Removal Of Phosphate Ions Research Articles

Exploiting RSM and ANN modeling methods to optimize phosphate ions removal using LDH/alginate composite beads

In the present work, layered double hydroxide (MgAl) and alginate composite beads (LDH/alginate) were developed and used as low-cost and environmentally friendly adsorbent for phosphate ions removal. The successful incorporation of sodium alginate into the LDH structure was confirmed through SEM analysis. The dried beads exhibited a notably rough surface, which promotes molecular movement and potentially enhances pollutant adsorption. The pH of zero charge point (pHPZC) of the composite was found to be 7.41. This result implies that negative ions have a tendency to draw positive charges on the adsorbent surface via electrostatic interaction forces when the pH is lower than the pHPZC. On the other hand, a surface that has a pH higher than pHPZC mostly has a negative charge. The percentage removal and adsorption capacity were investigated as a function of contact time.Experiments were carried out by simultaneously varying three factors, in order to evaluate and compare the predictive capabilities of the response surface methodology (RSM) and the artificial neural network approach (ANN) for the adsorption process. Both methods demonstrated a strong ability to accurately predict the adsorption process. However, the response surface methodology exhibited a lower prediction error compared to the artificial neural network approach.The central composite design within response surface methodology (CCD-RSM) was employed to optimize the experimental conditions for the adsorption process. The model, which considers three factors: adsorbent dose (A), initial concentration (B), and contact time (C), proved to be significant. Among these, the quadratic term (B2) had the most substantial impact on the phosphate ion adsorption rate. The analysis yielded an R2 value of 0.94, indicating an excellent fit to the data. The findings suggest that increasing contact time and reducing the initial concentration improve phosphate ion removal efficiency, while the adsorbent dose has little to no effect. The Artificial Neural Network (ANN) model effectively predicted the adsorptive remediation of phosphate ions onto LDH/alginate composite beads, achieving a high coefficient of determination (R2 = 0.984) between the model outputs and the experimental data. The study highlights the significant potential of LDH/alginate composite beads as a natural adsorbent for the removal of phosphate ions from aqueous solutions. These results underscore the environmental friendliness and efficiency of the adsorbent used for phosphate adsorption.

Dual-functional MnS nanomaterials: Efficient adsorbent for phosphate removal and sonocatalyst for textile dye degradation

Naturally abundant, environmentally friendly alternatives for replacing the expensive lanthanum-based phosphate removal technique are sought after. Solocatalysis is an emerging area for water remediation. This study introduces a dual-functional MnS nanomaterial for removing phosphate ions and Congo Red textile dye. MnS nanomaterials were synthesized via a hydrothermal route. Batch adsorption experiments revealed a phosphate adsorption capacity of 160.73 mg P/g, commendable for adsorbent in its bare form. Thermodynamic parameters of the process indicated a spontaneous, exothermic process, confirming favourable adsorption. FTIR analysis confirmed the adsorption mechanism, which includes electrostatic attraction, surface complexation, and ion exchange. MnS maintained its adsorption capacity despite competing ions, demonstrating a selective affinity for phosphate ions. MnS showed high sonocatalytic efficiency, degrading Congo Red dye within 10 min of ultrasonic irradiation. The degradation mechanism of Congo Red dye in the sonocatalytic process is proposed. This novel metal chalcogenide material exhibits exceptional affinity for phosphate ions and Congo Red dye molecules, surpassing La-based adsorbents in efficacy. The results suggest that MnS nanomaterials are promising for practical applications in phosphate removal and textile dye degradation from wastewater.

Multi-metal-doped transition metal compounds for high-performance asymmetric capacitive deionization

To address the limited ion adsorption capacity of carbon-based capacitive deionization (CDI) which primarily relies on double-layer mechanism, recent efforts have focused on the rational design and development of efficient Faradaic materials for CDI applications. In this study, we synthesized and applied Co- and Mn-doped transition metal compounds (Cu₂O@MCF) as the electrodes for asymmetric CDI using a simple hydrothermal method. The synthesized electrodes were analyzed using various characterization techniques, to confirm the successful doping and structural integrity. Electrochemical performance assessments revealed significant improvements in ion-capture capacity and overall desalination efficiency. Specifically, the optimized asymmetric CDI cell configuration, consisting of Cu₂O@MCF(Cl) as an anode and Cu₂O@MCF(Na) as a cathode, led to a significant increase in salt adsorption capacity (27.42 mg/g) over conventional symmetric carbon electrode (11.22 mg/g), an increase of over 2.4 times. Furthermore, the synthesized electrodes demonstrated effective phosphate ion removal, highlighting their potential applicability in wastewater treatment. The findings suggest that multi-metal doping significantly enhances electrode performance by synergistically combining electric double-layer capacitance and pseudocapacitance effects, due to their unique morphological and electrochemical properties. These results contribute to sustainable water treatment and resource recovery efforts, showcasing the effectiveness of the materials in improving CDI performance and opening new avenues for their application in environmental cleanup and resource management.

Vachellia nilotica sawdust-derived polymeric and magnetic biocomposites for phosphate ions removal: Kinetics, isothermal, and thermodynamic studies

Phosphorus is an important element for both animals and plants, but its excess can cause eutrophication in water. Excess phosphorus is present in wastewater mainly due to acid rain, the dissolving of rocks, and agricultural waste. There are many methods for the elimination of Phosphorus from aqueous solution, but their use is finite because of the high operational cost. Adsorption is a productive and popular method for removing phosphorus from aqueous solution. In this study, Vachellia nilotica sawdust and its different composites (Ppy/SD and MG/SD) were utilized for the effective adsorption of phosphorus from the solution. Prepared sorbents were characterized via BET, SEM, FTIR and XRD for their surface area and morphological, functional and crystallinity attributes. Adsorption tests were carried out to identify the optimal working parameters such as adsorbent dose, temperature, initial phosphorus concentration, pH, and contact time. Adsorption isotherm and kinetic model were accurately explained by the Langmuir model and pseudo 2nd order kinetics. The maximal adsorption capacity for Phosphate was 4.803, 5.32, and 6.27 mg/g for Native/SD, Ppy/SD, and MG/SD, respectively. Thermodynamic characteristics confirmed that the phosphorus adsorption was endothermic and spontaneous. Thus, sawdust is an eco-friendly and inexpensive adsorbent for phosphorus removal from wastewater.

Preparation of modified Jordanian bentonite with cetyltrimethylammonium bromide as novel adsorbent for phosphate ion removal from synthetic and real wastewater

Jordanian bentonite was examined for its capacity to remove phosphate ions from aqueous solutions, both synthetic and natural. by converting Jordanian bentonite to organo-bentonite (CTAB-bentonite). Investigation on the ability of organo-bentonite to remove phosphate ions under different conditions including initial concentration, temperature, particle size, pH levels, adsorbent dosage, and contact time. Kinetic experiments results were analyzed employing first and second pseudo order models. The results of R2 for both kinetic models confirmed that fill in the pseudo- second-order and was preferred for the transport of phosphates other than pseudo-first order. For both synthetic and actual wastewater, the activation energy for removal was computed and determined to be 22.88 kJ/mol and 58.73 kJ/mol, respectively. The rate of phosphate ion absorbing was investigated at different temperatures, particle sizes, agitation levels, and pH values. The study predicted both particle diffusion (Dp) and film diffusion (Df) coefficients, concluding that film diffusion (Df) determines rate.

Efficient Phosphate Ions Removal Using Multi-Layered Poly(allylamine hydrochloride)/ Poly(styrene sulfonate) Incorporated Electrospun Cellulose Membrane

Phosphate ion removal in wastewater via nanofiltration is a major challenge in wastewater treatment. In this study, cellulose acetate (CA) incorporated with graphene oxide/ sodium dodecyl sulphate (GO/SDS) and poly(allylamine hydrochloride)/poly(styrene sulfonate) (PAH/PSS) were synthesized using the electrospinning method. The membranes were characterized using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle, and field emission scanning electron microscope (FESEM). In addition, a multi-layered electrospun cellulose membrane was stacked using a layer-by-layer (LbL) technique to produce a functional ultra-filtration membrane for enhanced phosphate ions removal. The results showed that the modified membranes had better hydrophilicity and lower flux rates as compared to the unmodified membrane. The incorporation of compressed multi-layered for both unmodified and modified membranes also indicated increased phosphate ions removal efficiency up to 18.99 % and 43.08 %, respectively. In addition, post-filtration revealed that phosphate was adsorbed onto the three-layer modified membrane. PAH/PSS-modified CA/GO/SDS membrane is an innovative modification of the cellulose membrane for the phosphate-contaminated water system.

Removal of Phosphate and Ammonium Ion from Domestic Wastewater Using Clay Feldspar in Wupa Sewage Treatment Plant Abuja

The aim of this study is centered on the sustainability of feldspar as an adsorbent as opposed to other clay minerals such as plastic clay, red clay and barite. Brauner-Emmert-Teller (BET) analysis of the clay minerals considered in this study revealed that raw feldspar had the highest surface area and pore volume of 332.8 m²/g and 0.218 cc/g respectively. Similarly, the clay minerals were used in adsorption study with feldspar producing the best removal efficiency of 90.00%and 73.96% for ammonium and phosphate ions respectively. The BET results and the adsorption test showed that feldspar was a better adsorbent than the other adsorbents. Thermal activation of feldspar was carried out at temperatures of 500–700 ◦C using muffle furnace. The BET results of the thermal activation revealed that feldspar activated at 600 ◦C has the highest surface area and pore volume of 533.9 m²/g and 0.272 cc/g respectively. The Fourier’s transformed infrared (FT-IR) results indicated that several functional groups were involved in the adsorption process of the phosphate and ammonium ions some of which were O-H, N-H and C-O groups. The results showed that irregular-layered structures of the raw feldspar became smooth and regular after thermal activation. The effects of pH, adsorbent dosage, temperature, contact time and initial PO₄3− and NH₄⁺ concentrations on the adsorption of phosphate ions and ammonium ions were investigated using atomic adsorption spectroscopy (ASS). The adsorption studies of phosphate ion and ammonium ion onto feldspar increased with contact time, adsorbent dosage and temperatures until optimum values were reached.

Synthesis of graphene oxide-choline chloride in order to remove phosphate ion from aqueous samples: study of mechanism, isotherm and adsorption kinetics

In this study, a graphene oxide-choline chloride adsorbent was used as a highly efficient and environmentally friendly material for removing phosphate ions from aqueous samples. Graphene oxide was synthesized using the Hummers method and then modified with choline chloride to create the graphene oxide-choline chloride adsorbent. The synthesized adsorbent was characterized using Fourier transform infrared spectrophotometry (FT-IR), Field Effect Scanning Electron Microscopy (FESEM), and Energy-dispersive X-ray spectroscopy (EDX). It was then applied to remove phosphate ions at different pH levels and stirring times. The results of this study showed that the maximum removal efficiency of phosphate ions was achieved at pH 5, with an adsorbent amount of 0.015 g and a stirring time of 30 minutes. Furthermore, it was observed that the adsorption of phosphate ions on the adsorbent surface followed the Langmuir isotherm (monolayer adsorption), with a maximum adsorption capacity of 217.4 mg/g. The examination of absorption kinetics also revealed that the absorption of phosphate ions followed pseudo-second-order kinetics, and an increase in temperature favored the progress of the reaction.

COMPLEX TITANIUM-CONTAINING REAGENTS IN WASTEWATER TREATMENT PROCESSES OF THE FISHING INDUSTRY

The issues of removing nutrients from wastewater from various industries have recently received more and more attention. Traditional coagulants based on aluminum and iron salts can effectively remove phosphate ions from water, but these reagents are not effective against ammonium ions. As part of the work done, the possibility of using complex titanium-containing coagulants in the processes of dephosphatization of wastewater from the fish processing industry was considered. It has been proven that the use of magnesium titanium reagents makes it possible to carry out the coprecipitation of ammonium and phosphate ions in the form of the complex compound of magnesium ammonium phosphate (struvite) with high efficiency. To implement the purification process, a 10–20% stoichiometric excess of magnesium compounds from the calculated value is required, while the efficiency of precipitation of ammonium compounds exceeds 50%, and phosphate anion 95%. The optimal pH range for the process of coprecipitation of ammonium and phosphate ions in the form of a complex compound is 10.0 – 10.5. The results of studies conducted on real water from a fish processing plant demonstrated the increased efficiency of complex titanium-containing reagents compared to traditional coagulants based on aluminum, iron and magnesium salts. The possibility of using magnesium-containing waste from the production of refractory materials has been established both as a precursor for the production of complex coagulants and as an individual reagent. It has been proven that the use of complex titanium-containing reagents makes it possible to significantly intensify the processes of sedimentation (15%) and filtration (20%) of coagulation sludge. The use of complex reagents will significantly increase the level of environmental safety of production and reduce the anthropogenic load on the hydrosphere. For citation: Kuzin E.N. Complex titanium-containing reagents in wastewater treatment processes of the fishing industry. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 127-135. DOI: 10.6060/ivkkt.20246707.6997.

Two approaches to prepare cationic lignin‐based adsorbents for efficient removal of phosphate ion from wastewater

AbstractIn this work, two types of cationic lignin‐based adsorbents (AL‐METAC and AL‐GTA) were prepared through free radical polymerization or etherification reaction of alkali lignin with 2,3‐epoxypropyl‐3‐trimethylammonium chloride or methylacrylloxyethyl trimethyl ammonium chloride (METAC). The contents of quaternary ammonium groups in the adsorbents were adjusted by changing the dosages of 2,3‐epoxypropyl‐3‐trimethylammonium chloride and METAC to fabricate the adsorbents with excellent adsorption capacity. The structures, aqueous solubility, and physical properties of adsorbents were analyzed. Meanwhile, the effects of adsorbents dosage, pH value of solution, temperature, and ionic strength on the adsorption capacity of adsorbents were also analyzed. These two types of adsorbents exhibited outstanding affinity for phosphate, with a maximum removal efficiency of 51.8 and 73.2 mg/g, respectively. The adsorption processes followed pseudo‐second‐order and Langmuir models well. In addition, the AL‐GTA exhibited higher removal efficiency than AL‐METAC. Moreover, the AL‐METAC and AL‐GTA still retained 69.7% and 69.0% adsorption capacity after four times regeneration. The fabricated lignin‐based adsorbents have potential applications in the removal of phosphate from wastewater, which would promote the high‐value application of lignin.

Amine modification over activated carbon for an effective removal of phosphate ions in water

Amine modification over activated carbon for an effective removal of phosphate ions in water

Structural transformation investigations of δ to α manganese dioxides: Phosphate sorption and its mechanism

The elevation of environmental phosphate levels can negatively impact both the natural environment and human health. To address this issue, a series of MnO2 sorbents were investigated in this study. A facile one-pot synthesis method was employed to fabricate distinct morphologies and crystalline structures by controlling the hydrothermal duration. As the hydrothermal duration was prolonged, the samples demonstrated a pronounced enhancement of stability and crystalline phases, along with a corresponding increase in structural oxygen vacancies. A series of sorption performance tests were conducted, including pH effect, sorption isotherm, sorption kinetics, co-existing ions and sorption–desorption cycles experiments. It was revealed that manganese dissolution, the surface charge of the sorbents, and the phosphate species at different pH values collectively influenced the sorption process. The sorbent α-MnO2-120 h, with the highest oxygen vacancy ratio, exhibited the best sorption performance towards phosphate ions, with the maximum sorption capacity at pH 7. The highest removal rate and kd value were 82.63 % and 2.29 × 103 mL g−1, respectively, at the initial concentration of 30.7 mg PO4 g−1. The α-MnO2-120 h sorbent exhibited excellent selectivity in the presence of NO3−, SO42−, CO32−, and SiO32−. Furthermore, the regenerated material exhibited only a 6 % decrease in phosphate removal efficiency after five cycles, with no structural changes observed. A novel mechanism was proposed, highlighting the dominance of covalent chemical reactions in the sorption process. In particular, the participation of oxygen vacancies in sorbents contributed to enhancing the effective removal of phosphate ions. Overall, this study successfully demonstrated that synthesized α-MnO2 is a promising sorbent for phosphate removal.

Eco-friendly nanoparticles: mechanisms and capacities for efficient removal of heavy metals and phosphate from water using definitive screening design approach.

Can nano-zero-valent iron, synthesized using oak leaf extract, be the key solution for water preservation, efficiently removing heavy metal ions and phosphate anions simultaneously? This research unveils how this technology not only promises high efficiency in the remediation of water resources, but also sets new standards for environmentally friendly processes. The high antioxidant capacity and high phenol content indicate suggest the possibility of oak-nZVI synthesis using oak leaf extract as a stable material with minimal agglomeration. The simultaneous removal of Cd and phosphates, as well as and Ni and phosphates was optimized by a statistically designed experiment with a definitive screening design approach. By defining the key factors with the most significant impact, a more efficient and faster method is achieved, improving the economic sustainability of the research by minimizing the number of experiments while maximizing precision. In terms of significance, four input parameters affecting process productivity were monitored: initial metal concentration (1-9mgL-1), initial ion concentration (1-9mgL-1), pH value (2-10), and oak-nZVI dosage (2-16mL). The process optimization resulted in the highest simultaneous removal efficiency of 98.99 and 87.30% for cadmium and phosphate ions, respectively. The highest efficiency for the simultaneous removal of nickel and phosphate ions was 93.44 and 96.75%, respectively. The optimization process fits within the confidence intervals, which confirms the assumption that the selected regression model well describes the process. In the context of e of the challenges and problems of environmental protection, this work has shown considerable potential and successful application for the simultaneous removal of Cd(II) and Ni(II) in the presence of phosphates from water.

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.

Oyster shell-doped ground coffee waste biochars for selective removal of phosphate and nitrate ions from aqueous phases via enhanced electrostatic surface complexations: A mechanism study

Efficient removal of phosphate (PI) and nitrate ions (NI) from aqueous phases is crucial for securing drinking water sources. This study firstly explored the surface modification of ground coffee waste biochars (GCWB) via co-thermal decomposition of ground coffee wastes (GCWs) and oyster shells (OSs), focusing on their differences in the physicochemical properties and adsorption mechanisms of PI and NI related to the selectivity and adsorption capacity. OSs-doped GCWB (OS@GCWB) exhibited the higher adsorption capacities of PI (106.5 µg/g) and NI (57.9 µg/g) ions compared to GCWB (PI = 12.2 µg/g; NI = 35.2 µg/g) owing to its enriched calcium hydroxides and improved surface charge properties through co-thermal decomposition of GCWs and OSs. From the assessed kinetic, intra-particle diffusion, and isotherm parameters, physisorption and intra-particle diffusion were primarily responsible for the elimination of PI and NI by GCWB and OS@GCWB. Moreover, the obtained thermodynamic parameters revealed that the adsorptive removal of PI and NI using GCWB and OS@GCWB showed spontaneous and endothermic natures over the tested temperature ranges. The shifts in the dominant adsorptive removal mechanisms of GCWB toward PI and NI from the ligand exchanges to the electrostatic surface complexations supported that its improved surface characteristics through co-thermal decomposition of GCWs and OSs could improve the selectivity and adsorption capacities of PI and NI in the co-presence of Cl-, HCO3-, and SO42- ions. Based on these observations, OS@GCWB derived from co-thermal decomposition of GCWs and OSs may be a promising adsorbent for the elimination of PI and NI.

A pH-responsive covalent organic network: morphology change leads to capture and removal of phosphate ions from water

Development of water insoluble COF for efficient capture and recovery of phosphate from wastewater to mitigate the adverse effects of water eutrophication.

Preparation and characterization of biomaterial for phosphate ion removal: Kinetics, isotherms and thermodynamics studies

Phosphate ions are among the pollutants that pose a major risk to the environment and human health at high concentrations. The aim of this article is to evaluate the elimination capacity of these ions of the Carpobrotus edulis plant in its raw state and treated with (HCl, 0.5 M). Both biomaterials were characterized by scanning electron microscopy coupled to an energy dispersive X-ray spectrometer (SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), differential thermal analysis (DTA), and thermal gravimetric analysis (TGA). Retention power depends on several parameters, such as adsorbent mass, contact time, initial concentration, pH, and temperature. The acid treatment allows a reduction in soluble organic matter characterized by a decrease in BOD5 and COD of 30% and 70% respectively. For a fixed ratio of the order of 3.75 g.L−1 and an initial concentration of 1000 mg.L−1, phosphate ion removal percentages exceed 90%. The kinetics fit well with the pseudo-second-order model, and the results show strong agreement with the Langmuir isotherm. The maximum adsorption capacity of phosphate ions is 380.95 mg.g−1 for the plant native and 888.89 mg.g−1 in the modified state. The thermodynamics of adsorption are spontaneous and exothermic for plant native and endothermic for plant treated.

Fe(III) cross-linked cellulose-agar hydrogel beads for efficient phosphate removal from aqueous solutions.

Fe(III) cross-linked cellulose agar beads (Fe-CLCAB) were synthesized by sol-gel method and employed as adsorbents for the removal of phosphate ions from aqueous medium. The synthesized Fe-CLCAB was characterized by its swelling property, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and UV-Vis absorption spectroscopic analysis. Batch adsorption studies were carried out to find out the optimum conditions of phosphate uptake. The adsorption process was found to fit both Langmuir and Freundlich adsorption isotherm model, pseudo-second-order kinetic model, and Elovich kinetic model. Ninety-four percent phosphate adsorption was achieved with 500 beads at pH 5. Maximum monolayer adsorption capacity was 73.13mg/g. A two-step elution process using sodium chloride solution was suitable for complete desorption of phosphate from Fe-CLCAB. Six cyclic adsorption-desorption tests were conducted using a 0.1M NaCl solution as desorbing agent. The removal efficiency of regenerated Fe-CLCAB was 42% of its original value after six cycles, which validates good stability and effectiveness of the prepared hydrogel beads. Ion exchange plays a vital role during adsorption/desorption of phosphate.

Treatment and recovery of phosphate from submerged anaerobic membrane bioreactor effluent using thermally treated biowaste and powder activated carbon

This study presents a novel treatment system using a submerged anaerobic membrane bioreactor (SAnMBR) followed by adsorption onto thermally treated biowaste, and ending with a final treatment using powdered activated carbon (PAC). Despite limited phosphate and ammonium ion removal during SAnMBR operation, thermally treated eggshell (EGSL) and seagrass (SG) received SAnMBR effluent and enhanced phosphate recovery, achieving removal rates of 71.8–99.9% and 60.5–78.0%, respectively. The SAnMBR achieved an 85% COD removal, which was slightly reduced further by biowaste treatment. However, significant further reductions in COD to 20.2 ± 5.2 mg/L for EGSL effluent and 57.0 ± 13.3 mg/L for SG effluent were achieved with PAC. Phytotoxicity tests showed the SAnMBR effluent after PAC treatment notably improved seed growth compared to untreated wastewater. In addition, volatile organic compounds (VOCs) were significantly reduced in the system, including common wastewater contaminants such as dimethyl disulfide, dimethyl trisulfide, phenol, p-cresol, nonanal, and decanal. Fractionation analysis of the solid fraction, post-adsorption from both synthetic and domestic wastewater, indicated that for SG, 77.3%–94% of the total phosphorus (TP) was inorganically bound, while for EGSL, it ranged from 94% to 95.3%. This study represents the first attempt at a proof-of-concept for simultaneous treatment of domestic wastewater and phosphorus recovery using this integrated system.

Exploring shared adsorption capacity and thermodynamics for simultaneous removal of microcystin and phosphorus via green sorption media in eutrophic water

The recurrent events of harmful algal blooms due to an increase of nutrients in eutrophic water bodies have augmented concerns over the presence of cyanobacterial toxins, especially Microcystin. Microcystin-LR (MC-LR) is the most common cyanobacteria toxin, gaining focus in the literature for its effect on human health. The aim of this study is to investigate the simultaneous removal of MC-LR and phosphate via four green sorption media is the presence or absence of phosphorus or calcium ions and their shared adsorption capacity and thermodynamics to mimic eutrophic water condition in a karst environment (South Florida). The four green sorption media are known as: (1) CPS (clay, perlite, and sand), (2) ZIPGEM (Zero-valent-Iron and Perlite-Based Green Environmental Media), (3) BIPGEM-1 (Biochar-Zero-valent-Iron and Perlite-Based Green Environmental Media-1), and (4) BIPGEM-2 (Biochar-Zero-valent-Iron and Perlite-Based Green Environmental Media-2). Based on the MC-LR removal efficiency, BIPGEM-2 has the best performance, followed by BIPGEM-1, ZIPGEM, and CPS. In terms of simultaneous removal of phosphate ions and MC-LR, ZIPGEM achieves higher removals, ranging from 55 to 60%, followed by BIPGEM-2, BIPGEM-1, and CPS. The MC-LR adsorption capacity of BIPGEM-2 ranges from 16.9 to 29.49 μg·g−1 based on the Langmuir isotherm model under different influent conditions, whereas the MC-LR adsorption capacity of BIPGEM-1 in a dynamic environment is 1.19 μg·g−1 based on the Modified Dose Response model. The decrease in the adsorption capacity of BIPGEM-1 in a dynamic environment can be attributed to the presence of dissolved organic matter and inorganic ions, present in the influent water matrix. The influence of the water matrix is also observed in the isotherm studies because the presence of PO43− negatively impacts the removal efficiencies of MC-LR, whereas Ca2+ positively impacts the removal efficiencies of MC-LR. Similarly, the presence of MC-LR affects the PO43− adsorption capacity of the sorption media.