• Environmental engineer
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• s.323
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• pp.22-27
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• 2013

종이 펄프 공장의 폐수는 다른 공업에 비해서 폐수량이 많고 오염도가 높다. 목재로부터 종이를 제조하는 경우에 수율은 종이의 종류와 제법에 의해 큰 차이가 있어서 한마디로 말하기는 어렵지만 평균 50~70%로 보는 경우, 목재 성분의 30~50%는 용해 또는 SS의 상태로 폐수중에 존재하기 때문에, 이들이 직접 하천이나 바다에 방류되면 오염의 원인이 된다. 그 때문에 각 공장에서는 목재자원의 종합적인 이용의 입장으로서 제품의 수율을 좋게 하고 동시에 폐수의 양을 감소시키고 폐수에서 유용한 자원을 회수하거나 증해약품의 회수 등을 위하여 연구 및 노력을 계속하고 있는 것이 현 상태이다. 우리 나라의 거의 모든 제지회사에서는 물리적, 화학적 처리법과 생물학적 처리법 중 호기성 처리방법이 주 처리방법으로 사용되고 있으며 탈묵 폐수나 리그닌을 다량 함유하는 폐수의 경우에는 혐기성 처리방법을 이용하기도 한다. 본 실험에서는 우유팩을 재생하여 화장지 제조의 원료로 이용하는 G제지공장의 폐수를 이용하였고, 공장의 원폐수를 부상법으로 1차 처리한 처리수를 실험실로 운반하여 활성슬러지법으로 실험하였다. 처리효율의 영향인자인 HRT를 G제지공장에 맞추어 12시간으로 조정하고 적절한 F/M비(0.23)를 위해 COD와 MLSS가 유지된 후부터 실험을 시작했다. $20^{\circ}C{\sim}560^{\circ}C$까지 $10^{\circ}C$간격으로 온도를 변화시키면서 미생물의 상태변화를 관찰하고, 또한 각 용도에서의 처리수질을 비교해 보았다. 실험조건은 pH는 중성상태(6.5~7.5), DO는 $2{\sim}4mg/{\ell}$, 영양원은 BOD : N : P = 100 : 5 : 1로 맞추고 BOD, COD, SS, SVI를 측정하였으며, 현미경을 통하여 미생물과 Floc를 관찰하였다. $20^{\circ}C$부터 종균제를 초기 운전시 $200mg/{\ell}$ (분말상)을 폭기조에 투여하고 매일 $200mg/{\ell}$를 정기적으로 투입하여 온도변화에 따른 미생물의 상태 및 처리수질을 비교해보았다. 특히 종균제로는 기존의 G제G지공장에서 사용하는 신일 미생물(Bio sound S)종균제와 청림C&C의 종균제(Cell bio P)를 비교 관찰하였다. 고온성 종균제를 두배 투입하여 투입량에 대한 처리효율을 비교하였으며 종균제를 사용하지 않고 운용함으로써 그 차이도 비교할 수 있었다.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.2
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• pp.125-139
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• 2017

In this paper, the performance of a synthetic fiber filter aimed at high-speed operation and dosed with different coagulants or filter aids was investigated. Without a coagulant, the filter efficiency was about 62% which was greatly enhanced when three types of coagulants namely PAC, Alum, and $FeCl_3$ were used. Among the coagulants tested, PAC was the most effective, giving 91% filter efficiency, followed by Alum with 90%, and $FeCl_3$ with 78%. PAC worked effectively at a very small range of dose, but Alum was relatively effective in a wide range of concentration. Compared with PAC and Alum, $FeCl_3$ provided more or less contant efficiency regardless of its dose but gave the poorest filter efficiency. Moreover, as the inflow turbidity increased, headloss increased and the efficiency decreased at any dose and type of coagulant. The headloss recorded in this particular synthetic fiber filter is not significant as compared to that observed in typical granular filters. The recovery of solids estimated after filter cleaning was about 80% for both PAC and Alum, but poorer at 72% in the case of $FeCl_3$ due to the heavy and large floc characteristics. The recurrence of filter efficiency verified through repetitive filter runs was found to be satisfactory.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.194-201
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• 2012

In this research, a sewage sludge solubilization study using electrolysis was performed as a pre-treatment for anaerobic digestion efficiency improvement. SCOD potency increased as the treatment time and electric current density increased with sludge electrolysis treatment while SCOD, TN, and TP especially showed the highest increase of 7.4 times, 1.9 times, and 1.3 times respectively at the 60 minute point of treatment. Solubilization was high at the strong acidic and alkaline status for the sewage sludge electrolysis treatment results along early stage pH, and especially, a high solubilization percentage of 32.9% was seen at pH 12. The above result shows that there was an increase of organic matter able to be used by microorganisms from sludge floc and the destruction of EPS structure due to direct and indirect oxidation following electrolysis.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.625-630
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• 2004

Granular media filtration is used almost universally as the last particle removal process in conventional water treatment plants. Therefore, superb particle removal efficiency is needed during this process to ensure a high quality of drinking water. However, every particle can not be removed during granular media filtration. Besides the pattern of particle attachment is different depending on physicochemical aspects of particles and suspension. Filtration experiments were performed in a laboratory-scale filter using spherical glass beads with a diameter of 0.55 mm as collectors. A single type of particle suspension (Min-U-Sil 5) and alum coagulation was used to destabilize particles. The operating conditions were similar to those of standard media filtration practice: a filtration velocity of 5 m/h. More favorable particles, i.e., particles with smaller surface charge, were well attached to the collectors especially during the early stage of filtration when zeta potential of particles and collectors are both negative. This selective attachment of the lower charged particles caused the zeta potential distribution (ZPD) of the effluent to move to a more negative range. On the other hand, the ZPDs of the effluent moved from more positive to less positive when the surface charge of particles was positive and this result was thought to be caused by ion transfer between particles and collectors.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.233-241
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• 2015

Polytetrafluoroethylene (PTFE) membrane has high resistance to chlorine, which is a great advantages in chemical cleaning to recover water flux during membrane processes in drinking water systems. A humic kaolin water with approximately 4 mg/L of DOC and 10 NTU of turbidity was prepared as a feed water. Coagulation pretreatment with or without settling was applied. The coagulation with settling showed the greatest water production. The reduced flux was effectively recovered by NaOCl cleaning, i.e., 21% recovery by 50 mg/L of NaOCl cleaning and 49% recovery by 500 mg/L NaOCl cleaning. The images of SEM and AFM analyses were corresponded to the water flux variation. However, when the floc was accumulated on the membrane surfaces, the efficiency of NaOCl cleaning was substantially limited. In addition, dynamic contact angle became greater after cleaning, which indicates changes in characteristics of fouling layer such as surface hydrophobicity. Proper cleaning technologies during enhanced backwash using NaOCl would expand application of PTFE membranes in drinking water systems.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.4
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• pp.7-14
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• 2001

Recycled fibers usually give slow drainage in the paper forming process, which limits the application of more refining to the recycled fibers for improving paper strength and formation. To use recycled fibers more effectively, especially OCC, developing very efficient handling technique of short fibers and fines is inevitable. We tried to make hard flocs of fractionated short fibers and fines, which were the main cause of slow drainage, by adding excessive amount of retention aid selectively on them. This technique was proved to increase drainage considerably, but to decrease strength properties, compared to the conventional technique of adding the same amount of polymers to the whole furnish in the lab test. The bonding capability of short fibers and fines in Korean OCC was very poor. Various chemical treatment on the short fibers and fines of the Korean OCC did not improve their bonding and optical properties. One of the reasons of no improvement in their properties was their high amount of ashes.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.717-724
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• 1999

This experiment was performed on three parts with prepared coagulants. (1) The characterization of coagulation for PACI coagulants. (2) Comparison of the characterization of coagulation with PAS and PACI coagulants. And (3) Comparison of the characterization of coagulation for the addition of calcium with PACI. Coagulation experiments were conducted with several dosages and pH for each coagulants. For the characterization of coagulation with PACI coagulants, coagulation of Nakdong river waters with three PACls (r=2.0, 2.2, 2.35) showed that the effectiveness of the three coagulants can be considered as r=2.2 > 2.0 > 2.35 which are also the order of higher polymeric aluminum contents. For the comparison of the characterization of coagulation for PAS and PACI coagulants, PAS (r=0.75) coagulants was more effective than other coagulant for the removal of organic matters by sweep floc mechanism with $A;(OH)_{3(S)}$. For comparison of the characterization of coagulation for the addition of calcium with PACI, the presence of divalent cation like $Ca^{2+}$ was supposed to influence the complex formation of organic anions. From the result of test on coagulation at various pH ranges, the PACI was least affected by the coagulation pH, and the addition of calcium to PACI was very effective for the removal of turbidity and organic materials over broader pH range (pH 4-9).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.298-298
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• 2008

제지산업은 다량의 용수를 사용하면서 또한 많은 양의 폐수를 배출하고 있다. 기존의 폐수처리 공정에서는 침전처리를 위한 큰 공간과 오랜 시간이 요구되어 처리비용이 비교적 많이 드는 단점이 있다. 이러한 기존 기술의 문제점을 보완할 수 있는 새로운 고도처리가 가능한 초전도 마그네트를 이용한 자기분리 기술을 적용하고자 하였다. 자기분리의 기본 원리는 강력한 자기력에 의하여 액체에 포함된 자성입자를 분리해내는 것으로 자성입자들이 자계의 힘에 의하여 잡아당겨지고 포획될으로서 제거되는 것이다. 자기분리용 전자석으로서는 아주 이상적으로 이러한 초전도마그네트와 체(sieve) 형 자기필터를 결합시키면 아주 높은 고구배의 자장(HGMS; High Gradient Magnetic Separation)을 발생 시킬 수 있다. 초전도마그네트를 이용하면 대공간에 전력손실 없이 고자장을 발생시킬수 있기 때문에 미립자를 효과적으로 고속으로 분리하는 것이 가능해지며 또한 상자성 미세입자까지도 처리할 수 있다. 본 연구에서는 주로 유기물로 구성된 제지며|수의 부유물을 자성체와의 응집반응에 의해 플록을 형성하여 자성플록의 자기분리 효과를 연구하였다. 응집제의 종류와 응집반응 공정에 따른 자성플록의 형성 정도를 조사하였으며 자기분리 후 폐수의 탁도, COD 등의 특성을 분석하였다.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.99-106
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• 2005

The removals of organic matter, nitrogen and phosphate in wastewater were investigated with Sequencing Batch Reactor (SBR). Glucose and sodium acetate were Used for organic carbon source so as to know nutrient removal efficiency in proportion to MLSS concentration. In the case of glucose, the COD removal rate was $74\%,\;41\%\;and\;66\%$ in MLSS 5000, 3000 and 1000, respectively. On equal terms, the BOD was $57\%,\;21\%\;and\;38\%$, the T-N was $24\%,\;13\%\;and\;44\%$, and the T-P was $12\%,\;21\%\;and\;33\%$. As a result, the removal rate of organic materials showed the finest remove when MLSS was 5000, but the nutrient removal rate appeared as was best when MLSS was 1000. In the case of sodium acetate, the COD removal rate was $83\%,\;81\%\;and\;86\%$ in MLSS 5000, 3000 and 1000, respectively. On equal terms, the BOD was appeared by $76\%,\;82\%\;and\;92\%$, the T-N $57\%,\;42\%\;and\;78\%$, and the T-P $48\%,\;52\%\;and\;38\%$. As a result, organic and T-N removal rates were best when MLSS was 1000. But, the T-P removal rates were best when MLSS was 3000. Glucose was shown fast removal in reaction beginning, but screened by more efficient thing though sodium acetate removes organic matter, nitrogen and phosphate. Form of floc was ideal in all reactors regardless of carbon source and MLSS concentration. And its diameter was about $200\~500{\mu}m$.

• KSBB Journal
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• v.6 no.2
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• pp.167-174
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• 1991

Enzymatic cellulose hydrolysis depends on the several factors such as the structural features (CrI, particle size and surface area, etc.), the nature of cellulase enzyme system, the inhibitory effects of products, and enzyme deactivation. At the presence of products on the initial hydro- lysis rate of cellulose, cellobiose has more severe inhibitory effect than glucose. Othewise, the inhibition effect of products for adsorbed enzyme is related to the glucose and cellobiose conentration hyperbolically. Enzyme deactivation of FPA and ${\beta}-glucosidase$ were expressed by exponential decay profile.