(amidoxime-co-acrylonitrile) and chitin-(acrylate-co-acrylamide) graft copolymers, respectively. The reaction efficiency was observed to depend on the alkali concentration, time, temperature, and the reactant concentrations. The prepared chitin derivatives were evaluated to find potential applications for use in wastewater treatments for adsorption and desorption of heavy metal ions as well as acidic and basic dyes.

• 펄프종이기술
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• 제33권3호
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• pp.24-28
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• 2001

The utilization of wastepaper as a papermaking raw material is everlastingly required for the environmental protection of earth. However the recycling of wastepaper for this purpose cause another problem such as the increasing of the load of wastewater treatment, lower strength properties of paper, and poor printability, etc. The interest in the development of the environmentally friendly deinking technology is increased continuously. Thus, our research team have tried to apply the ozone to the deinking of white ledger and ONP, and obtained the positive results which can be considered as an alternative method for the conventional deinking method. The purpose of this study is to investigate the mechanism of ozone deinking. Styrene acrylate and polystyrene were treated with ozone and measured the change of molecular weight with the GPC. The molecular weight distribution obtained with GPC showed only slight increase by the ozone treatment, and gel formation by the polymerization was observed. Therefore the removal of ink particles with ozone treatment seems to be facilitated by the increase of the brittleness and decrease of adhesive property.

• Environmental Engineering Research
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• 제23권1호
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• pp.28-35
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• 2018

$17{\alpha}-ethinylestradiol$ (EE2), a synthetic estrogen which interfere the endocrine and reproductive function in living organisms, has been found extensively to be deposited into municipal wastewater treatment plants and the environment via human excretion. EE2 has long been known to be efficiently cometabolized by ammonia-oxidizing bacteria (AOB) during ammonia ($NH_3$) oxidation. Current study aims to investigate the effect of culture history on the biotransformation of EE2 by nitrifying sludge which was enriched under different ammonia loading rates in continuous flow reactors. Result showed that past growth condition largely affected not only the metabolic rate of $NH_3$ oxidation but also EE2 cometabolism. Sludge previously acclimated with higher $NH_3$ loads as well as sludge dominated with AOB belong to high growth cluster (Nitrosomonas europaea-Nitrosococcus mobilis) showed higher rate of EE2 biotransformation than those one being acclimated with lower $NH_3$ loads because of its ability to provide more reducing power from $NH_3$ oxidation. Moreover, the correlation between the degradation rates of $NH_3$ and EE2 was higher in sludge being acclimated with higher load of $NH_3$ in comparison with other sludge. Implication of the findings emphasized the role of volumetric $NH_3$ loading rate in determining EE2 removal in wastewater treatment system.

• Asian-Australasian Journal of Animal Sciences
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• 제26권11호
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• pp.1651-1658
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• 2013

Nitrate contamination in ground and surface water is an increasingly serious environmental problem and only a few bacterial strains have been identified that have the ability to remove nitrogen pollutants from wastewater under thermophilic conditions. We therefore isolated thermophilic facultative bacterial strains from wood chips that had been composted with swine manure under aerated high temperature conditions so as to identify strains with denitrifying ability. Nine different colonies were screened and 3 long rod-shaped bacterial strains designated as SG-01, SG-02, and SG-03 were selected. The strain SG-01 could be differentiated from SG-02 and SG-03 on the basis of the method that it used for sugar utilization. The 16S rRNA genes of this strain also had high sequence similarity with Geobacillus thermodenitrificans $465^T$ (99.6%). The optimal growth temperatures ($55^{\circ}C$), pH values (pH 7.0), and NaCl concentrations (1%) required for the growth of strain SG-01 were established. This strain reduced 1.18 mM nitrate and 1.45 mM nitrite in LB broth after 48 h of incubation. These results suggest that the G. thermodenitrificans SG-01 strain may be useful in the removal of nitrates and nitrites from wastewater generated as a result of livestock farming.

• 한국환경농학회지
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• 제18권1호
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• pp.48-53
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• 1999

본 연구에서는 폐기물의 재활용 측면에서 폐굴껍질을 이용하여 축산폐수에 함유되어 있는 $PO_4^{3-}-P$의 제거특성을 검토해본 결가, 다음과 같은 결론을 얻었다. 입경이 작을수록 흡착속도가 빠르게 진행되어 흡착평형에 도달하는 시간이 빠른 것을 알 수 있다. 주입량과 수온이 증가할수록 평형상태에 도달하는데 다소 더 긴시간을 요하는 것을 알 수 있다. 반응초기 낮은 pH에서는 흡착현상에 지배적으로 영향을 받는 것으로 추정되지만, 시간이 경과함에 따라 pH상승과 더불어 정석반응이 우세하게 진행되고 있는 것을 알 수 있다. 등온흡착식을 적용해본 결과에서도, 폐굴껍질은 $PO_4^{3-}-P$의 제거는 흡착현상 보다는 오히려 정석반응에 더 많은 영향을 받는 것으로 여겨진다. SEM 관측결과에 의하면 폐굴껍질 표면에서 뚜렷한 변화는 거의 볼 수 없으나 반응전에 비하여 폐굴껍질의 입경이 비교적 크고 조그만 판상의 형태를 간헐적으로 보이고 있다.

• Environmental Engineering Research
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• 제19권1호
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• pp.75-81
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• 2014

Methanotrophic denitrification under a non-aerated condition (without external supply of oxygen or air) was investigated in a bioreactor coupled with a membrane diffuser. Batch experiment demonstrated that both methane consumption and nitrogen production rates were not high in the absence of oxygen, but most of the nitrate was reduced into $N_2$ with 88% recovery efficiency. The methane utilized for nitrate reduction was determined at 1.63 mmol $CH_4$/mmol $NO_3{^-}$-N, which was 2.6 times higher than the theoretical value. In spite of no oxygen supply, methanotrophic denitrification was well performed in the bioreactor, due to enhanced mass transfer of the methane by the membrane diffuser and utilization of oxygen remaining in the influent. The denitrification efficiency and specific denitrification rate were 47% and 1.69 mg $NO_3{^-}-N/g\;VSS{\cdot}hr$, respectively, which were slightly lower than for methanotrophic denitrification under an aerobic condition. The average concentration of total organic carbon in the effluent was as low as 2.45 mg/L, which indicates that it can be applicable as a post-denitrification method for the reclamation of secondary wastewater effluent. The dominant fatty acid methyl ester of mixed culture in the bioreactor was $C_{16:1{\omega}7c}$ and $C_{18:1{\omega}7c}$, which was predominantly found in type I and II methanotrophs, respectively. This study presents the potential of methanotrophic denitrification without externally excess oxygen supply as a post-denitrification option for various water treatment or reclamation.

• 상하수도학회지
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• 제26권3호
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• pp.431-442
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• 2012

The purpose of this study, is to separate magnetic separation devices using permanent magnets by using magnetization characteristics remaining in treated water after adsorption and synthesizing phosphorus adsorbent capable of magnetic separation for efficient removal of phosphorus. The synthesis of the adsorbent which set Zirconium(Zr) having high friendly features for phosphorus as an element, and by synthesizing Iron Oxide($Fe_3O_4$, another name of $Fe_3O_4$ is magnetite) being able to grant magnetism to Zirconium Sulfate($Zr(SO_4)_2$), zirconium magnetic adsorbent(ZM) were manufactured. In order to consider the phosphorus adsorption characteristics of adsorbent ZM, batch adsorption experiment was performed, and based on the results, pH effect, adsorption isotherm, adsorption kinetics, and magnetic separation have been explore. As the experiment result, adsorbent ZM showed a tendency that the adsorption number was decreased rapidly at pH 13; however, it was showed a high amount of phosphorus removal in other range and it showed the highest amount of phosphorus removal in pH 6 of neutral range. In addtion, the Langmuir adsorption isotherm model is matched well, and D-R adsorption isotherm model is ranged 14.43kJ/mol indicating ion exchange mechanism. The result shown adsorption kinetics match well to the Pseudo-second-order kinetic model. The adsorbent ZM's capablility of regenerating NaOH and $H_2SO_4$, was high selectivity on the phosphorus without impacts on the other anions. The results of applying the treated water after adsorption of phosphorus to the magnetic separation device by using permanent magnets, shows that capture of the adsorbent by the magnetization filter was perfect. And they show the possibility of utilization on the phosphorus removal in water.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.351-354
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• 2002

부산광역시 수영 하수처리장의 소화조에서 농축조로 보내지는 혐기성 슬러지를 탈기된 증류수와 1:1로 희석하여 11.900 mg/L로 만든 후 혐기성 고정 생물막 반응기에 15일간 생물막을 부착시킨 후, 부유 슬러시를 제거하고 각 반응기에 각각 8.00 mgTOC/L, 9.76 mgTOC/L, 및 18.97mgTOC/L의 기질 농도를 유입하여 HRT 0.496일로 각 반응기에 연속적으로 주입하여 실험하였다. 기질 전달 현상과 관련하여 각 반응기에 대한 실험 결과는, 저농도로 기질이 유입된 반응기 l과 2에서는 생물막 두께 및 기질 제거율, 기질 소비 속도 상수($k_v$), 유효 확산 계수($D_{eff}$) 가 비슷하였으나, 고농도로 기질이 유입된 반응기 3에는 자농도로 기질이 유입된 반응기 1과 2 보다 높은 값을 나타내었다. 이는 본 실험에 사용된 혐기성 미생물이 고농도의 기질을 유입하였을 때, 더욱 원활하게 성장함에 따라 높은 기질 소비를 나타내었다.

• 청정기술
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• 제13권2호
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• pp.87-98
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• 2007

대도시의 인구집중과 환경문제에 대한 관심의 고조에 따른 환경배출기준의 강화로 환경처리시설에서 배출되는 슬러지의 양은 매년 급증하고 있는 실정이다. 2003년부터는 하수처리 슬러지의 매립지에의 직매립을 금지하고 있을 뿐만 아니라, 2012년부터는 해양투기 또한 전면 금지됨에 따라 육상에서의 자원화 혹은 감량화 등을 통한 소각, 퇴비화 등의 방법으로 처분해야 하는 실정이다. 그러나 이들 슬러지의 성상은 슬러지발생원, 발생 시기, 처리공정 등에 따라 그 성상이 다양하게 변하는 특성을 가지므로 슬러지처리, 재활용 및 처분방법을 결정하는데 있어서 슬러지성상에 대한 평가가 중요하게 작용한다. 이를 위하여 물리화학적 처리, 생물학적처리 등 서로 다른 처리방법에 의해 발생되는 슬러지의 성상평가방법을 표준화할 필요성이 크다고 하겠다. 그러나 아직까지 우리나라에서는 표준화된 슬러지 성상평가방법이 제정되어 있지 않다. 본 총설에서는 우리나라의 슬러지 성상평가방법에 관한 현황과 문제점 등을 파악하고, 독일 등 선진국의 사례를 바탕으로 적절한 슬러지의 재활용과 처분을 위한 우리나라에 적합한 15가지 항목의 표준화된 슬러지 성상평가방법을 제시하고자 하였다.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.136-142
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• 2007

최근 부영양화를 야기시키는 물질인 $PO_4^{3-}$ 이온을 제거하기 위해 고형반응물을 이용하는 것이 주목을 받고있다. 철광석의 정련 과정에서 생기는 슬래그는 용해된 무기 인산염을 폐수로부터 유리시켜 흡착 제거하는 것에 대한 근본적인 연구가 이루어져 왔다. 본 연구는 물 속의 인산염을 제거하기 위해 전로슬래그를 이용하였을 때 오랜 시간동안 hydroxyapatite 형태로 변화시켜 제거하고 인산염 제거를 향상시키기 위한 가능성을 찾기 위하여 여러 가지 조건을 변화시켜서 수행하였다. 본 연구 결과 전로슬래그를 이용한 등온흡착식을 적용했을 때 Freundlich 식을 적용할 수 있었으며, 인을 제거하는데 사용된 전로 슬래그의 크기는 $2{\sim}0.425mm$가 가장 적당한 것으로 나타났다. 특히, 연속반응탑을 이용할 경우, 유입수 농도가 1 mg/L일 때 80%까지 제거되는 것으로 나타났다.