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This study was aimed to use Cellulose dusts (CD) produced in drying section of paper mills of paper making industry as a potential adsorbent to remove methylene blue (MB) dye from aqueous solution.  The adsorbent was characterized by scanning electron microscopy and Fourier transform infrared spectrometer and X-ray Diffraction. The influences of the effective parameters including pH solution, adsorbent dosage, initial MB concentration, and contact time were optimized by CCD which stands for central composite design. The influence of these parameters on the adsorption capacity was analyzed using the batch process. The accuracy of the equation that is produced by CCD was affirmed by the variance analysis and also by calculating the correlation coefficient that connects the predicted and the empirical values of the percentage of removed MB dye. Maximum removal percentage of MB dye (98.05 %) which obtained at pH 9.84, adsorbent dosage 4.38 g L-1, MB concentration 75.50 g L-1 and time 208.13 min. Freundlich, Temkin, Harkins-Jura and Langmuir isotherms are used to analyze the empirical data. Results revealed that the data is in a satisfying agreement with the Freundlich isotherm (R2= 0.99). Pseudo-first order, Pseudo-second-order, Elovich and Intraparticle diffusion models were used to fit the kinetic data and it is found out that MB dye’s adsorption onto CD has a good agreement with the pseudo-second-order kinetic model. The results showed that CD can be an efficient and low-cost adsorbent for methylene blue adsorption.

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Precipitated calcium carbonate (PCC) filler is used in many industrial products like constructions, plastics, pharmaceutics, etc. In this study producing cationic precipitated calcium carbonate filler for paper industry was investigated. Hence, a cationic polyacrylamide and cationic corn starch have been incorporated into the PCC particles to produce a modified filler with cationic structure and improved hydrogen bonding ability with cellulose fibers. According to the FESEM and XRD results, cubic-like fillers with prominently calcite polymorph and a slight amount of aragonite were successfully produced from the industrial burnt lime using carbonation process. The presence of organic substances in the structure of the modified samples was confirmed by FT-IR analysis. Besides, based on the FESEM results, filler morphology and particle size could be affected by the polymer content. In conclusion, introducing cationic groups to mineral fillers could be considered as a possible strategy to overcome some detrimental effects of using mineral fillers in paper products.

The work demonstrates the utilization of fractionalized lignin from the black liquor of soda pulping for the development of starch-lignin biocomposites. The effect of ultrafine friction grinding on lignin particle size and properties of the biocomposites was investigated. Microscopic analysis and membrane filtration confirmed the reduction of lignin particle sizes down to micro and nanoparticles during the grinding process. Field Emission Scanning Electron Microscopy confirmed the compatibility between lignin particles and starch in the composites. The composite films were characterized for chemical structure, ultraviolet blocking, mechanical, and thermal properties. Additional grinding steps led to the reduction of large lignin particles and the produced particles were uniform. The formation of 7.7 to 11.3% lignin nanoparticles was confirmed in the two steps of membrane filtration. The highest tensile strain of the biocomposite films were 5.09 MPa, which displays a 40% improvement compared to starch films. Further, thermal stability of the composite films was better than that of starch films. The results from ultraviolet transmission showed that the composite films could act as an ultraviolet barrier in packaging applications.