• 펄프종이기술
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• 제48권2호
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• pp.5-12
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• 2016

White waste papers are very important resources in the paper industry, but their use is limited because of the residual of fluorescent whitening agent (FWA). So the removal of FWAs from waste paper is an important task in the recycling process to improve the use of recycled resources. In this study, we focused on the FWAs used for surface treatments and carried out physical and chemical treatments to remove them from white waste papers. The white waste papers were disintegrated with a surfactant in different pH and temperature conditions, and then handsheets were made for the measurement of the fluorescence index, which is proportional to the amount of FWAs on papers. The effect of the flotation process on the removal of FWAs after disintegration was also investigated. The fluorescence index decreased as the disintegration time increased, but over a relatively long time, the fluorescence index increased again, which indicated the readsorption of the FWAs detached from the cellulosic fibers of the white waste papers. The lowest fluorescence index was shown when the waste papers were disintegrated with a 0.3% surfactant addition at pH 10 and at $45^{\circ}C$. However, the flotation treatment was not effective, because the flotation induced contact between the detached FWAs and the cellulosic fibers, and re-adsorption occurred.

• 펄프종이기술
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• 제36권1호
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• pp.24-29
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• 2004

Alkaline cellulolytic enzymes from cultured medium of Coprinus cinereus 2249 were purified with gel and ion-exchange chromatography and characteristics of those enzyme proteins were investigated. A fiber length distribution and a crystallinity of cellulose and sugar composition of enzyme treated Mixed Office Wastepaper(MOW) and Unbleached Kraft Pulp(UKP) were analysed. The conclusion could summarized as follows; \circled1 Alkaline and acidic, endo- and exo-glucanases were purified from cultured medium of Coprinus cinereus 2249. \circled2 The approximate molecular weight of alkaline endo-glucanase was 42 kDa, and also that of alkaline exo-glucanase was 50 kDa. A fiber length distribution and a crystallization of cellulose and sugar composition of enzyme treated MOW and UKP were not so much changed with original paper and pulp.

• Journal of Forest and Environmental Science
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• 제17권1호
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• pp.29-36
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• 2001

제지공업은 다른 공업에 비해 용수 소비량이 많고 이에 따라 폐수의 배출량도 많은 용수 다소비 산업이다. 제지폐수의 처리는 물리적, 화학적, 처리로 1차 처리를 하고 생물학적 처리로 2차 처리를 한 후, 필요에 따라 고도처리를 행하여 재이용 하거나 방류하는 시스템으로 구성되어 있다. 물리적 처리 중 응집침전법에 의한 처리방법은 생물학적 처리의 전 단계로서 처리가 불량할 경우 생물학적 처리 시스템의 부하량이 높아져 처리율의 저하를 유발한다. 또한 가장 비용이 적게 드는 처리방법이므로 응집침전에서 많은 오염물을 제거하는 것이 비용 면에서도 유리하다고 할 수 있다. 제지공장의 폐수에는 Fiber, Filler, 그 밖의 유기용매가 포함되어 있으며, 폐수량이 많기 때문에 그 만큼의 설비자본과 운영비가 소요된다. 그러므로 폐수의 양을 줄이고 그 안에 함유된 여러 가지 물질들을 적은 비용으로 효율적으로 제거하는 방법이 필요하게 된다. 본 실험은 제지폐수를 보다 효율적으로 여과하는 방법을 찾고자 함에 있어 가압 여과시험을 채택하여 응집제의 종류 및 첨가량 그리고 압력의 변화를 주면서 여과의 특성 실험을 하였다. 폐수내의 섬유나 Filler 등은 미세하게 분산되어 콜로이드성 물질이 되는데 이것은 여과시에 여재 위에 쌓여 여과 조작을 방해한다. 여기에 응집제를 첨가하게 되면 분산된 콜로이드 입자를 응집제가 표면에 사슬처럼 붙어 안정화시킨다. 즉, 침전성과 여과성이 향상되고 SS가 떨어진다. 본실험에 사용된 응집제는 $FeCl_3$, Alum, $CaCl_2$, Polymer 이며, 네 가지 응집제를 0.01g, 0.03g, 0.05g 씩 첨가(폐수 100mL에 대해)하고 압력을 49, 98, 147, 196 kPa로 변화시키면서 실험을 하였다. 이와 같은 여러 변화의 실험을 통하여 각 단위 시간 별로 여과되는 여액량을 측정하여 여과 속도 및 탁도 등을 측정하였다.

• 청정기술
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• 제29권2호
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• pp.87-94
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• 2023

폐리튬계 이차전지로부터 유가금속을 회수하는 것은 한정된 지구자원의 활용 측면에서 매우 중요하다. 최근 자동차의 전지로 많이 사용하고 있는 LiFePO₄ 전지 양극재 성분에는 리튬이 약 5.2% 함유되어 있으며, 사용 후 전지에서 리튬 재활용을 통하여 다시 전지의 원료로써 사용할 수 있다. 본 연구에서는 폐LiFePO₄ 양극재 분말에 함유된 리튬을 선택적으로 침출하기 위하여 일반적으로 많이 사용하고 있는 무기산의 일종인 저농도 황산을 이용하였다. 그리고 각 성분의 침출율 및 분리효율을 비교·분석을 위하여 침출 시 광액농도를 변수로 2 스텝 침출 공정을 적용하여 최적의 침출조건을 도출하고자 하였다. 광액농도를 변수로 침출 시 철 및 인 성분이 거의 침출되지 않는 200 g/L의 광액농도 조건에서는 타 조건과 분리 효율이 약 200배 이상 높은 것으로 확인되었다. 이에 리튬의 선택적 침출 및 회수에 있어서 침출조건을 최적화하였다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.441-444
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• 2006

A lot of water is using in the paper mill for dilution, washing, sealing, and other process operation. As the regulation of water environment has been more tightened than ever before, water management in the paper mill becomes the most important task. Topics on reducing fresh water and increasing recycling water have been studied. Further, an interest in zero-effluent system has been increased. The pH of waste water in paper mill is usually weak acidic or neutral. The waste water in the paper mill includes water insoluble organic materials that are not easy to be dissolved in the water, inorganic materials that never react with water and chemical additives that are used to recycled fiber. This study investigated on the effect of various materials used in paper mill on COD. This data could be used to control the environmental load in paper mill. COD caused by raw materials and NBDCOD (Non Bio Degradable COD) after the activated sludge process are investigated in this study. Results obtained in this study can be used in a simulation program designed to control environmental load in the paper mill.

• 상하수도학회지
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• 제31권4호
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• pp.289-296
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• 2017

Pulp and paper industry produces large volumes of wastewater and residual sludge waste, resulting in many issues in relation to wastewater treatment and sludge disposal. Contaminants in pulp and paper wastewater include effluent solids, sediments, chemical oxygen demand (COD), and biological oxygen demand (BOD), which should be treated by wastewater treatment processes such as coagulation and biological treatment. However, few works have been attempted to predict the treatment efficiency of pulp and paper wastewater. Accordingly, this study presented empirical models based on experimental data in laboratory-scale coagulation tests and compared them with statistical models such as artificial neural network (ANN). Results showed that the water quality parameters such as turbidity, suspended solids, COD, and UVA can be predicted using either linear or expoential regression models. Nevertheless, the accuracies for turbidity and UVA predictions were relatively lower than those for SS and COD. On the other hand, ANN showed higher accuracies than the emprical models for all water parameters. However, it seems that two kinds of models should be used together to provide more accurate information on the treatment efficiency of pulp and paper wastewater.

• 펄프종이기술
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• 제36권4호
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• pp.41-48
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• 2004

To make a basepaper for multipurposed seed paper, old news print (ONP) and mixed office waste paper (MOW), modified and unmodified with a commercial cellulase, were investigated. Each handsheet was applied with different chemicals such as insecticides, germicides and herbicides. The interactions behaviors of chemicals used with base papers were evaluated by means of the contents of chemicals impregnation and dissolving behaviors in water and soil. The ONP and MOW treated with the cellulase had higher impregnation and dissolving capacities in both water and soil than untreated ONP and MOW. However, the modified ONP showed lower impregnation and dissolving capacities compared to the modified MOW. The content of impregnation of chemicals would be affected with the degree of microfibrils produced by the modification treatment. Otherwise, dissolving capacities of chemicals depend on the affinity of the residual lignin in the paper.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.347-350
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• 2000

Enzymatic deinking of office-waste paper was studied using crude cellulase and papain-hydrolyzed cellulase from Trichoderma reesei Rut C-30 in small-scale and mid-scale. The results were compared with deinkings using commercial enzyme(Novozym 342) and conventional chemical methods. Maximum brightness and freeness were obtained at 3 units/g Oven Dry Paper(ODP) of CMCase activity using crude cellulase in mid-scale deinking experiments. The deinked pulp had higher physical strength and brightness, and lower freeness and yield than the pulp deinked in small scale. In small scale deinking, maximum brightness and freeness were obtained at 2 unit/g ODP. Deinking by papain-hydrolyzed cellulase showed similar results with one by Novozym 342. It was better in brightness and freeness, but showed lower physical strength and yield, than the conventional deinking by sodium hydroxide. The ratio of endo-1,4-glucanase and exo-1,4-glucanase components in papain hydrolyzed cellulase from T. reesei Rut C-30 was similar to that of commercial enzyme, Novozym 342, implicating a successful application as a deinking enzyme.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2007년도 춘계학술대회논문집
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• pp.340-349
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• 2007

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 추계 총회 및 학술발표회
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• pp.120-123
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• 1999