Optimizing removal of ibuprofen from water by magnetic nanocomposite using Box-Behnken design

Mechanistic understanding of green synthesized cerium nanoparticles for the photocatalytic degradation of dyes and antibiotics from aqueous media and antimicrobial efficacy: A review

In recent years, extensive research endeavors are being undertaken for synthesis of an efficient, economic and eco-friendly cerium oxide nanoparticles (CeO2 NPs) using plant extract mediated greener approach. A number of medicinal plants and their specific parts (flowers, bark, seeds, fruits, seeds and leaves) have been found to be capable of synthesizing CeO2 NPs. The specific key phytochemical constituents of plants such as alkaloids, terpenoids, phenolic acids, flavones and tannins can play significant role as a reducing, stabilizing and capping agents in the synthesis of CeO2 NPs from their respective precursor solution of metal ions. The CeO2 NPs are frequently using in diverse fields of science and technology including photocatalytic degradation of dyes, antibiotics as well as antimicrobial applications. In this review, the mechanism behind the green synthesis CeO2 NPs using plant entities are summarized along with discussion of analytical results from characterization techniques. An overview of CeO2 NPs for water remediation application via photocatalytic degradation of dyes and antibiotics are discussed. In addition, the mechanisms of antimicrobial efficacy of CeO2 NPs and current challenges for their sustainable application at large scale in real environmental conditions are discussed.

Statistical optimization of nZVI chemical synthesis approach towards P and NO3- removal from aqueous solutions: Cost-effectiveness & parametric effects

This study aims to conduct statistical optimization of nZVI synthesis parameters towards the removal efficiency of phosphorus (P) and nitrate (NO₃^-), considering for the first time the cost-effectiveness index. The detailed statistical analysis was implemented to evaluate the main effects and interactions of eight synthesis parameters, including reductant concentration (R_C), reductant delivery rate (R_DR), reductant liquid volume (R_LV), pH, aging time (AG_T), mixing speed (M_S), temperature (T), and precursor concentration (P_C). Results revealed that the experimental optimization of the synthesis factors improved the removal efficiency of NO₃^- and P by 27 and 9%, respectively, with respect to that before the optimization. ANOVA statistical results indicated the significance of R_P (%) and [Formula: see text] (%) models with F-values of 4.480 × 10⁸ and 23,755.08, respectively. Moreover, the p-values of all the eight main linear effects were less than 0.05 in both two models of R_P (%) and [Formula: see text] (%). However, most of the interaction parameters were not statistically significant (higher than 0.05) in the case of [Formula: see text] (%), which is unlike R_P (%) where all interaction parameters were statistically significant (less than 0.05). The normal probability plots of factors effects provided significant evidence of the significance of the investigated parameters R_C had the highest positive statistically significant effect on R_P (%) followed by R_LV, R_DR, M_S and T. In case of [Formula: see text] (%), R_LV had the highest positive significant effect, followed by AG_T > R_DR > pH > T > M_S. The cost-effective optimal constraints in this study resulted in the best economically optimized values of the nZVI synthesis parameters in terms of higher reactivity and reduced synthesis cost.

Engineered Magnetic Carbon-Based Adsorbents for the Removal of Water Priority Pollutants: An Overview

This review covers the preparation, characterization, and application of magnetic adsorbents obtained from carbon-based sources and their application in the adsorption of both inorganic and organic pollutants from water. Different preparation routes to obtain magnetic adsorbents from activated carbon, biochar, hydrochar, graphene, carbon dots, carbon nanotubes, and carbon nanocages, including the magnetic phase incorporated on the solid surface, are described and discussed. The performance of these adsorbents is analyzed for the removal of fluoride, arsenic, heavy metals, dyes, pesticides, pharmaceuticals, and other emerging and relevant water pollutants. Properties of these adsorbents and the corresponding adsorption mechanisms have been included in this review. Overall, this type of magnetic adsorbents offers an alternative for facing the operational problems associated to adsorption process in water treatment. However, some gaps have been identified in the proper physicochemical characterization of these adsorbents, the development of green and low-cost preparation methods for their industrial production and commercialization, the regeneration and final disposal of spent adsorbents, and their application in the multicomponent adsorption of water pollutants.

Removal of non-steroidal anti-inflammatory drugs from water by zeolite-rich composites: The interference of inorganic anions on the ibuprofen and naproxen adsorption

Composites of two natural zeolites - clinoptilolite and phillipsite, and cationic surfactants (cetylpyridinium chloride and Arquad® 2HT-75) were tested for the removal of two emerging contaminants - ibuprofen and naproxen. For each zeolite-rich rock, two different modifications of the zeolitic surfaces were prepared (monolayer and bilayer surfactant coverage). The influence of the initial drug concentrations and contact time on adsorption of these drugs was followed in buffer solution. The Langmuir model showed the highest adsorption capacity for the composite characterized by a bilayered surfactant at the clinoptilolite surface: 19.7 mg/g and 16.1 mg/g for ibuprofen and naproxen, respectively. Also, to simulate real systems, drug adsorption isotherms were conducted in natural water (Grindstone creek water - Columbia, Missouri, USA) by using the best performing adsorbent; in this case, a slight decrease of drug adsorption was recorded. Kinetic runs were performed in distilled water as well as in the presence of ions such as sulfates and bicarbonates; also, in this case, the interfering agents defined an adsorption decrease for bilayer composites.

Producing Magnetic Nanocomposites from Paper Sludge for the Adsorptive Removal of Pharmaceuticals from Water-A Fractional Factorial Design

In view of a simple after-use separation, the potentiality of producing magnetic activated carbon (MAC) by intercalation of ferromagnetic metal oxide nanoparticles in the framework of a powder activated carbon (PAC) produced from primary paper sludge was explored in this work. The synthesis conditions to produce cost effective and efficient MACs for the adsorptive removal of pharmaceuticals (amoxicillin, carbamazepine, and diclofenac) from aqueous media were evaluated. For this purpose, a fractional factorial design (FFD) was applied to assess the effect of the most significant variables (Fe³⁺ to Fe²⁺ salts ratio, PAC to iron salts ratio, temperature, and pH), on the following responses concerning the resulting MACs: Specific surface area (S_BET), saturation magnetization (M_s), and adsorption percentage of amoxicillin, carbamazepine, and diclofenac. The statistical analysis revealed that the PAC to iron salts mass ratio was the main factor affecting the considered responses. A quadratic linear regression model A = f(S_BET, M_s) was adjusted to the FFD data, allowing to differentiate four of the eighteen MACs produced. These MACs were distinguished by being easily recovered from aqueous phase using a permanent magnet (M_s of 22-27 emu g^-1), and their high S_BET (741-795 m² g^-1) were responsible for individual adsorption percentages ranging between 61% and 84% using small MAC doses (35 mg L^-1).

Multi-objective optimization of permeable reactive barrier design for Cr(VI) removal from groundwater

The present study aims to develop a practical approach for the optimal permeable reactive barrier (PRB) design towards Cr(VI) removal from groundwater. Batch and column experiments were performed to investigate the characteristics of the four proposed reactive materials; nanoscale zero-valent iron (Fe⁰), bimetallic nanoscale zero-valent iron (Fe⁰/Cu), activated carbon (AC) and sand/zeolite mixture (S/Z). Kinetic analysis and dynamic modeling of the experimental data were implemented to determine the controlling conditions of the reactive performance of the PRB's materials. The sensitivity index of the design parameters was examined as an indicator of their effect on the reactive responses. Moreover, the Response Surface Methodology (RSM) was considered for optimizing the design variables of the PRB based on the practical factorial analysis. Results revealed that Fe⁰ and Fe⁰/Cu showed high performance in Cr(VI) removal, with a slight superiority to Fe⁰, with final removal efficiency values of 89.7 and 84.1%, respectively. Kinetic analysis depicted that pseudo second order was the best fitting model for Cr(VI) removal in the four materials' cases. ANOVA statistical analysis revealed that quadratic polynomial model was the best model, corresponding to the highest correlation efficiency and adequate precision, to describe the relationships in the four PRB's cases between the selected dependent variables; resident time (t_R), reactive material mass per sectional area of contaminant plume (M/A) and reactive material cost (Cost_PRB) towards the independent parameters; barrier thickness (b) and permeability (K_r). Additionally, sensitivity analysis has been conducted which depicted the high sensitivity, in the four PRB's cases, of average pore water velocity within the barrier (v_r) v_r and K_r with the highest and the second-highest sensitivity index (SI) values towards t_R, respectively. The RSM-optimization revealed that Fe⁰ is the most feasible reactive material, comparing to the other considered materials, with respect to the optimal conditions regarding the long residency (t_R = 22 days) and low cost (b = 0.521 m), with around 95.2% desirability of its optimal solution. Overall, the current study represents a significant contribution and a vital step towards an accurate PRB's design based on previously determined optimal conditions.

Optimization, equilibrium, adsorption behavior and role of surface functional groups on graphene oxide-based nanocomposite towards diclofenac drug

Aquatic contamination of diclofenac (DCF), an emergent non-steroidal anti-inflammatory drug (NSAIDs), can result in adverse effects to many ecosystems through biomagnification. Hence, introducing effective remediation techniques to sequester the pharmaceutical wastes is highly fundamental to prevent their accumulation in the environment. Generally, adsorption has been presented as a green and efficient approach. Herein, we report the characterization and application of the novel magnetic nanocomposite (GO@CoFe₂O₄) derived from cobalt-based ferrite (CoFe₂O₄) and graphene oxide (GO) for DCF adsorption. For the optimization procedure, the response surface methodology (RSM) was adopted to investigate the impacts of DCF concentration (1.6-18.4 mg/L), DCF dosage (0.08-0.92 g/L), and solution pH (2.6-9.4) to find the optimum conditions for DCF removal, at 10.5 mg/L, 0.74 g/L, and pH 4, respectively. For the adsorption experiments, the kinetic, isotherm, thermodynamic, and intraparticle diffusion models were systematically studied. Moreover, we have elucidated the role of functional groups on the surface of GO@CoFe₂O₄ in enhancing the adsorption of DCF drug. With good removal efficiency (up to 86.1%), high maximum adsorption capacity (32.4 mg/g), GO@CoFe₂O₄ can be a potential candidate to eliminate DCF drug from water.

Recent advances on the development and application of magnetic activated carbon and char for the removal of pharmaceutical compounds from waters: A review

The adsorption of pharmaceutical substances using carbonaceous materials, such as activated carbon (AC), biochar (BC) and hydrochar (HC), has received substantial attention by researchers working on water treatment, due to the simplicity, low-cost and high performance of this process. In order to widen the potentiality of these carbonaceous materials and to overcome some of their limitations, particularly the inefficient separation of powdered formulations from treated water, the incorporation of magnetic nanoparticles has been explored. The recovery of magnetic carbon materials (MCM) from the treated water can be attained by applying an external magnetic field, avoiding inefficient and costly filtration and centrifugation processes, typically applied in the case of non-magnetic carbonaceous adsorbents. In the last ten years, some work has been devoted to the preparation of MCM specifically from AC (MC_ACM), biochar (MC_BCM) and hydrochar (MC_HCM). This review aims to present the different aspects of using MCM in water treatment, namely in the removal of pharmaceutical compounds. The synthesis routes used to produce MCM, their physical, morphologic and chemical features, and their application in the removal of these micro-organic contaminants from water will be assessed. The advantages and disadvantages of using MCM in water treatment, and their comparative performance with the carbonaceous non-magnetic precursors will be also discussed in this review.

Basic red 2 and methyl violet adsorption by date pits: adsorbent characterization, optimization by RSM and CCD, equilibrium and kinetic studies

The potential of raw date pits as a natural, widely available and low-cost agricultural waste has been studied in order to adsorb cationic dyes from an aqueous solution. Date pits were characterized by FTIR, SEM, BET, and XRD analysis. To optimize removal of two industrial dyes, basic red 2 (BR2) and methyl violet (MV), from aqueous solution using date pits, response surface methodology (RSM) is employed. Tests were carried out as per central composite design (CCD) with four input parameters namely contact time, temperature, initial concentration of adsorbate, and pH. Second-order polynomial model better fits experimental data for BR2 and MV and optimum values were then determined. In the optimum conditions, kinetic study was conducted and the pseudo-second-order model was found the best fitted model compared to pseudo-first-order model. Moreover, it was shown that intraparticle diffusion was not the sole controlling step and could be associated with other transfer resistance. On other hand, equilibrium isotherms were obtained for BR2 and MV and their maximum adsorption capacities were 92 and 136 mg g^-1 respectively. Two-parameter isotherm models like Langmuir, Temkin, Freundlich, Dubinin-Radushkevich, and Halsay were investigated to fit equilibrium data. Three error functions of residual root mean square error, chi-square statistic, and average relative error were used to comfort us in the selected models, which were actually Dubinin-Radushkevich and Langmuir for BR2 and Frendlich, Temkin, and Halsay for MV.

Supercritical Fluid Extraction of Fat and Caffeine with Theobromine Retention in the Cocoa Shell

The cocoa shell is a residue of low commercial value, which represents an alternative for obtaining substances of added value for the food and pharmaceutical industry. Substances of interest in the shell include fat and methylxanthines (theobromine and caffeine). In order to obtain the extraction behavior with supercritical CO2, a 23 factorial design was proposed with six central points, taking dynamic extraction into consideration. The following factors were involved: pressure (2,000–6,000 psi), temperature (313–333 K), and time (30–90 min). The obtained yield was between 3.66% and 15.30%. Fat was the substance that was extracted most effectively (94.73%). Caffeine demonstrated variability in the residue, with at least six treatments that exceeded a removal rate of more than 90%, while it was practically impossible to extract theobromine. The difference with regard to the extraction of theobromine may be attributed to its low solubility. Characterization using FT–IR showed the modifications before and after the process, providing clear evidence of the changes corresponding to the fat at 2,924, 2,854 and 1,745 cm−1. The results presented establish the basis for the extraction of substances such as fats and methylxanthines from a cocoa shell with the use of CO2.

Biosorptive uptake of ibuprofen by steam activated biochar derived from mung bean husk: Equilibrium, kinetics, thermodynamics, modeling and eco-toxicological studies

The present study explores the use of steam activated mung bean husk biochar (SA-MBHB) as a potential sorbent for the removal of non-steroidal and anti-inflammatory drug ibuprofen from aqueous solution. SA-MBHB was characterized by SEM, FTIR, BET, TGA, point of zero charge (pHPZC) and UV-Vis spectrophotometer. The relation between removal percentages of ibuprofen and parameters such as adsorbent dose (0.05 g-250 g), contact time (5 min-210 min), pH (2-10), speed of agitation (40-280 rpm), temperature (293-308 K) and initial ibuprofen concentration (5-100 ppm) was investigated and optimized by a series of batch sorption experiments. The optimized conditions achieved were: adsorbent dose 0.1 g/L, agitation speed 200 rpm, pH 2, initial ibuprofen concentration 20 mg L(-1), equilibrium time 120 min and temperature 20 °C for more than 99% adsorptive removal of ibuprofen. The equilibrium adsorption data were well fitted into the Langmuir isotherm model while kinetic data suggested the removal process to follow pseudo second order reaction. The adsorption phenomena were optimized and simulated by using response surface methodology (RSM) and artificial neural network (ANN). Effect of process variables viz. dose, agitation speed and pH on the sorbed amount of IBP was studied through a 2(3) full factorial central composite design (CCD). The comparative analysis was done for ibuprofen removal by constructing ANN model training using same experimental matrix of CCD. The growth of Scenedesmus abundans was also observed to be affected by the IBP solution whereas the biochar treated with IBP solution did not significantly affect the growth of the Scenedesmus abundans. The results revealed that SA-MBHB could be a cost-effective, efficient and non-hazardous adsorbent for the removal of ibuprofen from aqueous solution.

Gallic acid magnetic nanoparticles for photocatalytic degradation of meloxicam: synthesis, characterization and application to pharmaceutical wastewater treatment

Gallic acid magnetic nanoparticles for photocatalytic degradation of meloxicam in pharmaceutical wastewater.

Synthesis, properties and application research of atrazine Fe₃O₄@SiO₂ magnetic molecularly imprinted polymer

INTRODUCTION

Magnetic Fe3O4 nanoparticles were prepared by coprecipitation and then were coated with SiO2 on the surface.

MATERIALS AND METHODS

Fe3O4@SiO2 composite microspheres were modified by KH570. Using molecular imprinting technology, atrazine magnetic molecularly imprinted polymer was prepared by using atrazine as template molecule, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linkers. The morphology, composition and magnetic properties of magnetic nanoparticles were characterized. The recognition selectivity of polymer was studied for template molecule and simulation by UV spectrophotometry. The adsorption properties and selectivity ability were analyzed by Scatchard analysis.

RESULTS

Scatchard linear regression analysis indicated that there are two binding sites of the target molecules. The magnetic molecularly imprinted polymer has been applied to the analysis of atrazine in real samples.

CONCLUSION

The results show that: the recovery rates and the relative standard deviation were 94.0∼98.7% and 2.1∼4.0% in corn, the recovery rates and the relative standard deviation were 88.7∼93.5% and 2.8∼7.2% in water.