Removal Of Diclofenac Research Articles

Recent advances in nano-based approaches for the removal of diclofenac: a comprehensive review

Recent advances in nano-based approaches for the removal of diclofenac: a comprehensive review

Insight into the Diclofenac and Carbamazepine Removal by Bacillus subtilis BMT4i Immobilized on Different Activated Carbons: A Comparative Removal Study by Activated Carbon, Bacterial Cell, and Its Composite

Insight into the Diclofenac and Carbamazepine Removal by Bacillus subtilis BMT4i Immobilized on Different Activated Carbons: A Comparative Removal Study by Activated Carbon, Bacterial Cell, and Its Composite

Optimisation of nanofiltration process for pharmaceutically active compounds: Removal of paracetamol, diclofenac and metoprolol

Optimisation of nanofiltration process for pharmaceutically active compounds: Removal of paracetamol, diclofenac and metoprolol

Diclofenac recovery by means of using Emulsion Liquid Membranes: A possible role of surfactant in the mass transfer process

Emulsion Liquid Membranes (ELM) are a useful method for drug extraction in aqueous solution, as they allow their recovery in a highly concentrated acceptor phase after passing through a membrane phase with a high surface area. The success of this process depends on system formulation and operation conditions. One of the most important aspects in the formulation is the addition of a surfactant that stabilizes the system, which can also participate in the mass transfer process. Recently, resistance to mass transfer caused by the use of polymeric surfactants, such as Abil® EM 90, has been reported. To verify this phenomenon observed in previous studies, the effect of various factors on the recovery of diclofenac (DCF) dissolved in an aqueous medium was analyzed using the ELM technique. The study concluded that using a membrane consisting of Abil® EM 90 (2 % w/V), trioctylamine (5 % w/V), and dodecane, along with a stripping phase formed by NaOH (0.10 mol/L), results in successful DCF removal. When emulsified at 15,000 rpm for 10 minutes at room temperature, it is possible to remove over 99 % of DCF after 15 minutes and recover 18.45 % after 30 min. Furthermore, it was determined that the action of the surfactant is the main cause of the resistance to the passage of DCF to the internal phase and its retention in the organic phase, as had already been observed. This is probably due to strong intermolecular interactions between Abil ® EM 90 and DCF and the formation of a complex and stable interfacial structure, similar to a hydrated bilayer, which favors the rigidity of the interface and keeps the drug trapped. A better understanding of the role surfactants play in the system is essential for the future design of more efficient and stable ELMs. This knowledge will enable the adaptation of the technology to a wider range of processes, including drug recovery. As a result, the maximum benefits of this technology can be fully realized.

A Kinetic Study on Chronic Response of Activated Sludge to Diclofenac by Respirometry

The present study investigated the chronic response of activated sludge to the emerging pollutant diclofenac as well as its aerobic biodegradation potential at different sludge retention times (SRTs). The impact of prolonged exposure to diclofenac on microbial process kinetics was explored with respirometric modelling. The long-term operation of lab-scale reactors revealed that continuous feeding of diclofenac at relevant concentrations observed in municipal wastewaters did not affect carbon removal efficiency independentl of SRT. However, in case of diclofenac removal, 34% efficiency could be achieved at a higher SRT of 20 days. Kinetic evaluation showed that the increment in diclofenac dosing resulted in no adverse effect on the microbial growth rate except that high concentrations of diclofenac exposure decreased the growth rate at SRT of 10 days. A significant increase in hydrolysis rate was determined in the diclofenac-acclimated biomass for both SRTs; even at high concentrations of diclofenac exposure, the hydrolysis rate remained unchanged. Long-term acclimation to diclofenac had a progressive impact on the hydrolysis kinetics, which could be attributed to an alteration in the microbial culture profile. Overall, the results suggest that the operation with diclofenac-acclimated biomass at higher SRTs could enrich a microbial culture capable of overcoming the adverse effect of the pollutant and improve the biodegradation potential as well.

On the Specific Diclofenac–Iron Cation Interaction for Selective Diclofenac Removal from a Water Solution

Diclofenac is one of the most common, commercially available, non-steroidal anti-inflammatory drugs (NSAIDs) in the world, with thousands of tons produced and consumed per year, which creates issues related to its presence in water bodies and the need for its removal from them. Diclofenac forms complexes with cations of each metal, which has inspired a study to check if the formation/precipitation of such complexes can be used for effective diclofenac removal from water solutions. It was found that iron salts, e.g., FeCl3, can be used to remove diclofenac from a water solution in the form a of precipitated complex, provided that a high excess of iron salt was used. It has been observed that the diclofenac initial concentration of 5 × 10−4 M, as a result of FeCl3 addition, after 48 h, decreased by two orders of magnitude. Salts of other metals were found less effective in reducing diclofenac concentration. The iron cation–diclofenac interaction was found to be specific, since the precipitation of other drugs by iron cations has not been observed. In order to quantitively analyze the diclofenac removal (precipitation) by iron and other metal cations, the HPLC/ESI-MS analyses were performed.

Walnut Shell Biomass Triggered Formation of Fe3C-Biochar Composite for Removal of Diclofenac by Activating Percarbonate

Percarbonate (SPC) as a promising substitute for liquid H2O2 has many advantages in the application of in situ chemical oxidation (ISCO). Developing efficient, cost effective and environmentally friendly catalysts for SPC activation plays the key role in promoting the development of SPC-based ISCO. Herein, the walnut shell biomass was combined with ferric nitrate for the catalytic synthesis of Fe3C@biochar composite (Fe3C@WSB), which demonstrated high efficiency in activating SPC for the removal of diclofenac (DCF). The Fe3C showed average crystallite size of 32.6 nm and the composite Fe3C@WSB demonstrated strong adsorptivity. The prepared Fe3C@WSB could activate both SPC and H2O2 with high efficiency at ca. pH 3 with extremely low leaching of iron, while in a weak acidic condition, higher efficiency of DCF removal was obtained in the Fe3C@WSB/SPC process than in the Fe3C@WSB/H2O2 process. Moreover, the Fe3C@WSB/SPC and Fe3C@WSB/H2O2 processes did not show significant differences when supplied with varying amounts of catalyst or oxidant, but the Fe3C@WSB/SPC process exhibited stronger capability in dealing with relatively highly concentrated DCF solution. Based on quenching experiments and electron spin resonance (ESR) analysis, heterogeneous activation of SPC was assumed as the dominant route for DCF degradation, and both the oxidation by radicals, including •OH, •O2− and CO3•−, combined with electron transfer pathway contributed to DCF degradation in the Fe3C@WSB/SPC process. The cycling experiment results also revealed the stability of Fe3C@WSB. This work may cast some light on the development of efficient catalysts for the activation of SPC.

Application of electro-membrane bioreactor in the treatment of pharmaceutical wastewater

In the present study, the integrated process of an electro-membrane bioreactor (EMBR) with conventional membrane bioreactor (MBR) was used for wastewater treatment. The removal rates of chemical oxygen demand (COD), phosphate (PO43-), turbidity, diclofenac (DCF), and UV254 were investigated in both reactors, which operated with a sludge retention time (SRT) of 60 d and a hydraulic retention time (HRT) of 24 h. The assessment of the current density effect on DCF removal in an electrocoagulation reactor indicated that 0.5 mA/cm² was an appropriate current for the operation of the EMBR. The results of conventional pollutant removal showed that applying an electric current to the MBR approximately increased COD removal by 1.1 times, PO43- removal by 1.56 times, UV254 removal by 1.26 times, and turbidity removal by 1.11 times compared to the conventional MBR. The DCF removal efficiency increased from 43.90 % in the MBR process to 76.46 % in the EMBR. Membrane fouling was investigated through transmembrane pressure (TMP) monitoring, and the findings showed an increase in membrane usage time in EMBR compared to conventional MBR. Finally, the results explained that the application of current to MBR improves the removal of contaminants, mitigates membrane fouling, and reduces the residual DCF concentration.

Kinetic study of the simultaneous removal of ibuprofen, carbamazepine, sulfamethoxazole, and diclofenac from water using biochar and activated carbon adsorption, and TiO2 photocatalysis

The growing number of pharmaceuticals released into the environment poses a threat not only to the aquatic environment but also to human health. This work introduces a novel approach for the simultaneous analysis of four pharmaceuticals—ibuprofen, carbamazepine, sulfamethoxazole, and diclofenac—each with distinct chemical structures. The study explores the kinetic behavior of these compounds during their removal from water, employing biochar and activated carbon as adsorbents, as well as titanium dioxide (TiO2) for photocatalytic degradation. This utilizes two distinct approaches incorporating adsorption mechanisms. The concentrations of pharmaceuticals were simultaneously measured using High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD). In addition to adsorption, photocatalysis with varying dosages of TiO2 was investigated as an alternative method for pharmaceutical removal. The HPLC- DAD analysis enabled the simultaneous monitoring of all four pharmaceuticals in a single analysis. The Langmuir-Hinshelwood model was applied to the photocatalysis data to assess reaction kinetics. The results demonstrate the efficacy of both adsorption methods in removing pharmaceutical contaminants from water. Integrating both adsorption and photocatalysis experiments in one manuscript allows for a comprehensive evaluation of these methods' individual strengths in water treatment applications, providing insights into their combined potential for addressing pharmaceutical contamination in water resources. The calculated removal efficiencies, Langmuir-Hinshelwood kinetics, half-life values, and equilibrium adsorption capacities provide a comprehensive understanding of the efficiency and mechanisms involved in the removal processes, emphasizing the importance of addressing pharmaceutical contamination in water treatment strategies.

Proof-of-concept for removing micropollutants through a combination of sub-atmospheric-pressure non-thermal plasma and hydrodynamic (super)cavitation

The persistence and toxicity of hazardous pollutants present in wastewater effluents require the development of efficient and sustainable treatment methods to protect water resources. In this study, the efficacy and efficiency of a novel combination of two advanced oxidation processes – sub-atmospheric-pressure plasma and hydrodynamic cavitation – were systematically tested for the removal of valsartan (VAL), sulfamethoxazole, trimethoprim, naproxen, diclofenac (DF), tramadol, propyphenazone, carbamazepine, 17β-estradiol (E2) and bisphenol A (BPA). The results show that both sample temperature and plasma power play a role and the highest removal, from 29–99 %, was achieved at 25 ℃ and 53 W of plasma power. E2, BPA, DF, and VAL were removed to the highest degree. These results are particularly important in the case of E2 and BPA, whose harmful environmental effects may start to occur already at sub-ng/L to µg/L levels. The differences in the removals obtained depend strongly on the physicochemical properties, and the compounds with the highest logKOW were removed to the highest extent. The energy yield, in terms of plasma power, was between 1 and 26 mg/kWh under optimal experimental conditions. Our results show that the novel plasma-cavitation treatment shows potential that could prove valuable for upcoming regulatory requirements.

Simultaneous photocatalytic degradation of remdesivir, favipiravir, and diclofenac from aqueous solutions using a quaternary plasmonic Ag/Ag-SG-TiO2-rGO photocatalyst: Synthesis, characterization, optimization, and toxicity assessment

This study presents a novel quaternary plasmonic photocatalyst, Ag/Ag-Sol-Gel(SG)-TiO2-rGO, designed for efficient removal of remdesivir (RDV), favipiravir (FAV), and diclofenac (DCF) as COVID-19 antiviral drugs from water samples. Various characterization techniques were employed to analyze the Ag/Ag-SG-TiO2-rGO nanocomposites, which were synthesized with different Ag to SG-TiO2-molar ratios. The photocatalyst, containing 30 % Ag plasmonic within its framework, exhibited the highest pollutant removal under visible light. This efficiency is attributed to the surface plasmon resonance (SPR) generated by metallic Ag nanoparticles and the optimal energy alignment between the TiO2 conduction band and the rGO work function. Trapping experiments were used to identify the most active species. It was confirmed that O2− and OH were the main active species in the photocatalytic process. The degradation kinetics, following a pseudo-first-order model, was assessed using an optimized LC-MS/MS. An optimization of the photodegradation process was done using a central composite design, as well as a study of the effects of prolonged irradiation. This resulted in the total elimination of the target compounds at a dosage of 0.087 g, irradiation time of 80 min, and pH value of 8. The photodegradation efficiency of sewage treatment plant effluent and tap water was reduced by matrix components, particularly in highly contaminated samples. An additional confirmatory MTT assay revealed a very low viability difference for mouse fibroblast cells, L929, in untreated, treated (97 %) and control samples. This study sheds light on the photodegradation of anti-COVID-19 drugs and offers insights into their remediation in aquatic environments.

Domestic wastewater treatment towards reuse by “self-supplied” microbial electrochemical system assisted UV/H2O2 process

Domestic wastewater is a potential source of water for non-potable reuse that may help address the global water, energy, and resource challenges. Herein, a “self-supplied” process through integrating microbial electrochemical system (MES) with UV/H2O2 was developed and investigated for wastewater treatment. H2O2 was “self-supplied” from MES while the MES catholyte was “self-supplied” from the final effluent of UV/H2O2. It was found that the MES accomplished > 80 % degradation of chemical oxygen demand (COD) through bioanode degradation, and produced 18 - 20 mg L−1 H2O2 via oxygen reduction reaction in the gas diffusion cathode. The MES effluent was further treated by the UV/H2O2 process, which achieved the complete removal of recalcitrant diclofenac and > 6 log inactivation of Escherichia coli. The enhanced treatment performance of UV/H2O2 was demonstrated via a comparison with the control experiments (UV or H2O2 treatment) and benefited from ·OH generation and sulfide removal. When treating the actual wastewater, the proposed system exhibited consistent treatment performance for the organic compounds and recalcitrant contaminants, and the quality of the treated water would meet the non-potable water reuse guidelines. The results of this study encourage the further exploration of emerging contaminant removal, system coordination, and use of renewable energy by the cooperation between MES and UV/H2O2.

Approach for concurrent detection and removal of diclofenac in wastewater: Integration of MOF with Poly(deep eutectic solvent) imprinting method

Diclofenac in medical wastewater poses a significant threat to the environment and human health. A simple and efficient enrichment strategy has been established for the selective identification and removal for diclofenac in environmental water samples applying MOF based polymeric deep eutectic solvent (Poly(DES)@MOF). Poly(DES)@MOF was synthesized using a surface imprinting method. The components included MOF-199 as the support material, diclofenac as the template, and a deep eutectic solvent (DES) composed of choline chloride and methacrylate (1:2) as the functional monomer. Density functional theory calculated the Gibbs free energy change during the reaction process, confirming that DES improved the binding performance and selectivity of polymer. Related experiments have shown that Poly (DES) @ MOF has high adsorption capacity, reaching equilibrium within 2 h. In real sample experiments, the maximum adsorption capacity of diclofenac in lake water by the extraction device was 19.39 mg·g−1, with an average recovery rate between 99.4 % and 105.8 %. After 5 repeated uses, the performance did not show significant degradation. After evaluating the principles of green analytical chemistry using agree software, the total score was 0.68, reflecting the high greenness of this study. This study combined molecular imprinting technology and computer theory simulation of MOF based and DES mediated polymerization processes to construct an extraction device that was easy to operate and could extract diclofenac from environmental water samples with high selectivity and adsorption capacity. It showed great potential in the field of environmental monitoring and provided a new approach for the detection of other pollutants in the environment.

CFs-supported La-BiOIO3/Bi2O3 heterostructures via in situ growth strategies for efficiently removing diclofenac: Fermi level modulation, intermediates identification and radical mechanism

The charge transfer efficiency and the recyclability were still the potential factors limiting the widespread application of photocatalysts for pollutant removal. Herein, a novel design perspective for BiOIO3-based S-scheme heterojunction (La-BiOIO3/Bi2O3) with modulated Fermi level and enhanced internal electric field was proposed by in situ liquid-phase growth strategy. Meanwhile, the CFs@La-BiOIO3/Bi2O3 catalysts with high stability and easy recyclability were assembled based on industrial carbon fiber cloths, which can achieve efficiently photocatalytic removal of diclofenac (DCF, 95.5 %, 20 min) and bisphenol A (BPA, 100 %, 30 min) under simulated sunlight irradiation. The photocatalytic degradation rates of DCF were 52.8 and 12.4 times that of pure BiOIO3 and Bi2O3, respectively. The high specific surface area (39.74 m2·g−1) and suitable bandgap structure (2.74 eV) also demonstrated the excellence of the CFs@La-BiOIO3/Bi2O3 degradation system. Verification of heteroatom-driven electron rearrangement and charge migration route in heterostructure was performed through XPS analysis and Mott-Schottky experiments. Gaussian calculations, LC-MS, and toxicity assessments demonstrated that reactive oxygen species (ROS) such as ·O2− and ·OH selectively attacked the electronic groups of DCF and its intermediates, which combined with holes (h+) retained in the valence bands of Bi2O3 to synergistically achieve efficient degradation and detoxification of DCF. Finally, the charge migration mechanism for the photocatalytic elimination of DCF over CFs@La-BiOIO3/Bi2O3 photocatalyst was proposed. Similar studies can be extended to other structures capable of achieving rational Fermi level modulation and synchronous carrier introduction for the remediation of polluted waters, providing novel perspectives for improving photocatalytic driving capacity.

All-in-one fabrication of NiO nanorods/carbon-containing porous catalytic polymer membranes for persulfate-facilitated oxidation-adsorption of diclofenac in flow–through

We introduce a novel all-in-one fabrication method for porous catalytic polyethersulfone (PES) membranes containing NiO nanorods and carbon nanoparticles. This method is based on the sonochemical in situ solidification of a metal salt with NaBH4 in presence of carbon particles in a PES-containing casting-reaction solution, directly followed by membrane preparation via film casting cum phase separation. In the catalytic flow-through degradation of 20 mg/L aqueous diclofenac with persulfate as oxidant, an as-prepared NiO-carbon-PES membrane achieved a 99 % aromatic content removal degree at a residence time of only 1.6 s. In comparison, NiO and CuO membranes without carbon particles exhibited < 40 % aromatic removal degrees. The high performance was attributed to a degradation-induced adsorption, with a diclofenac removal capacity of 950 mg/g of incorporated carbon particles. We demonstrated that diclofenac is catalytically mineralized in the membrane at incorporated NiO nanorods, followed by adsorption of remaining degradation products at nearby carbon particles. Our data further suggests that reducing NiO to Ni(0) via a membrane pretreatment shifts the catalytic persulfate activation from a radicaltoa non-radical pathway, and that HCO3– can function as sacrificial electron donor for Ni(0). This completely mitigated nickel leaching from the membrane in contact to persulfate. Moreover, even in the presence of NaHCO3 and NaCl, a Ni(0)–carbon–PES membrane consistently eliminated ∼ 90 % of the total organic carbon (TOC) from a 2 mg/L diclofenac feed containing persulfate in single-pass flow-through mode (continuously for 5 h, respectively for 500 L/m2 permeate volume), with no detectable release of degradation products or any nickel leaching.

Organo magadiites for diclofenac adsorption: influence of the surfactant chain.

The presence of drugs in aquatic environments has been considered a global challenge and several remediation technologies have been proposed, including adsorption. In this study, new diclofenac adsorbents were obtained from the reaction of sodium magadiite (Na-Mag) with surfactants dodecylpyridinium chloride hydrate (C12pyCl) and hexadecylpyridinium chloride monohydrate (C16pyCl)), 1-hexadecyltrimethylammonium bromide (C16Br), and dodecyltrimethylammonium bromide (C12Br). The synthesis was carried out in the microwave at 50°C for 5min using surfactant amounts of 100% and 200% in relation to the cation exchange capacity of Na-Mag. The elemental analysis indicated that surfactants with a longer organic chain were more incorporated into Na-Mag, whose values were 1.42 and 1.32mmolg-1 for C16pyMag200% and C16Mag200%, respectively. X-ray diffraction results suggested formation of intercalated products with basal space in the range of 2.81-4.00nm. Diclofenac was quickly adsorbed on all organophilic magadiites, at an equilibrium time of 1min. Drug capacity adsorption was influenced by the arrangement and packing density of organic cations, the basal distance, and the organic contents of the samples at high drug concentrations. Alkylpyridinium magadiites exhibited maximum adsorption capacities higher than alkylammonium magadiites, of 96.4, 100.7, 131.7, and 166.1mgg-1 for C12pyMag100%, C12pyMag200%, C16pyMag100%, and C16pyMag200%, respectively, at pH 6.0 and 30°C. Diclofenac removal by samples was not affected by the presence of ibuprofen, which was also removed from binary system by organophilic magadiites reaching removal of 76.5% and 86.9% by C16pyMag100% and C16pyMag200%, respectively. Regeneration studies demonstrated a drug removal percentage of 83-92% for C16pyMag and C16Mag after three cycles of adsorption.

Adsorptive removal of diclofenac on nanoporous anoxic sewage sludge biochar: Investigating the influence of carbonization temperature, residence time and specific Fe(III) infusion

This study explores the removal of the emerging contaminant diclofenac using pristine biochar and iron-impregnated biochar derived from anoxic sewage sludge. A biochar ensemble was prepared at varying pyrolysis temperatures (350 °C to 950 °C) and residence times (30 to 240 min). The iron-modified material was synthesized by incorporating FeCl3 with the precursor at 950 °C for 30 min. A comprehensive characterization based on the morphology, crystallinity, and functional groups confirmed the structural and chemical modifications in the pristine and modified biochar of interest. Adsorption experiments demonstrated that iron-modified biochar exhibited superior adsorption capacity for diclofenac (18.958±0.417 mg/g) compared to pristine biochar (0.814±0.001 mg/g), attributable to its larger surface area and more active sites. The adsorption mechanisms were identified as a combination of electrostatic interactions, hydrogen bonding, and complexation, with significant Fe3+ to Fe2+ reduction indicating electron transfer processes. Adsorption kinetics followed the Elovich model, and equilibrium studies fitted best to the Redlich-Peterson model for the iron-amended biochar. The study also assessed the reusability of the adsorbents, with pristine and iron-impregnated biochar maintaining around 70 % removal efficiency up to 3 and 5 cycles, respectively. Consequently, both the biochar serve as potentially efficient adsorbents for diclofenac removal from aqueous solutions.

Synthesis and characterization of Fe(III)-doped beta-cyclodextrin-grafted chitosan cryogel beads for adsorption of diclofenac in aqueous solutions: Adsorption experiments and deep-learning modeling

Diclofenac (DCF) is frequently detected in aquatic environments, emphasizing the critical need for its efficient removal globally. Here, we present the synthesis of Fe(III)-doped β-CD-grafted chitosan (Fe/β-CD@CS) cryogel beads designed for adsorbing DCF in aqueous solutions. The beads exhibited an average size of 2.94 ± 0.66 mm and a point of zero charge of 8.03. Adsorption experiments demonstrated that the Langmuir kinetic model provided the most accurate description of the kinetic data, while the Redlich–Peterson isotherm offered the best fit for the equilibrium data. The beads showcased a theoretical maximum adsorption capacity of 712.3 mg/g for DCF, with the adsorption process being identified as exothermic. DCF adsorption on the beads was attributed to hydrogen bonding, metal cation-π interactions, and electrostatic interactions. Reusability tests exhibited that the beads could be regenerated using 0.1 M NaOH. To perform deep learning modeling, adsorption experiments (n = 17), designed utilizing central composite design (CCD), were conducted in duplicate. The CCD framework incorporated input variables such as initial DCF concentration, adsorbent dosage, and solution pH, while the output variable was the DCF removal rate. Utilizing the adsorption data, an artificial neural network (ANN) model was constructed with a topology of 3: 7:10:1, featuring 3 input variables, 7 neurons in the first hidden layer, 10 neurons in the second layer, and 1 output variable. Employing the ANN model data, 3-D response surface plots were generated to elucidate the relationship between input variables and DCF removal rate. Additional adsorption tests were conducted to evaluate the developed ANN model, affirming its reliable predictability for the DCF removal rate. Analysis of the relative importance of the input variables revealed the following order of importance: solution pH (100 %) > adsorbent dosage (75.2 %) > initial DCF concentration (57.7 %).

Synthesis of Highly Porous Lignin-Sulfonate Sulfur-Doped Carbon for Efficient Adsorption of Sodium Diclofenac and Synthetic Effluents.

Herein, a novel sulfur-doped carbon material has been synthesized via a facile and sustainable single-step pyrolysis method using lignin-sulfonate (LS), a by-product of the sulfite pulping process, as a novel carbon precursor and zinc chloride as a chemical activator. The sulfur doping process had a remarkable impact on the LS-sulfur carbon structure. Moreover, it was found that sulfur doping also had an important impact on sodium diclofenac removal from aqueous solutions due to the introduction of S-functionalities on the carbon material's surface. The doping process effectively increased the carbon specific surface area (SSA), i.e., 1758 m2 g-1 for the sulfur-doped and 753 m2 g-1 for the non-doped carbon. The sulfur-doped carbon exhibited more sulfur states/functionalities than the non-doped, highlighting the successful chemical modification of the material. As a result, the adsorptive performance of the sulfur-doped carbon was remarkably improved. Diclofenac adsorption experiments indicated that the kinetics was better described by the Avrami fractional order model, while the equilibrium studies indicated that the Liu model gave the best fit. The kinetics was much faster for the sulfur-doped carbon, and the maximum adsorption capacity was 301.6 mg g-1 for non-doped and 473.8 mg g-1 for the sulfur-doped carbon. The overall adsorption seems to be a contribution of multiple mechanisms, such as pore filling and electrostatic interaction. When tested to treat lab-made effluents, the samples presented excellent performance.

Potassium permanganate-modified eggshell biosorbent for the removal of diclofenac from liquid environment: adsorption performance, isotherm, kinetic, and thermodynamic analyses.

This study assess how well diclofenac (DCF) can be separated from aqueous solution using potassium permanganate-modified eggshell biosorbent (MEB). The MEB produced was characterised using XRD, FTIR, and SEM. Batch experiments were conducted to examine and assess the impact of contact time, adsorbent dosage, initial concentration, and temperature on the adsorption capacity of the MEB in the DCF sequestration. The best parameters to obtained 95.64% DCF removal from liquid environment were 0.05g MEB weight, 50mg/L initial concentration, and 60min contact time at room temperature. The maximum DCF sequestration capacity was found to be 159.57mg/g with 0.05g of MEB at 298K. The adsorption isotherm data were more accurately predicted by the Freundlich model, indicating a process of heterogeneous multilayer adsorption. The results of the kinetic study indicated that the pseudo-second-order kinetic models best matched the experimental data. The findings revealed that the dynamic of DCF entrapment is largely chemisorption and diffusion controlled. Based on the values of thermodynamic parameters, the process is both spontaneous and endothermic. The primary processes of DCF sorption mechanism onto the MEB were chemical surface complexation, hydrogen bonding, π-π stacking, and electrostatic interactions. The produced MEB showed effective DCF separation from the aqueous solution and continued to have maximal adsorption capability even after five regeneration cycles. These findings suggest that MEB could be highly efficient adsorbent for the removal of DCF from pharmaceutical wastewater.