Volume 21 Issue 1

This study demonstrated the conversion of a harmful weed into value-added product, biochar. Pyrolysis of water hyacinth biomass was carried out  in a semi-automated charcolator at 500 ºC (yield 36.7% ± 1.2%) and applied into the soil at three different concentrations (low, medium, and high). The biochar presented alkaline pH (8.4±0.04), moderate cation exchange capacity (1.83±0.04 meq/100g) and moderate electrical conductivity (2709±44.73 mS/cm). Fourier-transform infrared spectra indicated diverse types of functional groups (phenols, alcohols, unsaturated carbon compounds, and aromatic compounds) in Eichhornia crassipes biochar (ECB). Scanning electron microscopy and element dispersive X-ray analysis confirmed the high porosity (2.5 µm to 7.8 µm) and abundance of micro and macronutrients on biochar surface. Thermogravimetric analysis of ECB showed high thermal stability. Ameliorated soil edaphic parameters improved plant growth conditions. ECB added at medium concentration, remarkably increased shoot length and germination, and those of ECB added at high concentration recorded the highest chlorophyll content (60.5 SPAD). The experimental results showed favorable prospects for sustainable waste biomass recycling to produce valuable biochar, enhance soil health, and increase productivity of okra (Abelmoschus esculentus L.).

Traditional dining tables often lack adjustability in height, legroom, and operability for wheelchair users and disabled older adults, limiting their suitability in accessible dining contexts. This study proposes and evaluates three multifunctional dining table concepts tailored to diverse physical abilities. Field observations of home mealtime routines were conducted, user-journey maps were developed, and affinity diagramming was applied to synthesize requirements. Principal Component Analysis (PCA) reduced the dimensionality of the requirements and revealed latent factors shaping the accessible dining experience. Order Relation Analysis (ORA) and the Criteria Importance Through Intercriteria Correlation (CRITIC) method were used to derive combined subjective and objective indicator weights that informed the design specifications. Three wheelchair compatible prototypes were generated and comparatively assessed, and the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) identified the top-performing concept. Results indicate improvements in functional reach, operational convenience, and dining safety relative to conventional tables. The study provides a replicable workflow that integrates user research with multi-criteria decision making for accessible furniture design. Future work will embed sensing and actuation to enhance automation and adaptability, facilitating broader deployment in universal design.

The concentrated sulfuric acid/tert-butyl alcohol (TBA) hydrolysis system efficiently converts lignocellulose into monosaccharides and tert-butyl alcohol lignin (TBL), which exhibits thermal plasticity and a high solubility in common organic solvents. However, the reaction mechanism and the TBL chemical structure remain unclear. In this study, 2-methoxy-4-methylphenol (creosol, 4-methylguaiacol) was used as a model compound for the guaiacyl ring of lignin, and was treated with the concentrated sulfuric acid/TBA system to elucidate the chemical structure of TBL. At the beginning of this reaction, TBA rapidly reacted with 4-methylguaiacol to produce two main products. These products were fractionated using high-performance liquid chromatography and analyzed using nuclear magnetic resonance (NMR) spectroscopy to determine their chemical structures. The NMR spectra of the products revealed that the tert-butyl group was incorporated into either the ortho position of the phenolic OH group or the para position of the methoxyl group of 4-methylguaiacol. The former product was stable, whereas the latter gradually decomposed in the presence of sulfuric acid. This model experiment suggests that the consumption of anionic species on the lignin aromatic ring could be effective in preventing lignin self-condensation between the aromatic ring and the benzyl position of lignin under sulfuric acid treatment.

Softwood bleached chemi-thermomechanical pulp (SW-BCTMP) was added in tissue paper manufacturing, focusing on bulk, absorbency and strength performance. The SW-BCTMP exhibited high fines content (52.4%), elevated polymeric cationic demand (83.0 μeq·L⁻¹), and substantial zeta potential (-93.0 mV), which initially impaired both dynamic drainage performance and first-pass retention of pulp furnishes. The optimal application of polyaluminum chloride (PAC) was found to effectively reduce the cationic demand of pulp furnishes and enhance first-pass retention. The addition of 5.0 to 10.0% SW-BCTMP consistently enhanced the bulk, water absorbency, and air permeability of the handsheets. In the absence of polyamide-epichlorohydrin resin (PAE), dry strength was well maintained or even improved when substituting the bleached hardwood kraft pulp (BHKP), despite a marginal decline upon replacing the bleached softwood kraft pulp (BSKP). However, in PAE-containing systems, a consistent reduction in both dry and wet strength was observed. This detrimental effect was more pronounced when the SW-BCTMP replaced BSKP in the furnishes, which can be attributed to the interference of the SW-BCTMP with the adsorption and effectiveness of the wet-strength resin. The SW-BCTMP showed potential for enhancing bulk and absorbency in tissue products, such as toilet paper, where wet strength agents are not used.

This study aimed to synthesize nanoparticles by using zinc sulphate (ZnSO₄) with seed extract and bacterial processing. The resulting nano-biofertilizers were used to treat maize crop. Zinc nanoparticles were prepared by green synthesis using extract from Nigella seeds. Seed germination experiment was followed under salt stress in sand with three replications. Treatments included control (non-saline), saline, no-fertilizer, biofertilizer, Zn nanoparticles, and complete nano-biofertilizers applied at different concentrations. The rate of emergence was high in control as compared to saline conditions. Results indicated that control (non-saline) conditions were more efficient in stimulating the plant growth and the product had more potential to promote maximum yield in maize crop. Plants with the treatment of nano-biofertilizers gave higher yield as compared to the plants which were treated with nanoparticles or biofertilizers separately. Nanoparticles and biofertilizers both showed variations in plant yield. Characterization and morphological representation of plant samples (Zn-nano, biofertilizers, and nano-biofertilizers) was done by various analyses including SEM, FTIR, and XRD. It was concluded that nanoparticles and biofertilizers in combination can enhance the maize crop’s productivity and growth under certain favorable conditions and under salt stress.

The effect of compost on mercury content in sweet potatoes grown on soil contaminated by tailings was investigated in this study. In a completely randomized factorial design with three repetitions, the sweet potato MZ119 clone was planted on soil with a mixture of tailings at a ratio of 0%, 30%, 50%, 70%, and 100% (w/w) and compost amendment (0 g/pot, 250 g/pot, 500 g/pot, and 750 g/pot). The results of this study showed that an increase in the tailing contamination ratio led to an increase in mercury accumulation in sweet potatoes. In contrast, an increase in compost dosage reduced mercury accumulation. The results of the study showed that the mercury concentration in sweet potato tubers ranged from 0.153 to 0.802 mg/kg, which is above the threshold required for crops set by the WHO/FAO and other international standards. However, sweet potatoes exhibited a high mercury accumulation potential for mercury phytoremediation purposes, as they can accumulate mercury up to 18.15 mg/kg in their leaves.

Driven by the “double carbon” strategy, aiming at the potential of walnut shell, an agricultural and forestry waste, to replace wood in particleboard production, this study used walnut shell powder and wood shavings as raw materials, with melamine-modified urea-formaldehyde resin as the adhesive. A four-factor, three-level orthogonal experiment was conducted to investigate the effects of hot-pressing temperature, pressure, duration, and adhesive application level on the physical and mechanical properties of the panels. The optimal process conditions were 160°C, 4 MPA, 6 min, and a 14% adhesive application percentage. Under these conditions, the panel had a density of 0.70 g/cm³, and its modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding strength (IB), and 2-hour thickness swelling (2hTS) all exceeded the limits specified in GB/T 4897 (2015) by 30% to 60%. The order of influence of each parameter was hot-pressing temperature > adhesive application level > hot-pressing pressure > hot-pressing duration. This study established for the first time the optimal process window for walnut shell-based particleboard, demonstrating that a 30% wood substitution can balance performance and resource conservation, providing technical support for the green and high-value utilization of agricultural and forestry wastes.

Two types of wastepaper and a filter paper as a reference cellulose source were used for nanocellulose production. The production process of cellulose nanofiber (CNF) was conducted via mechanical disintegration following TEMPO oxidation, while the sulfuric acid hydrolysis method was applied for cellulose nanocrystal (CNC) production. The equivalent spherical diameters of CNFs were determined as 1520 nm for waste office paper (OP), 4920 nm for waste newsprint (NP), and 2180 nm for filter paper (FP). In contrast, the equivalent spherical diameters of CNCs were found to be 652 nm for OP, 2110 nm for NP, and 1090 nm for FP. The maximum crystallinity index was established to be 96.9% in the FP-CNC sample. Thermal degradation of raw material and deinked fiber samples for three different paper types occurred between 270 and 390 °C. Thermal degradation of CNF and CNC obtained from these paper types measured in the range of 240 to 360 °C and 140 to 600 °C, respectively. The FTIR analysis revealed chemical bond structures, such as O–H, C–H, C–O, C=O, CH₂, C–C, C–O–C, etc., forming in the raw material, deinked fiber, CNF, and CNC of the samples. Especially considering their crystallinity and thermal properties, it can be said that waste office paper is more suitable for nanocellulose production than waste newsprint.