Cellulose-derived polyols as high-capacity adsorbents for rapid boron and organic pollutants removal from water

Phenylboronic acid functionalized magnetic ferroferric oxide nanoparticles and capillary electrophoresis for efficient isolation of flavonoid compounds from leaves of Lonicera japonica Thunb

Flavonoids are bioactive components in natural products, which possess anti-inflammatory, antibacterial, antioxidant, and cardiovascular protective properties. However, due to the complexity and low content of the components in these samples, developing rapid and sensitive methods for the isolation and extraction of flavonoids still remains a challenge in medical and food science. Herein, a 4-formylphenylboronic acid functionalized magnetic Fe3O4 nanomaterial (Fe3O4@FPBA) was synthesized and applied as a sorbent of magnetic solid-phase extraction (MSPE) to covalently extract flavonoids from leaves of Lonicera japonica Thunb.. The structure, morphology and magnetic properties of Fe3O4@FPBA particles were characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and scanning electron microscope (SEM) technologies. Employing luteoloside, luteolin, lonicerin, hyperoside, quercetin and rutin as model compounds, Fe3O4@FPBA as sorbent, a MSPE coupling with capillary electrophoresis (CE) method was developed and optimized to detect the flavonoids. Adsorption kinetics display that the adsorption of flavonoids by Fe3O4@FPBA is in line with the Quasi-second-order model, which is controlled by chemisorption mechanism, with the equilibrium adsorption capacity ranging from 3.66 to 6.16 mg/g. The isothermal adsorption model shows that the adsorption is more consistent with Freundlich isotherm equation, and the exponent n is around 1. In addition, the material was applied to the leaves of Lonicera japonica Thunb. extract. Four kinds of flavonoids and three other o-hydroxyl compounds were covalently extracted and magnetically separated. Moreover, the material can still maintain high adsorption properties after recycling 5 times. The material possesses strong magnetism and boric acid ligands, which can realize rapid and high-capacity separation and enrichment of flavonoids in liquid samples. Therefore, the strategy offers an innovative method for the extraction and purification of flavonoids from complex natural plants and also provides a research basis for the discovery of new medicinal compounds based on natural products.

High efficiency adsorption of boron by sodium alginate/polyethyleneimine/polysiloxane composite aerogel

In this work, a new biomass boron adsorbent of N-methyl-D-glucosamine embedded sodium alginate/polyethyleneimine/polysiloxane composite aerogel (SKPN) was reported. Relevant characterization proved that the aerogel exhibited 3D porous structure with plenty of hydroxyl and amino functional groups, which was beneficial to the diffusion of boron and the chelation between boron and SKPN. Various parameters affecting the adsorption performance including pH value, contact time initial concentration, temperature and reusability were investigated. The maximum adsorption capacity was found at pH 8.0, and the adsorption capacity reached equilibrium within 3.75-5.75 h. Adsorption kinetics were more in line with the pseudo-second order kinetic model, suggesting the predominance of chemisorption. The adsorption isotherm was more in line with the Langmuir model, and the maximum adsorption capacities were calculated up to 38.41-49.39 mg/g (3.55-4.57 mmol/g) within the temperature range of 298 to 318 K, which were higher than most of the previous works. In addition, SKPN still showed good resistance to external ion interference and good reusability. The adsorption mechanism proved that the chelation interactions between boron and cis-diol and amino groups were the main driving forces. These results instructed that the adsorbent exhibited a good application prospect for boron adsorption, with the advantages of high adsorption performance, simple preparation process and environmental friendliness.

Assembly of Chitosan/Caragana Fibers to Construct an Underwater Superelastic 2D Layer-Supported 3D Architecture for Rapid Congo Red Removal

Developing environmentally friendly bulk materials capable of easily and thoroughly removing trace amounts of dye pollutants from water to rapidly obtain clean water has always been a goal pursued by researchers. Herein, a green material with a 3D architecture and with strong underwater rebounding and fatigue resistance ability was prepared by means of the assembly of biopolymer chitosan (CS) and natural caraganate fibers (CKFs) under freezing conditions. The CKFs can randomly and uniformly distribute in the lamellar structure formed during the freezing process of CS and CKFs, playing a role similar to that of "steel bars" in concrete, thus providing longitudinal support for the 3D-architecture material. The 2D layers formed by CS and CKFs as the main basic units can provide the material with a higher strength. The 3D-architecture material can bear the compressive force of a weight underwater for multiple cycles, meeting the requirements for water purification. The underwater compression test shows that the 3D-architecture material can quickly rebound to its original shape after removing the stress. This 3D-architecture material can be used to purify dye-containing water. When its dosage is 3 g/L, the material can remove 99.65% of the Congo Red (CR) in a 50 mg/L dye solution. The adsorption performance of the 3D architecture adsorbent for CR removal in actual water samples (i.e., tap water, seawater) is superior than that of commercial activated carbon. Due to its porous block characteristics, this material can be used for the continuous and efficient treatment of wastewater containing trace amounts of CR dye to obtain pure clean water, meaning that it has great potential for the effective purification of dye wastewater.

Recent progress of bacterial cellulose-based separator platform for lithium-ion and lithium‑sulfur batteries

Bacterial cellulose (BC) has recently attracted a lot of attention as a high-performance, low-cost separator substrate for a variety of lithium-ion (LIBs) and lithium‑sulfur batteries (LISs). BC-base can be used in the design and manufacture of separators, mainly because of its unique properties compared to traditional polyethylene/polypropylene separator materials, such as high mechanical properties, high safety, good ionic conductivity, and suitability for a variety of design and manufacturing needs. In this review, we briefly introduce the sources, production methods, and modification strategies of BC, and further describe the preparation methods and properties of BC battery separators for various LIBs and LISs.

Boron quantification using ion chromatography tandem triple quadrupole mass spectrometry. Application to retention analysis in boron-treated wood

Boron compounds play a crucial role in various industries, and accurate quantification of boron is essential for quality control and environmental monitoring. This study presents a simple, rapid, and reliable method for determining boron in aqueous solutions using suppressed ion chromatography coupled to electrospray ionisation-triple quadrupole mass spectrometry (IC-ESI-QqQ-MS). Boric acid (B(OH)3) was retained as the tetrahydroxyborate ion (B(OH)4-) on a CarboPac PA300-4 μm anion-exchange column using isocratic elution with 40 mM KOH. During the neutralization process at the suppressor, B(OH)4- was converted to B(OH)3, which subsequently generated the metaborate ion [BO2]- (m/z 43) within the electrospray ionisation source. By employing a pseudo-selected reaction monitoring (SRM) transition from m/z 43 to m/z 43, the method achieved a limit of detection (LOD) of 2.45 μg/L of boron, the lowest reported in the literature to-date for an IC-based method. The analytical performance of the method demonstrated no carry-over issues, no matrix interferences, and excellent intra- and inter-run repeatability of 2.03% and 3.41%, respectively. The method was applied to the evaluation of boron uptake and retention by Tasmanian Oak timber blocks, treated by dip-diffusion in a boric acid solution of 2.5% Boric Acid Equivalent (BAE, m/m) under controlled laboratory conditions. Quantitative determination of the retained and unretained boron allowed a mass balance evaluation and confirmed the accuracy and reliability of the method, with recoveries ranging from 99.3% to 100.2%.

Recent advances in boron removal in aqueous media. An approach to the adsorption process and process optimization

The numerous oxidation states of the element boron bring great challenges in containing its contamination in receptor bodies. This scenario increases significantly due to the widespread use of boron compounds in various industries in recent years. For this reason, the removal of this contaminant is receiving worldwide attention. Although adsorption is a promising method in boron removal, finding suitable adsorbents, that is, those with high efficiency, and feasible remains a constant challenge. Hence, this review presents the boron removal methods in comparison to costs of adsorbents, reaction mechanisms, economic viability, continuous bed application, and regeneration capacity. In addition, the approach of multivariate algorithms in the solution of multiobjective problems can enable the optimized conditions of dosage of adsorbents and coagulants, pH, and initial concentration of boron. Therefore, this review sought to comprehensively and critically demonstrate strategic issues that may guide the choice of method and adsorbent or coagulant material in future research for bench and industrial scale boron removal.

Effective Removal of Boron from Aqueous Solutions by Inorganic Adsorbents: A Review

Increasing levels of boron in water exceeding acceptable thresholds have triggered concerns regarding environmental pollution and adverse health effects. In response, significant efforts are being made to develop new adsorbents for the removal of boron from contaminated water. Among the various materials proposed, inorganic adsorbents have emerged as promising materials due to their chemical, thermal, and mechanical stability. This review aims to comprehensively examine recent advances made in the development of inorganic adsorbents for the efficient removal of boron from water. Firstly, the adsorption performance of the most used adsorbents, such as magnesium, iron, aluminum, and individual and mixed oxides, are summarized. Subsequently, diverse functionalization methods aimed at enhancing boron adsorption capacity and selectivity are carefully analyzed. Lastly, challenges and future perspectives in this field are highlighted to guide the development of innovative high-performance adsorbents and adsorption systems, ultimately leading to a reduction in boron pollution.

Plants, animals, and fisheries waste-mediated bioremediation of contaminants of environmental and emerging concern (CEECs)-a circular bioresource utilization approach

The release of contaminants of environmental concern including heavy metals and metalloids, and contaminants of emerging concern including organic micropollutants from processing industries, pharmaceuticals, personal care, and anthropogenic sources, is a growing threat worldwide. Mitigating inorganic and organic contaminants, which can be coined as contaminants of environmental and emerging concern (CEECs), is a big challenge as traditional physicochemical processes are not economically viable for managing mixed contaminants of low concentrations. As a result, low-cost materials must be designed to provide high CEEC removal efficiency. One of the environmentally viable and energy-efficient approaches is biosorption, which involves using biomass or biopolymers isolated from plants or animals to decontaminate heavy metals in contaminated environments using inherent biological mechanisms. Among chemical constituents in plant biomass, cellulose, lignin, hemicellulose, proteins, polysaccharides, phenolic compounds, and animal biomass include polysaccharides and other compounds to bind heavy metals covalently and non-covalently. These functional groups include carboxyl, hydroxyl, carbonyl, amide, amine, and sulfhydryl. Cation-exchange capacities of these bioadsorbents can be improved by applying chemical modifications. The relevance of chemical constituents and bioactives in biosorbents derived from agricultural production such as food and fodder crops, bioenergy and cash crops, fruit and vegetable crops, medicinal and aromatic plants, plantation trees, aquatic and terrestrial weeds, and animal production such as dairy, goatery, poultry, duckery, and fisheries is highlighted in this comprehensive review for sequestering and bioremediation of CEECs, including as many as ten different heavy metals and metalloids co-contaminated with other organic micropollutants in circular bioresource utilization and one-health concepts.

Boron Adsorption Kinetics of Microcrystalline Cellulose and Polymer Resin

Tailoring boron-polysaccharide interactions is an important strategy for developing functional soft materials such as hydrogels, fire retardants, and sorbents for environmental remediation, for example, using lignocellulosic biomass. For such applications to be realized, it is paramount to understand the adsorption kinetics of borate anions on cellulose and their local structures. Here, the kinetic aspects of boron adsorption by microcrystalline cellulose, lignin, and polymeric resin are investigated and compared. Borate anions interact with the vicinal diols in the glucopyranoside moieties of cellulose to yield chemisorbed boron chelate complexes. In contrast to cellulose, technical lignin contains fewer cis-vicinal diols, and it does not have a tendency to form such chelate complexes upon treatment with the aqueous boric acid solution. The formation kinetics and stability of these chelate complexes strongly depend on nanoscale structures, as well as reaction conditions such as pH and concentration of the sorbate and sorbent. Specifically, insights into the distinct boron adsorption sites were obtained by solid-state one-dimensional (1D) ¹¹B magic-angle spinning NMR and the local structures and intermolecular interactions in the vicinities of boron chelate complexes are elucidated by analyzing two-dimensional (2D) ¹H-¹³C and ¹¹B-¹H heteronuclear correlation NMR spectra. The total boron adsorption capacity of cellulose is estimated to be in the 1.3-3.0 mg range per gram of sorbent, which is lower than the boron adsorption capacity of a polystyrene-based resin, ∼17.2 mg of boron per gram of Amberlite IRA 743. Our study demonstrates that the local backbone and side chain flexibility as well as the structures of polyol groups play a significant role in determining the kinetic and thermodynamic stability of chelate complexes, yielding to different boron adsorption capabilities of lignocellulosic polymers.

Preparation and Boron Removal Performance of Glycidol Modified PANI Nanorods: An Optimization Study Based on Response Surface Methodology

Boron removal from aqueous solutions has attracted increasing attention, offering benefits for animal and plant health as well as profound significance for exploiting Salt Lake boron resources. In this work, we synthesized novel glycidol-functionalized and hydrophilic polyaniline (PANI) nanorod adsorbents, which were prepared to separate boron compounds from boric acid aqueous solutions. The as-prepared adsorbents were significantly different from the traditional polymers' grafting reaction because they had a higher functional yield and more active position for adsorption. The maximum adsorption capacity (0.2210 mmoL∙g^-1) and optimal adsorption conditions (boric acid concentration of 1307 mg/L, pH = 9.82, time of 10 h) were obtained with single-factor experimentation and the response surface method (RSM). In addition, adsorption kinetics studies showed that the adsorption reaction belonged to the pseudo-first-order kinetic model, and diffusion was the key limiting factor; therefore, the adsorption equilibrium time is more than 10 h. Finally, the related possible adsorption mechanism was investigated based on the species and the diffusion of boron in the aqueous phase.

Removal of boron by a modified resin in fixed bed column: Breakthrough curve analysis using dynamic adsorption models and artificial neural network model

Continuous removal of toxic element boron from aqueous solution was investigated with new phenolic hydroxyl modified resin (T-resin) using a fixed bed column reactor operated under various flow rates, bed height and influent concentrations. The breakthrough time, exhaustion time and uptake capacity of the column bed increased with increasing column bed height, whereas decreased with increasing influent flow rate. The breakthrough time and exhaustion time decreased, but uptake capacity increased with increasing influent concentration, and actual uptake capacity was obtained as 6.52 mg/g at a concentration of 7.64 mg/L. The three conventional models of bed depth service time (BDST), Thomas and Yoon-Nelson were used to appropriately predict the whole breakthrough behavior of the column and to estimate the characteristic model parameters for boron removal. However, artificial neural network (ANN) model was more accurate than the conventional models with the least relative error and the highest correlation coefficients. By the relative importance of the operational parameters obtained from ANN model, the sequence is as follows: total effluent time > initial concentration > flow rate > column height. The adsorption capacity of boron was changed between 5.24 and 1.74 mg/g during the five time regeneration. From the life factor calculation, it is suggested that the column bed could avoid the breakthrough time of t = 0 for 6.8 cycles, whereas, the uptake capacity would be zero after 7.8 cycles.

Phosphorus Co-Existing in Water: A New Mechanism to Boost Boron Removal by Calcined Oyster Shell Powder

The removal of boron (B) from water by co-precipitation with hydroxyapatite (HAP) has been extensively studied due to its low cost, ease of use and high efficiency. However, there is no explicit mechanism to express how resolved B was trapped by HAP. Thus, in this work, the process of removing B from water was studied using a low-cost calcium (Ca) precipitation agent derived from used waste oyster shells. The results showed that the removal rate of B in the simulated wastewater by calcined oyster shell (COS) in the presence of phosphorus (P) is up to more than 90%, as opposed to virtually no removal without phosphate. For B removal, the treated water needs to be an alkaline solution with a high pH above 12, where B is removed as [CaB(OH)4]+ but is not molecular. Finally, the synergistic mechanism of co-precipitation between HAP and dissolved B, occlusion co-precipitation, was explained in detail. The proposed method discovered the relationship between Ca, P and B, and was aimed at removing B without secondary pollution through co-precipitation.

Unique metalloid uptake on microplastics: The interaction between boron and microplastics in aquatic environment

Boron pollution in the aquatic environment has a hazardous effect on human health and the ecosystem as a metalloid pollutant, and few researchers have focused on the potential interaction between boron and microplastics. We investigated the adsorption of boron on four types of microplastics (polyvinyl chloride (PVC), aged PVC, polystyrene (PS), and aged PS). The adsorption behavior was explored by kinetics, isotherm models, and several aqueous factors, including pH, humic acid, ionic strength (Na⁺), metal ion types (Mg²⁺, Ca²⁺, Cu²⁺, and Al³⁺), and the seawater environment. The adsorption capacities on microplastics were followed: aged PVC (0.91 mg/g) > aged PS (0.197 mg/g) > virgin PVC (0.1 mg/g) > virgin PS (0.005 mg/g). The adsorption kinetics and isotherm models suggested monolayer adsorption and chemisorption. Humic acid and high pH significantly inhibited the adsorption due to the complexation and hydrolysis of boric acid (B(OH)₃), respectively. The presence of metal ions may enhance or hinder adsorption, depending on the boron species, ion concentration, ion type, and microplastics categories. The unique interaction mainly depended on surface complexations of B(OH)₃ with oxygen-containing groups on microplastics surface. Because aged microplastics have more oxygen-containing groups, they can combine more B(OH)₃, and PVC can adsorb more boron due to the CCl bond and surface diffusion. In the aquatic environment, however, metal ions may occupy these binding sites, and the electrostatic force between borate ([B(OH)₄]^-) and microplastics will take precedence. In the simulated intestines of warm-blooded animals, we achieved the greatest boron desorption ratio on microplastics. This work explored the adsorption characteristics of boron by microplastics and revealed potential environmental risks of metalloid enrichment.