Functional CoFe2O4‐modified biochar derived from banana pseudostem as an efficient adsorbent for the removal of amoxicillin from water

The development of multifunctional biochar with NiFe2O4 for the adsorption of Cd (II) from water systems: The kinetics, thermodynamics, and regeneration

High concentrations of Cd (II) in wastewater have been reported several times which attracted top research attention to mitigate the pollution impacts of the contaminant. Therefore, this study aimed to develop a Zn-doped NiFe2O4- pinecone biochar composite (ZNiF@PB) for the adsorption of Cd (II) from wastewater. FTIR confirmed immobilization of PB on the surface of ZNiF by the presence of C = O at 1638 cm-1, COOH at 1385 cm-1, C-O at 1009 cm-1 and Fe-O at 756 cm-1. Similarly, XRD determined the crystallite structure of the adsorbents where the ZNiF crystallite size of 43 nm was obtained while the particle size of ZNiF@PB was found to be 38 nm. These XRD results agreed with those values obtained from TEM images showing ZNiF and ZNiF@PB had a spherical shape with similar particle sizes. On the other hand, the surface areas of ZNiF, PB, and ZNiF@PB were found to be 78.4 m2/g, 125 m2/g, and 104 m2/g, respectively. These high surface areas have a huge potential to enhance Cd removal. With these adsorbents, the maximum Cd (II) adsorption of 96% was recorded at the optimum experimental condition of adsorbent dosage 0.5g/50 mL, solution pH 6, initial Cd (II) concentration 100 mg/L, and contact time 120 min. Practical adsorption kinetics data were well described by the pseudo-second order model whereas the adsorption isotherm was a perfect fit to the Langmuir isothermal model implying the adsorption process to be a monolayer with mainly a chemically bonded mechanism. In conclusion, this adsorbent is efficient for the adsorption of Cd (II) from wastewater and has also a huge potential to be applied for industrial-scale water purification.

High removal of volatile organic compounds on hierarchical carbons prepared from agro-industrial waste of banana fruit production for air decontamination

Activated carbons were prepared from residues from agro-industrial banana production (banana pseudostem) and evaluated in the capture of five different volatile organic compounds (VOCs): dichloromethane, chloroform, ethyl acetate, hexane, and cyclohexane. The biomass was first submitted to a hydrothermal treatment in the presence of KOH or ZnCl2 as activating agents, followed by a dry pyrolysis. This new advance in methodology contributes to producing activated carbons with hierarchical porosity and high surface areas (701-1312 m2 g-1), promoting increased interest in managing waste from banana fruit agricultural production. VOC capture studies were performed by thermal analysis, and capture capacities were similar to or higher than those presented in the literature. Higher adsorption capacities were related to the amount of available micropores, and the capture capacity was enhanced by the contribution of small mesopores. As the highest adsorbed amounts of dichloromethane (933 mg g-1 at 25 °C) were obtained for the material activated with ZnCl2 (1:3), further studies were carried out for this system. The experimental data was fitted using a pseudo-first-order kinetic model. A study was carried out in different atmospheres (He, N2, air), showing that co-adsorption is occurring. Under simulated environmental conditions, the capture capacity decreased slightly at equilibrium, and the new adsorbent was used for up to ten cycles without significantly losing its efficiency, indicating good application in the field.

Biochar-alginate beads derived from argan nutshells for effective methylene blue removal: A sustainable approach to wastewater treatment

This study explores the use of biochar derived from Argan Nutshells as a core component in alginate beads for the removal of methylene blue (MB) from aqueous solutions. The characterization of BC/Alg composite was conducted using techniques like Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and size distribution to assess its structural properties and confirm the strong interaction between both components. The adsorbent exhibited surface functional groups characteristic of both biochar and alginate, and SEM confirmed the spherical morphology of the beads. A response surface methodology (RSM) was used to optimize the adsorption process by evaluating the effects of key parameters including pH, temperature, adsorbent mass, and dye concentration. The results showed that the BC/Alg effectively removed 96.4 % of MB. The pseudo-second order (PSO) kinetic model best described the MB removal process (R2 = 0.9990), while the Langmuir isotherm model accurately represented the adsorption equilibrium (R2 = 0.96879). After four cycles of regeneration trials, BC/Alg retained 82 % MB removal efficiency, indicating high reusability and stability. The remarkable adsorption capability of BC/Alg showed that it may be employed as an economical and environmentally friendly adsorbent in aqueous solutions, strengthening the case for employing Argan nutshells for water treatment.

Development of a new magnetic solid-phase extraction method prior to HPLC determination of naproxen in pharmaceutical products and water samples

In this study, a new magnetic solid phase extraction based on magnetic composite modified with biochar obtained from pumpkin peel was developed for the enrichment and extraction of Naproxen in lake water, tablet and urine samples. The effects of main parameters such as pH, extraction time, amount of adsorbent and sample volume, which affect magnetic solid phase extraction, were investigated. Under optimal conditions, intraday and interday precision values for naproxen were below 5.9, with accuracy (relative error) better than 7.0 %. The detection limit and preliminary concentration factor were 12 ng/mL and 10, respectively. The method proposed here can be used for routine analysis of naproxen in lake water, urine and tablets.

Sulfur Fluoride Exchange Enabled Polysufate Adsorbents: Flexible Group Embedded in Polymer Backbone Regulation Strategy for Organic Solvent Removal from Water

Removal of organic solvents (such as chloroform, toluene, etc.) in trace amounts using adsorbents from water is a challenge due to their low removal efficiencies and poor selectivities. Herein, four polysulfates (P1-P4) with different flexible group embedded backbones were synthesized via a sulfur fluoride exchange (SuFEx) reaction, and their swelling behaviors in organic solvents were investigated. P1 with a flexible ethyl group on its backbone can selectively swell in aprotic organic solvents with medium and high polarities about 30-fold its original weight, which is much higher than that of P4 with rigid benzene on its backbone. Moreover, molecular dynamic (MD) simulation results showed that the swelling mechanism could be put down to the electrostatic and van der Waals forces between the polysulfates and organic solvents. Surprisingly, the polysulfates can be used to remove chloroform and toluene from water with removal efficiencies of up to 99.26 and 99.42%, respectively. Furthermore, the polysulfates also exhibited high selectivities and anti-interference performances toward chloroform in the presence of other pollutants and different acid/base environments. Our work provides a strategy to construct adsorbents with high efficiencies for removal of low concentrations of organic solvents from water.

Adsorptive removal of phosphate from water with biochar from acacia tree modified with iron and magnesium oxides

A novel biochar (BC) from Acacia tortilis trees pruning waste was synthesized and tested for the removal of phosphate from aqueous solutions. The BC was prepared by calcination at 600 °C and doped with Fe3O4 and MgO by hydrothermal process. The presence of iron and magnesium ions in the modified BC was confirmed by EDS analysis and X-ray diffraction (XRD) methods. Both unmodified and doped BCs were tested for phosphate removal from synthetic 1-500 ppm aqueous solutions. While the unmodified BC did not show any significant removal of phosphate from aqueous solutions, the modified BC almost completely removed phosphate from water. The enhancement in removal efficiency is due to an increase in the overall surface charge and surface area of BC as a result of doping with Fe3O4 and MgO salts. The average porosity and BET surface area corresponding to the plain BC increased by more than 20% from 322 to 394 m2/g after modification by impregnation with iron oxide and magnesium oxide. The modificaiton of BC with Fe3O4 and MgO nanoparticles was observed to increase the point of zero electric charge (PZC) from pH 3.4 (corresponding to plain BC) to pH 5.3 (corresponding to modified BC). The adsorption process was very fast and a phosphate removal value of 82.5% was reached only after 30 min of adsorption, while the removal efficiency after 4 h of adsorption was 97.5%. The rapid removal efficiency in short contact time is attributed to the high surface area of BC and strong bonding between the modified BC surface and PO43- ions. The highest adsorption capacity was observed to correspond to 98.5 mg/g which was achieved at PO43- concentration of 500 ppm and pH 8.5. Moreover, after fitting the adsorption data onto four of the most widely used adsorption isotherm models, the adsorption of PO43- onto BC can be better described by the Langmuir isotherm model.

Properties and Possibilities of Using Biochar Composites Made on the Basis of Biomass and Waste Residues Ferryferrohydrosol Sorbent

Biochar enriched with metals has an increased potential for sorption of organic and inorganic pollutants. The aim of the research was to identify the possibility of using biochar composites produced on the basis of waste plant biomass and waste FFH (ferryferrohydrosol) containing iron atoms, after CO2 capture. The composites were produced in a one-stage or two-stage pyrolysis process. Their selected properties were determined as follows: pH, ash content, C, H, N, O, specific surface area, microstructure and the presence of surface functional groups. The produced biochar and composites had different properties resulting from the production method and the additive used. The results of experiments on the removal of methylene blue (MB) from solutions allowed us to rank the adsorbents used according to the maximum dye removal value achieved as follows: BC1 (94.99%), B (84.61%), BC2 (84.09%), BC3 (83.23%) and BC4 (83.23%). In terms of maximum amoxicillin removal efficiency, the ranking is as follows: BC1 (55.49%), BC3 (23.51%), BC2 (18.13%), B (13.50%) and BC4 (5.98%). The maximum efficiency of diclofenac removal was demonstrated by adsorbents BC1 (98.71), BC3 (87.08%), BC4 (74.20%), B (36.70%) and BC2 (30.40%). The most effective removal of metals Zn, Pb and Cd from the solution was demonstrated by BC1 and BC3 composites. The final concentration of the tested metals after sorption using these composites was less than 1% of the initial concentration. The highest increase in biomass on prepared substrates was recorded for the BC5 composite. It was higher by 90% and 54% (for doses of 30 g and 15 g, respectively) in relation to the biomass growth in the soil without additives. The BC1 composite can be used in pollutant sorption processes. However, BC5 has great potential as a soil additive in crop yield and plant growth.

Constructing N,S co-doped network biochar confined CoFe2O4 magnetic nanoparticles adsorbent: Insights into the synergistic and competitive adsorption of Pb2+ and ciprofloxacin

To solve the problem of biochar lack of adsorption sites for heavy metal ions and the difficulty of recycling, CoFe2O4 magnetic nanoparticles confined in nitrogen, sulfur co-doped 3D network biochar matrix (C-CoFe2O4/N,S-BC) was designed and fabricated successfully. The obtained C-CoFe2O4/N,S-BC displays remarkable adsorption performance for both Pb2+ and ciprofloxacin (CIP) removal at the single or binary system due to the role of N,S as metal ion anchoring compared to the N,S-free sample (CoFe2O4/BC). N,S co-doped BC not only participates in adsorption reaction but also effectively inhibites the agglomeration of CoFe2O4 nanoparticles and increases the active sites as a carrier at the same time. In the single system, CoFe2O4/N,S-BC demonstrates a fast adsorption rate (equilibrium time: 30 min) and high adsorption capacity (224.77 mg g-1 for Pb2+, 400.11 mg g-1 for CIP) towards Pb2+ and CIP. The adsorption process is befitted pseudo-second-order model, and the equilibrium data are in great pertinence with Langmuir model. In the binary system, the maximum adsorption capacity of CoFe2O4/N,S-BC for Pb2+ and CIP is 244.80 mg g-1 (CIP: 10.00 mg L-1) and 418.42 mg g-1 (Pb2+: 10.00 mg L-1), respectively. The adsorption mechanism is discussed based on the experimental results. Moreover, C-CoFe2O4/N,S-BC shows good practical water treatment capacity, anti-interference ability and stable reusability (the removal efficiency＞80% after eight cycles). The rapid, multifunctional, reusable, and easily separable adsorption properties make C-CoFe2O4/N,S-BC promising for efficient environmental remediation. This study also offers a viable method for the construction of adsorption material for complex wastewater treatment.

Cellulose beads supported CoFe2O4: A novel heterogeneous catalyst for efficient rhodamine B degradation via advanced oxidation processes

In this study, a novel mechanical process was used to produce cellulose beads (CB). These beads were then doped with cobalt ferrite nanoparticles (CoFe2O4 NPs) to serve as catalysts for the degradation of rhodamine B (RhB) through peroxymonosulfate (PMS) activation. The physical and chemical properties of CoFe2O4 and CoFe2O4@CB catalysts were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) combined with energy dispersive X-ray spectrometer (EDX), scanning transmission electron microscopy (STEM) techniques, and thermogravimetric analysis (TGA). To optimize RhB degradation efficiency, Response Surface Methodology (RSM) was employed, utilizing the Box-Behnken design (BBD). Under the optimized conditions of a catalyst dosage of 0.40 g/L, PMS dosage of 0.98 mM, RhB concentration of 40 mg/L, pH of 5.27, and reaction time of 60 min, a remarkable degradation efficiency of 98.51 % was achieved at a temperature of 25 °C. In quenching experiments, 1O2, SO4•-, and HO• species are produced in the CoFe2O4@CB/PMS system, with 1O2, and SO4•- species dominating RhB degradation. Remarkably, the new CoFe2O4@CB catalyst has demonstrated exceptional stability and reusability, validated by recycling tests (up to 78 % of RhB degradation efficiency after a 5-cycle experiment) and subsequent characterizations (FTIR, SEM, and EDX) emphasizing unchanged bands, uniform distribution, and consistent composition after reuse cycles. These results demonstrate the effectiveness of mechanically produced CoFe2O4@CB catalysts for advanced oxidation processes (AOPs), with promising applications in wastewater treatment.

Heterogeneous porous biochar-supported nano NiFe2O4 for efficient removal of hazardous antibiotic from pharmaceutical wastewater

Due to the dual issues of antibiotic resistance and bioaccumulation toxicity, antibiotics are ubiquitously present in aquatic environments, and this is causing serious concern. Herein, novel nickel ferrite (NiFe2O4) nanoparticles were successfully loaded onto activated biochar (BC) derived from banana peel (BP) to obtain magnetic nanocomposite (BC-NiFe2O4) as an effective biosorbent for the ciprofloxacin antibiotic (CIP) elimination from pharmaceutical effluent. A facile co-precipitation approach was utilized to construct the heterogeneous BC-NiFe2O4. The synthesized materials were systematically characterized using techniques such as XRD, FE-SEM, EDX, HR-TEM, BET, FTIR, and XPS. In addition, the magnetic measurements indicated the ferromagnetic behavior of the BC-NiFe2O4 sample. The influencing factors (i.e., pH, contact time, initial concentration, dose of adsorbent, ions interference, and solution temperature) of the adsorption process were also well studied. The adsorption capacity of the BC-NiFe2O4 heterostructure was 68.79 mg g-1 compared to the BC sample (35.71 mg g-1), confirming that the loading of magnetically NiFe2O4 nanoparticles onto the surface of porous biochar enhanced its stability and adsorption performance for CIP removal, wherein the metal-antibiotic complex has a significant effect for the removal of CIP. Moreover, the Langmuir adsorption isotherm and the pseudo-second-order model displayed a good fit for the experimental data. The values of △H° and △G° revealed that the adsorption process was endothermic and spontaneous. The coordination affinities, π-π stacking, and H-bonding interactions play a more critical role in the adsorption mechanism that confirmed by FTIR and XPS analysis. To study the stability of BC-NiFe2O4 nanocomposites, desorption and recycling studies were investigated. The results revealed that after three cycles, no significant loss in removal efficiency was detected, reflecting the stability and reusability of the prepared BC-NiFe2O4 nanocomposite.

Spinel ferrite nanoparticles as potential materials in chlorophenol removal from wastewater

Persistent organic pollutants (POPs) including chlorophenols (CPs) are increasing in water effluents, creating serious problems for both aquatic and terrestrial lives. Several research attempts have considered the removal of CPs by functionalised nanomaterials as adsorbents and catalysts. Besides the unique crystal structure, spinel ferrite nanomaterials (SFNs) own interesting optical and magnetic properties that give them the potential to be utilised in the removal of different types of CPs. In this review, we highlighted the recent research work that focused on the application of SFNs in the removal of different CP substances based on the number of chlorine atom attached to the phenolic compound. We have also discussed the structure and properties of SFN along with their numerous characterisation tools. We demonstrated the importance of identifying the structure, surface area, porosity, optical properties, etc. in the efficiency of the SFN during the CP removal process. The reviewed research efforts applied photocatalysis, wet peroxide oxidation (WPO), persulfate activated oxidation and adsorption. The studies presented different paths of enhancing the SFN ability to remove the CPs including doping (ion substitution), oxide composite structure and polymer composite structure. Experimental parameters such as temperature, dosage of CPs and SFN structure have shown to have a major effect in the CP removal efficiency. More attention is needed to investigate the different properties of SFN that can be tailored through different techniques and expected to have major role in the removal mechanism of CPs.

Extensive sorption of Amoxicillin by highly efficient carbon-based adsorbent from palm kernel: Artificial neural network modeling

In the present study, a new sorbent was fabricated from Palm kernel (PK) by dry thermochemical activation with NaOH and characterized by FTIR, X-ray diffraction, FE-SEM and BET, which was used for the Amoxicillin (AMX) sorption from aqueous solution. The influence of effective parameters such as pH, reaction time, adsorbent dosage, AMX concentration and ionic strength on the sorption efficacy of AMX removal were evaluated. The main functional groups on the surface of the magnetic activated carbon of Palm Kernel (MA-PK) were C-C, C-O, C[bond, double bond]O and hydroxyl groups. The specific surface of char, activated carbon Palm Kernel (AC-PK) and MA-PK were 4.3, 1648.8 and 1852.4 m2/g, respectively. The highest sorption of AMX (400 mg/L) was obtained by using 1 g/L of sorbent at solution pH of 5 after 60 min contact time, which corresponding to 98.77%. Non-linear and linear models of isotherms and kinetics models were studied. The data fitted well with Hill isotherm (R2 = 0.987) and calculated maximum sorption capacity were 719.07 and 512.27 mg/g from Hill and Langmuir, respectively. A study of kinetics shows that the adsorption of AMX follows the Elovich model with R2 = 0.9998. Based on the artificial neural network (ANN) modeling, the MA-PK dosage and contact time showed the most important parameters in the removal of AMX with relative importance of 36.5 and 25.7%, respectively. Lastly, the fabricated MA-PK was successfully used to remove the AMX from hospital wastewater.

Development of shelf life-extending packaging for vitamin C syrup based on high-density polyethylene and extracted lignin argan shells

Biobased packaging is an essential parameter in the pharmaceutical industry. In the present work, bio-composites consisting of high-density polyethylene (HDPE) as a matrix and lignin recovered from argan nut shells as filler were developed to investigate their potential use as packaging materials for vitamin C drugs. The lignin was extracted via alkali and klason processes, and the effects of the extraction method as well as the lignin content on the thermal, morphological, mechanical, and rheological properties of the produced composites, as well as their application for vitamin C packaging, were investigated. Among all the prepared packaging materials, the one with desirable results in pH, color stability, hardness, and mechanical characteristics was based on alkali lignin. It achieved its highest Young's modulus enhancement, 10.12 %, at 10 % alkali lignin loading, while the highest yield strain enhancement (4.65 %) was obtained with 2 % loading. When compared to neat HDPE and HDPE/klason lignin packaging materials, vitamin C solutions packed with this composite showed a lower oxidation rate, attributed to the extremely low pH variation and high color stability of the material, which decreased the rate of vitamin C degradation. According to these findings, HDPE/alkali lignin composite is a promising vitamin C syrup packaging material.

Bio-inspired sustainable synthesis of novel SnS2/biochar nanocomposite for adsorption coupled photodegradation of amoxicillin and congo red: Effects of reaction parameters, and water matrices

This study aims to fabricate a novel integrated photocatalytic adsorbent (IPA) via a green solvothermal process employing tea (Camellia sinensis var. assamica) leaf extract as a stabilizing and capping agent for the removal of organic pollutants from wastewater. An n-type semiconductor photocatalyst, SnS_2, was chosen as a photocatalyst due to its remarkable photocatalytic activity supported over areca nut (Areca catechu) biochar for the adsorption of pollutants. The adsorption and photocatalytic properties of fabricated IPA were examined by taking amoxicillin (AM) and congo red (CR) as two emerging pollutants found in wastewater. Investigating synergistic adsorption and photocatalytic properties under varying reaction conditions mimicking actual wastewater conditions marks the novelty of the present research. The support of biochar for the SnS₂ thin films induced a reduction in charge recombination rate, which enhanced the photocatalytic activity of the material. The adsorption data were in accordance with the Langmuir nonlinear isotherm model, indicating monolayer chemosorption with the pseudo-second-order rate kinetics. The photodegradation process follows pseudo-first-order kinetics with the highest rate constant of 0.0450 min^-1 for AM and 0.0454 min^-1 for CR. The overall removal efficiency of 93.72 ± 1.19% and 98.43 ± 1.53% could be achieved within 90 min for AM and CR via simultaneous adsorption and photodegradation model. A plausible mechanism of synergistic adsorption and photodegradation of pollutants is also presented. The effect of pH, Humic acid (HA) concentration, inorganic salts and water matrices have also been included.The photodegradation activity of SnS₂ under visible light coupled with the adsorption capability of the biochar results in the excellent removal of the contaminants from the liquid phase.

Comparison between nanocellulose-polyethylenimine composites synthesis methods towards multiple water pollutants removal: A review

Nanocellulose/polyethylenimine composites have attracted growing attention due to their versatility as new materials for application in different fields. Water remediation is one of the traditional applications of these composites and their investigation as adsorbents for single water pollutants is well established. However, most water resources such as rivers, lakes, and even oceans contain complex mixtures of pollutants. Despite several recently published reviews on water purification technology, they only focused on these material as single pollutant removers and hardly mentioned their capacity to simultaneously recover multiple pollutants. Therefore, there is still a gap in the archived literature considering nanocellulose/polyethylenimine composites targeting water remediation with multiple water pollutants. In this review, methods for synthesizing such composites are classified and compared according to the mechanism of reactions, such as chemical crosslinking and physical adsorption, while outlining advantages and limitations. Then, the water pollutants mainly targeted by those composites are discussed in detail to expound the relationship between the synthesis method and the type and adsorption capacity. Finally, the last section presents challenges and opportunities of these nanocellulose/polyethylenimine composites as emerging sorbents for sustainable multiple water pollutants purification technologies. This review aims to lay out the basis for future developments of these composites for multiple water pollutants.

In-situ construction of Zr-based metal-organic framework core-shell heterostructure for photocatalytic degradation of organic pollutants

Photocatalysis is an eco-friendly promising approach to the degradation of textile dyes. The majority of reported studies involved remediation of dyes with an initial concentration ≤50 mg/L, which was away from the existing values in textile wastewater. Herein, a simple solvothermal route was utilized to synthesize CoFe2O4@UiO-66 core-shell heterojunction photocatalyst for the first time. The photocatalytic performance of the as-synthesized catalysts was assessed through the photodegradation of methylene blue (MB) and methyl orange (MO) dyes at an initial concentration (100 mg/L). Under simulated solar irradiation, improved photocatalytic performance was accomplished by as-obtained CoFe2O4@UiO-66 heterojunction compared to bare UiO-66 and CoFe2O4. The overall removal efficiency of dyes (100 mg/L) over CoFe2O4@UiO-66 (50 mg/L) reached >60% within 180 min. The optical and photoelectrochemical measurements showed an enhanced visible light absorption capacity as well as effective interfacial charge separation and transfer over CoFe2O4@UiO-66, emphasizing the successful construction of heterojunction. The degradation mechanism was further explored, which revealed the contribution of holes (h+), superoxide (•O2 -), and hydroxyl (•OH) radicals in the degradation process, however, h+ were the predominant reactive species. This work might open up new insights for designing MOF-based core-shell heterostructured photocatalysts for the remediation of industrial organic pollutants.

Synthesis of biochar-CoFe2O4 nanocomposite for adsorption of methylparaben from wastewater under full factorial experimental design

The presence of endocrine-disrupting chemicals in municipal wastewater has emerged as a threat to human health and the environment. Therefore, this study aimed to develop biochar-cobalt ferrite (BCF) nanocomposite for the removal of methylparaben from water under the full factorial experimental design of 4 factors with 3 levels (3⁴). The biochar-CoFe₂O₄ nanocomposite was developed by co-precipitation method from cobalt ferrite and biochar of Eucalyptus tree bark. Adsorbent surface morphology and functional and elemental composition were carried out by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDS) techniques which showed the presence of cracks with a rough surface, reasonable surface chemical composition, and many chemical functional groups, respectively. The experimental and predicted adsorption efficiencies ranged from 25.3 to 85.6% and 21.8 to 80.3%, respectively. The maximum adsorption performance (85.6%) reduced the methylparaben concentration from 27.5 to 4.0 mg/L at the optimum condition of adsorbent dose of 55 mg/100 mL, pH 6, contact time 90 min, and the initial methylparaben concentration of 27.5 mg/L. However, the adsorbent dose was the most influential main factor whereas the least influential was the interaction between solution pH and contact time under the regression model. The model also showed that 69% methylparaben removal was described by the regression model. The experimental data best fitted with the Freundlich model indicate multilayer adsorption which is the implication of physisorption. The sorption mechanism is attributed to Vander Waals forces, H-bonding, and dipole interaction. This BCF nanocomposite adsorbent appears to be promising for the removal of methylparaben from wastewater, but a further optimization process is essential to boost the treatment performance.

Biochar-mediated removal of pharmaceutical compounds from aqueous matrices via adsorption

Pharmaceutical is one of the noteworthy classes of emerging contaminants. These biologically active compounds pose a range of deleterious impacts on human health and the environment. This is attributed to their refractory behavior, poor biodegradability, and pseudopersistent nature. Their large-scale production by pharmaceutical industries and subsequent widespread utilization in hospitals, community health centers, and veterinary facilities, among others, have significantly increased the occurrence of pharmaceutical residues in various environmental compartments. Several technologies are currently being evaluated to eliminate pharmaceutical compounds (PCs) from aqueous environments. Among them, adsorption appears as the most viable treatment option because of its operational simplicity and low cost. Intensive research and development efforts are, therefore, currently underway to develop inexpensive adsorbents for the effective abatement of PCs. Although numerous adsorbents have been investigated for the removal of PCs in recent years, biochar-based adsorbents have garnered tremendous scientific attention to eliminate PCs from aqueous matrices because of their decent specific surface area, tunable surface chemistry, scalable production, and environmentally benign nature. This review, therefore, attempts to provide an overview of the latest progress in the application of biochar for the removal of PCs from wastewater. Additionally, the fundamental knowledge gaps in the domain knowledge are identified and novel strategic research guidelines are laid out to make further advances in this promising approach towards sustainable development.

Preparation of magnesium Ferrite-Doped magnetic biochar using potassium ferrate and seawater mineral at low temperature for removal of cationic pollutants

Magnetic biochar has captured a great interest for remediation of environment as an easily separable carbonous adsorbent. Herein, a highly adsorptive magnetic biochar was manufactured through seawater mineral and K₂FeO₄ co-promoted pyrolysis of jackfruit peel at 300 °C for removal of different cationic pollutants, and characterized by element analysis, FTIR, SEM-EDS, XRD, XPS and so on. MgFe₂O₄ was generated without external base and a 19.42 emu/g saturation magnetization was achieved. Simultaneously, iron oxides and oxygen containing groups were introduced. The magnetic biochar exhibited 61.30 mg/g, 129.61 mg/g, and 1238.30 mg/g adsorption capacities for Cu²⁺, methylene blue (MB), and malachite green (MG) at 25 °C, respectively, and remarkably surpassed the corresponding pristine biochar. The adsorption of MB and MG was mainly realized by electrostatic interaction, hydrogen bonding, complexation, and π-π electron-donor-acceptor interaction, and that of Cu²⁺ was attributed to electrostatic interaction, hydrogen bonding, and complexation.

Use of Biochar from Rice Husk Pyrolysis: Part A: Recovery as an Adsorbent in the Removal of Emerging Compounds

One of the main products of pyrolysis is char. For the better performance and improvement of its physicochemical properties, it is necessary to make temperature changes. In this study, different temperatures have been tested for the pyrolysis of rice husk, and the biochar obtained from the process went through an evaluation to test its yield in the removal of emerging compounds such as azithromycin (AZT) and erythromycin (ERY). For this, pyrolysis of rice husk has been carried out at temperatures of 450, 500, 550, and 600 °C, and the biochars have been characterized by ultimate analysis and proximate analysis, as well as specific surface area tests. Then, different adsorption tests have been carried out with a 200 mg L^-1 drug (AZT and ERY) solution prepared in the laboratory. All biochars have been found to present removal percentages higher than 95%. Therefore, obtaining biochar from rice husk at any temperature and using it in the removal of high-molecular-weight compounds are quite suitable.

Synthesis and Application of Cobalt Oxide (Co3O4)-Impregnated Olive Stones Biochar for the Removal of Rifampicin and Tigecycline: Multivariate Controlled Performance

Cobalt oxide (Co₃O₄) nanoparticles supported on olive stone biochar (OSBC) was used as an efficient sorbent for rifampicin (RIFM) and tigecycline (TIGC) from wastewater. Thermal stabilities, morphologies, textures, and surface functionalities of two adsorbents; OSBC and Co-OSBC were compared. BET analysis indicated that Co-OSBC possesses a larger surface area (39.85 m²/g) and higher pore-volume compared to the pristine OSBC. FT-IR analysis showed the presence of critical functional groups on the surface of both adsorbents. SEM and EDX analyses showed the presence of both meso- and macropores and confirmed the presence of Co₃O₄ nanoparticles on the adsorbent surface. Batch adsorption studies were controlled using a two-level full-factorial design (2^k-FFD). Adsorption efficiency of Co-OSBC was evaluated in terms of the % removal (%R) and the sorption capacity (q_e, mg/g) as a function of four variables: pH, adsorbent dose (AD), drug concentration, and contact time (CT). A %R of 95.18% and 75.48% could be achieved for RIFM and TIGC, respectively. Equilibrium studies revealed that Langmuir model perfectly fit the adsorption of RIFM compared to Freundlich model for TIGC. Maximum adsorption capacity (q_max) for RIFM and TIGC was 61.10 and 25.94 mg/g, respectively. Adsorption kinetics of both drugs could be best represented using the pseudo-second order (PSO) model.