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Lahore, Pakistan

Aujla M.I.,Forman Christian College | Kashmiri M.A.,Board of Intermediate and Secondary Education Lahore | Ali B.,Packages Ltd
International Journal of Environment and Waste Management | Year: 2011

Characterisation and treatment of the black liquor coming from Chemi-thermo-mechanical pulping (CTMP) of wheat straw was evaluated in this research. Toxicity of the liquor was evaluated and it was found high in Biological Oxygen Demand (BOD) 0.45%, Chemical Oxygen Demand (COD) 1.85%, dissolved solids 1.04%, suspended solids 0.33%, total sulphur contents 2.42% and silica contents 0.45%. Activated sludge and chemical treatments were employed to make it environment-friendly. Activated sludge removed 63% total solids, suspended solids 90%, BOD 67% and COD up to 60%. Chemical treatment of this liquor involved use of anionic and cationic polymers together with alum to remove soluble COD and suspended solids from the liquor. Effluent thrown out after combined treatment was below 200 ppm in total solids, 300 FAU in turbidity, 700 ppm in BOD and 800 ppm in COD. Copyright © 2011 Inderscience Enterprises Ltd.

Yaqoob N.,Lahore College for Women University | Stack K.,University of Tasmania | Cheema K.J.,Lahore College for Women University | Mateen B.,Lahore College for Women University | Ishtiaq-Ur-rehman,Packages Ltd
Asian Journal of Chemistry | Year: 2011

In this study, the oxidative delignification and bleaching of alkaline sulphite-anthraquinone (AS/AQ) wheat straw pulp is reported. Oxygen, oxone and hydrogen peroxide were used to achieve targeted brightness > 80 % ISO without compromising the other pulp properties i.e., burst, tensile and tear index, kappa number, CED viscosity, hexenuronic acid, accelerated ageing and percentage yield of bleached pulp. The effect of various reaction parameters such as alkali, pulp consistency, temperature, time and bleaching agent dosage were optimized for each stage of bleaching.

Yaqoob N.,Lahore College for Women University | Stack K.,University of Tasmania | Ishtiaq-Ur-Rehman,Packages Ltd | Cheema K.J.,Lahore College for Women University | And 2 more authors.
Asian Journal of Chemistry | Year: 2011

The effect of each individual bleaching stage on the percentage composition of α-cellulose, acid insoluble lignin and hemicelluloses in multistage total chlorine free bleaching of alkaline sulphate/anthraquinone (AS/AQ) wheat straw pulp was studied by using standard TAPPI and GC methods, respectively. With AOOxP bleaching, > 85 % of pulp fibers were calculated to be composed of true cellulosic fibers, while acid insoluble lignin (%) contents decreased to as low as < 2.0 % as compared to an unbleached sample where pulp fiber constitutes 76.6 % α-cellulose and 7.6 % acid insoluble lignin. A statistical correlation was established and it was found that hemicelluloses are also responsible for ageing of pulp. Burst and tensile index were also found to be effected by changes in hemicelluloses (%) in pulp structure.

Ali I.,Packages Ltd | Ali I.,Joseph Fourier University | UrRehman S.,Packages Ltd | UrRehman S.,Jilin University | And 2 more authors.
Journal of Applied Polymer Science | Year: 2013

This study was focused on the improvement of mechanical strength properties of wheat straw-based paper through modification of wet-end cationic starch with borax. Borax has been used extensively in many industrial applications for its unique physical and chemical properties. We investigated the strengthening effect of borax-modified starch (BMS) as wet-end paper strength additive on the mechanical strength properties especially the tensile strength of wheat straw-based paper. Hand-sheets made of typical wheat straw-based papermaking furnish were investigated. Experimental results showed that BMS substantially increased the strength properties. Tensile index, elongation, tensile energy absorption, and wet tensile index were increased by 17%, 23%, 20%, and 21%, respectively. A short mill trial was also conducted on papermaking machine in which the impact of BMS on wheat straw-based low grammage paper (<90 gsm) was investigated. The objective of mill trial was to reduce costly virgin softwood pulp content in wheat straw-based paper recipe. Mill trial results showed similar trends in strength properties as in case of laboratory studies. Virgin softwood pulp was reduced from 30% to 25% in papermaking furnish. Furthermore, no sheet breaks were reported during trial which often happened due to poor strength of paper web. This study strongly suggests that modification of wet-end cationic starch with borax holds a tremendous potential as wet-end strength additive. It can provide significantly improved strength properties, reduction in softwood pulp costs, and better papermaking machine performance. © 2012 Wiley Periodicals, Inc.

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