Removal of phthalate esters (PAEs) by zeolite/Fe 3 O 4 : Investigation on the magnetic adsorption separation, catalytic degradation and toxicity bioassay

Composite biopolymer foams fabricated from natural aldehyde functionalized chitosan-whey protein amyloid fibrils: Application for removal of phthalate esters from water

In this work, composite biopolymer foams from chitosan and whey isolate protein amyloid fibrils were prepared for the removal of phthalate esters from water. Natural aldehyde functionalization enhanced the affinity for dibutyl phthalate (DBP), with citral being the most effective. The citral-grafted foams (WCGC) had tunable hydrophobicity, strong mechanical properties, and good water stability. WCGC1.5 foam exhibited a high removal efficiency (96.06 %) of DBP. The adsorption process reached adsorption equilibrium rapidly within 8 h and could be described by pseudo-second-order kinetic and Freundlich isotherm models, indicating a non-homogeneous and chemisorptive sorption process. The maximum adsorption capacity for DBP reached 332.42 mg/g. Moreover, DBP adsorption could be enhanced in alkaline environment and the removal efficiency increased to 98.27 % at pH 10. The removal efficiency of DBP by WCGC1.5 remained above 85 % after the five adsorption-desorption cycles. WCGC1.5 also showed broad-spectrum adsorption behavior, with strong affinity and removal efficiency for six common plasticizers, including DIBP (85.97 %), DPP (91.7 %), DHXP (99.1 %), DEHP (99.09 %), DNOP (91.6 %) and BBP (89.88 %).

Fabrication of novel glutathione-Fe3O4-loaded/activated carbon encapsulated sand bionanocomposites for enhanced removal of diethyl phthalate from aqueous environment in a vertical flow reactor

The extensive use of plasticizers in various industries has made Diethyl phthalate (DEP), a serious threat to the environment and ecological water security, owing to its complex-structure and low-biodegradability. Thus, the present study aimed to design a sustainable sand-coated nano glutathione (GSH) -Fe3O4-loaded/activated carbon (AC) bionanocomposite (AC-GSH-Fe3O4@sand bionanocomposite) for effective removal of DEP from water. Characterization results suggested bionanocomposites' rough and irregular texture due to the uneven distribution of AC and Fe3O4 nanoparticles over the sand. The XRD spectra indicated high crystallinity of bionanocomposites, while the FTIR spectra confirmed the presence of all individual components, i.e., GSH, AC, Fe3O4, and sand. EDX-mapping, AFM, and TGA further verified its elemental composition, topographical changes and thermal stability. The influence of pH (3, 7, 9), bed height (2, 4, 6) cm, and flow rate (2.5, 3.5, 4.5) mL min-1 were studied in a dynamic system with an initial DEP concentration of 50 mg L-1 to investigate the removal behavior of the bionanocomposites. The best DEP removal efficiency (90.18 %) was achieved over 28-h at pH 9, bed-height-4 cm, and flow-rate-3.5 mL min-1, with an optimum qmax-200.25 mg g-1 as determined through Thomas-model. Breakthrough curves were predicted using various column models, and the corresponding parameters essential for column-reactor process design were calculated. The high reusability up to the 10th cycle (≥83.32%) and the effective treatment in complex matrices (tap-water: 90.11 %, river-water: 89.72 %, wastewater: 83.83%) demonstrated bionanocomposites' prominent sustainability. Additionally, the production cost at 6.64 USD per Kg, underscores its potentiality for industrial application. Phytotoxicity assessment on mung-bean revealed better root (5.02 ± 0.27 cm) and shoot (17.64 ± 0.35 cm) growth in the bionanocomposite-treated DEP samples over the untreated samples. Thus, AC-GSH-Fe3O4@sand bionanocomposites could be considered a highly-sustainable, low-cost technique for the effective removal of DEP and other phthalate-esters from contaminated matrices.

Rapidly reducing cadmium from contaminated farmland soil by novel magnetic recyclable Fe3O4/mercapto-functionalized attapulgite beads

Reducing cadmium (Cd) content from contaminated farmland soils remains a major challenge due to the difficulty in separating commonly used adsorbents from soils. This study synthesized novel millimeter-sized magnetic Fe3O4/mercapto-functionalized attapulgite beads (MFBs) through a facile one-step gelation process incorporating alginate. The MFBs inherit the environmental stability of alginate and enhance its mechanical strength by hybridizing Fe3O4 and clay mineral components. MFBs can be easily separated from flooded soils by magnets. When applied to 12 Cd-polluted paddy soils and 14 Cd-polluted upland soils, MFBs achieved Cd(II) removal rates ranging from 16.9% to 62.2% and 9.8%-54.6%, respectively, within a 12-h period. The MFBs predominantly targeted the exchangeable and acid soluble, and reducible fractions of Cd, with significantly enhanced removal efficiencies in paddy soils compared to upland soils. Notably, MFBs exhibited superior adsorption performance in soils with lower pH and organic matter (OM) content, where the bioavailability and mobility of Cd are heightened. The reduction of Cd content by MFBs is a sustainable and safe method, as it permanently removes the bioavailable Cd from soil, rather than temporarily reducing its bioavailability. The functional groups such as -SH, -OH, present in attapulgite and alginate of MFBs, played a crucial role in Cd(II) adsorption. Additionally, attapulgite and zeolite provided a porous matrix structure that further enhanced Cd(II) adsorption. The results of X-ray photoelectron spectroscopy suggested that both chemical precipitation and surface complexation contributed to Cd(II) removal. The MFBs maintained 87.6% Cd removal efficiency after 5 regeneration cycles. The surface of the MFBs exposed new adsorption sites and increased the specific surface area during multiple cycles with Cd-contaminated soil. This suggests that MFBs treatment with magnetic retrieval is a potentially effective pathway for the rapid removal of Cd from contaminated farmland soils.

Analysis and remediation of phthalates in aquatic matrices: current perspectives

Phthalic acid esters (PAEs) are high production volume chemicals used extensively as plasticizers, to increase the flexibility of the main polymer. They are reported to leach into their surroundings from plastic products and are now a ubiquitous environmental contaminant. Phthalate levels have been determined in several environmental matrices, especially in water. These levels serve as an indicator of plasticizer abuse and plastic pollution, and also serve as a route of exposure to different species including humans. Reports published on effects of different PAEs on experimental models demonstrate their carcinogenic, teratogenic, reproductive, and endocrine disruptive effects. Therefore, regular monitoring and remediation of environmental water samples is essential to ascertain their hazard quotient and daily exposure levels. This review summarises the extraction and detection techniques available for phthalate analysis in water samples such as chromatography, biosensors, immunoassays, and spectroscopy. Current remediation strategies for phthalate removal such as adsorption, advanced oxidation, and microbial degradation have also been highlighted.

Reutilization of scrap tyre for the enhanced removal of phthalate esters from water: immobilization performance, interaction mechanisms, and application

Waste scrap tyre as microbial immobilization matrix enhanced degradation of phthalate esters (PAEs), di (2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and diethyl phthalate (DEP). The hybrid (physical adsorption and microbial immobilization) degradation process performance of scrap tyres was examined for the PAEs degradation. The scrap tyre was shown with competitive adsorption capacity toward PAEs, influenced by pH, temperature, dosage of adsorbent (scrap tyre), and concentration of PAE. The primary adsorption mechanism for tyres toward PAEs was considered hydrophobic. The immobilization of previously isolated Bacillus sp. MY156 on tyre surface significantly enhanced PAEs degradation as well as bacterial growth. The enzymatic activity results implied immobilization promoted dehydrogenase activity and decreased esterase activity. The cell surface response during PAEs degradation, in terms of morphological observation, FTIR and XRD analyses, and extracellular polymeric substance (EPS) release, was further assessed to better understand the interactions between microorganisms and tyre surface. Waste scrap tyres could be a promising potential candidate to be reused for sustainable environmental management, including contaminants removal.

Novel fabrication of the recyclable Bi7O9I3/chitosan and BiOI/chitosan heterostructure with improved photocatalytic activity for degradation of dimethyl phthalate under visible light

Among the bismuth oxyhalides, bismuth oxide has the shortest band gap and high absorption power in the visible light region. Dimethyl phthalate (DMP) has been identified as endocrine-disrupting plasticizer and emerging pollutant, which was selected as the target pollutant to evaluate the efficacy of the studied catalytic process. In this work, Bi₇O₉I₃/chitosan and BiOI/chitosan were efficaciously synthesized by the hydrothermal process method. Characterizing prepared photocatalysts was done by employing transmission electron microscopy, X-ray diffraction, scanning electron microscopy energy-dispersive spectroscopy, and diffuse reflectance spectroscopy. For this study, the test design was performed using the Box-Behnken Design (BBD) method in which the variables of pH, Bi₇O₉I₃/chitosan dose, and dimethyl phthalate concentration were examined for the catalytic removal of dimethyl phthalate in the presence of visible light. Our detected results disclosed that the order of efficiency in DMP removal was as follows: Bi₇O₉I₃/chitosan > BiOI/chitosan > Bi₇O₉I₃ > BiOI. Also, the maximum pseudo-first-order kinetic coefficient for Bi₇O₉I₃/chitosan was 0.021 (min)^-1. When the synthesized catalysts were exposed to visible light irradiation, the predominant active species were O₂^- and h⁺ for degradation of DMP. The study on the reuse of Bi₇O₉I₃/chitosan showed that this catalyst could be reused 5 times without significant reduction in efficiency, which indicates the cost-effectiveness and environmental friendliness of using this catalyst.

Molecular Design and Mechanism Analysis of Phthalic Acid Ester Substitutes: Improved Biodegradability in Processes of Sewage Treatment and Soil Remediation

Phthalic acid esters (PAEs) have the characteristics of environmental persistence. Therefore, improving the biodegradability of PAEs is the key to reducing the extent of ecological harm realized. Firstly, the scoring function values of PAEs docking with various degrading enzymes in sewage treatment were calculated. Based on this, a 3D-quantitative structure-activity relationship (3D-QSAR) model for PAE biodegradability was built, and 38 PAE substitutes were created. By predicting the endocrine-disrupting toxicity and functions of PAE substitutes, two types of PAE substitutes that are easily degraded by microorganisms, have low toxicity, and remain functional were successfully screened. Meanwhile, the differences in the mechanism of molecular degradation difference before and after PAE modification were analyzed based on the distribution characteristics of amino acid residues in the molecular docking complex. Finally, the photodegradability and microbial degradability of the PAE substitutes in the soil environment was evaluated. From the 3D-QSAR model design perspective, the modification mechanism of PAE substitutes suitable for sewage treatment and soil environment degradation was analyzed. We aim to improve the biodegradability of PAEs at the source and provide theoretical support for alleviating the environmental hazards of using PAEs.

Magnetic NH2-MIL-101(Al)/Chitosan nanocomposite as a novel adsorbent for the removal of azithromycin: modeling and process optimization

In the present study, the magnetic NH₂-MIL-101(Al)/chitosan nanocomposite (MIL/Cs@Fe₃O₄ NCs) was synthesized and used in the removal of azithromycin (AZT) from an aqueous solution for the first time. The as-synthesized MIL/Cs@Fe₃O₄ NCs was characterized by SEM, TEM, XRD, FTIR, BET, and VSM techniques. The effect of various key factors in the AZT adsorption process was modeled and optimized using response surface methodology based on central composite design (RSM-CCD). The low value of p-value (1.3101e-06) and RSD (1.873) parameters, along with the coefficient of determination > 0.997 implied that the developed model was well fitted with experimental data. Under the optimized conditions, including pH: 7.992, adsorbent dose: 0.279 g/L, time: 64.256 min and AZT concentration: 10.107 mg/L, removal efficiency and AZT adsorption capacity were obtained as 98.362 ± 3.24% and 238.553 mg/g, respectively. The fitting of data with the Langmuir isotherm (R²: 0.998, X²: 0.011) and Pseudo-second-order kinetics (R²: 0.999, X²: 0.013) showed that the adsorption process is monolayer and chemical in nature. ΔH° > 0, ΔS° > 0, and ∆G° < 0 indicated that AZT removal was spontaneous and endothermic in nature. The effect of Magnesium on AZT adsorption was more complicated than other background ions. Reuse of the adsorbent in 10 consecutive experiments showed that removal efficiency was reduced by about 30.24%. The performance of MIL/Cs@Fe₃O₄ NCs under real conditions was also tested and promising results were achieved, except in the treatment of AZT from raw wastewater.

Development of clinoptilolite zeolite-coated magnetic nanocomposite-based solid phase microextraction method for the determination of Rhodamine B in cosmetic products

Green synthesis of clinoptilolite zeolite/Fe₃O₄ nanocomposite (MZNC) was carried out using Laurus Nobilis L. leaf extract. Characterization of this MZNC was performed using Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and Vibrating Sample Magnetometer. According to the VSM analysis results, the saturation magnetization of 23 emu/g and coercivity of 23.5 Oe indicate that the synthesized magnetic nanocomposite is superparamagnetic. A new ultrasonic assisted clinoptilolite zeolite-coated magnetic nanocomposite-based solid phase microextraction (MZNC-SPME) method combined with high performance liquid chromatography was developed for the extraction and determination of Rhodamine B. The preconcentration factor for the MZNC-SPME method was found to be 40 under optimal conditions. Under optimal conditions, the linear range, correlation coefficient (R²), limit of detection (LOD), and intra- and interday relative standard deviation (RSD) were found to be 1.00-100.00 ng mL^-1, 0.9995, 0.16 ng mL^-1, 1.89% and 2.49%, respectively. The developed method was successfully performed to determine Rhodamine B in 6 different cosmetic samples. 6 ions and 5 different dyes were added to the sample solution to show the selectivity of the method. The obtained results show that the determination of Rhodamine B is possible in the presence of these ions and dyes. In order to determine the accuracy of the MZNC-SPME method, two different concentrations of Rhodamine B concentration in cosmetic samples were added as 10 and 50 ng mL^-1. Extraction recoveries were found in the range of 92.03-101.52% and these results are quite satisfactory. It is seen that the developed method for the extraction and determination of Rhodamine B from cosmetic samples is applicable due to the easy synthesis of the sorbent and the short, simple, environmentally friendly and low cost of the method.

Use of Typical Wastes as Biochars in Removing Diethyl Phthalate (Det) from Water

Diethyl phthalate (DEP), one of the six typical PAEs priority pollutants declared by the US EPA, has attracted tremendous attention due to its widespread pollution and was selected as the adsorbate in this study. Properties of biochar samples obtained from three different feedstocks, i.e., sawdust (SDBC), rice straw (RSBC), and giant reed (GRBC), pyrolyzed at 400 °C as well as their ability to adsorb DEP from an aqueous solution were investigated. The results showed that the adsorption kinetics were well fitted with the pseudo-second-order model (R2 > 0.99) and the intraparticle diffusion model (R2 > 0.98). The maximal adsorption capacity of the DEP by the prepared biochar was in an order of GRBC (46.04 mg g−1) > RSBC (31.54 mg g−1) > and SDBC (18.39 mg g−1). The higher adsorption capacity of DEP by GRBC is mainly attributed to the higher surface area. The reduction in adsorption capacity of the biochar against DEP with an increase in the solution pH (from 2.5 to 10.0) was possibly due to promoting the electrostatic repulsion between the DEP and the surface of the biochar. However, the increasing sodium ionic strength promoted the adsorption of the biochar, which could be interpreted by the reduced solubility of the DEP due to enhancing “salting out” effects as increasing sodium concentration. In addition, it was favorable for the adsorption of DEP onto the biochars at a lower temperature (15 °C) and the calculated ∆G0 was less than zero, indicating that the adsorption was a spontaneous and exothermic process. These experiments designate that these derived biochars can be used as an inexpensive adsorbent for the purification of PAEs contaminated water.

Prediction of methyl orange removal by iron decorated activated carbon using an artificial neural network

Date Stones were used as a bio-degradable waste source for preparing iron impregnated activated carbon. The prepared activated carbon-containing oxides of iron were characterized using SEM, XRD, FTIR, and BET. The specific surface area of the iron decorated activated carbon was 738.65 m²/g. The XRD confirmed the presence of magnetite and hematite while the SEM images assured the presence of pores. The prepared activated carbon was used to remove methyl orange from wastewater. Genetic Algorithm was used to develop a model which could predict the removal efficiency of the dye. The ANN model was validated and the effect of different parameters like adsorbent dosage (0.1-1 g/L), initial dye concentration (2-20 mg/L), pH (2-11), time (10-55 min) and temperature (30-75°C) was estimated both experimentally and predicted using the model. The adsorption process follows the Freundlich isotherm and pseudo-second-order kinetic model. The values of 1/n and K_F obtained from the Freundlich isotherm designate good adsorption capacity. Both experimental and model-predicted data agrees with the kinetic model. The adsorption rate is proportionate to the square of the number of vacant adsorption sites. From the thermodynamic study, the positive worth of ΔH° indicates the energy-absorbing nature of the surface assimilation method and the process is endothermic in nature. The low values of each ΔG° (-200 to 0 kJ/mol) and ΔH° correspond to physical surface assimilation. A positive worth of ΔS° reflects the inflated randomness at the solid-aqueous interface with some structural changes in adsorbate and adsorbent.

Occurrence and removal characteristics of phthalate esters from bottled drinking water using silver modified roasted date pits

BACKGROUND

This paper aims to investigate the occurrence and removal characteristics of phthalate esters from bottled drinking water using silver modified roasted date pits. Three adsorbents, namely roasted date pits (RODP), silver-modified roasted date pits (S-RODP), and activated carbon (AC) were used to investigate their adsorption characterizations in removing dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP), and di-n-octyl phthalate (DNOP) from the collected bottle water samples.

METHODS

The occurrences of the phthalate esters in the collected bottled water samples were carried out at different temperatures (30, 50, and 60 °C), and analyzed using gas chromatography-mass spectrometry analysis - selected ion monitoring. Batch adsorption isotherms were used to study and establish the efficiency of such adsorbents in removing phthalate esters, in which they describe the adsorbent-adsorbate interaction systems. Adsorption efficiency of the various adsorbents was investigated by using different adsorbent masses (0.05 g, 0.10 g, and 0.15 g) and temperature (30 °C, 50 °C, and 60 °C). Different physical and chemical characterizations were studied using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET) surface area, pore radius, and pore volume.

RESULTS

The results indicated that the most abundant phthalate esters were DMP followed by DEP under 30 °C; however, DNOP was not detected in any of the tested water samples, except for one sample under 30 °C with a concentration of 0.031 μg/mL. The obtained results showed that phthalate esters leaching to the bottled drinking water were affected by storage temperature. The phthalate esters levels were increased with increasing the temperature to 60 °C. It was concluded that the ability of S-RODP for the adsorption of phthalate esters was better than the removal percentage obtained by AC and RODP. The removal percentage was increased from 90 to 99% by increasing the temperature from 30 to 50 °C and then decreased to 92.3% at 60 °C.

CONCLUSION

RODP was successfully used as an effective adsorbent for phthalate esters removal from drinking water. However, S-RODP has the highest removal abilities than other adsorbents due to the newly formed functional groups on its surface.

Biodegradation of phthalic acid esters (PAEs) by Cupriavidus oxalaticus strain E3 isolated from sediment and characterization of monoester hydrolases

Phthalic acid esters (PAEs) are teratogenic and carcinogenic and mainly metabolized by microorganisms in sediment. A novel strain, Cupriavidus oxalaticus strain E3, was isolated and characterized from sediment for PAEs degradation. The transformation of dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) as the sole carbon source by strain E3 was systematically studied in the darkness through the kinetic studies and analysis of intermediates. After the initial lag pause of 5 h-8 h, the strain efficiently degraded 87.4%-94.4% of DBP and 82.5%-85.6% of DEHP at an initial amount of each phthalate of 200 mg/L after 60 h of incubation. The biodegradation rate of DBP and DEHP followed a first-order kinetic model, and degradation rate constants (k) of them by E3 were 1.37 and 0.86 d^-1, respectively. Gas chromatography-mass spectrometry (GC-MS) results revealed that the tentative PAEs degradation pathway, included the transformation from PAEs to phthalic acid (PA) and the complete mineralization of PA. In the phase of PAEs to PA, DBP with short sides reduced the chain length via hydrolyzation, and DEHP with long sides reduced the chain length via hydrolyzation and β-oxidation. The 3D model of monoester hydrolase from C. oxalaticus was predicted and used for docking with mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MBP). The docking results showed that the conserved catalytic triplet structure (Ser140, His284, and Asp254) acted as active sites and participated in degrading PMEs. This study provided novel insights into the mechanisms of PAEs degradation at a molecular level and widened the scope of functional bacteria by isolating strain E3.

New advances on Au-magnetic organic hybrid core-shells in MRI, CT imaging, and drug delivery

Magnetic nanoparticles have been widely studied for various scientific and technological applications such as magnetic storage media, contrast agents for magnetic resonance imaging (MRI), biolabelling, separation of biomolecules, and magnetic-targeted drug delivery. A new strategy on Au-magnetic nano-hybrid core-shells was applied in MRI, CT imaging, and drug delivery, which has been received much attention nowadays. Herein, the designing of different magnetic core-shells with Au in MRI and cancer treatment is studied.

The Comparison between Magnetite Nanoparticles Co-Precipitated by Different Bases and Their Effects on Human Cells

The superparamagnetic magnetite nanoparticles were synthesized through co-precipitation method by using a strong base such as sodium hydroxide or a weak base such as ammonium hydroxide. The magnetite co-precipitated by ammonium hydroxide (MA) has different properties than the magnetite co-precipitated by sodium hydroxide (MS). The cytotoxicity effects of MA and MS on the breast cancer cells and normal hepatocytes cells were studied. The magnetite nanoparticles with two ways were characterized by using Vibrating Sample Magnetometer. X-ray fluorescence, Dynamic Light Scattering, Zeta Potential, pH changes, Wide-angle X-ray Diffraction, Fourier Transforms Infrared spectroscopy, MTT assay test and High-Resolution Transmission electron microscopy. The results showed that the final pH of MA and MS were 5 and 7.5, respectively. MA nanoparticles have salts which act as weak oxidizing agent and they were exposed to oxidation at high temperature and lost their magnetic property. They have a cytotoxic effect against breast cancer cells and normal hepatocytes cells more than the MS.

Magnetic carnosine-based metal-organic framework nanoparticles: fabrication, characterization and application as arsenic adsorbent

This study centers on the controllable synthesis, characterization, and application of a novel magnetic bio-metal-organic framework (Bio-MOF) for the adsorption and subsequent removal of arsenic from aqueous solutions. Zinc ions and carnosine (Car) were exploited to construct the Car-based MOF on the surface of magnetite (Fe₃O₄ NPs). The Magnetite precoating with Car led to an increase in the yield and the uniform formation of the magnetic MOF. The prepared magnetic Bio-MOF nanoparticles (Fe₃O₄-Car-MOF NPs) had semi-spherical shape with the size in the range of 35-77 nm, and the crystalline pattern of both magnetite and Car-based MOF. The NPs were employed as an adsorbent for arsenic (As) removal. The adsorption analyses revealed that all studied independent variables including pH, adsorbent dose, and initial arsenic concentration had a significant effect on the arsenic adsorption, and the adsorption data were well matched to the quadratic model. The predicted adsorption values were close to the experimental values confirming the validity of the suggested model. Furthermore, adsorbent dose and pH had a positive effect on arsenic removal, whereas arsenic concentration had a negative effect. The adsorption isotherm and kinetic studies both revealed that As adsorption fitted best to the Freundlich isotherm model. The maximum monolayer adsorption capacity (94.33 mg/g) was achieved at room temperature, pH of 8.5 and adsorbent dose of 0.4 g/L. Finally, the results demonstrated that the adsorbent could be efficiently applied for arsenic removal from aqueous environment.

Effect of the type of soil on dimethyl phthalate degradation by ozone

In the present study, ozone was applied for the removal of dimethyl phthalate (DMP) from soil. The effect of several experimental parameters was investigated considering, the initial DMP concentration, ozone flow, the type of soil (sand and agricultural soil) and the presence of α-FeOOH as a potential catalyst in the reaction system with sand. The elimination of DMP using ozone is significantly affected by the type of soil. In the case of sand, conventional ozonation was capable to degrade 74% of the initial DMP concentration (0.5 mg g^-1) after 8 h of the reaction, however, the mineralization degree was below 50%. Under the same experimental conditions, the complete elimination of DMP was achieved when calcined agricultural soil was present reaching a 70% of mineralization. The presence of metal oxides in calcined agricultural soil combined with ozone produced oxidants species which were responsible of incrementing the mineralization degree (around 20% in comparison with the sand). The toxicity tests on lettuce seed demonstrated lower toxicity of DMP byproducts after ozonation. The DMP high removal efficiencies and the lower toxicity of generated byproducts in soil prove the applicability of ozone treatment for soil remediation.

High frequency discharge plasma induced plasticizer elimination in water: Removal performance and residual toxicity

Plasticizers are widely present in water and soil environment, and they can bring enormous threats to environmental safety and human health. A discharge plasma system driven by a high-frequency electric source was used to remove the plasticizer from wastewater; and dimethyl phthalate (DMP) was chosen as the representative of plasticizer. DMP elimination performance at various operating parameters, roles of active species in DMP degradation, DMP decomposition process, and its residual toxicity after decomposition were systematically investigated. The experimental results demonstrated that almost all of the DMP and 80.4% of the total organic carbon (TOC) were removed after 30 min of treatment. The DMP decomposition process fitted well with the first-order kinetic model. Relatively higher applied voltage, lower initial concentration, and alkaline conditions favored its decomposition. •OH was the decisive species for DMP decomposition, in addition to •O₂^- and ¹O₂; while the role of hydrated electrons was negligible. The analysis of DMP decomposition process showed that the molecular structures of the DMP were destroyed, and 3-hydroxy-dimethyl phthalate, monomethyl phthalate, and phthalic acid were detected. Furthermore, the residual toxicity after DMP decomposition was analyzed via seed germination and photobacterium bioassay.

Fast degradation of phthalate acid esters by polyoxometalate nanocatalysts through adsorption, esterolysis and oxidation

A novel route was created to facilitate the degradation of diethyl phthalate (DEP) upon micellar polyoxometalate (POM) catalysts and H₂O₂. The best catalytic activity was obtained using [C₁₆H₃₃N(CH₃)₃]H₄PMo₁₀V₂O₄₀ (N-hexadecyl-N,N,N-trimethylammonium tetrahydrogen decamolybdo-divanadophosphate, abbreviated as (CTA)H₄PMoV) with 90.2% degradation efficiency within 30 min, while the chemical oxygen demand (COD) and total organic carbon (TOC) removal efficiency were about 77.7% and 74.3% within 40 min. The highest efficiency was attributed to the concentration of DEP by amphiphilic POM catalyst, coupling with its strong Brønsted acidity and higher redox potential to catalyze esterolysis and oxidation of DEP. This allowed the phthalate acid esters (PAEs) with long carbon chains in super low concentration of 0.03 μM to be efficiently decomposed. The above synergistic effects explored DEP being degraded into ethanol, lactic acid and CO₂, which were non-toxic to the water surroundings. And the reaction activation energy (Ea) of 12.49 kJ/mol was obtained upon the degradation of DEP with (CTA)H₄PMoV followed first-order kinetics. Meanwhile, (CTA)H₄PMoV acted as a heterogeneous catalyst, which showed long duration and higher stability with only 3.7% loss amount during ten recycles.

Fe3O4/SO3H@zeolite-Y as a novel multi-functional and magnetic nanocatalyst for clean and soft synthesis of imidazole and perimidine derivatives

In this study, SO₃H@zeolite-Y was synthesized by the reaction of chlorosulfonic acid with zeolite-NaY under solvent-free conditions, which was then supported by Fe₃O₄ nanoparticles to give SO₃H@zeolite-Y (Fe₃O₄/SO₃H@zeolite-Y) magnetic nanoparticles. Several techniques were used to evaluate the physical and chemical characterizations of the zeolitic nanostructures. Fe₃O₄-loaded sulfonated zeolite was applied as a novel multi-functional zeolite catalyst for the synthesis of imidazole and perimidine derivatives. This efficient methodology has some advantages such as good to excellent yield, high purity of products, reusability of nanocatalyst, simple reaction conditions, environmental friendliness and an economical chemical procedure from the viewpoint of green chemistry.

Fe₃O₄/SO₃H@zeolite-Y was applied as a novel, effective and environmentally friendly magnetic nanocatalyst for the synthesis of imidazole and perimidine scaffolds.

Synthesis, characterization and in vitro validation of a magnetic zeolite nanocomposite with T2-MRI properties towards theranostic applications

This study focusses on the development of a magnetic zeolite nanocomposite as a suitable platform towards the design of a theranostic system. Herein, we explored its ability to act as a T₂-MRI contrast enhancer when magnetic nanoparticles are incorporated in its structure.

Accelerated crystallization of magnetic 4A-zeolite synthesized from red mud for application in removal of mixed heavy metal ions

To cope with the increasing environmental issues of red mud, an integrated technological route for its comprehensive utilization was developed through the extraction of valuable components and the synthesis of magnetic 4A-zeolite. To accelerate the crystallization process of the synthesized 4A-zeolite, sodium chloride (NaCl) was innovatively employed under hydrothermal treatment. The effects of various parameters, including mass ratio of red mud/NaOH, alkali fusion temperature, alkali fusion time and molar ratio of NaCl/Al₂O₃, were systematically investigated. The results showed that approximately 81.0% Al, 76.1% Si and 95.8% Fe were utilized from red mud using alkali fusion and acid leaching methods. The optimal conditions of the alkali fusion process were determined as: mass ratio of red mud/NaOH = 1/2, alkali fusion temperature of 800 °C, and time of 90 min. Furthermore, when the molar ratio of NaCl/Al₂O₃ was kept at 1.5, the crystallization time reduced from 240 min to 150 min, and particle size distributions narrowed from 20-100 μm to 1-10 μm. The practical applications in removal of mixed heavy metal ions (Zn²⁺, Cu²⁺, Cd²⁺, Ni²⁺, and Pb²⁺) from wastewater indicated that the as-synthesized magnetic 4A-zeolite is a promising candidate for heavy metals adsorption.

Data for efficiency comparison of raw pumice and manganese-modified pumice for removal phenol from aqueous environments-Application of response surface methodology

Present deadest collection was aimed to evaluate the efficiency of raw pumice (RWP) and Mn-modified pumice (MMP). Response surface methodology (RSM) based on the central composite designs (CCD) was applied to evaluate the effects of independent variables including pH, adsorbents dosage, contact time and adsorbate concentration on the response function and the best response values were predicted. The Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the adsorbents. Based on acquired data, the maximum efficiency removal of phenol was obtained 89.14% and 100% for raw and Mn-modified pumice respectively. The obtained data showed pH was effective parameter on phenol removal among the different variables. Evaluation of data using isotherms and kinetics models showed the fitted with Langmuir isotherm and pseudo second order kinetic for both adsorbents. According to obtained data was observed that modification of pumice can improve the efficiency removal of phenol to meet the effluent standards.