Volume 19 Issue 4

In order to alleviate environmental pollution and the waste of resources caused by improper disposal of fungal residue, this study used fungal residue waste, which was treated with NaClO alkaline solution and nitric acid ethanol method for rough fiber preparation. The enzymatic hydrolysis of cellulase conditions were optimized using response surface optimization method, and the optimal preparation parameters were: enzyme addition of 5000 U/g, enzymatic hydrolysis temperature of 52 °C, enzymatic hydrolysis time of 2.65 h, and solid-liquid ratio of 1:20. The Fr-MCC purity reached over 97%. The Fr-MCC obtained had an irregular granular or lamellar aggregation morphology, typical I-type cellulose crystal structure and molecular features, good thermal stability, and was similar in properties to commercial MCC. It was judged to be suitable for further processing and manufacturing of biological base materials. This approach was shown to improve the utilization efficiency of cultivation residues, reducing environmental pollution caused by the accumulation of cultivation residues, and providing new methods and ideas for the preparation of MCC and other bio-based materials.

This study used a sub-model within system dynamics to simulate and quantify CO₂ emissions in the residential sector, focusing on the Nishikawa forestry region in Saitama Prefecture. The model evaluated emissions from the life cycle of houses, including production, transportation, use, maintenance, and disposal. The business as usual (BAU) scenario projects annual new housing inflows. The woody biomass utilization (WBU) scenario showed a 10% carbon reduction over 30 years by replacing new housing with timber construction, despite increased emissions from new constructions. The study highlights the economic benefits of utilizing carbon credits to support reforestation, making it possible to secure the sustainability of regional forestry to supply timber materials to the residential sector.

Addressing the issue of low effective utilization of moso bamboo in Zhejiang Province, this study investigated the impact of varying camphor leaf powder content on the granulation quality of bamboo fiber biomass pellets, using moso bamboo fibers and camphor tree leaves from Zhejiang as raw materials. Experimental analysis examined moisture content, mixing ratio, and molding pressure effects on pellet density and mechanical durability. The experimental results revealed that under the same conditions, the performance of bamboo fiber pellets without camphor leaf powder is significantly inferior to those containing camphor leaf powder. As moisture content rose from 3% to 9%, pellet density and durability increased, but further increases to 18% led to their decline. Orthogonal experiments demonstrated that both moisture content and molding pressure had significant effects on density and mechanical durability. The calorific value test results indicated that the higher heating value of the mixed pellets reached 4380 Kcal/kg. The findings of this study provide insights for enhancing the utilization efficiency of moso bamboo and camphor tree leaf resources.

Radial variation in uniseriate ray characteristics of six Korean oak species was observed to provide information for wood identification and quality evaluation. Radial variations in uniseriate ray characteristics, such as ray height, number, and spacing, were observed at five growth ring intervals from the pith to near the bark using optical microscopy. The transition point between the juvenile and mature wood was evaluated using a segmented regression model. All species showed a comparable trend in uniseriate ray number and spacing, gradually decreasing from the pith to near the bark. Transition zones for the six Korean oak species ranged from 21 to 39 years of growth. The highest uniseriate ray heights and spacings were observed in Quercus aliena. Quercus dentata exhibited the highest number of uniseriate rays. Across all species, uniseriate ray number and spacing were higher in juveniles than in mature wood. A negative correlation was observed between the uniseriate ray number and spacing and the uniseriate ray height. The strongest positive correlation was observed between uniseriate ray number and ray spacing. The most reliable parameters for estimating the demarcation point were uniseriate ray number and spacing. The ray characteristics may be used to identify the six Korean oak species.

This study examines the potential of integrating leaching and torrefaction processes to create an enhanced solid biofuel from lignocellulosic biomass. The focus is on evaluating the impact of these combined methods on ash removal efficiency and the melting characteristics of the treated biomass. Two possible strategies were considered: implementing torrefaction first followed by leaching, or conducting leaching first followed by torrefaction. By incorporating both leaching and torrefaction treatments, regardless of order, a solid biofuel with improved properties was attained, especially in terms of higher heating value yield and ash melting temperature compared to individual treatment (either only torrefaction or only leaching). Depending on the sequencing of the leaching treatment, there was a reduction in ash yield from raw biomass ranging between 60% – 86%, while for torrefied biomass it ranged between 47% – 68%. Leaching treatment before torrefaction treatment was determined to be a more effective combination.

The valorization potential of industrial walnut pruning wastes was investigated as a value-added product. Nanofibrillated cellulose (NFC) was prepared from walnut pruning wastes via hydrated choline chloride-lactic acid deep eutectic solvent (ChCl-LA DES) pretreatment followed by grinding, and these were used as paper strength additives. The effect of reaction time on NFC properties were investigated and compared. The structure of nanocellulose was determined by Fourier transform infrared, scanning electron microscopy (SEM), and rheological analysis. The results show that carboxylated NFC having high aspect ratio could be successfully isolated after DES-pretreatment with the average diameter of 39 to 77 nm. Prepared NFC was added to the bulk suspensions of papermaking slurries at various percentages (up to 8%) together with poly(diallyldimethylammonium chloride). The drainage and electrokinetic properties of the pulp and mechanical properties of fabricated handsheets were analyzed and compared. The addition of 1% NFC to the bulk suspensions increased tensile index by 14.2% and burst index by 6.3%. There were further increases observed up to 71.8% in tensile index and up to 72.3% in burst index at 8% NFC addition. Results indicate that DES pretreated cellulose nanofibrils have great potential as reinforcing agent in papermaking.

The effects of pressing time were evaluated relative to the physical, mechanical, and morphological properties of flat-pressed composites made from Gmelina arborea bark and recycled polypropylene (RPP). Bark powder (5% moisture content) was mixed with RPP pellets in a weight ratio of 40:60 with added maleic anhydride (MAH) as compatibilizer. The materials were mixed in a rotary blender for 15 min at speed 80 rpm until homogeneous. The mixture was heated from 175 to 200 °C until RPP pellets were completely melted and then cooled to room temperature. Afterwards, the mixture was made into powder and molded using a steel plate mold at 175 to 200 °C and pressure of 30 kg/cm² for 2, 4, and 6 min to a targeted density of 1.0 g/cm³.  The tested physical properties were covered density, moisture content, water absorption, and thickness swelling. The mechanical properties modulus of elasticity (MOE) and modulus of rupture (MOR), tensile strength parallel to length of panel were also examined. Research results showed that the properties were significantly affected by pressing time and it can be concluded that the optimum condition was obtained at 4 min of pressing.

In China, many tea seeds, the ripe seeds of the tea plant (Camellia sinensis (L.) O. Kuntze), are discarded as agricultural waste. Therefore, the tea seed oil that could have been obtained from tea seeds has also been wasted. To fully understand the content and efficacy of the main active ingredients in tea seed oil (TSO), the chemical composition and activity characteristics of TSO in different areas of Guizhou, China were investigated. The results demonstrated that TSO had high content of unsaturated fatty acids (UFA) and good skincare properties, such as anti-oxidation, anti-ultraviolet, moisturizing, whitening, and bacteriostasis. Furthermore, TSO showed a scavenging effect on reactive oxygen species in mouse fibroblasts cells (L929) and rat cardiomyocytes cells (H9C2). TSO exhibited high biocompatibility and promoted the proliferation and migration of L929. Southwest Guizhou (T4) and southern Guizhou (T6) might be used as high-quality producing areas for cosmetic oil by the weight analysis of each indicator. In summary, as the main producing area of tea in the world, this study helps to alleviate the problem of low oil self-sufficiency in China. The work offers a scientific basis for the in-depth development of TSO, especially in the field of skin care.

The high global market value of fresh mushrooms implies high importance of spent mushroom substrate (SMS) as a by-product that poses environmental challenges, if not properly treated. Reported studies demonstrate the positive effects of SMS on earthworm growth and reproduction, particularly when combined with other substrates such as cow dung (CD). This study utilized SMS and CD as substrates in varying ratios. A total of 375 young non-clitellated Eisenia fetida were randomly assigned to plastic containers, ensuring similar average individual worm weight, and maintained at 50% to 60% moisture. Weekly observations were made on earthworm average weight, cocoon production, and hatchling count. The growth and reproduction of earthworms differed significantly among treatments, with Treatment 3 (T3) (50:50 SMS and CD) showing the highest growth and Treatment 5 (T5) (0:100 SMS and CD) the lowest. Changes in pH, EC, total Kjeldahl nitrogen (TKN), total organic carbon (TOC), C/N ratio, and total available phosphorus (TAP) were observed over the experimental period, indicating dynamic nutrient dynamics within the substrates. The exchangeable potassium decreased with increasing proportions of CD, while the exchangeable sodium content showed variation across treatments. The observed variations can be attributed to differences in initial substrate composition and microbial activity during vermicomposting.

There is a growing demand for wood products from forests located in dry regions, which includes the Caatinga, a biome in Northeast Brazil. This study evaluates the relationship between volumetric production, energy potential, and the rotation cycle. Information was collected from forest stands in different stages of regeneration located in an arid region of Brazil. Based on the forest management plan, four fields were selected with post-logging ages of 9, 11, 13, and 16 years. This inventory recorded circumference at chest height, circumference at base height, total height, volume, stored energy, technical cutting age, and rainfall index. The results showed that the species that presented the most significant quantity of stems did not always correspond to those that obtained the most significant amount of biomass. The technical cutting age was determined at 16 years, aiming to maximize wood utilization. Regarding energy density, the 9-year-old field reached 7,281 kcal ha^-1, the 11-year-old field obtained 14,448 kcal ha^-1, the 13-year-old field recorded 41,526 kcal ha^-1, and the 16-year-old field reached 98,190 kcal ha^-1. The species that contributed most to energy accumulation included Mimosa tenuiflora with 3,740 kcal m^–³, Piptadenia stipulacea with 3,271 kcal m^-3, and Cenostigma pyramidale with 3,101 kcal m^-3.