Environmental and strength properties evaluation of bleached recycled pulp with calcium hydroxide

Document Type : Research Paper

Authors

1 M.Sc. Graduate, Wood Industry Engineering and Cellulosic Products, Gorgan University of Agricultural Sciences and Natural Resources, Iran.

2 Associate Prof., Dept. of Paper Science and Engineering, Faculty of Wood and Paper Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Iran.

3 Assistant Professor- Gorgan University of Agricultural Sciences and Natural Resources (GUASNR)- Faculty of Wood and Paper Engineering- Department of Paper Science and Engineering

Abstract

The aim of the current study was to investigate the effect of using different charges of calcium hydroxide (as an alternative alkali source for sodium hydroxide) in hydrogen peroxide bleaching system of recycled pulp on paper strength properties and chemical oxygen demand (COD) of wastewater. The pulp mixture including recycled 70% newspaper and 30% magazine was deinked using a conventional (chemical) system and then bleached using a conventional hydrogen peroxide system under specified process conditions. The results indicated that the use of calcium hydroxide was relatively effective in enhancing the paper strength properties so that at the usage range of 2-4% calcium hydroxide, no significant reduction was observed in strength properties. On the other hand, with increasing the charge of calcium hydroxide to more than 4%, the strength properties of the paper increased relatively compared to the control sample (conventional peroxide bleaching system including sodium hydroxide alkali). Maximum values of tensile (35.64 Nm/g) and burst (2.98 kPa.m2g-1) indices were determined in experimental run C5 (10% calcium hydroxide) and maximum tear index (6.88 mN. m2g-1) was observed in experimental run C1 (2% calcium hydroxide). The amount of wastewater COD was much less than the control sample when sodium hydroxide was removed completely and replaced by calcium hydroxide in hydrogen peroxide bleaching, so that with increasing calcium hydroxide usage from 2% to 10%, the wastewater COD amount was still less than the control sample. Also, the results of the evaluation of the scale amount in the experimental run included 2% calcium hydroxide in comparison with the control sample indicated that the amount of scale in the bleaching wastewater was 145.24 mg/ml with 2% calcium hydroxide and in the control sample was obtained 32.87 mg/ml.

Keywords

References

 
[1] Akbarpour, I., Ghasemian, A., Resalati, H. and Saraeian, A., 2018. Biodeinking of mixed ONP and OMG waste papers with cellulase. Cellulose Journal, 25 (2): 1265-1280.
[2] Khristova, P., Kordsachia, O., Patt, R. and Dafaalla, S., 2006. Alkaline pulping of some eucalypts from Sudan. Bioresource Technology, 97(4): 535-544.‏
[3] Bajpai, P., 2018. Fiber from Recycled Paper and Utilization. Biermann's Handbook of Pulp and Paper (3rd Edition), p. 547-582.
[4] Mehri Iraie, H.R., Ghasemian, A., Resalati, H., Saraeyan, A.R. and Akbarpour, A., 2014. Investigation on bleaching of mixed old newspaper and magazine deinked pulp with hydrogen peroxide. Journal of Forests and Wood Products, 67(3): 503-516. (In Persian).
[5] Helmling, O., Süss, U. and Eul, W., 1986. Upgrading of waste paper with hydrogen peroxide. In: Tappi Pulping Conference, Proceedings, Tappi Press, Atlanta, p. 407.
[6] Zeinali, F. and Dehghani, M., 2012. Evaluation of alkaline peroxide process and activated peroxide in chemical-mechanical pulp bleaching from hardwoods. Journal of Iranian Wood and Paper Industries, 3(2): 91-103. (In Persian).
[7] Doelle, K. and Bajrami, B., 2018. Sodium Hydroxide and Calcium Hydroxide Hybrid Oxygen Bleaching with System. In IOP Conference Series: Materials Science and Engineering, 301 (1): 1-12; IOP Publishing, doi:10.1088/1757-899X/301/1/012136.
[8] Strand, A., Korotkova, E., Willför, S., Hakala, J. and Lindstedt, E., 2017. The use of calcium hydroxide as alkali source in peroxide bleaching of kraft pulp. Nordic Pulp and Paper Research Journal, 32(3): 444-451.
[9] Qinghua, Xu., Yingjuan, Fu., Yang, Gao. and Menghua, Qin., 2009. Performance and efficiency of old newspaper deinking by combining cellulase/hemicellulase with laccase-violuric acid system. Journal of Waste Management 29(5): 1486-1490. https://doi.org/10.1016/j.wasman.2008.10.007
[10] Tschirner, U. and Wang, D., 1998. Hydrogen peroxide bleaching of recycle fiber. Paprican, Progress in Paper Recycling, 8(1):15-25.
[11] William, Scott., 1995. An introduction to paper properties (Translated by Afra, A) Tehran: Aiezh Publications, 2016. (In Persian).
[12] Bhardwaj, N. K. and Nguyen, K.L., 2005. Charges aspects of hydrogen peroxide bleached de-inked pulps. Colloids Surf. A, 262 (1): 232-2337.
[13] Environmental Express MicroVials provide quality COD test results at a savings for your laboratory. Using MicroVials for COD analysis is quick and easy. https://www.environmentalexpress. com/ee/s/article/cod-testing, Oct 28, 2021.
[14] Abd Rahman, N. S. and Azahari, B., 2012. Effect of calcium hydroxide filler loading on the properties of banana stem handsheets. BioResources Journal, 7(3): 4321-4340.‏
Iranian Journal of Wood and Paper Industries
Volume 13, Issue 1
June 2022
Pages 71-81

Files

Share

How to cite

Statistics