La3+@BC500-S2O82- system for removal of sulfonamide antibiotics in water.

Sulfonamide antibiotics (SAs) widely used have potentially negative effects on human beings and ecosystems. Adsorption and advanced oxidation methods have been extensively applied in SAs wastewater treatment. In this study, compared with Al3+@BC500 and Fe3+@BC500, La3+@BC500 for activating persulfate (S2O82-) had the best effect removal performance of sulfadiazine (SDZ) and sulfamethoxazole (SMX). Morphology, acidity, oxygen-containing functional groups, and loading of La3+@BC500 were analyzed by techniques, including EA, BET, XRD, XPS, FT-IR. XRD results show that with the increase of La3+ loading, the surface characteristics of biochar gradually changed from CaCO3 to LaCO3OH. Through EPR technology, it is proved that LaCO3OH on the surface of La3+@BC500 can not only activate S2O82- to generate SO4-•, but also to produce •OH. In the optimization experiment, the optimal dosage of La3+ is between 0.05 and 0.2 (mol/L)/g. SDZ had a good removal effect at pH (5-9), but SMX had a good removal effect only at pH=3. Zeta potential also proves that the material is more stable under acidic conditions. The removal process of SDZ is more in accord with pseudo-first-order kinetics (R2=0.9869), while SMX is more in line with pseudo-second order kinetics (R2=0.9926).

Effective removal and adsorption mechanism of fluoride from water by biochar-based Ce(III)-La(III)-crosslinked sodium alginate hybrid hydrogel.

An eco-friendly macroparticle biochar (BC)-based Ce(III)-La(III) crosslinked sodium alginate (SA) hybrid hydrogel (BC/Ce-SA-La) was synthesized by droplet polymerization and characterized by SEM-EDS, XRD, FTIR, UV-Vis and XPS. The effects of dosage, pH, contact time, temperature and coexisting ions on the F- ions removal by hybrid hydrogel, and the adsorption performance, interaction mechanism and reusability were investigated. The results demonstrate that the composite has a fancy wrinkle structure with a particle size of about 1.8 mm and abundant porosity on the surface. The removal rate of F- ions by BC/Ce-SA-La reached 90.2 % under the conditions of pH 2.0, 200 min of contact time and 298 K. The adsorption behavior was perfectly explained by Langmuir model, and the maximum adsorption capacity reached 129 mg/g. The adsorption process was an endothermic spontaneous reaction and followed Pseudo-second-order rate model. The strong adsorption was attributed to multi-interactions including complexation, hydrogen bonding and electrostatic adsorption between the composite and F- ions. Coexisting ions hardly interfered with the adsorption of F- ions by BC/Ce-SA-La except for a slight effect of phosphate. The composite after F- ion adsorption was easily separated and could be reused at least three times. BC/Ce-SA-La is a cost-effective and promising granular biosorbent.

Deep eutectic solvent-assisted synthesis of La-Ce hybrid nanorods for the colorimetric determination of tetracycline in foods.

Tetracycline (TC) as a broad-spectrum antibiotic, is widely used in the prevention and treatment of various bacterial diseases. However, its abuse in the livestock industry may lead to interference in human microecology, thereby causing various side effects. In this study, deep eutectic solvents (DESs) were synthesized using L-(-)-threonine (L-(-)-Thr) and cerium nitrate hexahydrate (Ce(NO3)3·6H2O), and later lanthanum nitrate hexahydrate (La(NO3)3·6H2O) was doped to synthesize La-Ce hybrid nanorods. These nanorods can be used for the determination of TC with high sensitivity and selectivity by the colorimetric method. This approach has a linear response to TC between 0.05 µM and 10 µM, with a detection limit of 0.016 µM. In this system, good dispersion provides the substance with a distinct peroxidase activity, which is used to create a colorimetric sensor for detecting TC. Mechanism studies show that the superoxide radical generated by the La-Ce nanomembrane plays a key role in peroxidase catalysis. Finally, the practicality of the method was verified by the determination of TC in food products (milk, pork and honey), which demonstrated that a good recovery rate can be obtained (91.4-102%).

Ion-imprinted aminoguanidine-chitosan for selective recognition of lanthanum (III) from wastewater.

Developing a sorbent for the removal of La3+ ions from wastewater offers significant environmental and economic advantages. This study employed an ion-imprinting process to integrate La3+ ions into a newly developed derivative of aminoguanidine-chitosan (AGCS), synthesized via an innovative method. The process initiated with the modification of chitosan by attaching cyanoacetyl groups through amide bonds, yielding cyanoacetyl chitosan (CAC). This derivative underwent further modification with aminoguanidine to produce the chelating AGCS biopolymer. The binding of La3+ ions to AGCS occurred through imprinting and cross-linking with epichlorohydrin (ECH), followed by the extraction of La3+, resulting in the La3+ ion-imprinted sorbent (La-AGCS). Structural confirmation of these chitosan derivatives was established through elemental analysis, FTIR, and NMR. SEM analysis revealed that La-AGCS exhibited a more porous structure compared to the smoother non-imprinted polymer (NIP). La-AGCS demonstrated superior La3+ capture capability, with a maximum capacity of 286 ± 1 mg/g. The adsorption process, fitting the Langmuir and pseudo-second-order models, indicated a primary chemisorption mechanism. Moreover, La-AGCS displayed excellent selectivity for La3+, exhibiting selectivity coefficients ranging from 4 to 13 against other metals. This study underscores a strategic approach in designing advanced materials tailored for La3+ removal, capitalizing on specific chelator properties and ion-imprinting technology.

Striking the balance: Unveiling the interplay between photocatalytic efficiency and toxicity of La-incorporated Ag3PO4.

Persistent molecules, such as pesticides, herbicides, and pharmaceuticals, pose significant threats to both the environment and human health. Advancements in developing efficient photocatalysts for degrading these substances can play a fundamental role in remediating contaminated environments, thereby enhancing safety for all forms of life. This study investigates the enhancement of photocatalytic efficiency achieved by incorporating La3+ into Ag3PO4, using the co-precipitation method in an aqueous medium. These materials were utilized in the photocatalytic degradation of Rhodamine B (RhB) and Ciprofloxacin (CIP) under visible light irradiation, with monitoring conducted through high-performance liquid chromatography (HPLC). The synthesized materials exhibited improved stability and photodegradation levels for RhB. Particularly noteworthy was the 2% La3+-incorporated sample (APL2), which achieved a 32.6% mineralization of CIP, nearly three times higher than pure Ag3PO4. Toxicological analysis of the residue from CIP photodegradation using the microalga Raphidocelis subcapitata revealed high toxicity due to the leaching of Ag + ions from the catalyst. This underscores the necessity for cautious wastewater disposal after using the photocatalyst. The toxicity of the APL2 photocatalysts was thoroughly assessed through comprehensive toxicological tests involving embryo development in Danio rerio, revealing its potential to induce death and malformations in zebrafish embryos, even at low concentrations. This emphasizes the importance of meticulous management. Essentially, this study adeptly delineated a thorough toxicological profile intricately intertwined with the photocatalytic efficacy of newly developed catalysts and the resultant waste produced, prompting deliberations on the disposal of degraded materials post-exposure to photocatalysts.

Phosphorus immobilization/release behavior of lanthanum-modified bentonite amended sediment under the dual effects of pH and dissolved organic carbon.

Lanthanum modified bentonite (LMB) is typical P-inactivating agent that has been applied in over 200 lakes. Dissolved organic carbon (DOC) and high pH restrict the phosphorus (P) immobilization performance of LMB. However, the P immobilization/release behaviors of LMB-amended sediment when suspended to overlying water with high pH and DOC have not yet been studied. In the present work, batch adsorption and long-term incubation experiments were performed to study the combined effects of pH and DOC on the P control by LMB. The results showed that the coexistence of low concentration of DOC or preloading with some DOC had a negligible effect on P binding by LMB. In the presence of DOC, the P adsorption was more pronounced at pH 7.5 and was measurably less at pH 9.5. Additionally, the pH value was the key factor that decided the P removal at low DOC concentration. The increase in pH and DOC could significantly promote the release of sediment P with a higher EPC0. Under such condition, a higher LMB dosage was needed to effectively control the P releasing from sediment. In sediment/water system with intermittent resuspension, the alkaline conditions greatly facilitated the release of sediment P and DOC, which increased from 0.087 to 0.581 mg/L, and from 11.05 to 26.56 mg/L, respectively. Under the dual effect of pH and DOC, the P-immobilization performance of LMB was weakened, and a tailor-made scheme became essential for determining the optimum dosage. The desorption experiments verified that the previously loaded phosphorus on LMB was hard to be released even under high pH and DOC conditions, with an accumulative desorption rate of less than 2%. Accordingly, to achieve the best P controlling efficiency, the application strategies depending on LMB should avoid the high DOC loading period such as the rainy season and algal blooms.

Ultrasonic-induced grafted lanthanum sulfide decorated multi-walled carbon nanotube onto bacterial cellulose applied for adsorption of pesticides in environmental waters.

A new biosorbent was fabricated by modification of bacterial cellulose biopolymer grafted with lanthanum sulfide decorated carboxylated multiwall carbon nanotube (La2S3@MWCNT@BC). The sorbent was employed in a green alternative dispersive-solid phase extraction of a variety of 14 pesticides in environmental water samples. The analyses were performed using GC-µECD. The properties and structure of La2S3@MWCNT@BC nanocomposite were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and adsorption-desorption isotherms. The composition of the sorbent was also investigated to evaluate the adsorptive properties of its constituents. The impact of various parameters influencing extraction efficacies such as sorbent dose, adsorption time, sample pH, ionic strength, and desorption conditions was investigated. The method was validated by specificity, matrix effect % (-0.4 to -7.4), enrichment factor (4-10), limits of quantification (0.007-0.31 µg L-1), matrix-matched calibration linearity (0.01-200 µg L-1), determination coefficients (r2=0.9921-0.9998), and precision. The optimized method was applied for the analysis of multiclass pesticides in seven environmental and drinking waters and the recoveries were obtained in the 81-108 % range with RSDs of 2.5-4.7 %. This paper is the first report on the synthesis and use of La2S3@MWCNT@BC nanocomposite to extract pesticides from different water samples. The greenness of the procedure was evaluated by the AGREE protocols.

Lanthanum-modified pyroaurite as a geoengineering tool to simultaneously sink Microcystis cyanobacteria and immobilize phosphorus in eutrophic water.

Excessive phosphorus (P) in eutrophic water induces cyanobacterial blooms that aggravate the burden of in-situ remediation measures. In order to ensure better ecological recovery, Flock & Lock technique has been developed to simultaneously sink cyanobacteria and immobilize P but requires a combination of flocculent and P inactivation agent. Here we synthesized a novel lanthanum-modified pyroaurite (LMP), as an alternative for Flock & Lock of cyanobacteria and phosphorus at the background of rich humic acid and suspended solids. LMP shows a P adsorption capacity of 36.0 mg/g and nearly 100 % removal of chlorophyll-a (Chl-a), turbidity, UV254 and P at a dosage (0.3 g/L) much lower than the commercial analogue (0.5 g/L). The resultant sediment (98.2 % as immobile P) exhibits sound stability without observable release of P or re-growth of cyanobacteria over a 50-day incubation period. The use of LMP also constrains the release of toxic microcystins to 1.4 µg/L from the sunk cyanobacterial cells, outperforming the commonly used polyaluminum chloride (PAC). Similar Flock & Lock efficiency could also be achieved in real eutrophic water. The outstanding Flock & Lock performance of LMP is attributable to the designed La modification. During LMP treatment, La acts as not only a P binder by formation of LaPO4, but also a coagulant to create a synergistic effect with pyroaurite. The controlled hydrolysis of surface La(III) over pyroaurite aided the possible formation of La(III)-pyroaurite networking structure, which significantly enhanced the Flock & Lock process through adsorption, charge neutralization, sweep flocculation and entrapment. In the end, the preliminary economic analysis is performed. The results demonstrate that LMP is a versatile and cost-effective agent for in-situ remediation of eutrophic waters.

Biochemical and biophysical interaction of rare earth elements with biomacromolecules: A comprehensive review.

The growing utilization of rare earth elements (REEs) in industrial and technological applications has captured global interest, leading to the development of high-performance technologies in medical diagnosis, agriculture, and other electronic industries. This accelerated utilization has also raised human exposure levels, resulting in both favourable and unfavourable impacts. However, the effects of REEs are dependent on their concentration and molecular species. Therefore, scientific interest has increased in investigating the molecular interactions of REEs with biomolecules. In this current review, particular attention was paid to the molecular mechanism of interactions of Lanthanum (La), Cerium (Ce), and Gadolinium (Gd) with biomolecules, and the biological consequences were broadly interpreted. The review involved gathering and evaluating a vast scientific collection which primarily focused on the impact associated with REEs, ranging from earlier reports to recent discoveries, including studies in human and animal models. Thus, understanding the molecular interactions of each element with biomolecules will be highly beneficial in elucidating the consequences of REEs accumulation in the living organisms.

Lanthanum and Indium intermetallics nanomaterial for thermal photovoltaic applications - A full potential study.

In this work Full Potential study performed on Lanthanum compounds to analyze its photovoltaic properties. Five different combinations of Lanthanum and Indium with phosphorus are chosen in this study are La3P, La2InP, LaIn2P, LaP and InP. The optical, structural, thermoelectric, thermal, and electronic properties of all the above-mentioned compounds are analyzed using Density Functional Theory (DFT) applied in the WIEN2k software. Based on the analysis of electronic properties is concluded that La3P, LaP, La2InP and LaIn2P are conductors whereas InP is semiconductor (direct band gap) with band gap (energy) value 0.39 eV. The optical properties analysis shows these materials have desirable properties in the near UV or in the UV region. The low value of Gibbs energy indicates high thermodynamic stability. Power factor values for La2InP, LaP, InP and La3P are found to be in agreement with existing thermoelectric material, rendering them as potential thermal photovoltaic materials.

Design and fabrication of La-based perovskites incorporated with functionalized carbon nanofibers for the electrochemical detection of roxarsone in water and food samples.

The pentavalent arsenic compound roxarsone (RSN) is used as a feed additive in poultry for rapid growth, eventually ending up in poultry litter. Poultry litter contains chicken manure, which plays a vital role as an affordable fertilizer by providing rich nutrients to agricultural land. Consequently, the extensive use of poultry droppings serves as a conduit for the spread of toxic forms of arsenic in the soil and surface water. RSN can be easily oxidized to release highly carcinogenic As(III) and As(IV) species. Thus, investigations were conducted for the sensitive detection of RSN electrochemically by developing a sensor material based on lanthanum manganese oxide (LMO) and functionalized carbon nanofibers (f-CNFs). The successfully synthesised LMO/f-CNF composite was confirmed by chemical, compositional, and morphological studies. The electrochemical activity of the prepared composite material was examined using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained results confirmed that LMO/f-CNF showed enhanced electrocatalytic activity and improved current response with a good linear range (0.01-0.78 µM and 2.08-497 µM, respectively), exhibiting a low limit of detection (LOD) of 0.004 µM with a high sensitivity of 13.24 µA µM-1 cm-2 towards the detection of RSN. The noteworthy features of LMO/f-CNF composite with its superior electrochemical performance enabled reliable reproducibility, exceptional stability and reliable practical application in the analysis of tap water and food sample, affording a recovery range of 86.1-98.87%.

Lanthanum-fluoride electrode-based methods to monitor fluoride transport in cells and reconstituted lipid vesicles.

Fluoride (F-) export proteins, including F- channels and F- transporters, are widespread in biology. They contribute to cellular resistance against fluoride ion, which has relevance as an ancient xenobiotic, and in more modern contexts like organofluorine biosynthesis and degradation or dental medicine. This chapter summarizes quantitative methods to measure fluoride transport across membranes using fluoride-specific lanthanum-fluoride electrodes. Electrode-based measurements can be used to measure unitary fluoride transport rates by membrane proteins that have been purified and reconstituted into lipid vesicles, or to monitor fluoride efflux into living microbial cells. Thus, fluoride electrode-based measurements yield quantitative mechanistic insight into one of the major determinants of fluoride resistance in microorganisms, fungi, yeasts, and plants.

High-performance electrosorption of lanthanum ion by Mn3O4-loaded phosphorus-doped porous carbon electrodes via capacitive deionization.

Transition-metal-oxide@heteroatom doped porous carbon composites have attracted considerable research interest because of their large theoretical adsorption capacity, excellent electrical conductivity and well-developed pore structure. Herein, Mn3O4-loaded phosphorus-doped porous carbon composites (Mn3O4@PC-900) were designed and fabricated for the electrosorption of La3+ in aqueous solutions. Due to the synergistic effect between Mn3O4 and PC-900, and the active sites provided by Mn-O-Mn, C/PO, C-P-O and Mn-OH, Mn3O4@PC-900 exhibits high electrosorption performance. The electrosorption value of Mn3O4@PC-900 was 45.34% higher than that of PC-900, reaching 93.02 mg g-1. Moreover, the adsorption selectivity reached 87.93% and 89.27% in La3+/Ca2+ and La3+/Na+ coexistence system, respectively. After 15 adsorption-desorption cycles, its adsorption capacity and retention rate were 50.34 mg g-1 and 54.12%, respectively. The electrosorption process is that La3+ first accesses the pores of Mn3O4@PC-900 to generate an electric double layer (EDL), and then undergoes further Faradaic reaction with Mn3O4 and phosphorus-containing functional groups through intercalation, surface adsorption and complexation. This work is hoped to offer a new idea for exploring transition-metal-oxide @ heteroatom doped porous carbon composites for separation and recovery of rare earth elements (REEs) by capacitive deionization.

Synthesis and performance evaluation of S-scheme heterostructured LaFeO3/TiO2 photocatalyst for the efficient degradation of thiamethoxam.

The application of perovskite lanthanum ferrite (LaFeO3) as a photocatalyst has shown significant potential in the removal of persistent organic and inorganic contaminants. In the present research, LaFeO3 and various composites consisting of LaFeO3 and TiO2 were prepared. The photocatalytic efficiency of the produced catalysts was assessed by measuring their effectiveness in degrading thiamethoxam, a pesticide belonging to the second generation of neonicotinoids. Experimental investigations were carried out to examine the impact of various factors on the degradation process, including variables like concentration of thiamethoxam, catalyst amount, and pH level. The produced catalysts were characterized by various techniques, including field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS). The highest degradation rates were observed when using the synthesized catalyst, 1% LaFeO3/TiO2 (LFTO1), under both UV-C and direct sunlight conditions. This performance outperformed TiO2 and bare LaFeO3. When exposed to ultraviolet (UV-C) radiation at an intensity of 15 W m-2 and under neutral pH conditions, LFTO1 achieved approximately 97% degradation, while under direct sunlight, the LFTO1 photocatalyst exhibited a degradation rate of 79% within a 120-min reaction period. The enhanced activity of LFTO1 could be attributed to its increased surface area, reduced bandgap, and lower electron-hole recombination. The investigation of reaction kinetics showed that the degradation of thiamethoxam followed a pseudo-first-order rate law. Furthermore, LFTO1 can be employed up to 5 times without experiencing any loss in its catalytic activity, thus confirming its long-term utility.

Efficient phosphate removal by Mg-La binary layered double hydroxides: synthesis optimization, adsorption performance, and inner mechanism.

Layered double hydroxides (LDH) hold great promise as phosphate adsorbents; however, the conventional binary LDH exhibits low adsorption rate and adsorption capacity. In this study, Mg and La were chosen as binary metals in the synthesis of Mg-La LDH to enhance phosphate efficient adsorption. Different molar ratios of Mg to La (2:1, 3:1, and 4:1) were investigated to further enhance P adsorption. The best performing Mg-La LDH, with Mg to La ratio is 4:1 (LDH-4), presented a larger adsorption capacity and faster adsorption rate than other Mg-La LDH. The maximum adsorption capacity (87.23 mg/g) and the rapid adsorption rate in the initial 25 min of LDH-4 (70 mg/(g·h)) were at least 1.6 times and 1.8 times higher than the others. The kinetics, isotherms, the effect of initial pH and co-existing anions, and the adsorption-desorption cycle experiment were studied. The batch experiment results proved that the chemisorption progress occurred on the single-layered LDH surface and the optimized LDH exhibited strong anti-interference capability. Furthermore, the structural characteristics and adsorption mechanism were further investigated by SEM, BET, FTIR, XRD, and XPS. The characterization results showed that the different metal ratios could lead to changes in the metal hydroxide layer and the main ions inside. At lower Mg/La ratios, distortion occurred in the hydroxide layer, resulting in lower crystallinity and lower performance. The characterization results also proved that the main mechanisms of phosphate adsorption are electrostatic adsorption, ion exchange, and inner-sphere complexation. The results emphasized that the Mg-La LDH was efficient in phosphate removal and could be successfully used for this purpose.

Lanthanum-modified tobermorite synthesized from fly ash for efficient phosphate removal.

Phosphate removal from water by lanthanum-modified tobermorite synthesized from fly ash (LTFA) with different lanthanum concentrations was studied. LTFA samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer‒Emmett‒Teller specific surface area analysis. The results showed that the LTFA samples were mainly composed of mesoporous tobermorite-11 Å, and LTFA1 with a lanthanum concentration of 0.15 M had a high specific surface area (83.82 m2/g) and pore volume (0.6778 cm3/g). The phosphate adsorption capacities of LTFA samples were highest at pH 3 and gradually decreased with increasing pH. The phosphate adsorption kinetics data on LTFA samples were most accurately described by the Elovich model. The adsorption isotherms were in the strongest agreement with the Temkin model, and LTFA1 showed the highest phosphate adsorption capacity (282.51 mg P/g), which was higher than that of most other lanthanum-modified adsorbents. LTFA1 presented highly selective adsorption of phosphate with other coexisting ions (HCO3-, Cl-, SO42-, and NO3-). In addition, phosphate was adsorbed onto LTFA samples by forming inner-sphere phosphate complexes and amorphous lanthanum phosphate. This study provides technical support for development of efficient fly ash-based phosphate adsorbents.

Mechanistic study of highly effective phosphate removal from aqueous solutions over a new lanthanum carbonate fabricated carbon nanotube film.

The effective purification of phosphate-containing wastewater is considered as increasingly important. In this study, a highly effective LC-CNT film was developed for efficient phosphate removal. Kinetic results showed that the adsorbent exhibited an improved mass transfer efficiency and a fast adsorption rate during adsorption (reaching 80% and 100% equilibrium adsorption capacity within 175 and 270 min, respectively). Kinetic model analysis suggested that the adsorption was a combined chemical physical process. Isotherm study revealed that the LC-CNT film showed a superior adsorption capacity (178.6 mg/g, estimated from the Langmuir model) with multiple adsorption mechanisms. pH study suggested that surface complexation and ligand exchange played important roles during adsorption, and the adsorbent worked well within the pH range of 3-7 with little La leakage. The ionic strength and competing anions showed little influence on the adsorbent effectiveness except for the carbonate and sulfate ions. The characterization and mechanism study revealed that the phosphate adsorption of the LC-CNT film was controlled by inner-sphere complexation, outer-sphere complexation and surface precipitation. The LC-CNT film also showed excellent regenerability and stability in cycling runs, further demonstrating its potential in industrial applications.

Zeta potential of Z-DNA: A new signature to study B-Z transition in linear and branched DNA.

Zeta potential is commonly referred as surface charge density and is a key factor in modulating the structural and functional properties of nucleic acids. Although the negative charge density of B-DNA is well understood, there is no prior description of the zeta potential measurement of Z-DNA. In this study, for the first time we discover the zeta potential difference between B-DNA and lanthanum chloride-induced Z-DNA. A series of linear repeat i.e. (CG)n and (GC)n DNA as well as branched DNA (bDNA) structures was used for the B-to-Z DNA transition. Herein, the positive zeta potential of Z-DNA has been demonstrated as a powerful tool to discriminate between B-form and Z-form of DNA. The generality of the approach has been validated both in linear and bDNA nanostructures. Thus, we suggest zeta potential can be used as an ideal signature for the left-handed Z-DNA.

Nano La(OH)3 modified lotus seedpod biochar: A novel solution for effective phosphorus removal from wastewater.

Effective removal of phosphorus from water is crucial for controlling eutrophication. Meanwhile, the post-disposal of wetland plants is also an urgent problem that needs to be solved. In this study, seedpods of the common wetland plant lotus were used as a new raw material to prepare biochar, which were further modified by loading nano La(OH)3 particles (LBC-La). The adsorption performance of the modified biochar for phosphate was evaluated through batch adsorption and column adsorption experiments. Adsorption performance of lotus seedpod biochar was significantly improved by La(OH)3 modification, with adsorption equilibrium time shortened from 24 to 4 h and a theoretical maximum adsorption capacity increased from 19.43 to 52.23 mg/g. Moreover, LBC-La maintained a removal rate above 99% for phosphate solutions with concentrations below 20 mg/L. The LBC-La exhibited strong anti-interference ability in pH (3-9) and coexisting ion experiments, with the removal ratio remaining above 99%. The characterization analysis indicated that the main mechanism is the formation of monodentate or bidentate lanthanum phosphate complexes through inner sphere complexation. Electrostatic adsorption and ligand exchange are also the mechanisms of LBC-La adsorption of phosphate. In the dynamic adsorption experiment of simulated wastewater treatment plant effluent, the breakthrough point of the adsorption column was 1620 min, reaching exhaustion point at 6480 min, with a theoretical phosphorus saturation adsorption capacity of 6050 mg/kg. The process was well described by the Thomas and Yoon-Nelson models, which indicated that this is a surface adsorption process, without the internal participation of the adsorbent.

Amendment of Sargassum oligocystum bio-char with MnFe2O4 and lanthanum MOF obtained from PET waste for fluoride removal: A comparative study.

The use of biomass and waste to produce adsorbent reduces the cost of water treatment. The bio-char of Sargassum oligocystum (BCSO) was modified with MnFe2O4 magnetic particles and La-metal organic framework (MOF) to generate an efficient adsorbent (BCSO/MnFe2O4@La-MOF) for fluoride ions (F-) removal from aqueous solutions. The performance of BCSO/MnFe2O4@La-MOF was compared with BCSO/MnFe2O4 and BCSO. The characteristics of the adsorbents were investigated using various techniques, which revealed that the magnetic composites were well-synthesized and exhibited superparamagnetic properties. The maximum adsorption efficiencies (BCSO: 97.84%, BCSO/MnFe2O4: 97.85%, and BCSO/MnFe2O4@La-MOF: 99.36%) were achieved under specific conditions of pH 4, F- concentration of 10 mg/L, and adsorbent dosage of 3, 1.5, and 1 g/L for BCSO, BCSO/MnFe2O4, and BCSO/MnFe2O4@La-MOF, respectively. The results demonstrated that the experimental data adheres to a pseudo-second-order kinetic model. The enthalpy, entropy, and Gibbs free energy were determined to be negative; thus, the F- adsorption was exothermic and spontaneous in the range of 25-50 °C. The equilibrium data of the process exhibited conformity with the Langmuir model. The maximum adsorption capacities of F- ions were determined as 10.267 mg/g for BCSO, 14.903 mg/g for the BCSO/MnFe2O4, and 31.948 mg/g for BCSO/MnFe2O4@La-MOF. The KF and AT values for the F- adsorption were obtained at 21.03 mg/g (L/mg)1/n and 100 × 10+9 L/g, indicating the pronounced affinity of the BCSO/MnFe2O4@La-MOF towards F- than other samples. The significant potential of the BCSO/MnFe2O4@La-MOF magnetic composite for F- removal from industrial wastewater, makes it suitable for repeated utilization in the adsorption process.