Functionalized cellulose nanocrystals prepared from microwave-acidic deep eutectic solvent pretreated pineapple leaf waste for heavy metal adsorption

Nitrocellulose is widely used as a key energetic material due to its high combustion efficiency and strong ignition characteristics. This study investigates the effect of nitration temperature and reaction time on the synthesis of nitrocellulose derived from pineapple leaf waste, an abundant lignocellulosic by-product. Pineapple leaf cellulose was nitrated using 65% HNO 3 and 98% H 2 SO 4 at temperatures of 5°C, 10°C, and 15°C with reaction times of 40, 50, and 60 min. The resulting nitrocellulose was washed and neutralized before undergoing combustion analysis and FTIR characterization. The combustion test showed that samples treated at 10°C and 15°C for 60 min exhibited the strongest flame intensity, indicating a higher degree of nitration. FTIR spectra confirmed the formation of nitro groups, as demonstrated by absorption peaks around ~1270 cm −1 and ~1645 cm −1 accompanied by a reduction in −OH intensity. The combined results confirm that both temperature and duration strongly influence the nitration process, with optimal conditions achieved at 60 min and moderate temperatures. Nitrocellulose synthesized under these conditions demonstrates properties consistent with potential applications in propellant formulations.

Bioprocessing of pineapple leaf waste biomass using an integrated ultrasound-deep eutectic solvent pretreatment approach for improved bioethanol production.

Adsorption of heavy metals on the surface of nanofiltration membranes: “A curse or blessing”?

"Various agricultural and industrial activities produce natural fibre waste that can harm the environment if not disposed properly. These wastes contain valuable plant nutrients that need to be recycled to sustain soil quality and health, and reduce environmental pollution. Composting is an efficient, sustainable, and inexpensive way to treat solid wastes. This study focused on the preparation of composts from jute leaf waste, pineapple leaf wastes, banana pseudo stem waste along with retting liquors as bio-enhancers and to evaluate their quality. The quality of compost determines its ability to perform its projected function. The feedstocks are the main factor that affects the compost qualities, but the composting process also counts. The compost and retting liquors were tested in the laboratory for different parameters such as electrical conductivity, pH, organic carbon, total nitrogen, total phosphorus and potassium, micronutrients, heavy metals and C/N ratio. The results showed that compost made from natural fibre and bio-enhancer i.e. retting liquor can be a good source of plant nutrition and microbial activity. Pineapple leaf waste had a higher C: N ratio than jute leaf waste which resulted faster decomposition of jute leaves. Retting liquor had more bacteria than fungi. No actinomycetes were seen in the liquor. Waste wool had the highest nitrogen content among other fibre residues, so it can be a sustainable alternative to nitrogen source for crop nutrition. The quality evaluation will give us an insight on influence of compost produced from natural fibre waste in crop production."

Investigation of the adsorption of heavy metals (Cu, Co, Ni and Pb) in treatment synthetic wastewater using natural clay as a potential adsorbent (Sale-Morocco)

Pineapple leaf waste (Ananas cosmosus) contains a constituent component in the form of cellulose and lignin. Cellulose, hemicellulose, and lignin bind to each other to form lignocellulose. The high cellulose content can be used as an adsorbent through the process of delignification or removal of lignin. This study aims to determine the characteristics and ability of pineapple leaf cellulose to remover heavy Cu metals. Applied pineapple leaves to be used are equalized to 60 mesh then delignified for 70 and 90 minutes by mixing pineapple powder using 9% NaOH with a ratio of 1:30 (w/v). Pineapple leaves are characterized by chesson, SEM, and XRD analysis. The results of Chesson analysis showed that pineapple leaf cellulose had a cellulose content of 25.33% and the delignification time of 70 minutes resulted in the highest cellulose content of 59.12%. The XRD diffractogram showed pineapple leaf cellulose including type I cellulose. The highest degree of crystallinity was obtained by pineapple leaf cellulose with a delignification time of 90 minutes which was equal to 65.98%. The adsorption process was observed with variations in contact time 30, 60, 90, and 120 minutes. The highest Cu metal adsorption was pineapple leaves with a delignification process of 70 minutes with a contact time of 90 minutes.

Adsorption of heavy metals onto alkali-activated pervious concrete: Mechanism, long-term performance, and leaching behaviour.

Preparation and characterization of amino/thiol bifunctionalized magnetic nanoadsorbent and its application in rapid removal of Pb (II) from aqueous system.

This paper presents a comprehensive study of the differences in heavy metal adsorption on natural, modified, and synthetic zeolites. Heavy metal treatment and adsorption are critical issues in today's modern world, and despite advancements in technology, they remain a global challenge. Industrial effluents are a major source of heavy metal pollutants, which have a severe impact on human health and the environment. Therefore, removing heavy metals from contaminated water and wastewater is a necessity. Adsorption is the most commonly used method for removing heavy metals from the environment due to its cost-effectiveness, design, and performance. Among various adsorbents, zeolites are currently considered a suitable method due to their cost-effectiveness, simplicity, and the varying ion-exchange capacity of natural zeolites worldwide for cations such as ammonium and heavy metal ions. The findings of this research could provide useful information for developing efficient and cost-effective methods for the removal of heavy metals from water and wastewater, thus addressing a critical global issue. The outcomes of this research contribute to promoting a green and healthy environment.

Heavy metal pollution has become one of the most important global environmental issues. The human health risk posed by heavy metals encountered through the food chain and occupational and environmental exposure is increasing, resulting in a series of serious diseases. Ingested heavy metals might disturb the function of the gut barrier and cause toxicity to organs or tissues in other sites of the body. Probiotics, including some lactic acid bacteria (LAB), can be used as an alternative strategy to detoxify heavy metals in the host body due to their safety and effectiveness. Exopolysaccharides (EPS) produced by LAB possess varied chemical structures and functional properties and take part in the adsorption of heavy metals via keeping the producing cells vigorous. The main objective of this paper was to summarize the roles of LAB and their EPS in the adsorption and detoxification of heavy metals in the gut. Accumulated evidence has demonstrated that microbial EPS play a pivotal role in heavy metal biosorption. Specifically, EPS-producing LAB have been reported to show superior absorption, tolerance, and efficient abatement of the toxicity of heavy metals in vitro and/or in vivo to non-EPS-producing species. The mechanisms underlying EPS-metal binding are mainly related to the negatively charged acidic groups and unique steric structure on the surface of EPS. However, whether the enriched heavy metals on the bacterial cell surface increase toxicity to local mammal cells or tissues in the intestine and whether they are released during excretion remain to be elucidated.

The isolation of nanocellulose has been extensively investigated due to the growing demand for sustainable green materials. Cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs), which have the same chemical composition but have different morphology, particle size, crystallinity, and other properties depending on the precursor and the synthesis method used. In comparison, CNC particles have a short rod-like shape and have smaller particle dimensions when compared to CNF particles in the form of fibers. CNC synthesis was carried out chemically (hydrolysis method), and CNF synthesis was carried out mechanically (homogenization, ball milling, and grinding), and both can be modified because they have a large surface area and are rich in hydroxyl groups. Modifications were made to increase the adsorption ability of heavy metal ions. The Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric (TG), and dynamic light scattering (DLS) can reveal the characteristics and morphology of CNCs and CNFs. The success and effectiveness of the heavy metal adsorption process are influenced by a few factors. These factors include adsorbent chemical structure changes, adsorbent surface area, the availability of active sites on the adsorbent’s surface, adsorption constants, heavy metal ionic size differences, pH, temperature, adsorbent dosage, and contact time during the adsorption process. In this review, we will discuss the characteristics of CNCs and CNFs synthesized from various precursors and methods, the modification methods, and the application of CNCs and CNFs as heavy metal ion adsorbents, which includes suitable isotherm and kinetics models and the effect of pH on the selectivity of various types of heavy metal ions.

A new approach to “Greening” plastic composites using pineapple leaf waste for performance and cost effectiveness

Various kinds of plant natural fibers have been studied. Many of these are purposely grown for the fiber while some are derived from agricultural waste. A few types of plant natural fibers have been produced on a commercial scale. With various current problems facing us all today, the needs of plant natural fibers are even greater. There remains some fiber containing agricultural wastes which are underutilized. One of these is pineapple leaf waste. Pineapple leaf fiber (PALF) is known to possess high mechanical properties and can be obtained from pineapple leaf waste using different extraction methods. However, most of these methods are not suitable for large-scale production of the fiber for industrial uses. In addition, PALF produced with these methods is normally large in size, and this limits its applications. Recently, a novel method for the extraction of PALF has been presented. The method allows short and fine PALF to be produced. This PALF has diameter as small as 3 μm and with a cut length of 6 mm, the aspect ratio (length to diameter ratio) could be up to 2000. These characteristics make this PALF very suitable for the effective reinforcement of both plastics and rubbers. It will be demonstrated how to best utilize this PALF. This PALF could be surface treated or used in conjunction with compatibilizer or adhesion promoter as in other cellulose fibers. Recent progress will be presented and potential applications will be reviewed.

Pineapple leaf waste (PALW) is often perceived as an agricultural by-product with limited utility and lacking economic value. This study pioneers the evaluation of added value from pineapple leaf waste in Prabumulih. It explores innovative strategies for developing the Wiwa Producer Cooperative using the Hayami method and SWOT analysis. The findings reveal that all processed products, such as woven fabric and cloths, derived from pineapple leaf waste generated a high and profitable value-added ratio. A key strength factor is that the Miwa Pineapple Producer Cooperative is a pioneer of pineapple leaf processing in Prabumulih. However, significant weaknesses include limited human resources and capital, while opportunities exist in promotional events, and threats arise from the lengthy production process. The cooperative adopts an aggressive strategy, emphasising market penetration, market development, and product innovation through the Strengths-Opportunities (S-O) approach. The findings underline the economic potential of pineapple leaf waste as a sustainable resource, offering a pathway to rural economic empowerment and environmental conservation. This study provides actionable strategies for policymakers and cooperative leaders to enhance competitiveness, foster innovation, and promote sustainable practices in the agricultural sector. By participating in broader promotional events, maintaining product quality, expanding market reach, and innovating product offerings, the cooperative can ensure sustainable growth and contribute to the circular economy.

The use of lignocellulosic materials for extracting functionalized cellulose nanocrystals (FCNs) in a green and sustainable method under mild conditions is limited owing to the strong hydrogen bonding in cellulose. A facile, green, and high-efficient avenue was developed to produce FCNs with high yield through the mechanochemistry synergetic effect of recyclable p-toluenesulfonic acid (PTSA)-catalyzed deep eutectic solvent (PDES) and microwave- solvothermal (MWS). FCNs with a high charge density of 1.59 e nm−2, a crystallinity of 81%, a better thermostability and dispersibility were obtained at a high yield of 87.6% by the one-step processing. The PDES could be easily recycled, and thus was beneficial to cost reduction and waste liquor treatment. Generated FCNs could be used to develop functional bionanocomposites due to their enhanced effect. When a loading of 1 wt% FCNs was added into gelatin matrix, the tensile strength and Young’s modulus of the bionanocomposites increased 188 and 131%, respectively, suggesting their remarkable stress transfer potential. Thus, the study demonstrates a green and cost-effective approach for the mass production of FCNs, contributing to strong potential in building high-performance bionanocomposites.