• Journal of the Korean Wood Science and Technology
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• v.12 no.3
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• pp.9-14
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• 1984

The removal and readsorption effects of pine and oak bark grown in Korea on water pollution caused by heavy metal ions have been investigated. Bark saturated with heavy metal ions is refleshed with 0.1 N ammonium acetate and then its readsorption has been done. The results obtained are as follows: 1. Adsorption effect of pine bark is similiar to that of oak bark, and 20-40 meshed bark gives the best results. 2. 0.1 N amonium acetate of pH 7 shows more elutriative than the others such as pH 3 hydrochloric acid, pH 10 ammonium hydroxide and pH 7 water. 3 Pine bark refleshed with 0.1 N ammonium acetate gets two times as effective in adsorption as raw bark, and shows more effective than oak bark.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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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.