Transformative and sustainable insights of agricultural waste-based adsorbents for water defluoridation: Biosorption dynamics, economic viability, and spent adsorbent management.

With the progression of civilization, the harmony within nature has been disrupted, giving rise to various ecocidal activities that are evident in every spheres of the earth. These activities have had a profound and far-reaching impact on global health. One significant example of this is the presence of fluoride in groundwater exceeding acceptable limits, resulting in the widespread occurrence of "Fluorosis" worldwide. It is imperative to mitigate the concentration of fluoride in drinking water to meet safety standards. While various defluoridation techniques exist, they often have drawbacks. Biosorption, being a simple, affordable and eco-friendly method, has gained preference for defluoridation. However, its limited commercialization underscores the pressing need for further research in this domain. This comprehensive review article offers a thorough examination of the defluoridation potential of agro-based adsorbents, encompassing their specific chemical compositions and preparation methods. The review presents an in-depth discussion of the factors influencing fluoride biosorption and conducts a detailed exploration of adsorption isotherm and adsorption kinetic models to gain a comprehensive understanding of the nature of the adsorption process. Furthermore, it evaluates the commercial viability through an assessment of regeneration potential and a cost analysis of these agro-adsorbents, with the aim of facilitating the scalability of the defluoridation process. The elucidation of the adsorption mechanism and recommendations for overcoming challenges in large-scale implementation offer a comprehensive outlook on this eco-friendly and sustainable approach to fluoride removal. In summary, this review article equips readers with a lucid understanding of agro-adsorbents, elucidates their ideal conditions for improved performance, offers a more profound insight into the fluoride biosorption mechanism, and introduces the concept of effective spent adsorbent management.

Synthesis of Cellulose Nanocrystals/HKUST-1 Composites and Their Applications: Crystal Violet Removal and Doxorubicin Loading.

This study developed a novel composite material containing cellulose nanocrystals (CNCs) and HKUST-1. Here, the addition of CNCs was used to enhance the characteristics of HKUST-1 in terms of surface area, adsorption ability, and functional groups. Here, the fabrication of CNCs@HKUST-1 composites was carried out by adding CNCs into the fabrication process of HKUST-1. The addition of CNCs provides additional functional groups on the surface of composite material which can be used to attach other organic compounds, such as in waste management and drug delivery systems. Here, CNCs@HKUST-1 composites were tested as a material for crystal violet (CV) removal and doxorubicin (DOX) loading. The removal capacity of CNCs@HKUST-1 composite towards CV molecules reached 1182.25 ± 27.74 mg/g, while the loading capacity for DOX drugs was around 1514.94 ± 11.67 mg/g. Both applications showed that CNCs@HKUST-1 composite had higher adsorption capacity and ability compared to its precursor materials, i.e., CNCs and HKUST-1.

Statistically Optimum HKUST-1 Synthesized by Room Temperature Coordination Modulation Method for the Adsorption of Crystal Violet Dye.

Due to its excellency and versatility, many synthesis methods and conditions were developed to produce HKUST-1 ([Cu3(BTC)2(H2O)3]n). However, the diversity of HKUST-1 was actually generated both in terms of characteristics and morphologies. Hence, the consistency of HKUST-1 characteristics and morphologies needs to be maintained. The statistical analysis and optimization provide features to determine the best synthesis condition. Here, a room-temperature coordination modulation method was proposed to maintain the morphology of HKUST-1 while reducing energy consumption. In addition, response surface methodology (RSM) was used to demonstrate the statistical analysis and optimization of the synthesis of HKUST-1. The molar ratio of ligand to metal, reaction time, and acetic acid concentration were studied to determine their effects on HKUST-1. The optimum HKUST-1 was obtained by the synthesis with a molar ratio of ligand to metal of 0.4703 for 27.2 h using 5% v/v acetic acid concentration. The statistical analysis performed a good agreement with the experimental data and showed the significance of three desired parameters on HKUST-1. The optimum HKUST-1 had the adsorption capacity of 1005.22 mg/g with a removal efficiency of 92.31% towards CV dye. It could be reused up to 5 cycles with insignificant decrease in performance.

Facile and Green Synthesis of Starfruit-Like ZIF-L, and Its Optimization Study.

Due to its excellent characteristics, zeolitic imidazole framework-L (ZIF-L) is widely used in various applications, such as drug delivery, wastewater treatments and energy storage. In the synthesis of ZIF-L, the molar ratio of ligand to metal, the reaction time and the temperature are essential parameters to produce excellent ZIF-L. In this work, ZIF-L was synthesized using a facile and green synthesis method. It was statistically investigated and optimized to obtain the best operating conditions. The optimization was carried out toward the amount of adsorbed crystal violet (CV) dye (q) as the response in the statistics. The optimal ZIF-L was obtained using a molar ratio of ligand to metal of 8.2220 for 97 min at 29 °C, where the q value of the CV adsorption onto this optimal ZIF-L reached 823.02 mg/g. The obtained ZIF-L was characterized using SEM, XRD, FTIR and TGA analyses to ensure its excellent characteristics.

A Review of Lignocellulosic-Derived Nanoparticles for Drug Delivery Applications: Lignin Nanoparticles, Xylan Nanoparticles, and Cellulose Nanocrystals.

Due to their biocompatibility, biodegradability, and non-toxicity, lignocellulosic-derived nanoparticles are very potential materials for drug carriers in drug delivery applications. There are three main lignocellulosic-derived nanoparticles discussed in this review. First, lignin nanoparticles (LNPs) are an amphiphilic nanoparticle which has versatile interactions toward hydrophilic or hydrophobic drugs. The synthesis methods of LNPs play an important role in this amphiphilic characteristic. Second, xylan nanoparticles (XNPs) are a hemicellulose-derived nanoparticle, where additional pretreatment is needed to obtain a high purity xylan before the synthesis of XNPs. This process is quite long and challenging, but XNPs have a lot of potential as a drug carrier due to their stronger interactions with various drugs. Third, cellulose nanocrystals (CNCs) are a widely exploited nanoparticle, especially in drug delivery applications. CNCs have low cytotoxicity, therefore they are suitable for use as a drug carrier. The research possibilities for these three nanoparticles are still wide and there is potential in drug delivery applications, especially for enhancing their characteristics with further surface modifications adjusted to the drugs.

Hydrophobic Cetyltrimethylammonium Bromide-Pillared Bentonite as an Effective Palm Oil Bleaching Agent.

To promote a minimal use of acid in the activation of bentonite and to maintain oil quality during refinery and storage, a new class of bleaching agent, cetyltrimethylammonium bromide (CTAB)-pillared bentonite (CTAB@Bent), is fabricated. The influences of three independent intercalation variables, including temperature T (40, 50, and 60 °C), time t (2, 4, and 6 h), and CTAB loading m c (0.2, 0.25, 0.33, 0.50, and 1.00%, w/w), on the ß-carotene removal rate are studied. The multilevel factorial design combined with the response surface methodology and three-way analysis of variance is employed to design and optimize experiments in regard to the three independent variables. Based on the optimization results, the highest ß-carotene removal rate is monitored at 71.04% (w/w) using CTAB@Bent obtained at optimum intercalation conditions (CTAB@Ben-Opt): T = 40 °C, t = 3.2 h, m c = 1.00% (w/w). The mechanism study shows that the adsorption of ß-carotene onto CTAB@Bent-Opt is spontaneous and endothermic, with the governing steps of physical interaction and ion exchange between ß-carotene and the cationic head of CTAB. CTAB@Bent-Opt also exhibits characteristics superior to those of commercial raw bentonite and acid-activated bentonite, indicating that a more efficient ß-carotene removal can be achieved using this new bleaching agent.

Hydrophobic Modification of Cellulose Nanocrystals from Bamboo Shoots Using Rarasaponins.

Because of their hydrophilic tendencies, the modification of cellulose nanocrystals (CNCs) is needed for applying them as a hydrophobic drug carrier. Previous studies have investigated several modification agents, such as cetyltrimethylammonium bromide. Natural surfactants, such as rarasaponins (RSs), are suitable to avoid human health and environmental issues. In this work, RSs were attached onto CNCs from bamboo shoots to enhance their hydrophobicity. The initial RS concentration and the operating temperature were studied to obtain the best conditions for the modification process, which had significances (p-value < 5%) toward the amount of RSs linked on the CNCs (q) as the response. A q as high as 203.81 ± 0.98 mg/g was obtained at an initial RS concentration of 2000 mg/L and an operating temperature of 30 °C. The curcumin uptake on CNCs-RSs reached 12.40 ± 0.24%, while it was slowly released until approximately 78% in 3 days.

Optimization of cellulose nanocrystals from bamboo shoots using Response Surface Methodology.

Cellulose-based advanced materials, such as cellulose nanocrystals (CNC), have high potential application for drug delivery system. In this study, the CNC were produced from bamboo shoots using acid hydrolysis process. The delignification of bamboo shoots was conducted using alkali and hydrogen peroxide pretreatment processes. The operating condition of the production of CNC from bamboo shoots was optimized using Response Surface Methodology (RSM) based on the yield and crystals recovery as the responses. The optimum CNC yield of 50.67 ± 0.74% with a crystals recovery of 77.99 ± 1.14% was obtained at the sulfuric acid concentration of 54.73 wt% and a temperature of 39 °C from the optimization based on the yield. This optimization has been validated to confirm the accuracy.

Cellulose nanocrystals from passion fruit peels waste as antibiotic drug carrier.

Due to its excellent chemical and physical properties, cellulose nanocrystals (CNC) possess many potential advanced functional applications. In this study, CNC was extracted from natural product by hydrolyzing cellulose segment of passionfruit peels using sulphuric acid solution. The capability of CNC as drug carrier was tested toward tetracycline antibiotic. The drug loading processes were carried out at various pH (3-7) with the optimum uptake of tetracycline achieved at pH 3. The in vitro release of tetracycline drug was carried out in phosphoric buffer medium with two different pH conditions at 37°C. The highest release of tetracycline (82.21%) was achieved at pH 7.2, while the lowest one (25.1%) was achieved at pH 2.1, where the release pattern follow a second order kinetic model. This study highlight the potential application of CNC derived from natural resources as drug carrier without harmful chemical excipients that comply with health safety, biocompatible, biodegradable.