Boric Acid Complexes Research Articles

Complexation of Boronic Acid with Chiral α-Hydroxycarboxylic Acids and the Ability of the Complexes to Catalyze α-Hydroxycarboxylic Acid Esterification.

The complexation of boric acid (BA) with various α-hydroxycarboxylic acids (HCAs) was examined by analyzing the change in the optical rotation after the addition of BA to aqueous HCA solutions, and the catalytic properties of the complexes were examined by catalyzing the esterification of the HCAs. The absolute values of the optical rotation of the HCAs increased with increasing BA-to-HCA molar ratio, and the rate of change of the optical rotation gradually decreased as the BA-to-HCA molar ratio increased, reaching a minimum value at a molar ratio of approximately three. As a catalyst, BA could catalyze the acetylation of hydroxyl groups in addition to the esterification of HCAs. Compared to the conventional synthesis routes of ATBC and ATOC, a synthesis route with BA as the catalyst allowed for a lower frequency of catalyst separation and replacement while providing light-colored products. BA could catalyze the formation of triethyl citrate, and the yield of triethyl citrate reached 93.8%. BA could also catalyze the reaction between malic acid and pinene to produce borneol malate. After saponification of borneol malate, borneol was obtained with a yield of 39%.

Sustainable treatment of boron industry wastewater with precipitation-adsorption hybrid process and recovery of boron species

Boron removal from wastewater has been investigated by using various processes, including ion exchange resins, membrane processes and adsorption. Each method has various advantages and disadvantages, but most produce excessive waste in addition to high operational costs. Therefore, more sustainable methods are required for wastewater containing high concentrations of boron. In this study, a sustainable treatment process was developed for wastewater containing high concentrations of boron. This study investigated the removal of boron from wastewater by Al(OH)3 sorption. The reuse of adsorbent (Al(OH)3) and the potential recovery of boric acid was the main goal of the study. It was observed that although lower concentrations of boron were obtained at pH 10.5 (980 mg/L and 635 mg/L at pH of 9.0 and 10.5, respectively), the amount of sorbed boron at pH 9 was substantially higher (94.7 mg B/g Al(OH)3 and 27.8 mg B/g Al(OH)3 at pH of 9.0 and 10.5, respectively). This was attributed to the higher initial boron concentrations and the formation of boric acid and polyborate complexes at pH 9.0. Results showed that polyborate species sorption was an outer sphere complex formation, which led to the desorption of boron as pH lowered. Adsorbed boron species to Al(OH)3 could effectively be desorbed at low pH values (pH<5.0); which allows Al(OH)3 to be used in successive adsorption studies. Approximately 55% of boron recovery from pretreated wastewater was possible with the effective reuse of adsorbent. A net profit of 2.85 $/m3 could be obtained based on the amounts of chemical consumptions and boron recovery.

Boron citrate esters as boron daily food supplementing agents. Synthesis and structural characterizations

Boric acid, H3BO3, is a weak acid and is in the form of an uncharged small molecule at physiological pH. Acting as a Lewis acid, it forms complexes (esters) with amino and hydroxy acids, carbohydrates, nucleotides and vitamins through electron donor-acceptor interactions. These interactions are believed to be beneficial for human health. Therefore, synthetic bichelate complexes of boric acid with organic biomolecules are considered for nutritional and/or pharmaceutical applications. Research is needed to better elucidate the mechanisms of action of boron and to identify requirements in different areas. In this study, the complexation of citric acid, which is widely used in the food industry, with boric acid was investigated considering that it would be more beneficial in bio applications. Mono-chelate (1:1) and bichelate (1:2) anionic complexes of citric acid and boric acid, which are thought to be used as food supplements, were isolated from aqueous solutions in salt form with K+, Mg+2, Na+ and Ca+2 ions. The complexes were characterized by elemental analysis, FT-IR, X-ray crystallography and thermal methods.

Study on Synthesizing Isobornyl Acetate/Isoborneol from Camphene Using α-Hydroxyl Carboxylic Acid Composite Catalyst.

This study examined the preparation of isobornyl acetate/isoborneol from camphene using an α-hydroxyl carboxylic acid (HCA) composite catalyst. Through the study of the influencing factors, it was found that HCA and boric acid exhibited significant synergistic catalysis. Under optimal conditions, when tartaric acid-boric acid was used as the catalyst, the conversion of camphene and the gas chromatography (GC) content and selectivity of isobornyl acetate were 92.9%, 88.5%, and 95.3%, respectively. With the increase in the ratio of water to acetic acid, the GC content and selectivity of isobornol in the product increased, but the conversion of camphene decreased. The yield of isobornol was increased by adding ethyl acetate or titanium sulfate/zirconium sulfate to form a ternary composite catalyst. When a ternary complex of titanium sulfate, tartaric acid, and boric acid was used as the catalyst, the GC content of isobornol in the product reached 55.6%. Under solvent-free conditions, mandelic acid-boric acid could catalyze the hydration reaction of camphene, the GC content of isoborneol in the product reached 26.1%, and the selectivity of isoborneol was 55.9%. The HCA-boric acid composite catalyst can use aqueous acetic acid as a raw material, which is also beneficial for the reuse of the catalyst.

An amino trimethylene phosphonic acid‐based chelated boric acid complex that works as a synergistic flame retardant for enhancing the flame retardancy of cotton fabrics

AbstractThe chelating ligands of boric acid and amino trimethyl phosphonate prepared a novel flame retardant (BAP) for the cotton fabric. A stable chemical and coordination bond was formed on the surface of the cotton fibers by a simple three‐curing finishing process to make the fabric exhibits excellent durable flame retardancy. Cotton fabrics' tensile strength and whiteness got substantially retained after BAP treatment. 90 g/L BAP‐treated samples (3 curing times, 50 laundry cycles) showed good flame retardancy and durability, holding the largest limit oxygen index, 29.7%, and the shortest damage length, 61 mm. A condensed phase and gas phase synergistic flame retardant mechanism was concluded by thermogravimetric, cone calorimeter tests, and thermogravimetric infrared analysis.

Thermodynamics for complex formation of boric acid and borate with hydroxy acids and diols

The complex formation of boric acid (B(OH)3) and borate (BOH4-) with glycolic acid, lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, malic acid, and (s)-1,2-propanediol in aqueous solutions has been investigated using 11B NMR and mass spectroscopy. The formation constants and the thermodynamic parameters, ΔH° and ΔS°, of the 1:1 and 1:2 complexes of boric acid for the hydroxy acid (B-HA) systems were compared with those for the polyol (B-OL) systems previously reported, together with those for a polyol of (s)-1,2-propanediol presently examined. The 1:1 complex formation was enthalpically driven in both B-HA and B-OL systems. In the former, the enthalpic gain is caused by the structural change of boric acid, accompanied by the dehydration condensation of boric acid with hydroxy acid. In the latter, the enthalpic gain only arises from the dehydration condensation of borate with polyol. The ΔH° values for the B-HA and B-OL systems are comparable with each other, despite the different numbers of dehydration of water molecules, i.e., one and two water molecules, respectively. The formation of 1:2 complex was entropically driven in the B-HA systems, while that in the B-OL systems was enthalpically progressed. This difference between the two systems is attributed to the flexibility of isolated ligand molecules. Since the isolated hydroxy acids form the intramolecular hydrogen bond, the entropic gain of the hydroxy acids is generated as the hydroxy acid is bound to 1:1 complex due to the breaking of the intramolecular hydrogen bond. Thus, the stabilities of the complexes in the B-HA systems mainly depend on the gain for the freedom of ligand.

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.

EPR-Effect Enhancers Strongly Potentiate Tumor-Targeted Delivery of Nanomedicines to Advanced Cancers: Further Extension to Enhancement of the Therapeutic Effect.

For more than three decades, enhanced permeability and retention (EPR)-effect-based nanomedicines have received considerable attention for tumor-selective treatment of solid tumors. However, treatment of advanced cancers remains a huge challenge in clinical situations because of occluded or embolized tumor blood vessels, which lead to so-called heterogeneity of the EPR effect. We previously developed a method to restore impaired blood flow in blood vessels by using nitric oxide donors and other agents called EPR-effect enhancers. Here, we show that two novel EPR-effect enhancers—isosorbide dinitrate (ISDN, Nitrol®) and sildenafil citrate—strongly potentiated delivery of three macromolecular drugs to tumors: a complex of poly(styrene-co-maleic acid) (SMA) and cisplatin, named Smaplatin® (chemotherapy); poly(N-(2-hydroxypropyl)methacrylamide) polymer-conjugated zinc protoporphyrin (photodynamic therapy and imaging); and SMA glucosamine-conjugated boric acid complex (boron neutron capture therapy). We tested these nanodrugs in mice with advanced C26 tumors. When these nanomedicines were administered together with ISDN or sildenafil, tumor delivery and thus positive therapeutic results increased two- to four-fold in tumors with diameters of 15 mm or more. These results confirmed the rationale for using EPR-effect enhancers to restore tumor blood flow. In conclusion, all EPR-effect enhancers tested showed great potential for application in cancer therapy.

Feasibility of Manufacturing Strand-Based Wood Composite Treated with β-Cyclodextrin-Boric Acid for Fungal Decay Resistance.

The feasibility of using β-cyclodextrin (βCD) as an eco-friendly carrier of boric acid for the protection of strand-based wood composites against decay fungi was evaluated. The formation of a βCD–boric acid (βCD–B) complex was confirmed by the appearance of the boron–oxygen bond by using attenuated total reflection–Fourier transform infrared spectroscopy. Chemical shifts of around 6.25 and 1.41 ppm were also observed in 1H Nuclear Magnetic Resonance (NMR) and 11B NMR spectra, respectively. The βCD–B preservatives at two levels (5 and 10 wt.%) were uniformly blended with southern pine strands that were subsequently sprayed with polymeric methylene diphenyl diisocyanate (pMDI) resin. The blended strands were formed into a loose mat by hand and consolidated into 25 × 254 × 12 mm oriented strand boards (OSB) using a hot-press. The OSB panels were cut to end-matched internal bonding (IB) strength and fungal decay resistance test specimens. The vertical density profiles (VDPs) of the IB specimens were measured using an X-ray based density profiler and the specimens with statistically similar VDPs were selected for the IB and decay tests. The IB strength of the treated specimens was lower than the control specimens but they were above the required IB strength of heavy-duty load-bearing boards for use in humid conditions, specified in the BS EN 300:2006 standard. The reduced IB of preservative-treated OSB boards could be explained by the destabilized resin upon the addition of the βCD–B complex, as indicated by the differential scanning calorimetry (DSC) results. The resistance of the OSB panels against two brown-rot fungi (i.e., G. trabeum or P. placenta) was evaluated before and after accelerated leaching cycles. The treated OSBs exposed to the fungi showed an average mass loss of lower than 3% before leaching, while the untreated OSBs had 49 and 35% mass losses due to decay by G. trabeum or P. placenta, respectively. However, upon the leaching, the treatment provided protection only against G. trabeum to a certain degree (average mass loss of 15%). The experimental results suggest that protection efficacy against decay fungi after leaching, as well as the adhesion of the OSB strands, can be improved by increasing the amount of pMDI resin.

Acidity Study of Donor-Acceptor Complexes of Boric Acid with Polyols for Oil Displacing Compositions

The results of theoretical and experimental studies of the acidity of donor-acceptor complexes of boric acid with polyols – glycerol and sorbitol, which were used in the development of oil-displacing compositions, are presented. A model of donor-acceptor acid-base equilibria in coordinating polyol solvents has been created, due to which the constants of polyolboric acids formation and ionization were determined by pH-meter and electrical conductivity methods. The obtained constant values were used to calculate the compositions buffer capacity. Due to the using a mixture of polyolboric acids in the compositions at various ratios it was possible to regulate the range of the buffer action

The Study of Donor-Acceptor Equilibria in Oil-Displacing Compositions Based on Acid Coordinating Solvents

The acidity of donor-acceptor complexes of boric acid with glycerol and sorbitol has been studied in aqueous solutions using pH-metry and electrical conductivity methods. A theoretical model of donor-acceptor acid-base equilibria in boric acid – polyol – water systems has been created. The constants of polyol boric acids formation and ionization were determined. The constants of glycerol and sorbitol boric acids formation were 0.05 and 0.06 l2·mol−2, and those of glycerol and sorbitol boric acids ionization were 7.1·10−6 mol·l−1 and 3.2 · 10−3 mol·l−1, respectively. The systems studied were used to create new oil-displacing compositions for enhanced oil recovery.

Influence of Composition of Zosteran–Boric Acid Supramolecular Complexes on the Efficiency of Growth Processes of Cereals

Background. Boron is recognized as an important trace element for the processes of functioning of higher plants. The role of boron is specific, it is an indispensable element of nutrition, without which the life of plants is impossible. The main source of boron for plant nutrition is boric acid, which in interstitial water is in the form of non-dissociated molecules and is characterized by rather low solubility and bioavailability. Pectin, which forms boric acid complexes with 1:1 and 2:1 molar ratios, can be used to transport boric acid to a plant. Determining the bioavailability of each of these complexes will optimize the process of boron fertilizers introduction.Objective. The aim of the paper is introduction of boron into plants in the form of supramolecular complexes of boric acid with pectin in order study of bioactivity of such complexes depending on their composition.Methods. Pectin was extracted from leaves of hydrobiont of Zostera marina. Distribution area of this higher plant in Ukraine is the Black Sea coast of the Odessa region. Test cultures of corn and wheat were used as the objects of the study of biological activity effect of zosteran-boron supramolecular complexes on the growth function of the root and the ground part. The mass of the root system and the ground part of the plant was measured according to original methodology in 96 hours after the experiment was started (seed soaking in distilled water for 24 h and in the solution of the supramolecular complex zosteran–boric acid for 72 h).Results. As a result of seed germination on the solutions of supramolecular complexes of different composition, it was found out that complexes have a significant activating effect on the growth processes of aboveground part of plants. It was demonstrated that the biological activity of solutions substantially depends on the nature of culture. Corn showed a higher overall biological activity of supramolecular complexes (up to 108%) compared with wheat (60%). Solution of the supramolecular complex of zosteran–boric acid in a 1:1 molar ratio was found to be effective for both cultures. Zosteran–boric acid complexes in the molar ratio of 2:1 did not demonstrate high biological activity.Conclusions. High biological activity (107.87% for corn and 60.35% for wheat) was demonstrated by complex with zosteran–boric acid mass ratio of 1:20. In such instance, the formation of zosteran–boric acid complexes with molar ratio of 1:1 is the most probable case. It is caused by smaller sizes and therefore better bioavailability of such complexes. Complexes with pectin-boric acid 2:1 molar ratio demonstrated lower biological activity (103.33% for corn and 11.18% for wheat). It can be explained by steric restrictions during penetration into the plant.

Chiral Separation by NACE Using Polyol Derivative-Boric Acid Complexes.

Nonaqueous capillary electrophoresis (NACE) is an effective method for chiral separation. Many polyol derivatives (e.g., D-(+)-xylose, lactobionic acid, diacetone-D-mannitol, L-sorbose, and D-gluconic acid δ-lactone) can react with boric acid in methanol to produce polyol derivative-boric acid complexes which can be utilized as chiral selectors of enantioseparations. The enantiomers of more than a dozen basic analytes can be resolved under the optimized NACE using these chiral selectors.

Flow-injection determination of boric acid concentration with conductometric detection

The flow-injection determination of boric acid with conductometric detection in technological environments of the primary circuit of WWER-type nuclear power plant is described. The method consists in periodical dosing a fixed sample volume into the flow of the mannitol solution. As a of the Formation of an anionic boric acid complex with mannitol and equivalent amount of hydroxonium ions, results in an abrupt increase in the electrical conductivity, which is recorded by a conductometric detector. The hydraulic and measuring circuits of the analyzer are implemented using standard ionochromatographic equipment. It is shown than in the concentration range of the analyte 1 – 16 g/liter, the correcting additives of ammonium and potassium hydroxides do not interfere with the results of the analysis. To eliminate the interfering effect of correcting additives at low concentrations of boric acid (0.2 – 1.0 g/liter) we propose to use a Donnan dialysis through a cation exchange membrane. Optimal conditions of the analysis are specified and the metrological characteristics are determined. At a concentration of boric acid of 0.2 g/liter, the standard deviation does not exceed 2%.

Synthesis and in vitro antimicrobial characterization of Boron-PVA Electrospun nanofibers

Polyvinyl alcohol (PVA) electrospun nanofibers and boric acid (BA) complexes of these nanofibers were synthesized with and without using TritonX-100(TX-100) as a water soluble surfactant (PVA, PVA/BA, PVA/TX-100, PVA/TX-100/BA). The electrospun nanofibers were characterized by SEM, FTIR and TGA. Preliminary results showed that certain amount of boric acid decreased the number of Stapylococcus aureus from 6,8x107(CFU/mL) to 3x107(CFU/mL). In the preparation of polymer, boric acid was used as a crosslinker and antimicrobial agent whereas TX-100 was used as surfactant. The viscosity and conductivity measurements indicated that the BA increased viscosity but decreased conductivity. In contrast, TX-100 increased conductivity without considerable effect on viscosity, which affects the production and resulting nanofiber properties such as diameter and bead formation. The antimicrobial activities of the nanofibers were assayed in vitro by Gram-negative (E. coli) and Gram-positive(S. aureus) bacteria. It was observed that PVA/TX-100/BA showed better antibacterial activity against S.aureus bacteria compared to PVA and PVA/TX-100 nanofibers.

Synthesis Conditions on the Nature of GdBO3 Phase Formed

AbstractPresent study has been carried out to develop a facile synthetic methodology for preparing single phase monoclinic and triclinic forms of GdBO3, a potential phosphor material. This is achieved by varying annealing temperatures and annealing steps. Detailed structural studies, using X‐ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopic techniques confirmed that, Gd3+‐boric acid complexes formed initially at low temperatures (300 °C or less) get converted to monoclinic and triclinic forms of GdBO3 depending upon annealing temperatures, annealing steps and heating rates. Multiple steps with slow heating rates (∼3 °C/min) lead to the formation of single phase triclinic form of GdBO3. Two step heating with relatively faster heating rates (5 °C/min and above) results in single phase monoclinic GdBO3. FTIR and Raman studies also confirmed that boron exists only as BO4 structural units (in the form of B3O93− rings) in monoclinic GdBO3 and as BO3 structural units in triclinic GdBO3. Luminescence studies carried out with Eu3+ as a probe species confirmed more covalent nature around Eu3+/Gd3+ ions with improved red colour emission from triclinic form of GdBO3 compared to the monoclinic form.

Complex of polyvinyl alcohol with boric acid: Structure and use

The investigation of a structure of the complex of polyvinyl alcohol and boric acid was carried out by means of IR and Raman spectroscopy, X-ray diffraction and quantum mechanical calculations. The formation of inorganic polymeric chains (OB(OH))n within a hybrid interpolymeric complex with PVA is substantiated. Most convincingly this conclusion is supported by PVA-boric acid complex’s Raman spectrum. It consists of superposition of slightly changed PVA spectrum and strongly changed boric acid spectrum. It means that boric acid structure is changed significantly within the complex and PVA structure is not changed. Observed and calculated frequencies are in good agreement. Also the structural-sensitive theoretical neutron shielding ability of the complex is analyzed. It was found better than known one.

Enantiomeric separation of seven β-agonists by NACE—Study of chiral selectivity with diacetone-d-mannitol–boric acid complex

A rapid and effective nonaqueous capillary electrophoresis (NACE)–ultraviolet (UV) method was developed for the enantiomeric separation of seven β-agonists. Diacetone-d-mannitol–boric acid complex was used as a new chiral selector. It was in situ synthesized by the reaction of diacetone-d-mannitol and boric acid in methanol medium containing triethylamine. The effects of diacetone-d-mannitol, boric acid, and triethylamine concentrations on the enantioseparation were carefully investigated. Under the optimized conditions, baseline enantioseparation could be obtained for six of the tested β-agonists within 12min. These results were better than that obtained with d-mannitol–boric acid complex in previous work. 11B nuclear magnetic resonance (11B NMR) was applied to determine the fraction of boron species and confirm the formation of diacetone-d-mannitol–boric acid complex. Validation of the established NACE method was also carried out according to ICH guidelines. Calibration curves showed good linearity with correlation coefficients (r)≥0.9992 over a certain concentration range for each enantiomer of the tested five β-agonists. The relative standard deviations (RSDs) of intra-day precisions and inter-day precisions of migration times were ≤1.4% (n=6), and ≤6.3% (n=10), respectively. That of peak areas were ≤3.7% (n=6), and ≤5.6% (n=10), respectively. The limits of detection (LODs) and the limits of quantitation (LOQs) based on the signal-to-noise ratios of 3 and 10 were found below 1.25μgmL−1 and 5.00μgmL−1, respectively. The proposed method was successfully applied to the determination of clenbuterol enantiomers in a multi-component pharmaceutical dosage form called “Ambroxol Hydrochloride and Clenbuterol Hydrochloride Oral Solution”.

Polycomplexes of the polycondensation products of boric acid and p-phenylenediamine

An extreme dependence of the softening temperature of polycomplexes of p-phenylenediamine and low-molecular-weight polycondensation products of boric acid on the ratio thereof is revealed. The stoichiometric ratio of the BA/p-PDA complex is 75/25 wt %, which corresponds to a molar ratio of BA trimer/p-PDA = 1: 1. At a higher content of the amine, the softening temperature of the polycomplex decreases sharply, from 250 to 60°C, which is explained by the complexation of boric acid with the amine, a factor that prevents its dehydration. The energies of the intermolecular interaction between the components of the complex in a vacuum are calculated, and quantum-chemical calculations of the energy of interaction between the components of the complex are performed. The resulting products exhibit paramagnetic and fluorescent properties.

Boron as a promoter in the goethite (α-FeOOH) phase: Organic compound degradation by Fenton reaction

The aim of this study was to obtain iron oxides (goethite phase, α-FeOOH) to be used as Fenton catalysts in the catalytic oxidation of methylene blue (MB). Moreover surface modifications were attempted by treating the oxides with boric acid in order to improve the materials’ catalytic properties through the generation of more active groups on the surface of goethite. The types of structures formed on the surface were investigated through the following characterization techniques: vibrational infrared spectroscopy, Mössbauer spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and BET surface area measurements. The results of these characterization analyses the showed complexation of boric acid on the surface of goethites and the partial reduction of some Fe(III) to Fe(II) species, resulting of a hybrid material containing both goethite and magnetite phases. When tested in the oxidation of organic compounds, the new class of iron oxide showed high capacity for degradation of organic compounds present in the solution. The Gt-B catalyst exhibited enhanced catalytic activity in degradation of methylene blue compared with the pure goethite, especially Gt-B1×4 which, after 240min of reaction, was able to degrade about 80% of the MB in solution. The increase in the catalytic activity was assigned to the role of boron as a promoter in the transfer of electrons from iron to hydrogen peroxide, the increasing of surface area and the presence of Fe(II) species, which are kinetically more favourable for the Fenton’s reaction. In addition, theoretical calculations were carried out at the density functional theory (DFT) level in order to investigate the interaction between goethite and boric acid. The theoretical findings showed that the treatment with the H3BO3 significantly modifies the electron density of goethite (100).