PAPER making! g! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 11, Number 3, 2025
removed in anaerobic process through CaCO 3 precipitation, which mainly accumulated in the granular sludge core, and caused the decrease of sludge VSS/TSS. Sludge with low VSS/TSS located at the bottom and the top of the reactors. The ash content of sludge at the bottom of the reactors reached more than 70%, and CaCO 3 accounted for over 55% of the total anaerobic sludge. The calculation of chemical equilibrium model and water stability showed that the effluent of the anaerobic reactors still had a strong tendency towards scaling, although 50% of Ca 2+ was removed. These findings highlight the importance of managing calcium levels in zero-liquid discharge paper mills to optimize wastewater treatment and prevent operational issues. “Membrane-Assisted Technologies for Treating Pulp and Paper Industry Wastewater”, Richa Aggrawal, Jitender Dhiman, Anshu, Shrutikona Das, Kumar Anupam & Ashwani Kumar Dixit, in Green Technologies for Industrial Contaminants , Book Editors:Riti Thapar Kapoor, Rachana Singh, Wiley. The pulp and paper industry (PPI) is a water-intensive industry. It utilizes billions of cubic meters of water in the papermaking process. After that it produces an enormous amount of wastewater enriched with various contaminants, including biological oxygen demand, chemical oxygen demand, turbidity, color, heavy metal ions, etc. Eliminating these contaminants from PPI wastewater is necessary to meet the norms of various regulatory authorities to preserve the environment and human health. Literature suggests that these water pollutants from PPI can be treated using various technologies such as filtration, adsorption, precipitation, electrodialysis, coagulation, flocculation, floatation, ion-exchange, etc. Nevertheless, these techniques have several de-merits, like the massive requirement of physicochemical reagents, non- uniform pollutant removing capacity, generation of secondary hazardous solid waste, etc. Though these methods can sufficiently treat the above-mentioned impurities from PPI wastewater, the membrane technologies are known for a higher level of performance either implemented individually (reverse osmosis, ultrafiltration, and nanofiltration) or in hybrid configuration (reverse osmosis + ultrafiltration + nanofiltration, membrane + adsorption, membrane distillation, etc.). This chapter aims to present an anthology of different membrane-based techniques; operating parameters; and types, configuration, and characterization of membranes used for evaluation of membrane-based processes concerning the PPI wastewater treatment. WOOD PANEL “Use of secondary fibres from recycling processes of fibreboard manufacturing and post-consumer waste in medium density fibreboard”, Changling Xu, Joran van Blokland, Inês F. Mota, Percy Alao, Geoffrey Daniel & Stergios Adamopoulos, European Journal of Wood and Wood Products , 83(5), article number 170, (2025). Recycling medium-density fibreboard (MDF) enhances material efficiency and contributes to waste management. This study investigates the impact of secondary fibres, generated from recycling of both processing and post-consumer waste, on the properties of new MDF panels. The fibres were recycled using a modified thermo-mechanical pulping (mTMP) and steam treatment (ST) processes. Virgin pine and secondary fibres were studied for their size distributions and morphological features. MDF panels were fabricated by substituting virgin fibres with secondary fibres at 15% and 25% rates, with additional 100% recycled MDF produced using ST-obtained fibres. Secondary fibres from both waste sources were shorter and had more fines than virgin fibres. For recycled MDF incorporating ST fibres, a notable drop in internal bond strength was observed when using fibres from post-consumer fibreboard waste, while modulus of rupture, modulus of elasticity, thickness swelling, and water absorption remained consistent. Increasing substitution rates from 15 to 25% resulted in an insignificant change in the aforementioned physical and mechanical properties.
Technical Abstracts
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