Modulating the production of xylanase by Bacillus pumilus BS131 through optimization using waste fiber sludge

In recent days, cheapest alternative carbon source for fermentation purpose is desirable to minimize production cost. Xylanases have become attractive enzymes as their potential in bio-bleaching of pulp and paper industry. The objective of the present study was to identify the potential ability on the xylanase production by locally isolated Bacillus pumilus BS131 by using waste fiber sludge and wheat bran media under submerged fermentation. Culture growth conditions were optimized to obtain significant amount of xylanase. Maximum xylanase production was recorded after 72 hours of incubation at 30 °C and 7 pH with 4.0% substrate concentration. In the nutshell, the production of xylanase using inexpensive waste fiber sludge and wheat-bran as an alternative in place of expensive xylan substrate was more cost effective and environment friendly.

Effects of Flotation Deinking on Environmentally Friendly Offset Paper Printing Ink

Waste paper has become a promising raw material for the pulp and paper industry due to its low cost and because it is conducive to sustainable development. Unfortunately, waste paper contains a high volume of printed paper that is difficult to deink, which restricts its applications. Flotation deinking plays an essential role in the product quality and process cost of wastepaper recycling. This study was performed to evaluate the deinkability of environmentally friendly offset inks by flotation deinking. For this purpose, three series of four-color inks, namely, hybrid light emitting diode ultraviolet (LED‒UV), LED‒UV, and vegetable oil‒based inks, were printed on white lightweight coated papers under laboratory conditions. The deinking methodology involves repulping, deinking agent treatment, flotation, hand sheet making, and evaluation of the produced hand sheets. The obtained results indicated that the hybrid LED‒UV prints had the best deinkability. After flotation deinking, the deinking efficiency and the whiteness of the hybrid LED‒UV ink increased by 58.1% and 47.6%, respectively. LED‒UV ink had a 46.9% increase in the deinking efficiency and a 37.0% increase in the whiteness of the hand sheet. The deinking efficiency of the vegetable oil‒based ink was the lowest, at 42.1%, and the whiteness of the hand sheet increased only by 23.8%. The particle size distribution analysis demonstrated that the hybrid LED‒UV four-color ink exhibited a larger value of the average particle size than the two other. Scanning electron microscopy revealed that the hybrid LED‒UV ink particles on the surface of the fibers were the least abundant after deinking. The physical strength properties of the hand sheets, including tensile index, folding resistance, and cohesion of the hybrid LED‒UV, LED‒UV inks, and vegetable oil‒based inks, increased.

The Impacts of Calamity Logging on the Sustainable Development of Spruce Fuel Biomass Prices and Spruce Pulp Prices in the Czech Republic

Currently, due to the calamity of unplanned harvesting, the amount of biomass from wood products has increased. Forests occupy 33.7% of the total area of the Czech Republic; therefore, wood and non-wood forest products are important renewables for the country. Wood biomass consists mainly of branches and bark that are not used in the wood or furniture industry. However, it can be used in bioenergy, including wood processing for fuel. As spruce production in the Czech Republic increased from the planned 15.5 million to almost 36.8 million trees in 2020, the price of wood biomass can be expected to be affected. This study aims to develop a predictive model for estimating the decline in the price of wood biomass for wood processors, such as firewood or sawdust producers, as well as for the paper industry. Wood biomass prices are falling with each additional million m3 of spruce wood harvested, as is the decline in wood pulp, which is intended for the paper and packaging industries. The proposed predictive model based on linear regressions should determine how the price of wood biomass will decrease with each additional million harvested spruce trees in the Czech Republic. This tool will be used for practical use in the forestry and wood industry. The linear regression model is suitable for practical forestry use due to its simplicity and high informative value. The aim of the research is to model the dependence of the prices of firewood in the form of wood briquettes and pellets for domestic and industrial processing, as well as the prices of wood pulp on the volume of unplanned logging. It is a guide for the practice of how to use excess spruce wood from unplanned mining in the field of alternative processing with a sustainable aspect for households or heat production for households. The intention is to carry out modelling in such a way that it does not include prices of higher quality wood assortments, which are intended for the woodworking industry.

Performance of Alfa Fibres in Cementitious Materials Exposed to Diverse Surface Treatments

Alfa plant presents a great ecological and socio-economic interest in the Maghreb countries. It is used in several fields of applications such as craft production and paper industry. However, a few research work has been realized on the valorisation of Alfa fibres in the construction sector. The main objective of this work is to develop an Alfa fibre-reinforced mortar with significant mechanical properties for the facade panel’s manufacturing. It was highlighted that Alfa fibres enhance the flexural strength of reinforced mortars. Therefore, a decrease in the flexural strength of the composite after 90 days of curing. In addition, the incorporation of Alfa fibres reduced the compressive strength of the composite. In this regard, to enhance the mechanical properties of the composite, various treatments were explored: alkaline treatment with sodium hydroxide, hydrothermal treatment by water boiling, and coating with sulfoaluminate cement. It was noted that the treatments could provide a partial elimination of the non-cellulosic components and enhance the Alfa fibre roughness. Raw and treated Alfa fibres were incorporated into cement mortars at different lengths of the (10 and 20 mm) with an addition ratio of 1 %vol.. Compared to untreated fibres, fibres treated chemically provide an improvement of 38 % of the flexural strength at 28 days for both fibres length. Unlike the coated fibres, the efficiency of treatment was noted at 90 days of curing. Otherwise, a slight increase in compressive strength was observed compared to the untreated fibres mortar. These results were approved by porosity accessible to water and calorimetric tests.

Effect of incorporating different types of Sentang tree waste particle on the thermal stability of Wood Polymer Composite (WPC)

This article presents the potential use of tree waste materials such as the leaves (L), branches (B) and trunks (T) of Azadirachta excelsa (Sentang) tree in the production of wood polymer composite (WPC). The WPC was fabricated from high-density polyethylene (HDPE) as bonding matrix, maleic anhydride (MA) as coupling agent, and Sentang tree waste particles (L, B and T) as filler, prepared using twin-screw extruder followed by injection moulding machine. The effects of incorporating these types of Sentang tree waste particle (at 35% and 45% particles loading by weight) on the thermal stability of WPC were reported. The chemical compositions of L, B and T were also determined and their influences on the thermal stability of WPC were discussed. The thermal behaviour was determined by using thermogravimetric analysis (TGA), whereas the chemical analysis using Technical Association of the Pulp and Paper Industry (TAPPI) methods. The addition of these tree waste particles as filler has increased the thermal stability of WPC compared to virgin HDPE (without any particle incorporation). The highest mass loss was experienced by virgin HDPE. It was also observed that chemical compositions of the particles played vital role in influencing the thermal stability of WPC.

The Potential of Paper Industry Sludge Potency as Organic Soil Amandment

Sludge from the paper industry can affect soil fertility due to its organic content. However, sludge as waste has a contamination risk of polluting the soil. This research focused on the chemical properties content of sludge from the paper industry (pH, organic C, macro and micronutrients, heavy metals) and contaminant microbes (E. coli and Salmonella sp.) in order to evaluate to the potency of sludge to be soil amendment. Sludge sample was taken in 0-20 cm depth from Sumengko Village, Wringinanom, Gresik. The chemical properties were measured in Soil Chemistry Laboratory in Soil Science Department, and the biological properties were measured in Pest and Disease Laboratory in the Agricultural Faculty of Brawijaya University. The chemical and biological properties of sludge were compared to quality standards according to Keputusan Menteri Pertanian No. 261/2019 (Kepmentan No. 261/2019) from the Ministry of Agriculture, Indonesia. Sludge from the paper industry has the potency to be soil amendment because it meets the requirement from Kepmentan No. 261/2019. Its pH was neutral (6.9), the macro and micronutrients contents fit the requirement, and it had no microbial contaminant content. However, the organic C was under expectation, and it has over Hg content.

Delivery of DNA into Human Cells by Functionalized Lignin Nanoparticles

Lignin is an aromatic plant cell wall polymer that is generated in large quantities as a low-value by-product by the pulp and paper industry and by biorefineries that produce renewable fuels and chemicals from plant biomass. Lignin structure varies among plant species and as a function of the method used for its extraction from plant biomass. We first explored the impact of this variation on the physico-chemical properties of lignin nanoparticles (LNPs) produced via a solvent exchange procedure and then examined whether LNPs produced from industrial sources of lignin could be used as delivery vehicles for DNA. Spherical LNPs were formed from birch and wheat BioLignin™ and from poplar thioglycolic acid lignin after dissolving the lignin in tetrahydrofuran (THF) and dialyzing it against water. Dynamic light scattering indicated that the diameter of these LNPs was dependent on the initial concentration of the lignin, while electrophoretic light scattering indicated that the LNPs had a negative zeta potential, which became less negative as the diameter increased. The dynamics of LNP formation as a function of the initial lignin concentration varied as a function of the source of the lignin, as did the absolute value of the zeta potential. After coating the LNPs with cationic poly-l-lysine, an electrophoretic mobility shift assay indicated that DNA could adsorb to LNPs. Upon transfection of human A549 lung carcinoma basal epithelial cells with functionalized LNPs carrying plasmid DNA encoding the enhanced green fluorescent protein (eGFP), green foci were observed under the microscope, and the presence of eGFP in the transfected cells was confirmed by ELISA. The low cytotoxicity of these LNPs and the ability to tailor diameter and zeta potential make these LNPs of interest for future gene therapy applications.