Enhanced removal of phosphate and nitrate ions from aqueous media using nanosized lanthanum hydrous doped on magnetic graphene nanocomposite

Lanthanum hydroxide@cellulose membranes with tunable pore sizes for selective removal of dyes with the same charges

Adsorptive membranes for the efficient separation of dyes with the same charges are quite desirable. Herein, a novel membrane of lanthanum hydroxide/cellulose hydrogel coated filter paper (LC) was prepared through a facile strategy of dip-coating followed by freeze-shaping. With the aid of cellulose gel, the generated La(OH)3 achieved fine dispersion. In addition, the pore size of LC membrane could be regulated by altering the cellulose concentration or the lanthanum chloride dosage, which was crucial for its water flux. In particular, the obtained membrane possessed a high water flux (128.4 L m-2 h-1) and a high dye rejection (97.2 %) for anionic Congo red (CR) only driven by the gravity, which outperformed many previously reported membranes. More intriguingly, its dye rejection for anionic methyl orange (MO) was only 0.9 %, exhibiting high selectivity for dyes with the same charges. Single-solute adsorption experiments indicated that the CR adsorption on the membrane was best fitted by the pseudo-first-order kinetic model, and it followed the Langmuir monolayer adsorption mechanism.

Effective removal of nitrate and phosphate using graphene nanosheets synthesized from waste plastics

In this work, waste plastics have been used with bentonite clay to produce silica-containing graphene nanosheets (GNs) for adsorption of nitrate and phosphate from synthetic water. The GNs were obtained by the two steps process, namely (1) pyrolysis at 750 °C and (2) ball milling. Then, GNs were characterized by Raman spectroscopy, FTIR, XRD, FESEM, HRTEM and EDX spectroscopy, which provided the details of material's morphology, surface properties, and composition. From Raman spectroscopy, D and G bands were found at 1342 cm-1 and 1594 cm-1, respectively, which confirmed the presence of nanosheets on the graphene surface. Furthermore, the layers of nanosheets were confirmed by the HRTEM analysis and XRD peaks. In analytical study, the batch experiment was conducted to investigate the influence of operational parameters such as pH (03-12), contact time (05-120 min), adsorbent dosage (0.01-0.06 g), and initial concentrations of adsorbates (10-50 mg/L for nitrate and 03-15 mg/L for phosphate) on adsorption process. The removal percentage of nitrate and phosphate at optimum dosage = 0.05 g, pH = 6.5, contact time = 60 min, nitrate concentration = 30 mg/L, and phosphate concentration = 09 mg/L were found to be 85 and 91, respectively. The highest adsorption capacity of nitrate and phosphate was found to be 53 mg/g and 16.4 mg/g, respectively. The adsorption behaviour of both nitrate and phosphate showed chemisorption as the experimental data were well fitted by the pseudo-2nd-order kinetic and Langmuir isotherm model. Life cycle cost analysis (LCCA) of the synthesis process was conducted to evaluate the cost-benefit analysis for commercial feasibility. The estimated price for the synthesis of GNs using 1 kg of waste plastics and bentonite clay as precursor was $4.21, suggesting commercialization.

Optimum phosphate ion removal from aqueous solutions using roller kiln industrial solid waste

Water scarcity is the most imperative predicament that concerns the population. In this research, a roller kiln (RK) industrial solid waste was used in the adsorption of phosphate ions from aqueous solutions thus converting a waste to wealth through aiding in serving as a water treatment application. The RK waste was produced from an Egyptian factory with a flow rate of million tons/day. Surface characterization for this solid waste was performed including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infra-red (FTIR), zeta potential (ZP), and particle size distribution (PSD). Based on the kinetics and isotherm studies, the pseudo first order (PFO) kinetic model and Freundlich isotherm model were the best-fitted models with the experimental data as well as the Dubinin-Radushkevich isotherm model indicated that the adsorption type was physical. The attained experimental results were then optimized to attain the experimental conditions at which the optimum adsorption percentage was achieved using response surface methodology (RSM). The optimum percentage removal of phosphate ions 99.5 (%) was achieved at the following experimental conditions; pH 8, temperature = 25 °C, contact time = 9 min, initial phosphate ion concentration = 10 mg/L and adsorbent dose 0.5 = g/L.

Kinetics and Isotherm Studies for Adsorption of Gentian Violet Dye from Aqueous Solutions Using Synthesized Hydroxyapatite

Water is the most important resource for life, but it has been greatly exhausted over the past century as a result of the human population and environmentally harmful activities. The excessive quantity of dyes exists in the wastewater produced from the textile industries which is the main reason for serious human health and environmental problems. There are many dye removal techniques, and the most promising one is the adsorption technique. The novelty of this research is using unmodified synthesized hydroxyapatite (HAp) as an adsorbent for the removal of gentian violet (GV) dye from aqueous solutions as there are no sufficient data in the literature about using it in the adsorption of GV dye from aqueous solutions. Unmodified HAp was synthesized by a combined precipitation microwave method. The prepared adsorbent was characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and zeta potential analyses. The kinetic study showed that the pseudo-second-order (PSO) model was the best fitted model with the experimental data. Analysis of adsorption isotherms using different models showed that this adsorption system was better described by the Halsey isotherm with a maximum adsorption capacity (q_max)  of 1.035 mg/g. The effects of experimental factors such as initial solution pH, initial dye concentration, adsorbent dose, and contact time were studied during the investigation of GV dye removal efficiency. The experimental results indicated that the maximum adsorption efficiency (99.32%) of the GV dye using HAp adsorbent was achieved at the following conditions: contact time = 90 min, pH = 12, initial GV dye concentration = 3 mg/L, and adsorbent dose = 1 g/L. The adsorption mechanism of the GV dye using HAp might be explained by the electrostatic interaction between the negatively charged surface of the HAp and the positively charged group of the GV dye. Thermodynamics study was performed on the adsorption process of GV dye from aqueous solutions using the synthesized HAp which revealed that this process was endothermic and spontaneous due to positive values of ΔH and ΔS and negative values of ΔG.

Encapsulated Co-ZnO nanospheres as degradation tool for organic pollutants: Synthesis, morphology, adsorption and photo luminescent investigations

Zinc oxide (ZnO) nanostructures, both undoped and Co-doped, were synthesized through the solution combustion process. The diffraction patterns from powder XRD revealed that the materials were crystalline. The morphology of the spherically formed nanoparticles was visualized in SEM micrographs. FTIR spectra verified the existence of a defect-associated peak in Co-encapsulated ZnO (Zn_0.98Co_0.02O) NPs. Photoluminescence studies are undertaken. Malachite Green (MG) dye is used as a representative organic pollutant to study the adsorptive degradation of Co-doped ZnO nanomaterial. Moreover, the adsorption properties, including isotherm and kinetics, are investigated by analyzing the degradation of MG dye. Experimental parameters, such as the concentration of the MG dye, dosage and pH, were varied to ascertain favorable conditions for the degradation study. The results indicate that the MG dye is 70% degraded. After Co-doping, near-band edge emission in undoped ZnO changed into intense red defect emission and was directly correlated with changes in PL emission.

Isolation of organophosphate pesticides from water using gold nanoparticles doped magnetic three-dimensional graphene oxide

Pesticides are a large group of pristine organic contaminants, which are widely discharged into environmental water due to agricultural activities. Hence, extraction, determination, and removal of pesticides from water resources are necessary for human health. In this study, novel adsorbent was developed based on three-dimensional magnetic graphene coated with gold nanoparticles (3D-MG@AuNPs) for extraction of chlorpyrifos, dicrotophos, fenitrothion, and piperophos as four specific organophosphorus pesticides (OPPs) from wastewater and tap water samples. The proposed nanocomposite was characterized; FTIR and EDX are performed for the expected functional groups and elemental analysis, SEM showed the unique and spherical AuNPs are well dispersed over graphene sheets. In this investigation, the important parameters that have effect on the extraction efficiency, including the desorbing solvent, desorbing solvent volume, vortex time, the extraction time, adsorbent dosage, pH of sample solutions, and salt effect were evaluated. In conclusion, the measured amounts of the chosen OPPs were determined using the gas chromatography microelectron capture (μECD-GC) method. Limits of quantification (S/N ratio of 10) and detection (S/N ratio of 3) were attained at concentrations of 0.26-0.43 μg.L^-1 and 0.08-0.14 μg.L^-1, respectively. According to the results of the investigations, the synthesized 3D-MG@AuNPs did not require any complicated sample preparation methods; therefore, it is a very good choice for solid magnetic phase extraction studies.

nZVI-Based Nanomaterials Used for Phosphate Removal from Aquatic Systems

In the last decade, the application of nanoscale zero-valent iron (nZVI) has garnered great attention as an adsorbent due to its low cost, non-toxicity, high porosity, and BET-specific surface area. In particular, the immobilization of nZVI particles onto inorganic and organic substrates (nanocomposites) decreased its agglomeration, allowing them to be effective and achieve greater adsorption of pollutants than pristine nanoparticles (NPs). Although nZVI began to be used around 2004 to remove pollutants, there are no comprehensive review studies about phosphate removal from aquatic systems to date. For this reason, this study will show different types of nZVI, pristine nZVI, and its nanocomposites, that exist on the market, how factors such as pH solution, oxygen, temperature, doses of adsorbent, initial phosphate concentration, and interferents affect phosphate adsorption capacity, and mechanisms involved in phosphate removal. We determined that nanocomposites did not always have higher phosphate adsorption than pristine nZVI particles. Moreover, phosphate can be removed by nZVI-based nanoadsorbents through electrostatic attraction, ion exchange, chemisorption, reduction, complexation, hydrogen bonding, and precipitation mechanisms. Using the partition coefficient (PC) values, we found that sepiolite-nZVI is the most effective nanoadsorbent that exists to remove phosphate from aqueous systems. We suggest future studies need to quantify the PC values for nZVI-based nanoadsorbents as well as ought to investigate their phosphate removal efficiency under natural environmental conditions.

Synthesis of K+ and Na+ Synthetic Sodalite Phases by Low-Temperature Alkali Fusion of Kaolinite for Effective Remediation of Phosphate Ions: The Impact of the Alkali Ions and Realistic Studies

Two sodalite phases (potassium sodalite (K.SD) and sodium sodalite (Na.SD)) were prepared using alkali fusion of kaolinite followed by a hydrothermal treatment step for 4 h at 90 °C. The synthetic phases were characterized as potential adsorbents for PO43− from the aqueous solutions and real water from the Rákos stream (0.52 mg/L) taking into consideration the impact of the structural alkali ions (K+ and Na+). The synthetic Na.SD phase exhibited enhanced surface area (232.4 m2/g) and ion-exchange capacity (126.4 meq/100 g) as compared to the K.SD phase. Moreover, the Na.SD phase exhibited higher PO43− sequestration capacity (Qmax = 261.6 mg g−1 and Qsat = 175.3 mg g−1) than K.SD phase (Qmax = 201.9 mg g−1 and Qsat = 127.4 mg g−1). The PO43− sequestration processes of both Na.SD and K.SD are spontaneous, homogenous, and exothermic reactions that follow the Langmuir isotherm and pseudo-first-order kinetics. Estimation of the occupied active site density validates the enrichment of the Na.SD phase with high quantities of active sites (Nm = 86.1 mg g−1) as compared to K.SD particles (Nm = 44.4 mg g−1). Moreover, the sequestration and Gaussian energies validate the cooperation of physisorption and weak chemisorption processes including zeolitic ion exchange reactions. Both Na.SD and K.SD exhibit significant selectivity for PO43− in the coexisting of other common anions (Cl−, SO42−, HCO3−, and NO3−) and strong stability properties. Their realistic application results in the complete adsorption of PO43- from Rákos stream water after 20 min (Na. SD) and 60 min (K.SD).

Role of emerging chitosan and zeolite-modified adsorbents in the removal of nitrate and phosphate from an aqueous medium: A comprehensive perspective

Due to industrialization and population growth, freshwater supplies are diminishing and becoming impure with high organic pollutant concentrations such as nitrate and phosphate, which shows a high adverse impact on aquatic and human lives. In drinking water sources, particularly groundwater, nitrate is considered as one of the major pollutants which causes methemoglobinemia (in newborn infants), carcinogenic activities and diabetes. Excess concentration of phosphate leads to eutrophication and death of aquatic species due to reduced dissolved oxygen content. Therefore, all countries must implement highly effective technologies for treating wastewater. Chitosan and zeolite are naturally occurring and cost-effective adsorbent materials with a higher surface area that exhibit greater nitrate and phosphate adsorption. Surface modification of chitosan and zeolite increases the adsorption capacity of adsorbents for the removal of both anions selectively. This paper reviews the current development of modified chitosan and zeolite adsorbents for anion adsorption, with an emphasis on modification by zero and multivalent metals and metal oxides, different surfactants, biomass-derived carbon, and natural and synthetic polymers. Multiple adsorption parameters, optimum adsorption condition, adsorption mechanism, regeneration study, research gap and future aspects have been explained for further research work.

Lanthanum doped magnetic polyaniline for removal of phosphate ions from water

Herein, magnetic polyaniline was modified with lanthanum nanoparticles (MPANI@La) as adsorbent, aiming to the treatment of high phosphate-containing aquatic solutions. High valent lanthanum doped with polyaniline was a promising adsorbent to uptake phosphate ions with possible electrostatic interaction and cation exchange process. The functional groups, composition, surface morphology, and magnetic property of the adsorbent were investigated using Fourier Transform-Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX), Scanning Electron Microscopic (SEM), and Vibrating Sample Magnetometer (VSM), respectively. During the experimental process, MPANI@La has removed phosphate ions from water >90%, with 80 mg adsorbent, and shaking for 150 min at room temperature. In this regard, the process was fitted with the Pseudo-second-order kinetic model (R2 > 0.999) and the Langmuir isotherm (R2 > 0.99). The proposed nanoparticles provided an appropriate adsorption capacity (qm) of 45.24 mg.g-1 at pH 4 for phosphate ions. Besides, the adsorbent can be used with an efficiency of 92.49% up to three times that reduced to 52.89% after ten times. In addition, the adsorption process was justified by thermodynamics which confirmed the proposed adsorption mechanism. Hence, the models were provided surface adsorption, monolayer pattern, and the physical mechanism of the phosphate removal process using MPANI@La. Hence the proposed adsorbent can be used as an alternative adsorbent in environmental water remediation.

Synthesis and optimization of spherical nZVI (20-60 nm) immobilized in bio-apatite-based material for efficient removal of phosphate: Box-Behnken design in a fixed-bed column

In the present study, bio-apatite/nZVI composite was synthesized through Fe(III) reduction with sodium borohydride and was fully characterized by FTIR, XRD, SEM-EDX, TEM, BET, BJH, and pH_PZC. Column experiments were carried out for the removal of phosphate as a function of four operational parameters including initial phosphate concentration (100-200 mg L^-1), initial solution pH (2-9), bed height (2-6 cm), and influent flow rate (2.5-7.5 mL min^-1) using a response surface methodology (RSM) coupled with Box-Behnken design (BBD). 2D contour and 3D surface plots were employed to analyze the interactive effects of the four operating parameters on the column performance (e.g., uptake capacity and saturation time). According to ANOVA analysis, the influent flow rate and bed height are the most important factor on phosphate uptake capacity and saturation time, respectively. A quadratic polynomial model was excellently fitted to experimental data with a high coefficient of determination (> 0.96). The RSM-BBD model predicted maximum phosphate adsorption capacity of 85.71 mg g^-1 with the desirability of 0.995 under the optimal conditions of 135.35 mg L^-1, 2, 2 cm, and 7.5 mL min^-1 for initial phosphate concentration, initial solution pH, bed height, and influent flow rate, respectively. The XRD analysis demonstrated that the reaction product between bio-apatite/nZVI composite and phosphate anions was Fe₃ (PO₄)₂. 8H₂O (vivianite). The suggested adsorbent can be effectively employed up to five fixed-bed adsorption-desorption cycles and was also implemented to adsorb phosphate from real samples.

Synthesis of Fe3O4@Phoslock® composites and the application in adsorption of phosphate from aqueous solution

Assisted with an organosilane, Fe₃O₄@Phoslock^® composites with different constituents were synthesized to separate phosphate from aqueous solution. The experimental adsorption data of kinetics and isothermal studies by the composites were well fitted by pseudo-second order and Freundlich models, respectively, suggesting the chemical and heterogeneous adsorption process, i.e., ligand exchange and precipitation. After loading of Fe₃O₄, Phoslock^® became magnetic at the expense of the certain decrease of phosphate uptake from 10.4 to 8.1 mg P/g when [P]₀ = 1.0 mmol/L and the solid/liquid ratio of 1.0 g/L were applied. However, compared with the original Fe₃O₄ nanoparticles, Fe₃O₄@Phoslock^® showed more favorable phosphate uptake and stability against pH variation. The inhibitory influence of anionic ions on phosphate adsorption by three composites followed the order: HCO₃^-  > humate > SiO₃^2-  > NO₃^- ≈ Cl^- ≈ SO₄^2-, while the facilitating effect of cations followed the order: Ca²⁺  > Mg²⁺  > NH₄⁺. The regeneration rate was higher than 50% for all composites after recycled for 5 times by NaOH, and two of the composites successfully removed 75% phosphate from the landfill leachate treated by the Anammox process with the solid/liquid ratio of 5.0 g/L. This suggests that Fe₃O₄@Phoslock^® composites would be a competitive adsorbent for phosphate removal from real wastewater.

Mechanisms of orthophosphate removal from water by lanthanum carbonate and other lanthanum-containing materials

Removing phosphorus (P) from water and wastewater is essential for preventing eutrophication and protecting environmental quality. Lanthanum [La(III)]-containing materials can effectively and selectively remove orthophosphate (PO₄) from aqueous systems, but there remains a need to better understand the underlying mechanism of PO₄ removal. Our objectives were to 1) identify the mechanism of PO₄ removal by La-containing materials and 2) evaluate the ability of a new material, La₂(CO₃)_3(s), to remove PO₄ from different aqueous matrices, including municipal wastewater. We determined the dominant mechanism of PO₄ removal by comparing geochemical simulations with equilibrium data from batch experiments and analyzing reaction products by X-ray diffraction and scanning transmission electron microscopy with energy dispersive spectroscopy. Geochemical simulations of aqueous systems containing PO₄ and La-containing materials predicted that PO₄ removal occurs via precipitation of poorly soluble LaPO_4(s). Results from batch experiments agreed with those obtained from geochemical simulations, and mineralogical characterization of the reaction products were consistent with PO₄ removal occurring primarily by precipitation of LaPO_4(s). Between pH 1.5 and 12.9, La₂(CO₃)_3(s) selectively removed PO₄ over other anions from different aqueous matrices, including treated wastewater. However, the rate of PO₄ removal decreased with increasing solution pH. In comparison to other solids, such as La(OH)_3(s), La₂(CO₃)_3(s) exhibits a relatively low solubility, particularly under slightly acidic conditions. Consequently, release of La³⁺ into the environment can be minimized when La₂(CO₃)_3(s) is deployed for PO₄ sequestration.

Removal of lead ions from wastewater using lanthanum sulfide nanoparticle decorated over magnetic graphene oxide

In this study, the new lanthanum sulfide nanoparticle (La₂S₃) was synthesized and incorporated onto magnetic graphene oxide (MGO) sheets surface to produce potential adsorbent (MGO@LaS) for efficient removal of lead ions (Pb²⁺) from wastewater. The synthesized MGO@LaS adsorbent was characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effective parameters on the adsorption process including solution pH (~5), adsorbent dosage (20 mg), contact time (40 min), initial Pb²⁺ concentration and temperature were studied. The removal efficiency was obtained >95% for lead ions at pH 5 with 20 mg adsorbent. To validate the adsorption rate and mechanism, the kinetic and thermodynamic models were studied based on experimental data. The Langmuir isotherm model was best fitted to initial equilibrium concentration with a maximum adsorption capacity of 123.46 mg/g. This indicated a monolayer adsorption pattern for Pb²⁺ ions over MGO@LaS. The pseudo-second-order as the kinetic model was best fitted to describe the adsorption rate due to high R² > 0.999 as compared first-order. A thermodynamic model suggested a chemisorption and physisorption adsorption mechanism for Pb²⁺ ions uptake into MGO@LaS at different temperatures; ΔG° < -5.99 kJ mol^-1 at 20 °C and ΔG° -18.2 kJ mol^-1 at 45 °C. The obtained results showed that the novel nanocomposite (MGO@LaS) can be used as an alternative adsorbent in wastewater treatment.

Strategic management of nitrate pollution from contaminated water using viable adsorbents: An economic assessment-based review with possible policy suggestions

Groundwater contaminated with nitrate has prompted a flurry of research studies around the world in the recent years to address this burning environmental issue. The common presence of nitrates in groundwater, wastewater, and surface waters has thrown an enormously critical challenge to the global research communities to provide safe and clean drinking water to municipalities. As per WHO, the maximum permissible limit of nitrate in drinking water is 10 mg/L and in groundwater is 50 mg/L; exceeding the limits, several human health problems are observed. Adsorption, ion-exchange processes, membrane-based approaches, electrochemical and chemical procedures, biological methods, filtration, nanoparticles, etc. have been well investigated and reviewed to reduce nitrate levels in water samples in the recent years. Process conditions, as well as the efficacy of various approaches, were discovered to influence different techniques for nitrate mitigation. But, because of low cost, simple operation, easy handling, and high removal effectiveness, adsorption has been found to be the most suitable and efficient approach. The main objectives of this review primarily focuses on the creation of a naturally abundant, cost-effective innovative abundant material, such as activated clay particles combined with iron oxide. Oxide-clay nanocomposite materials, effectively remove nitrate with higher removal efficiency along with recovery of nitrate concentrated sludge. Such methods stand out as flexible and economic ways for capturing stabilized nitrate in solid matrices to satisfy long-term operations. A techno-economic assessment along with suitable policy suggestions have been reported to justify the viability of the brighter processes. Indeed, this kind of analytical review appears ideal for municipal community recommendations on abatement of excess nitrate to supply of clean water.

Synthesis of zeolite/geopolymer composite for enhanced sequestration of phosphate (PO43-) and ammonium (NH4+) ions; equilibrium properties and realistic study

Zeolite impeded geopolymer (Z/G) was synthesized from natural kaolinite and diatomite. The structure (Z/G) was characterized as an enhanced adsorbent for PO₄^3- and NH₄⁺ ions from aqueous solutions, groundwater, and sewage water. The synthetic Z/G structure exhibits sequestration capacities of 206 mg/g and 140 mg/g for PO₄^3- and NH₄⁺, respectively which are higher values than the recognized results for the geopolymer and other adsorbents in literature. The sequestration reactions of PO₄^3- and NH₄⁺ by Z/G are of Pseudo-Second order kinetic behavior considering both the Chi-squared (χ²) and correlation coefficient (R²) values. The sequestration reactions occur in homogenous and monolayer forms considering their agreement with Langmuir behavior. The Gaussian energies (12.4 kJ/mol (PO₄^3-) and 10.47 kJ/mol (NH₄⁺)) demonstrate the operation of a chemical sequestration mechanism that might be involved zeolitic ion exchange process and chemical complexation. Additionally, these reactions are exothermic processes of spontaneous and favorable properties based on thermodynamic studies. The Z/G structure is of significant affinity for both PO₄^3- and NH₄⁺ even in the existence of other anions as Cl^-, HCO₃^-, SO₄^2-, and NO₃^-. Finally, the structure used effectively in the purification of groundwater and sewage water from PO₄^3- and NH₄⁺ in addition to nitrate, sulfate, and some metal ions.

Single-Step Topochemical Synthesis of NiFe Layered Double Hydroxides for Superior Anion Removal from Aquatic Systems

Layered double hydroxides (LDHs) have attracted significant attention as adsorbents for the removal of anions from wastewater. However, it is challenging to develop a simple, economical, and environmentally friendly method for fabricating efficient LDH adsorbents. In this paper, we present an alternative approach for preparing a superb NiFe LDH adsorbent via a single-step topochemical synthesis method based on density functional theory (DFT) calculation. The NiFe LDH adsorbent [Ni_0.75Fe_0.25(OH)₂]·(CO₃)_0.125·0.25H₂O was obtained via the topotactic transformation of an oxide precursor (NaNi_0.75Fe_0.25O₂), which was prepared by utilizing the high-temperature flux method, in ultrapure water. When the oxide precursor was soaked in ultrapure water, the host layer valence state changed from Ni³⁺ and Fe³⁺ to Ni²⁺ and Fe³⁺, and carbonate (CO₃^2-) ions were simultaneously intercalated in the interlayer. Thereafter, the CO₃^2- ions were deintercalated by Cl^- ions to increase the adsorption capacity. The adsorbent exhibited high crystallinity, cation state, and porosity, and unique particle shape. In addition, it showed superior adsorption capacities of approximately 194.92, 176.15, and 146.28 mg g^-1 toward phosphate, fluoride, and nitrate ions, respectively. The adsorption capacity toward all the anions reached over 70% within 10 min. The adsorption behavior was investigated by performing from adsorption kinetics, isotherm, and thermodynamics studies. The results showed that the anions were endothermically and spontaneously chemisorbed through an ion exchange process onto the adsorbent in a monolayer. In addition, the as-prepared NiFe LDH adsorbent showed high stability after multicycle testing.

Application of Modified Spent Mushroom Compost Biochar (SMCB/Fe) for Nitrate Removal from Aqueous Solution

The public is already aware that nitrate pollution caused by nutrient runoff from farms is harmful to aquatic life and human health, and there is an urgent need for a product/technology to solve this problem. A biochar adsorbent was synthesized and used to remove nitrate ions from aqueous media based on spent mushroom compost (SMC), pre-treated with iron (III) chloride hexahydrate and pyrolyzed at 600 °C. The surface properties and morphology of SMCB/Fe were investigated using Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effect of main parameters such as the adsorbent dosages, pH of the solutions, contact times, and ion concentrations on the efficiency of nitrate removal was investigated. The validity of the experimental method was examined by the isothermal adsorption and kinetic adsorption models. The nitrate sorption kinetics were found to follow the pseudo-second-order model, with a higher determination coefficient (0.99) than the pseudo-first-order (0.86). The results showed that the maximum percentage of nitrate adsorption was achieved at equilibrium pH 5-7, after 120 min of contact time, and with an adsorbent dose of 2 g L-1. The highest nitrate adsorption capacity of the modified adsorbent was 19.88 mg g-1.

Plasticized magnetic starch-based Fe3O4 clay polymer nanocomposites for phosphate adsorption from aqueous solution

Plastics contribute a magnificent role to modern civilization, but the waste becomes a huge burden to ecology and remains intact for a thousand years. Hence, the recent movement is shifted to biodegradable plastic. In this study, an attempt was made to introduce an added value to the environment where the bio-plasticized materials were used for phosphate removal. A G-plasticized magnetic starch-based Fe₃O₄ clay polymer nanocomposite (PNC) was synthesized to remove phosphate from the aqueous solution. It was synthesized from activated carbon (AC), coated iron oxide nanoparticles (CIONP), nanoclay (NC), and glycerol (G) as a plasticizer. The synthesized adsorbents were characterized with UV-Vis, SEM, XRD, and FTIR. The PNC and constituent (CIONP) were tested for phosphate removal through batch adsorption experiments. The adsorption capacity increases with increasing the adsorbent dose and decreases with an increase in phosphate concentration. The synthesized PNC effectively raised the constituent optimum phosphate ion adsorption pH from acidic (pH = 3) to slightly acidic (pH = 6). At the optimal pH, the CIONP and PNC maximum phosphate adsorption capacity (MPAC) was 3.12 and 2.31 mg P/g, respectively. In addition, the phosphate removal efficiency of PNC (45-95% at pH 6) was comparable to CIONP (58-97% at pH 3) under an initial 2–100 mg P/L. The adsorbents adsorption kinetics and isotherm study best described by the pseudo-second-order and Freundlich model, in turn. The SEM images support the conclusion, in which the PNC shows a heterogenous porous surface. Therefore, the adsorption mechanisms were mainly described by multilayer and chemical adsorption, such as electrostatic and ion exchange. It can be concluded that there is a positive synergistic effect between the biopolymer (starch) and nanomaterials that form the PNC. This study results propose the multiple added values of modified bio-plasticized material (with adsorbent) for environmental (phosphate) remediation.

High phosphate removal using La(OH)3 loaded chitosan based composites and mechanistic study

Our present study was to prepare a biomass-supported adsorbents with high adsorptive capacity and high selectivity to prevent the accelerated eutrophication in water body. To this end, different metal hydroxide (La, Zr and Fe) first was successfully loaded on chitosan microspheres. Then the quaternary ammonium group with different content was introduced into the adsorbent by polymerization. By comparison of adsorption properties, chitosan-La(OH)₃-quaternary ammonium-20% (CS-La-N-20%) has strong adsorption to phosphate (160 mg/g) by immobilizing nano-sized La(OH)₃ within a quaternary-aminated chitosan and it maintain high adsorption in the presence of salt ions. The pH results indicated that the CS-La-N-20% would effectively sequestrate phosphate over a wide pH range between 3 and 7 without significant La³⁺ leaching. What's more, adsorption capacity on the introduce of positively charged quanternary-aminated groups was significantly higher than that of the unmodified adsorbents at alkaline conditions. The column adsorption capacity reached 1300 bed volumes (BV) when phosphate concentration decreased until 0.5 mg/L at 6 BV/hr. The column adsorption/desorption reveals that no significant capacity loss is observed, indicating excellent stability and repeated use property. Characterizations revealed that phosphate adsorption on CS-La-N-20% through ligand exchange (impregnated nano-La(OH)₃) and electrostatic attraction (positively charged quanternary-aminated groups). All the results suggested that CS-La-N-20% can serve as a promising adsorbent for preferable phosphate removal in realistic application.

Review of phosphate removal from water by carbonaceous sorbents

In the last decades, phosphate is considered the main cause of eutrophication and has received substantial attention from the scientific community. Phosphate is a major pollutant that deteriorates water quality, which has been increasing in water resources, primarily due to the increasing global population and corresponding activities. Adsorption technology is amongst the different technologies used to decrease the phosphate levels in water, and has been found to be highly effective even at low phosphate concentrations. Carbonaceous materials and their composites have been widely used for phosphate removal due to their exceptional surface properties and high phosphate sorption capacity. Considering the importance of the topic, this study reviews the reported literature in the field of adsorptive removal of phosphate over various carbon-based adsorbents such as activated carbon, charcoal, graphene, graphene oxide, graphite and carbon nanotubes. Moreover, insights into the adsorption behaviour, experimental parameters, mechanisms, thermodynamics, effect of coexisting ions and the possible desorption processes of phosphate onto modified and unmodified carbonaceous adsorbents are also considered. Finally, research challenges and gaps have been highlighted.

Graphene-Based Composites for Phosphate Removal

A variety of methods, including chemical precipitation, biological phosphorus elimination, and adsorption, have been described to effectively eliminate phosphorus (P) in the form of phosphate (PO₄ ^3-) from wastewater sources. Adsorption is a simple and easy method. It shows excellent removal performance, cost effectiveness, and the substantial option of adsorbent materials. Therefore, it has been recognized as a practical, environmentally friendly, and reliable treatment method for eliminating P. Nanocomposites have been deployed to remove P from wastewater via adsorption. Nanocomposites offer low-temperature alteration, high specific surface area, adjustable surface chemistry, pore size, many adsorption sites, and rapid intraparticle diffusion distances. In this Mini-Review, we have aimed to summarize the last eight years of progress in P removal using graphene-based composites via adsorption. Ultimately, future perspectives have been presented to boost the progress of this encouraging field.

Highly efficient and antibacterial ion exchanger based on graphene oxide for removal of chromate and nitrate from water: synthesis, characterization and application

A novel recyclable antibacterial anion exchanger based on graphene oxide (GO) and quaternary ammonium chloride (TMSQA) as a crosslinker/ion exchanger was prepared and used for the removal of chromate and nitrate from water.

Turn-on detection of assorted phosphates by luminescent chemosensors

This review illustrates a variety of luminescent chemosensors for the selective detection of assorted phosphates via the “Turn-On” emission mechanism with focus on their design aspects, chemical structures and sensing mechanism.

Synthesis of layered double hydroxides with nitrate and its adsorption properties of phosphate

In the present study, different ratios of layered double hydroxides (LDHs) were synthesized via co-precipitation method. The synthesized LDHs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nitrogen adsorption-desorption analysis, point of zero charges (pH_pzc), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phosphate adsorption performances were estimated by batch adsorption experiments; desorption hysteresis and adsorption mechanism were also investigated. The XRD, SEM and TEM results confirmed the multilayer structure of the synthesized LDHs. The pseudo-second-order kinetic model and the Freundlich model describe the adsorption behavior of LDHs best. The maximum adsorption capacity is 185.86 mg-KH₂PO₄/g for Mg₂Al-NO₃ LDH. When the dosage of LDHs was greater than 2 g/L, the phosphorus content in the solution decreased from 30 mg-P/L to 0.077 mg-P/L after adsorption by Mg₂Al-NO₃ LDH. All the results reveal that Mg₂Al-NO₃ LDH is a potential adsorbent for removing phosphate from aqueous solution.

Emerging lanthanum (III)-containing materials for phosphate removal from water: A review towards future developments

The last two decades have seen a rise in the development of lanthanum (III)-containing materials (LM) for controlling phosphate in the aquatic environment. >70 papers have been published on this topic in the peer-reviewed literature, but mechanisms of phosphate removal by LM as well as potential environmental impacts of LM remain unclear. In this review, we summarize peer-reviewed scientific articles on the development and use of 80 different types of LM in terms of prospective benefits, potential ecological impacts, and research needs. We find that the main benefits of LM for phosphate removal are their ability to strongly bind phosphate under diverse environmental conditions (e.g., over a wide pH range, in the presence of diverse aqueous constituents). The maximum phosphate uptake capacity of LM correlates primarily with the La content of LM, whereas reaction kinetics are influenced by LM formulation and ambient environmental conditions (e.g., pH, presence of co-existing ions, ligands, organic matter). Increased La solubilization can occur under some environmental conditions, including at moderately acidic pH values (i.e., < 4.5-5.6), highly saline conditions, and in the presence of organic matter. At the same time, dissolved La will likely undergo hydrolysis, bind to organic matter, and combine with phosphate to precipitate rhabdophane (LaPO₄·H₂O), all of which reduce the bioavailability of La in aquatic environments. Overall, LM use presents a low risk of adverse effects in water with pH > 7 and moderate-to-high bicarbonate alkalinity, although caution should be applied when considering LM use in aquatic systems with acidic pH values and low bicarbonate alkalinity. Moving forward, we recommend additional research dedicated to understanding La release from LM under diverse environmental conditions as well as long-term exposures on ecological organisms, particularly primary producers and benthic organisms. Further, site-specific monitoring could be useful for evaluating potential impacts of LM on both biotic and abiotic systems post-application.

Promoting the decontamination of different types of water pollutants (Cd2+, safranin dye, and phosphate) using a novel structure of exfoliated bentonite admixed with cellulose nanofiber

Exfoliated bentonite sheets admixed with nano-cellulose fibers (EXB/CF) were prepared as advanced bio-composite of enhanced decontamination properties for different species of water pollutants (Cd²⁺, safranin dye, and phosphate). The composite achieved promising adsorption capacities with experimental values of 206.8 mg/g (Cd²⁺), 336 mg/g (safranin), and 296 mg/g (phosphate); and predicted maximum capacities of 212.9 mg/g (Cd²⁺), 341 mg/g (safranin), and 305 mg/g (phosphate). The adsorption systems for the three species follow the Freundlich isotherm model and Pseudo-First order as kinetic model considering both the linear and nonlinear fitting demonstrating heterogeneous and multilayer uptake properties of physisorption type. The operation of physisorption mechanisms was supported by the obtained adsorption energies from D-R model that are less than 8 kJ/mol as well as the calculated free energies and enthalpies. The thermodynamic investigation revealed the nature of the adsorption reactions of the three pollutants by EXB/CF as exothermic, favorable, and spontaneous reactions. The EXB/CF composite also is of significant recyclability value and applied in five decontamination reusing runs for Cd²⁺, safranin dye, and phosphate achieving promising removal percentages.

Modification of NaY zeolite by lanthanum and hexadecyl trimethyl ammonium bromide and its removal performance for nitrate

Nitrate in the effluent of wastewater treatment plants (WWTPs) is the main nitrogen resource in natural water. The excessive nitrogen in natural water causes ecological issues such as aqueous eutrophication. A novel modified NaY zeolite (SMZ-La) with hexadecyl trimethyl ammonium bromide (HDTMA) and lanthanum (La) as modifying agents for NO 3 - -N adsorption was investigated in this study. Results showed that SMZ-La had a higher adsorption capacity (3.82 mg NO 3 - -N/g) than zeolite only modified with HDTMA or La (2.75 and 2.23 mg NO 3 - -N/g, respectively). Moreover, the adsorption process was endothermic with a maximum theoretic adsorption of 14.49 mg NO 3 - -N/g. X-ray photoelectron spectroscopy (XPS) analysis indicated that adsorption rate principally depended on chemisorption between SMZ and NO 3 - -N. Thermogravimetric analysis showed that HDTMA was loaded on the surface of NaY zeolite with double layer. Scanning electron microscope and X-ray spectroscopy analysis illustrated that La was primarily loaded in the pore of NaY zeolite, and the loading of HDTMA and La did not affect the original crystal structure of NaY zeolite. The novel adsorbent provided a promising perspective for nitrogen control in WWTPs and natural water. PRACTITIONER POINTS: A novel modified zeolite (SMZ-La) was prepared successfully with HDTMA and La. SMZ-La had an excellent adsorption capacity compared to SMZ and NaY-La. There were both physical and chemical adsorptions in the adsorption process of SMZ-La on NO 3 - -N.

Effective Sequestration of Phosphate and Ammonium Ions by the Bentonite/Zeolite Na-P Composite as a Simple Technique to Control the Eutrophication Phenomenon: Realistic Studies

A bentonite/Zeolite-P (BE/ZP) composite was synthesized by controlled alkaline hydrothermal treatment of bentonite at 150 °C for 4 h for effective sequestration of phosphate and ammonium pollutants. The composite is of 512 m²/g surface area, 387 meq/100 g ion-exchange capacity, and 5.8 nm average pore diameter. The experimental investigation reflected the strong effect of the pH value in directing the uptake behavior and the best results were attained at pH 6. The kinetic properties showed an excellent agreement for phosphate and ammonium adsorption results with the pseudo-second-order model showing equilibrium intervals of 600 and 360 min, respectively, and maximum experimental capacities of 170 and 155 mg/g, respectively. Additionally, their equilibrium modeling confirmed excellent fitness with the Langmuir hypothesis, signifying homogeneous and monolayer uptake processes with a theoretical q _max of 179.4 and 166 mg/g for phosphate and ammonium, respectively. Moreover, the calculated Gaussian adsorption energies of phosphate (0.8 kJ/mol) and ammonium (0.72 kJ/mol) suggested physisorption for them with mechanisms close to the zeolitic ion-exchange process or the coulumbic attractive forces. This was supported by the assessed thermodynamic parameters which also suggested spontaneous uptake by endothermic reaction for phosphate and exothermic reaction for ammonium. The BE/ZP composite is of excellent reusability and used for eight recyclability runs achieving removal percentages of 61.5 and 74.5% for phosphate and ammonium, respectively, in run 8. Finally, the composite was applied in the purification of sewage water and groundwater, achieving complete removal for phosphate from sewage water and ammonium from groundwater and reduction of the ammonium ions in the sewage water to 2.3 mg/L.

An innovative lanthanum carbonate grafted microfibrous composite for phosphate adsorption in wastewater

Excessive presence of phosphorus in waters can cause eutrophication, a global unsolved environmental problem that has caused harmful effects to our eco-system and the source of our drinking water. In the study presented in this paper, a novel lanthanum carbonate grafted microfibrous composite (LC-MC) adsorbent was synthesized aiming at removing large amount of phosphate in wastewater efficiently. An optimized LC-MC was firstly prepared. The most suitable pH for the phosphate uptake was pH 7 to 9. The adsorption showed similar behavior in a wide range of ionic strength. The presence of co-existing anions was proved to have a less significant effect on the removal. The adsorption isotherm data were better fitted by the Freundlich isotherm than the Langmuir isotherm. The equilibrium was reached at about 300 min of contact time. 80 % of original adsorption capacity can be achieved even after 5 cycles of adsorption- desorption operations, indicating great regenerative performance of the adsorbent. The adsorption mechanism study showed that the ligand exchange played a key role during the phosphate adsorption.

Removal of Phosphate Ions from Aqueous Solutions by Adsorption onto Leftover Coal

High loadings of wastewater with phosphors (P) require purification measures, which can be challenging to realize in regions where the technical and financial frame does not allow sophisticated applications. Simple percolation devices employing various kinds of adsorbents might be an alternative. Here, we investigated the application of leftover coal, which was collected from Ethiopian coal mining areas, as an adsorbent for the removal of phosphate from aqueous solutions in a classical slurry batch set-up. The combined effects of operational parameters such as contact time, initial concentration, and solution pH on P retention efficiency was studied employing the Response Surface Methodology (RSM). The maximum phosphate adsorption (79% removal and 198 mg kg−1 leftover coal) was obtained at a contact time of 200 min, an initial phosphate concentration of 5 mg/L, and a solution pH of 2.3. The Freundlich isotherm was fitted to the experimental data. The pseudo second-order equation describes the experimental data well, with a correlation value of R2 = 0.99. The effect of temperature on the adsorption reveals that the process is exothermic. The results demonstrate that leftover coal material could potentially be applied for the removal of phosphate from aqueous media, but additional testing in a flow-through set-up using real wastewater is required to draw definite conclusions.

Modified biogas residues as an eco-friendly and easily-recoverable biosorbent for nitrate and phosphate removals from surface water

Effective managements of organic solid waste and surface water eutrophication can reuse/reduce solid waste resources, and ensure surface water safety. Herein, an easily-recoverable amine-functionalized biosorbent was developed from biogas residue (BR-N) for nitrate and phosphate removals from surface water. Physicochemical characteristics revealed that BR-N has a cross-staggered structure with abundant quaternary-amine groups to enhance the diffusion and electrostatic attraction of nitrate/phosphate. In batch studies, nitrate/phosphate could be effectively removed by the BR-N within a wide pH range of 5.0-9.0, and the maximum adsorption capacities of BR-N were 64.12 mg/g for nitrate and 34.40 mg P/g for phosphate. After continuous 8 cycles of adsorption-desorption, BR-N still exhibited >82% adsorption capacity for nitrate/phosphate removals, implying the high chemical stability and reusability for water treatment. Whereafter, BR-N has real application prospect in water treatment, which could effectively treat ˜380, ˜260 and ˜760 bed volumes (BV) of three actual eutrophic surface water to satisfy the surface water standard of China (GB3838-2002). The cost of BR-N was 2.89 $/kg evaluated by energy-economy assessment, indicating the low-cost production of biogas residue-based adsorbent for treating eutrophic surface water. Overall, this study provides a new idea for high-value utilization of organic solid waste and purification of eutrophic water.

Removal of phosphate from aqueous solution using MgO-modified magnetic biochar derived from anaerobic digestion residue

A novel MgO-modified magnetic biochar (MgO@MBC) was made by chemical co-precipitation of Mg²⁺/Fe³⁺ on anaerobic digestion residue (ADR) and subsequently pyrolyzing at different temperatures. MgO@MBC was used for phosphate recovery from aqueous solution. The physicochemical properties of MgO@MBC were comprehensively investigated using TEM-EDS, FT-IR, XRD, VSM, N₂ adsorption-desorption and TGA. Results showed that MgO/γ-Fe₂O₃ nanoparticles were successfully deposited onto the surface of BC. The effects of reaction temperature, initial solution pH, MgO@MBC dosage, coexisting anions and phosphate concentration on the removal of phosphate by MgO@MBC were researched. Additionally, the adsorption process of phosphate onto MgO@MBC was well described by the pseudo second-order and pseudo first-order models, which indicated a chemisorption and physisorption process. Besides, the maximum adsorption capacity of MgO@MBC for phosphate by the Langmuir model were 149.25 mg/g at 25 °C. Moreover, the thermodynamic study suggested that the adsorption of phosphate onto MgO@MBC was a spontaneous and endothermic process. The adsorption mechanisms including physical absorption, surface electrostatic attraction, surface complexation and precipitation were revealed. It could be concluded that MgO@MBC exhibited high removal efficiency of phosphate and excellent magnetic property for the recovery. MgO@MBC could be utilized as a magnetically recoverable adsorbent to realize phosphate recovery and MgO@MBC after the adsorpion of phosphate could be applied in agricultural production as a fertilizer.

Magnetic polymer-supported adsorbent with two functional adsorption sites for phosphate removal

In this paper, a new magnetic polymer-supported phosphate adsorbent MPVC-EDA-Ce was prepared by loading cerium (hydr)oxides onto ethylenediamine-functionalized polyvinyl chloride for the first time. MPVC-EDA-Ce showed excellent adsorption performances towards phosphate and easy recovery. The adsorption isotherm and kinetics of MPVC-EDA-Ce followed Langmuir monolayer model and the pseudo-second-order model, respectively. The pH results demonstrated that the MPVC-EDA-Ce could effectively remove phosphate in a wide range of pH with insignificant cerium leaching. Furthermore, analyses on adsorption mechanism and effect of competing anions demonstrated the formation of strong inner-sphere complexation between cerium (hydr)oxides and phosphate, which was a selective adsorption process, while positively charged quaternary ammonium groups adsorbed phosphate via relatively weak electrostatic attraction which was a non-selective adsorption process. The study provided a good reference to design novel phosphate adsorbents with two even more functional adsorption sites and a deep insight to investigate the adsorption mechanism towards phosphate.

Synthesis and characterization of a new magnetic adsorbent for removal of 4-nitrophenol: application of response surface methodology

Magnetic modified graphene oxide was synthesized as a new modified magnetic nano-composite (MMNC) by a simple sonochemical-hydrothermal method. The sonochemical reaction was employed to exfoliate, functionalize and decorate neomycin on graphene oxide sheets. Nickel ferromagnetic particles were synthesized by hydrothermal co-precipitation method and decorated on neomycin-modified graphene oxide. The morphology and chemical structure of MMNC were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction spectroscopy. The adsorption capability of MMNC for removal of phenolic compounds was assessed through adsorption of 4-nitrophenol (4-NP) from aqueous solution. The three-factor Box-Behnken design coupled with response surface method was applied to evaluate and optimize the important variables which affect the adsorption process. A significant quadratic model (p-value <0.05, R² _(adj) = 0.9593) was derived using analysis of variance. The maximum adsorption capacity of 125.4 mg 4-NP/g MMNC at pH 6 was obtained, which was comparable in some cases and higher than most adsorbents reported in the literature. The presence of neomycin on graphene oxide sheets improved the maximum adsorption capacity of the nano-sorbent up to 28% (from 98.7 to 125.4 mg 4-NP/g adsorbent). The adsorption isotherms fitted well with the Langmuir model (Langmuir constant b = 0.064 l/mg, R² = 0.9989) and the kinetic study showed that the nitrophenol uptake process followed the pseudo-second-order rate expression (R² ≥ 0.9960, pseudo-second-order constant K₂ ≥ 1.7 × 10^-3).

Fabrication of a Novel Bifunctional Nanocomposite with Improved Selectivity for Simultaneous Nitrate and Phosphate Removal from Water

Phosphorus and nitrogen compounds are both the main sources of eutrophication and coexist in some municipal effluents or eutrophic waters; elimination of phosphorus and nitrogen from wastewater is becoming an imperative but also a hard task. Herein, an innovative bifunctional nanocomposite HFO@TPR was developed for synchronous nitrate/phosphate elimination from water. A macroporous polystyrene microspheres modified with triethylamine functional groups was synthesized as the host of HFO@TPR for selective nitrate removal, and Fe(III) hydroxide (HFO) nanoparticles were implanted inside as the active species for specific phosphate removal. Compared to other commercial adsorbents, HFO@TPR exhibited outstanding selectivity and preference toward nitrates and phosphates, and the coexisting anions exert an insignificant effect on adsorption performance. Such exceptional bifuntionality of HFO@TPR was achieved through two pathways, that is, nitrate was preferentially adsorbed by the fixed triethylamine groups through the electrostatic attraction, and phosphate was preferentially captured by the encapsulated HFO nanoparticles through the inner-sphere complexation. The exhausted HFO@TPR could be effectively regenerated by using a NaOH-NaCl mixed reagent for cyclic use with a relative constant efficiency. In addition, column adsorption experiments demonstrated that HFO@TPR could eliminate nitrate from 18 to <10 mg N/L with the treatment capacity of ∼600 bed volume (BV), and meanwhile remove phosphate from 2.5 to <0.2 mg P/L with the treatment capacity of ∼750 BV. We believe what we found in this study could advance the method on how to develop bifunctional adsorbents for synchronous removal of coexisting contaminants from water.