PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 8, Number 1, 2022
From the comparative analysis, the bleaching wastewater sample was more polluted than that from pulping. EC, TDS, BOD5, COD, TOC and Pb were higher in the pulping wastewater sample which could be attributed to the organic nature of the starting material; bamboo and residues of the pulping agents; caustic soda and ammonia while Acidity, Turbidity, Temperature, DO, Ni, Co, THB and TF were higher in the bleaching wastewater sample and could be caused by the bleaching agents and the availability of microorganisms. The result showed that some parameters except BOD5, turbidity, COD, DO and pH from pulping fell within regulatory limit. This could be linked to the virgin fibre from bamboo applied which contains less pollutant compared to other industries using waste papers from different sources. WOOD PANEL “ Strength Properties of Full-Size Oriented Strand Board Panels Following Submergence in Potable and Salt Water ”, Tyler Strayhorn, Phil Mitchel & David Tilotta, Forest Products Journal , 72(1):, pp.58-66, (2022). One of the largest contributors to the economic loss from floods is the complete or partial destruction of residential buildings, and finding ways to eliminate or minimize this loss is important. Oriented strand board (OSB) is a wood product commonly used in home construction, so a better understanding of how flood water affects its mechanical properties is warranted. In this study, the moduli of elasticity and rupture (MOE and MOR, respectively) of representative samples removed from full-size (4 by 8-ft [1.2 by 2.4 m]) OSB panels were examined following the submergence of the panels in potable and salt water (surrogates for flood water) for increasing periods of time (i.e., 8, 24, 48, 72, 168, and 336 h). The results of our study show that after 8 hours of panel submersion in potable water, MOR and MOE is reduced by 15 percent and 16 percent, respectively; no significant change was observed in MOR and MOE for panels soaked in salt water. After 168 hours, the MOR loss was 43 percent for panels soaked in potable water and 38 percent for panels soaked in salt water. For MOE, there was a 35 percent loss regardless of water type. Submersion of panels in either water type for an additional 168 hours resulted in no significant change in MOR or MOE. The MOR and MOE of samples removed from the edges of the submerged panels, for both water types, were lower than those of the interior samples. Finally, the decreases in average MOR and MOE following submergence in either water type were approximately independent of brand. “ Utilization of activated carbon as an additive for urea-formaldehyde resin in medium density fiberboard (MDF) manufacturing ”, Rohullah Zamani, Saeed Kazemi Najafi & Habibollah Younesi, Journal of Adhesion Science and Technology , (2021) online. In this study, the MDF sanding dust was examined as a precursor for synthesizing activated carbon (AC). For this purpose, MDF sanding dust was impregnated with KOH at two different weight ratios 1:0.50 and 1:1 (sanding dust/KOH). The process was done in one step at a temperature of 750 °C and a heating rate of 8 °C/min. The synthesized ACs at different content were added into urea-formaldehyde (UF) resin for medium density fiberboard (MDF) production. The laboratory MDF boards were produced using a hot press at a temperature of 190 °C and pressure of 40 MPa. The ACs content in UF resin was set at 0.25%, 0.50% and 1% based on the dry weight of the resin. The ACs were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The BET equation was used to determine the specific surface area of the AC samples. Water absorption, thickness swelling, internal bonding, flexural modulus and strength, and the formaldehyde emission from MDF boards were determined. The curing behavior of UF resins were evaluated using Differential Scanning Calorimetry (DSC). The results revealed that surface area and micropore volume of ACs increase with
Technical Abstracts
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