Efficient Boron Removal Research Articles

Comparative Evaluation of Boron Sorption Dynamics on Zeolites in Irrigation Waters: An Isothermal Modeling Approach.

Efficient boron removal from irrigation waters is crucial for sustainable agriculture, as elevated levels of boron can be toxic to many plants, limiting growth and crop productivity. In this context, the present study investigated the sorption equilibrium of boron using zeolites in two types of aqueous matrices: a synthetic solution containing only boron and natural irrigation waters. Through the application of various isothermal sorption models (Langmuir, Freundlich, Sips, Toth, Jovanovic, Temkin, Dubinin-Radushkevich, and Redlich-Peterson), the efficacy of zeolite for boron removal under controlled and real conditions was evaluated. The results indicated a notable difference in sorption behavior between the two matrices, reflecting the complexity and heterogeneity of interactions in the boron-zeolite system. In the synthetic solution, the Freundlich model provided the best fit (R2 = 0.9917), suggesting heterogeneous and multilayer sorption, while the Sips model showed high efficacy in describing the sorption in both matrices, evidencing its capability to capture the complex nature of the interaction between boron and zeolite under different environmental conditions. However, in natural irrigation waters, the Jovanovic model demonstrated the most accurate fit (R2 = 0.999), highlighting the importance of physical interactions in boron sorption. These findings underscore the significant influence of the water matrix on the efficacy of zeolite as a boron removal agent, emphasizing the need to consider the specific composition of irrigation water in the design of removal treatments. Additionally, the results stress the importance of selecting the appropriate isothermal model to predict boron sorption behavior, which is crucial for developing effective and sustainable treatment strategies. This study provides a basis for optimizing boron removal in various agricultural and industrial applications, contributing to the design of more efficient and specific water treatment processes.

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.

Highly efficient B(OH)3 removal by single-layered graphene membrane with embedded crown nanopores

Trace boron in seawater, usually presented as boric acid (B(OH)3), should be firstly transformed into ionic state, in desalination plants, which represents high energy consumption and high cost. Therefore, direct removal of B(OH)3 is significant and energy-efficient for industrial boron removal, which is still a great challenge. A very recent work [Desalination, 533 (2022) 115755] provides strong theoretical guidance on making efficient boron removal devices utilizing 2D materials with hydrophilic pores. However, limited effort has devoted to explore other 2D porous membrane aiming at further improving the performance of boron acid removal. Herein, using molecular dynamics (MD) simulation, we investigated the effect of single-layered graphene nanosheet embedded with hydrophilic crown nanopores on the direct removal of boric acid. We construct six typical graphene crown pores with varied pore dimensions. Our MD results demonstrate that the utilized graphene crown pores show high water permeability, simultaneously accompanied by an outstanding B(OH)3 rejection (mostly over 90%). The water permeabilities through the crown pores achieve a highest value of 6.01 L cm−2 day−1 MPa−1. Remarkably, the water fluxes in each pore are evaluated to be 2.15 ∼ 20.1 × 1013 per day per MPa per pore, featuring 1–2 orders of magnitude improvement compared with the previous best report of 2-dimensional nanopores, with the comparable B(OH)3 rejection. Free energy calculations indicate that a water molecule is energetically more favorable to transport through graphene crown nanopore than B(OH)3. Our findings highlight that a porous graphene embedded with hydrophilic crown nanopores can be not only used for efficaciously removing B(OH)3 but also enable the fast water flow, which is desirable in desalination plants.

In-situ rapid construction of aliphatic amine combined polyamide seawater reverse osmosis membrane for efficient boron removal

Polyamide (PA) reverse osmosis membranes are commonly employed in seawater desalination owing to their effective salt rejection and water permeability; however, the elimination of small and neutral boron molecules from seawater remains a significant hurdle in energy-efficient and cost-effective desalination processes. In this work, a seawater reverse osmosis (SWRO) membrane with powerful boron removal competence was designed by adopting an in-situ rapid integration protocol, which utilized aliphatic amines as hydrophobic barriers by bonding the residual chloride groups upon the membrane surface and as molecular plugs by embedding in the PA networks. Consequently, it resulted in a notable improvement in the rejection of neutral boron molecules due to enhanced steric hindrance caused by immobilized amine plugs and synergistically tunned hydrophobic interactions. The permeability coefficient of boron decreased from 4.8 to 0.9 L m−2 h−1, and the boron rejection increased from 80.7 to 90.5% under the modification conditions with the optimal type and concentration of amines, while displaying a NaCl rejection of 99.8% and an acceptable water permeability of 0.55 L m−2 h−1 bar−1. Meanwhile, the alteration of membrane chemical compositions and structure properties was kept to a minimum. This study offers intuitive insights into the critical roles played by the aliphatic amines in the selective layer of the membrane for the removal of neutral boron molecules and salts, thereby enabling the fabrication of highly selective SWRO membranes, which may have significant implications for more efficient membrane-based seawater desalination and boron removal.

Study on boron removal performance of covalent organic skeleton membrane by hydroxyl groups

Growing demand for water desalination promoted the vigorous development of reverse osmosis (RO) membrane. How to effectively remove boron from seawater is the key problem to be solved by RO membrane. It is important to select suitable membrane materials for experimental design before complicated and expensive experimental attempts. In this paper, we demonstrate that pore chemistry plays a key role in boron removal capability of RO membranes via nonequilibrium molecular dynamics simulations. This study shows that the introduction of hydroxyl (-OH) groups into the Covalent organic frameworks (COFs) pore allows for better boron removal without changing water permeability. The optimal boron rejection of AB-COF membranes is 76.67%, and that of ATFG-COF membranes with hydroxyl groups can achieve 90%. This is caused by the hydrophilic pore of ATFG-COF that will preferentially adsorb water molecules to prevent the passage of boric acid molecules through membrane zone. Additionally, -OH groups on the pore will also adsorb a part of boric acid in the membranes, reducing the amount of boric acid entering into the permeate side. The results obtained in this paper can provide guidance for the rational design of RO membranes to achieve more efficient boron removal.

Boron removal from produce water through adsorption

Boron (B) is essential for the development and functioning of organisms, involving their growth, health, and development of plants, animals, and humans. Nevertheless, the increasing use of boron in various applications has led to environmental problems and health issues. Several separation technologies have been employed to remove boron, and adsorption is one such technology that utilizes adsorbents to address solutions containing extremely low levels of boron. This finding investigates the residual boron from a synthesized solution through adsorption, using CRB05 as the adsorbent. The impact of adsorbent dosage, contact time, boron concentration, and pH on residual boron was examined. The findings indicate that the pH plays a substantial role impact on the residual boron efficiency from all adsorbents. The highest residual of boron was achieved at pH 4.5, adsorbent dosage 1125 mg/L, time 255 minutes, and concentration 1150 mg/L with 98% removal. Adsorption of boron using CRB05 proved to be an effective method for recovering boron from the synthesis solution. The findings of this study enhance our comprehension of the adsorption behavior of CRB05 and provide insights into the optimal operating conditions for efficient boron removal.

Designing sub-nanometer pores for efficient boron removal

Efficient boron removal is one of the key challenges for reverse osmosis membranes. Understanding the transport behavior of boric acid (B(OH)3) at the molecular level is of great importance to design pores with high permselectivity. Herein, via non-equilibrium molecular dynamics simulations, the B(OH)3 rejection is found to be closely related to the hydrophilicity, shape, and size of sub-nanometer pores. Among these structure parameters, the role of the pore shape is dominant as the slit pore has ≤20% B(OH)3 rejections regardless of the pore hydrophilicity and slit width. It is due to the nature of the B(OH)3 molecule being plate-like, even when it is hydrated. Such a unique structure makes the B(OH)3 rejection depend on the major diameter of the non-circular pores. On the other hand, the circular pore, which has the same diameter in all directions, is the most suitable to reject B(OH)3 molecules while providing high water permeance. With a circular pore shape, hydrophilic pores favor the B(OH)3 rejection because the preferentially adsorbed water molecules inside pores can impede the passage of B(OH)3. These findings are expected to guide the rational design and screening of the nanoporous materials for efficient boron removal.

Nanorod‐Like Polymer Adsorbents with Intermediate Dihydroxy Functional Groups for Efficient Boron Removal

AbstractIntermediate dihydroxy (m‐diol) compounds act as grafting groups and one‐dimensional Poly(VBC‐DVB) copolymer as supporter, the short rod‐like adsorbents were prepared by grafting trihydroxymethyl aminomethane (TRIS) and 2‐amino‐1, 3‐propanediol (APD) on the polymer Poly(VBC‐DVB). The as‐synthesized adsorbents exhibit excellent boron adsorption capacities in neutral and weakly alkaline solutions because of the formation of stable six‐membered ring complexes. The novel boron adsorbents have potential applications in boron removal.

Thin-film nanocomposite membrane comprised of a novel phosphonic acid derivative of titanium dioxide for efficient boron removal

The separation of toxic boron from seawater is the main concern for the desalination industries. The membrane-based boron separation is challenging due to the existence of boron in the neutral boric acid form. According to World Health Organization, a Boron above 0.5 ppm is not recommended for human health and agricultural use. The design of NF membranes for the Boron separation is tricky due to its neutral charge. In this study, a novel modification of titanium dioxide (TiO2) nanoparticles is performed by reacting with the cyclic propyl phosphonic anhydride (T3P) reagent in the presence of triethylamine as a base to obtain the phosphonic acid derivative of TiO2 (PTiO2). The PTiO2 was used as inorganic filler during the coating of the polyamide layer on the ultrafiltration support. Better dispersion of the nanoparticles was achieved due to the effective interactions between the –POOH (of PTiO2) and –NH2 (of meta-phenylene diamine groups) as evidenced by the ATR-IR spectrum. The resultant nanocomposite membranes showed a high potential to reject scalant divalent ions (>98%) and sodium chloride (>60%) with improved permeation characteristics. The boron adsorption study revealed a strong adsorption of boric acid ~12 mg/g by the PTiO2 nanoparticles causing the pore narrowing effect. Due to the same reason, the boron diffusion coefficient of the membranes reduced at neutral pH. The boron rejection offered by the membrane with 0.1 wt% PTiO2 was ~2.5 times higher than the commercial NF90 membrane.

A functionalized bio-based material with abundant mesopores and catechol groups for efficient removal of boron

Pursuing a low-cost yet sustainable material with a high performance of removing boron is necessary for replacement of the synthetic adsorbents, but remains challengeable. Herein, we fabricated an mesopore-dominated bio-based material (LS-CPAM-TA) with abundant catechol groups by the electrostatic-interaction-driven self-assembly of lignosulfonate (LS), tannic acid (TA) and cationic polyacrylamide (CPAM) for efficient removal of boron. LS-CPAM-TA presented a mesopore area of 53.9 m2/g with a mesoporous distribution of 2–25 nm, as well as a mesopore/micropore volume ratio of 129.7. Such a mesopore-rich feature not only promoted the exposure of catechol groups in TA, which served as the adsorption sites, but also contributed to enhance the fast mass transport of boron. Consequently, a maximum adsorption capacity of 119.05 mg/g was observed for LS-CPAM-TA, surpassing some reported adsorbents. Even for the low concentration boron, LS-CPAM-TA also displayd the high adsorption efficiency. Moreover, LS-CPAM-TA followed the Langmuir isotherm adsorption model, and presented the excellent regeneration performance due to its robust self-assembled structure driven by the electrostatic interaction among LS, CPAM and TA. This work would provide guidelines for target design of bio-based materials with tunable porous structure and versatile adsorption or catalytic sites for various applications.

Experimental Investigation of Boron Removal Mechanism from Wastewater by Calcined Ettringite

The development of efficient and inexpensive boron removal techniques is required to treat wastewater from many industrial processes. We investigated the removal mechanism of boron from wastewater by calcinated ettringite, a concrete sludge, and compared the advantage of this method to coprecipitation with ettringite. The amount of boron remaining in solution decreased slightly from an initial concentration of 2.3 mmol/dm3 to 1.3–1.4 mmol/dm3 after reaction for 60 min with ettringites calcinated at 55 and 65 °C. The boron removal efficiency increased greatly, with only 0.30 mmol/dm3 remaining in solution after treatment for 60 min with samples calcinated at 75 °C, but samples calcinated at 95 and 175 °C removed slightly less boron than those calcinated at 75 °C. This enhancement of boron removal performance is due to the amorphization of the ettringite structure by calcination. However, excess heating inhibits ion exchange between the sulfate ions in the ettringite and the borate ions in the solution. The coprecipitation method also achieved efficient boron removal at high Al/B molar ratio (0.44 mmol/dm3 boron remaining after 60 min). However, uptake by a different amorphous precipitant became the dominant removal mechanism. Large amounts of sludge are generated by this method. Adsorption using calcinated ettringite is therefore the optimal method for the efficient and inexpensive removal of boron from wastewater.

Boron removal for solar-grade silicon production by metallurgical route:A review

Solar energy has received considerable attention over the past few decades, due to its importance as a green and renewable energy. Low-cost solar-grade silicon production is critical for the widespread use of solar cells. Conventional routes (e.g., modified Siemens process: chlorosilane and hot filament) have still dominated the production of solar-grade silicon. The metallurgical route offers benefits in the productivity and cost, but efficient removal of boron is one of the most daunting challenges in front of us. This paper reviews thermodynamic and kinetic properties (solubility, diffusivity, diffusion coefficients, mass transfer rate, and activity coefficient) of boron and recent research topics (slag treatment, solvent refining, gas injection, plasma treatment, and acid leaching) for boron removal.

Synthesis of Negatively Charged Polyol-Functional PSF Membranes with Good Hydrophilic and Efficient Boron Removal Properties.

Boron removal remains a major barrier to water purification, it is important to develop a specialized adsorption membrane for boron removal. By means of a simple and effective method, a hydrophilic membrane for boron removal with a polyhydroxy functional group on the surface was prepared. Firstly, a polysulfone (PSF) membrane was modified by co-depositing polyethyleneimine (PEI) with dopamine (DA) in one-step to produce amine-rich surfaces, then the DA/PEI-functionalized membranes were reacted with glycidol, with the prepared membranes corresponding to PSF-PDA/PEI membranes and PSF-diol membranes. The prepared membranes were characterized by water-uptake, FTIR, (X-ray photoelectron spectroscopy) XPS, (Field emission scanning electron microscope) FESEM, and zeta potential measurements. The hydrophilicity of the membrane was characterized by the static water contact angle (WCA) test. In addition, we systematically studied the impact of initial boron concentration, chelating time, and pH value on boron removal performance. The results showed that the PSF-diol membrane had strong hydrophilicity with a WCA of about 38°. The maximum adsorption capacity of boron appeared to be 1.61 mmol/g within 10 min at a boron concentration of 300 mg/L. Adsorption kinetics showed that saturation adsorption can be achieved in minutes at the initial concentration of 5 mg/L, which is beneficial to a rapid filtration process.

Synthesis, Characterization, Adsorption, and Isotopic Separation Studies of Pyrocatechol-Modified MCM-41 for Efficient Boron Removal

Selected by the conductive value change (Δ) caused by generated proton in the boric acid-polyol solutions, pyrocatechol (CL) and nitropyrocatechol (NCL) were grafted into the mesoporous MCM-41 mate...

Techno-economic evaluation of different seawater reverse osmosis configurations for efficient boron removal

Techno-economic evaluation of different seawater reverse osmosis configurations for efficient boron removal

The Importance of Slag Structure to Boron Removal from Silicon during the Refining Process: Insights from Raman and Nuclear Magnetic Resonance Spectroscopy Study

Slag structure plays an important role in determining the relative ease of boron removal from silicon. Correlation between slag structure and boron removal thermodynamics was experimentally studied by Raman and nuclear magnetic resonance (NMR) spectroscopy using CaO-SiO2-Na2O slags with different optical basicities (0.6 to 0.71). Optimization of slag depolymerization leads to efficient removal of boron. The extent of nonbridged oxygen content (NBO/T) and boron removal gradually increased with an increase in optical basicity from 0.6 to 0.66: B2O3 derived from boron oxidation captured nonbridging oxygens of Q 0(Si), Q 1(Si), and Q 2(Si), and was incorporated into the silicate network in the form of Q 3(Si and B). When optical basicity increased to 0.71, NBO/T rapidly increased and boron removal decreased considerably. Quick depolymerization of Q 3(Si and B) deteriorated the stability of boron. Various structural forms of boron in the silicate network were successfully detected: the BO3 trihedrons [3]B-3Si, [3]B-2Si-1NBO, and BO3 (nonring), and the BO4 tetrahedrons BO4 (1B, 3Si) and BO4 (0B, 4Si). BO4 (1B, 3Si) was the main structure contributing to the increase of boron capacity; BO3 (nonring), detected under higher optical basicity conditions, may cause deterioration of boron removal by suppressing its oxidation.

Development of Novel Diol-Functionalized Silica Particles toward Fast and Efficient Boron Removal

Ion-exchange adsorption may be a promising way to tackle the boron contamination in various waterbodies on condition that an effective boron-specific adsorbent with fast sorption kinetics, high efficiency and capacity, easy regeneration, and low cost is accessible. In this work, a group of novel silica-based adsorbents were synthesized for boron removal, with the objectives of assessing their adsorption behaviors and improving their boron separation performance. The adsorption efficiency was systematically evaluated and optimized under various synthesis and operating conditions, i.e., reactant ratio, chelating temperature, particle loading, contact time, and ion strength. In addition, the adsorption kinetics and isotherm were adequately demonstrated. The adsorption kinetics followed the pseudo-second order kinetic model while the adsorption isotherm was described by Langmuir, Freundlich, and Sips models. The silica adsorbent exhibited a high adsorption rate; equilibrium was reached in few minutes, due to its high hydrophilicity and nontortuous structure. A high adsorption capacity was predicted, and a heterogeneous sorption behavior was validated by the isotherm models. Finally, regeneration performance of the adsorbent in both batch experiments and liquid chromatographic (LC) column-based experiments demonstrated that the adsorption capacity was marginally sacrificed (less than 10%) after three cycles of measurements, illustrating promising reusability. These findings may open up new ways to design high-performance boron-specific adsorbents.

Radiation synthesis and performance of novel cellulose-based microsphere adsorbents for efficient removal of boron (III)

A novel cellulose-based microsphere containing glucamine groups, referred as CVN, was successfully synthesized by radiation-induced graft polymerization of 4-vinylbenzyl chloride onto cellulose microspheres and subsequent functionalization with N-methyl-d-glucamine. The adsorption by CVN for boron (III) from aqueous solutions was evaluated systematically by batch adsorption technique. Langmuir models could fit well with the adsorption behavior of CVN. The CVN adsorbents exhibited a high adsorption capacity up to 12.4mgg−1 towards boron (III) over the wide pH range of 5–8. After the addition of chloride salts, the boron uptake of CVN was enhanced that was attributed to the compensation of the surface charge generated by boron (III) adsorption leading to favor the adsorption. At high concentrations of salts, the ionic strength and different salts have no effect on the adsorption of boron(III). This work provides a new sustainable, cost effective material as a promising specific adsorbent for the removal of boron (III) from saline solutions.

Rapid and efficient removal of boron from deep sea water using synthesized polymer resin

The present investigation aims to remove boron from deep sea water using the n-methyl d-glucamine-modified polymeric resin as synthesized in the laboratory. The resins are characterized by IR analysis and the morphology is discussed with the help of scanning electron microscopic images. Further, the resin is distributed in three different bead sizes i.e. 0.25, 0.5 and 1.0 mm, and assessed their removal efficiency for the boron removal under batch and column operations. Batch data show that a very fast uptake of boron took place and within 20 min of contact, almost a complete removal of boron occurred. Further, the kinetics of boron uptake is performed using linear equations of pseudo-first-order and pseudo-second-order rate equations. The applicability of pseudo-second-order rate law inferred that the boron is sorbed onto the solid surface by strong chemical forces, forming an “inner sphere complexes”. The batch and column data obtained for the boron removal is then critically compared with the commercially available resin. Further, reusability of this resin is also obtained taking the repeated operations using the same used resin. These results may, perhaps, enable to reduce the input cost of deep sea water treatment.

Novel boron specific copolymers with quaternary amine segments for efficient boron removal via PEUF

In this study, a copolymer, poly (vinyl amino-N, N′-bis-propane diol-co-DADMAC) (GPVA-co-DADMAC) was synthesized in three comonomer ratios (2%, 5% and 10%) and efficiently exploited for boron removal via polymer enhanced ultrafiltration (PEUF). Boron concentration could be reduced from 10ppm down to 0.8ppm by the employment of novel copolymer in continuous PEUF at pH 9 and boron-to-polymer mass ratio (loading) of 0.001. Polymer precipitation was not observed even after complexation with boron. Boron retention was found to be highly pH dependent and boron concentration dependent at constant loading. Hence, efficient polymer regeneration can be expected due to high pH and concentration dependency of boron complexation. Moreover, permeate flux was not affected by the polymer concentration in the conditions studied (polymer concentration ≤10g/L; pressure drop: 2bar). Dynamic and static light scattering measurements showed that gyration radius of the polymers rises by dilution or by increasing pH of the solutions. Furthermore, a two-step equilibrium model was correlated with the experimental boron retention data. Having high boron binding affinity, hydrolytic stability and efficiency in boron removal, the synthesized copolymers possessing DADMAC segments seemed to be attractive and useful for large scale water treatment with PEUF systems.