Sorbent Dosage Research Articles

Dissolution-precipitation method concatenated sodium alginate/MOF-derived magnetic multistage pore carbon magnetic solid phase extraction for determination of antioxidants and ultraviolet stabilizers in polylactic acid food contact plastics

Antioxidants and UV stabilizers have some endocrine disrupting effects and liver toxicity. Both types of additives are still widely used in food contact plastics to improve the durability of plastic products. However, efficient and rapid detection of antioxidants and UV stabilizers has been a challenge due to the complexity of the plastic matrix and the low content of antioxidants and UV stabilizers. In this study, a sodium alginate/MOF-derived magnetic multistage pore carbon material (MIL-101(Fe)/SA-CAs) was developed, having the merits of abundant multistage pore structure, large specific surface area, and good magnetic separation properties. Thus, this material was selected as the sorbent for magnetic solid-phase extraction combined with a dissolution-precipitation method for the extraction and purification of antioxidants and UV stabilizers from polylactic acid food contact plastics. The extraction parameters such as sorbent type, sorbent dosage, sample solution pH, ionic strength, sorption time, elution solution type, volume, and time were investigated. Under the optimized conditions, all the analytes determined by UPLC-MS/MS showed good linear range (r > 0.99), detection limit (0.023–3.105 ng g−1), accuracy (70.6–102.3 %), and reproducibility (RSD<9.8 %). Further, the developed method was applied to determine the antioxidants and UV stabilizers in polylactic acid lunch boxes and straws, showing excellent applicability. The results showed that the antioxidants and UV stabilizers were detected in some of the samples, with a maximum detection of antioxidant 1010 at 7297 ng g−1. This study provided a sensitive, efficient, and environmentally friendly method for antioxidants and UV stabilizers in polylactic acid food contact plastics. The ideas for the design of environmentally friendly metal-organic frameworks and biomass composite multifunctional materials would promise in the sample pretreatment field for the emerging contaminants.

Unveiling antibacterial and antioxidant activities of zinc phosphate-based nanosheets synthesized by Aspergillus fumigatus and its application in sustainable decolorization of textile wastewater

BackgroundThe development of an environment-friendly nanomaterial with promising antimicrobial and antioxidant properties is highly desirable. The decolorization potentiality of toxic dyes using nanoparticles is a progressively serious worldwide issue.MethodsThe successful biosynthesis of zinc nanoparticles based on phosphates (ZnP-nps) was performed using the extracellular secretions of Aspergillus fumigatus. The antibacterial activity of the biosynthetic ZnP-nps was investigated against Gram-negative bacteria and Gram-positive bacteria using the agar diffusion assay method. The antioxidant property for the biosynthetic nanomaterial was evaluated by DPPH and H2O2 radical scavenging assay.ResultsRemarkable antibacterial and antiradical scavenging activities of ZnP-nps were observed in a dose-dependent manner. The minimum inhibitory concentration (MIC) for Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was 25 µg/ml, however, the MIC for Bacillus subtilis was 12.5 µg/ml. The maximum adsorptive performance of nanomaterial was respectively achieved at initial dye concentration of 200 mg/L and 150 mg/L using methylene blue (MB) and methyl orange (MO), where sorbent dosages were 0.5 g for MB and 0.75 g for MB; pH was 8.0 for MB and 4.0 for MO; temperature was 30 °C; contact time was 120 min. The experimental data was better obeyed with Langmuir’s isotherm and pseudo-second-order kinetic model (R2 > 0.999). The maximum adsorption capacity (qmax) of MB and MO dyes on nanomaterial were 178.25 mg/g and 50.10 mg/g, respectively. The regenerated nanomaterial, respectively, persist > 90% and 60% for MB and MO after 6 successive cycles. The adsorption capacity of the prepared zinc phosphate nanosheets crystal toward MB and MO, in the present study, was comparable/superior with other previously engineered adsorbents.ConclusionsBased on the above results, the biosynthesized ZnP-nanosheets are promising nanomaterial for their application in sustainable dye decolorization processes and they can be employed in controlling different pathogenic bacteria with a potential application as antiradical scavenging agent. Up to our knowledge, this is probably the first study conducted on the green synthesis of ZnP-nanosheets by filamentous fungus and its significant in sustainable dye decolorization.

Adsorption characteristics of nickel (II) from aqueous solutions by Zeolite Scony Mobile-5 (ZSM-5) incorporated in sodium alginate beads

Nickel, a prevalent metal in the ecosystem, is released into the environment through various anthropogenic activities, leading to adverse effects. This research explored utilizing zeolite scony mobile-5 (ZSM-5) nanoparticles encapsulated in sodium alginate (SA) for nickel (II) removal from aqueous solutions. The adsorption characteristics of SA/ZSM-5 were examined concerning contact duration, initial metal ion concentration, pH level, temperature, and sorbent dosage. The findings revealed that a rising pH reduced Ni (II) uptake by the sorbent while increasing the Ni (II) concentration from 25 to 100 mg L−1 led to a decrease in removal percentage from 91 to 80% under optimal conditions. Furthermore, as sorbent dosage increased from 4 to 16 g L−1, uptake capacity declined from 9.972 to 1.55 mg g−1. Concurrently, SA/ZSM-5 beads' Ni (II) sorption capacity decreased from 96.12 to 59.14% with a temperature increase ranging from 25 to 55 °C. The Ni (II) sorption data on SA/ZSM-5 beads are aptly represented by Langmuir and Freundlich equilibrium isotherm models. Moreover, a second-order kinetic model characterizes the adsorption kinetics of Ni (II) on the SA/ZSM-5 beads. A negative free energy change (ΔG°) demonstrates that the process is both viable and spontaneous. The negative enthalpy values indicate an exothermic nature at the solid–liquid interface while negative entropy values suggest a decrease in randomness. In conclusion, this novel adsorbent exhibits promise for removing nickel from aqueous solutions and could potentially be employed in small-scale industries under similar conditions.

Bimetallic metal–organic framework as an efficient sorbent for the extraction of tacrolimus and cyclosporine from plasma before HPLC-MS/MS analysis

This study investigated the application of pores-size protocols into metal–organic frameworks that can lead to improved adsorption capacity of sorbents. A selective, fast, and sensitive analytical procedure based on dispersive solid phase extraction using a bimetallic metal organic framework named ZrZnMOF coupled with high-performance liquid chromatography-tandem mass spectrometry was established for the simultaneous quantification of tacrolimus and cyclosporine in plasma. The effects of several parameters, such as the dosage of sorbent, separation and elution times, volume and type of elution solvent, were investigated. Under optimal conditions, high extraction recovery (70 and 89 for tacrolimus and cyclosporine, respectively), low limits of detection (0.15 and 0.31 μg L-1 for tacrolimus and cyclosporine, respectively) and quantification (1.0 and 0.51 μg L-1 for tacrolimus and cyclosporine, respectively) wide linearity (1.0–1000 and 0.51–500 μg L-1 for tacrolimus and cyclosporine, respectively), and acceptable repeatability (n = 5, relative standard deviation less than 5.6 %) were attained. The validated method was successfully applied to quantify tacrolimus and cyclosporine A in plasma samples obtained from different volunteers.

Influence of experimental parameters on the sorption behavior of Rare Earth Elements on manganese ferrite nanoparticles

Rare Earth Elements (REE) are nearly irreplaceable in many technologies, but their supply is limited by geopolitical factors. Additionally, their exploration and refinement bring serious environmental consequences. Therefore, alternative sourcing of these elements through methods such as sorption has recently been attempted. Nanoparticles are exceptional REE sorbents, however, difficulties in material separation post-sorption have fueled an interest in the use of magnetic nanoparticles, which can be easily separated from the solution by applying an external magnetic field. In this study, we explore the influence of sorbent dosage, pH and matrix complexity in the removal of trivalent cations of nine REE (Y, La, Ce, Pr, Nd, Eu, Gd, Tb and Dy) using manganese ferrite nanoparticles (MnFe2O4); herein the abbreviation REE is employed to indicate such elements including the trivalent cations. The REE removal increased for higher sorbent dosages and pH. More than 90% of REE in mono-elemental solutions were removed from water at pH 6 and 8. Removal below 10% was observed for pH < 4, due to the positive surface charge of the sorbent, which did not favor interaction with cationic REE species. Increasing the complexity of the matrix, the removal of REE from water decreased considerably, which can be attributed to an increase of total REE concentration and the limited number of sorption sites in the sorbent. Further sorption inhibition was reported in increased ionic strength scenarios (mineral and saline water), possibly due to competition with Na+, which may limit the application of this material in complex matrices.

SIMULTANEOUS REMOVAL OF ACIDIC AND NEUTRAL POLLUTANTS FROM WATER USING MIXED-MODE RESINS

Polycyclic aromatic hydrocarbons and endocrine-disrupting phenols are both ubiquitous pollutants in the environment. Human activities through urbanisation and rapid industrialisation are at the forefront of global environmental pollution. Therefore, removing pollutants in miscellaneous characteristics is important to eliminate the stage-by-stage reduction of pollutants, especially from wastewater, for a cost-effective and time-effective treatment. A simple preliminary study was conducted for the concurrent removal of acidic 2, 4, 6-trichlorophenol (2, 4, 6-TCP) and neutral fluorene (FLU) from water by mixed-mode resins that consist of Anion Exchange Chromatography (AEC) and reversed-phase C18 sorbents. The one-variable-at-time approach was applied in the optimisation of the removal process, where sorbent dosage, exposing time, stirring speed, and sample pH were investigated to enhance the removal efficiency. Under the optimal conditions, 20 mg of each AEC and C18 successfully removed 74.8% of 2, 4, 6-TCP and 96.5% of FLU from the water sample spiked with 50 mg/L of 2, 4, 6-TCP and 0.5 mg/L of FLU that was pre-modified to pH 9 and agitated at 600 rpm for 10 min. The AEC and C18 achieved a removal capacity of 37.4 mg/g for 2, 4, 6-TCP and 0.48 mg/g for FLU, respectively, upon treating 20 mL of the water sample. The mixed-mode resins combine the capabilities of two different retention mechanisms and allow for the simultaneous removal of a broad range of compounds from environmental samples.

Rhodamine B sequestration using acid-precipitated and microwave-treated softwood lignin: Comparative isotherm, kinetics and thermodynamic studies

Sustainable development goals have emphasized the need to focus on water treatment to mitigate the ever-rising demands for clean water. High costs and energy requirements have been the Achilles’ heel of most treatment technologies. Herein, we develop cheap lignin-derived sorbents prepared by microwave (MW) and acid precipitation (AP) treatments of raw lignin (RL) for Rhodamine-B (RhB) adsorption in aqueous solution. Our findings evidence micro- and mesoporous structures, with irregular grain size. X-ray diffraction revealed an amorphous material, while Fourier-transform infrared analysis points to the presence of carboxyl, hydroxyl and sulfite functional groups, which may facilitate the adsorption of the dye. Adsorption isotherm and kinetic data describe complex and pore-driven interactions, based on the Sips, D-R and intraparticle diffusion models, considering the sum of squared error values obtained from nonlinear regression analysis. Adsorption efficiency of ∼97% is obtainable at optimal conditions for treated lignin (3 g/L sorbent dose, 720 min contact time and under acidic pH conditions). Thermodynamic studies revealed that RL-RhB and MW-RhB are driven by physisorption considering ∆H° values, while stronger interactions occurred for AP-RhB, considering the high enthalpy (∼49 kJ/mol) and adsorption capacity (∼2766 mg/g). Van der Waals attraction, π-π stacking, and pore-filling mechanisms are among the several interactions that may occur between RhB and the sorbents. Our findings offer a way to valorize lignin as an alternative pathway to economically viable and sustainable water purification.

Various forms of rice starch as iron cation polymer sorbents

Native, gelatinized and cross-linked rice starch was used to prepare "green sorbents". FTIR, XRD, SEM, DSC and TGA methods were used to evaluate the properties of the obtained materials. The influence of the type of starch, sorbent dose and contact time on the sorption efficiency was examined. The swelling properties, the degree of solution purification and the efficiency of Fe(III) ion removal were determined. The sorption properties of the materials strongly depended on the type of starch and the conditions of their use.

Green synthesis and characterization of silver and copper nanoparticles and their use as an effective adsorbent for chromium removal and recovery from wastewater.

Chromium (Cr) is one of the hazardous heavy metals that is naturally carcinogenic and causes various health problems. Metallic nanoparticles such as silver and copper nanoparticles (Ag NPs and Cu NPs) have gained great attention because of their unique chemical, physical, and biological attributes, serving diverse and significant role in various useful and sustainable applications. In the present study, both of these NPs were synthesized by green method in which Azadirachta indica plant extract was used. These nanoparticles were characterized by using advanced instrumental techniques such as Fourier transmission infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope attached with energy-dispersive spectroscopy (SEM-EDS), and elemental mapping. These environmentally friendly nanoparticles were utilized for the batch removal of Cr from the wastewater. For analysis of adsorption behaviour, a range of kinetic isotherm models (Freundlich, Temkin, Dubinin, and Langmuir) and kinetic models (pseudo-first-order and pseudo-second-order) were used for the Cu-NPs and Ag-NPs. Cu NPs exhibited the highest Cr removal efficiency (96%) within a contact time of 10-15 min, closely followed by Ag NPs which achieved a removal efficiency of 94% under the similar conditions. These optimal outcomes were observed at a sorbent dose of 0.5 g/L for Ag NPs and 0.7 g/L for Cu NPs. After effectively capturing Cr using these nanoparticles, the sorbates were examined through SEM-EDX analysis to observe how much Cr metal was attached to the nanoparticles, potentially for future use. The analysis found that Ag-NPs captured 18% of Cr, while Cu-NPs captured 12% from the aqueous solution. More precise experimental conditions are needed for higher Cr removal from wastewater and determination of the best conditions for industrial-level Cr reuse. Although nanomaterial exhibit high efficiency and selectivity for Cr removal and recovery from wastewater, more research is necessary to optimize their synthesis and performance for industrial-scale applications and develop efficient methods for Cr removal and recovery.

Solid-Phase Separation and Green Removal of Amprolium Hydrochloride Veterinary Drug from Aqueous Media Using Dolomiaea Costus Roots as New Biosorbent

&lt;p&gt;The roots of the &lt;em&gt;Dolomiaea costus&lt;/em&gt; (SCO) plant were used as a new, low-cost, eco-friendly, and efficient biosorbent for the removal of Amprolium hydrochloride (AMP) antibacterial veterinary drug residues from aqueous media. The effect of different parameters, such as the initial concentration of AMP, pH, contact time, adsorbent dosage, and temperature, was investigated. The results showed that the best removal of the AMP drug by SCO was reached at a pH of 3.6 at a contact time of 80 min by a sorbent dosage of 0.04 g at a temperature of 45°C. Adsorption isotherm studies indicated that the AMP removal correlates more with the Freundlich isotherm with &lt;em&gt;R&lt;sup&gt;2&lt;/sup&gt;&lt;/em&gt;= 0.991. The maximum adsorption capacity has reached 83% based on the adsorption isotherm studies. The kinetics studies showed that adsorption follows a pseudo-second-order model with &lt;em&gt;R&lt;sup&gt;2 &lt;/sup&gt;&lt;/em&gt;= 0.999. The thermodynamic studies showed that the adsorption process of AMP on SCO is spontaneous in nature and exothermic, with an increase in randomness during the adsorption.&lt;/p&gt;

Chromium Disarmament from Veritable Tanneries Sewer Water Utilizing Carbonic Rice Straw as a Sorbent: Optimization and Carbonic Rice Straw Characteristics

This exploration focuses on the removal of chromium from actual tannery wastewater, collected from the HARBY TANNERY factory in Rubiki (Badr City), using an economical sorbent made from activated carbon derived from rice straw (CRS). The CRS sorbent is activated using H3PO4. The experiment aims to assess the impact of various parameters, including chromium initial concentration, sorbent dosage, treatment time, agitation velocity (rpm), sorbent particle size, and solution pH, on chromium removal from tannery wastewater. Structural, morphological, and electronic distinctive of raw and treated CRS, as well as carbonized CRS, were analyzed using FTIR, SEM, and TEM techniques. XRF analysis was conducted to investigate the chemical elemental composition of carbonized CRS before and after sorption. Zeta potential measurement was performed to assess the electrical charges of particles present in a suspension. The adsorption data was tested for both Langmuir and Freundlich adsorption isotherms, and most of the factors suggested that it follows the Langmuir adsorption isotherm with an R2 value of 99.67%. Additionally, adsorption kinetics were performed to identify the reaction order, which exhibited that sorption pursued pseudo-second-order kinetics with a rate constant (k) of 0.0658 g/mg g/min, a high correlation factor (R2) of 99.76%, and an estimated equilibrium chromium ion adsorption capacity (qe) of 1.597 mg/g, which closely matched the experimental data (1.4835 mg/g). The improved surface morphology and increased surface area of CRS resulted in approximately 98.9% chromium removal. Mechanism studies confirmed that intraparticle diffusion is not the sole rate-controlling step, and Boyd’s model demonstrated that film diffusion limited the rate of chromium adsorption. The desorption of chromium from the carbonized rice straw surface could be achieved by up to 96.4% of the sorbed amount by raising the solution pH to 10, indicating the potential reusability of carbonized rice straw for additional adsorption cycles. Finally, a statistical regression analysis and least square multivariate analysis were used to establish a correlation for predicting efficiency, yielding an R2 value of 97.54%.

Efficient Removal of Cd(lI) from Aqueous Solution using Pyroaurite Type Sorbent, Ceralite, Activated Carbon, Goethite and Rice Husk Adsorption Performance and Mechanism

The use of pyroaurite type sorbents for removal of Cd(II) from aqueous solution has been studied. In batch tests, the sorbents IRA, PTS, PAC, PLC, FeO(OH) and RH could remove 95.3 ,93.8 , 93.9, 90.4, 75.1 and 59.5% cd (II) at initial metal concentration 0.1 mg/l, pH 6.0, temperature 25°C, agitation time 5 h, sorbent dose 5 g/l and rpm 150. The order of cadmium removal capacities for these chemical adsorbents was found to be: IRA &gt; PTS &gt; PAC &gt; PLC &gt;FeO(OH) &gt; RH. The effects of various parameters affecting the adsorption such as initial metal concentration. Sorbent dose, contact time and pH were determined. Adsorption decreases with in cadmium concentration and pH but increases with increase in adsorbent dose and contact time. Equilibrium was attained in 5 h and the maximum removal was at pH 8. Thus, basic medium favoured the removal. The sorption data fitted very well to the Langmuir isotherm as well as the Freundlich equation.

Simultaneous removal of selenium and microbial contamination from drinking water using modified ferrihydrite-based adsorbent

The ferrihydrite and modified ferrihydrite-based adsorbents were explored in the present study to remove selenate and bacterial contamination from drinking water. All the zinc-modified absorbents show >80 % bacterial count reduction, contrary to the unmodified adsorbents (30–40 % reduction). Ferrihydrite-based adsorbent modified with zinc (FH2–10) was the most efficient for selenate adsorption and exhibited the highest bactericidal activity. Sorption experiments showed that for Se (VI) concentration of 400 μg L−1, a sorbent dose of 0.5 g L−1 was sufficient to meet drinking water guidelines within the first 10 min. The maximum adsorption capacity of 40.984 mg/ g was obtained for FH2–10. The regeneration and reuse studies show that the selenium removal efficiency retained was >85 % even after three consecutive adsorption-desorption cycles. Column adsorption studies were performed to assess the adsorbent's field applicability, which inferred the adsorption capacity of 1.3 mg/ g. The FH2–10 adsorbent also showed >95 % bacterial growth reduction against E. coli. Hence the present detailed studies infer that FH2–10 is an efficient material for the simultaneous removal of selenium and bacterial contamination from drinking water, with potential for field application if the sulfate co-ions are not present in higher concentrations.

Preparation and Use of Iron on Carbon Foam for Removal of Organic Dye from Water: Batch Studies.

The presence of dyes in effluents from textile industries has a detrimental effect on aquatic ecosystems as it hinders the process of photosynthesis by reducing the penetration of sunlight. The adsorption capacity of a carbon foam-based iron oxide sorbent obtained from natural sources for the removal of organic methylene blue (MB) dye from water was investigated. The adsorption capacities were examined by batch experiments, wherein the impacts of varying iron content, sorbent dosage, contact time, dye concentration, and characterization were assessed. The physical characteristics and surface morphology of the synthesized carbon foam were also investigated. The carbon precursor and iron oxide precursor were coalesced within a singular container and subjected to carbonization process. This resulted in the formation of a porous structure that is capable of effectively providing support to the iron oxide particles. The carbon foam produced is a self-assembled formation that possesses the characteristic shape and underlying network structure reminiscent of bread. As the number of nanoparticles went up, so did the number of active sites. At elevated temperatures, the interactions between the dye molecules were enhanced, resulting in a more efficient process of dye removal. The magnetite sample exhibited endothermic adsorption, and all other samples exhibited exothermic adsorption. The adsorption of MB onto iron supported by carbon foam did not exhibit intraparticle diffusion as the only rate-limiting step for all samples. The adsorption rate was governed by a multistep elementary reaction mechanism in which multiple processes occurred simultaneously. The experimental data in this study may be accurately modeled by the pseudo-second-order kinetic model (R2 > 0.96). Additionally, the Freundlich isotherm best describes the adsorption equilibrium, which is supported by the outstanding fit of data to the model (R2 > 0.999). The findings suggest that the utilization of a natural carbon foam as a support for an immobilized iron oxide sorbent demonstrates considerable effectiveness in the removal of methylene dye from industrial effluent.

Rice husk ash as sorbent for solid phase extraction of diclofenac, ibuprofen and carboplatin residues from waters

Carboplatin, ibuprofen and diclofenac are among drugs classified as emergent pharmaceutical contaminants that impact negatively the environment. Development of affordable procedures for their quantification and removal from waters is gained interest in the scientific community. The present study was aimed at the characterization of rice husk ash as sorbent for the solid phase extraction of mentioned drugs in waters. Optimal sorbent dose, pH dissolution and contact time were selected. Up to the best of our knowledge, the good performance of rice husk ash for extraction of carboplatin, ibuprofen and diclofenac from aqueous dissolutions is demonstrated for the first time in the present study, achieving a maximum sorption capacity of 5.843 mg.g−1, 2.321 mg.g−1 and 2.316 mg.g−1, respectively, which are higher than those reported for others pharmaceutical products with husk rice ashes. Kinetic of sorption was well modeled by a Lagergren pseudo first order model for diclofenac and by a pseudo second order model of Ho for ibuprofen and carboplatin. Sorption at equilibrium conditions was well modeled by Freundlich and Toth isotherms for diclofenac and ibuprofen, while Sips, Toth and Dubinin-Radushkevich isotherms adjusted well for carboplatin. Kinetic and at equilibrium conditions studies confirmed the high complexity of involved sorption mechanisms in the three adsorbate/rice husk ash systems considered.

Trace arsenic quantification by hydride generation-flame atomic absorption spectrometry using durian husk-derived nanocellulose as a solid-phase extraction biosorbent

&lt;p&gt;In the present study, nanocellulose was successfully extracted from durian husk via chemical treatment and then characterized by several analytical techniques, involving X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Nanocellulose was obtained with a crystallinity index of 77% and in the form of cellulose nanofibrils (30 nm in width and micrometers in length). Using nanocellulose as a biosorbent in solid-phase extraction technique, the inorganic arsenic ions were eluted using 0.1 M HNO3 and its content in the eluate solution was quantified by hydride generation-flame atomic absorption spectrometry (HG-FAAS), in which the recovery of arsenic ions using nanocellulose were assessed via contact time, pH and dosage of sorbent, reaching the equilibrium after 30 minutes. With the limit of detection (LOD) of 0.41 ng mL-1, the limit of quantification (LOQ) of 1.38 ng mL-1 and the relative standard deviation of repeatability (%RSD) of 3.44% (with ten replicates) for arsenic determination, the present method was practiced with the trace inorganic arsenic quantification in real samples (fish sauce with various protein levels) with reliable spike recoveries.&lt;/p&gt;&#x0D;

Maize cob (Zea mays) as natural biomass sorbent for crude oil biosorptive removal from contaminated seawater: Taguchi process optimization and biosorptive removal mechanism.

Crude oil pollution poses a serious threat to the aquatic environment. Hence, there is an increasing interest in developing an efficient cleaner process technique for oil spill cleanup via agricultural biomass waste-organic sorbent utilization. This work evaluated the effects of independent biosorptive removal at three varying levels (initial concentration of crude oil (Z1, 7.8-15.6 g/L), seawater-oil temperature (Z2, 25-45 °C), sorbent dose (Z3, 1-3 g), and sorbent particle size diameter (Z4, 1.18-4.72 mm)) on the biosorptive removal efficiency and biosorptive capacity performance of maize cob sorbent for crude oil biosorptive removal from seawater. Experiments were designed based on Taguchi orthogonal array experimental design (L9(34)) to study the effects and process optimization. The results revealed that the maize cob sorbent's crude oil biosorptive removal efficiency is related to Z1, Z3, and Z4, while the biosorptive capacity is related to Z1 and Z3. The optimum biosorptive removal efficiency and the biosorptive capacity values were 96.53% and 12.64 g/g, respectively, achieved at optimum factors of Z1 (7.8 g/L), Z3 (3 g), and Z4 (1.18 mm), as well as at Z1 (15.6 g) and Z3 (1 g). The isotherm and kinetic data, respectively, followed the Langmuir isotherms and the pseudo-second-order kinetics with a maximum monolayer biosorptive capacity of 23.31 g g-1. The mechanism of biosorptive crude oil removal was by physical sorption and film diffusion control. Therefore, the maize cob represents an inexpensive and effective natural sorbent for oil spill removal from water bodies.

Dispersive magnetic solid phase extraction of triazole fungicides based on polybenzidine/magnetic nanoparticles in environmental samples.

Apolybenzidine-modified Fe3O4@SiO2 nanocomposite was successfully synthesized through a chemical oxidation method and employed as a novel sorbent in dispersive magnetic solid phase extraction (DMSPE) for the preconcentration and determination of three triazole fungicides (TFs), namely diniconazole, tebuconazole, and triticonazole in river water, rice paddy soil, and grape samples. The synthesis method involved a polybenzidine self-assembly coating on Fe3O4@SiO2 magnetic composite. Characterization techniques such as FT-IR, XRD, FESEM, EDX, and VSM were used to confirm the correctness of the synthesized nano-sorbent. The target TFs were determined in actual samples using the synthesized nanocomposite sorbent in combination with gas chromatography-flame ionization detection (FID). Several variables were carefully optimized , including the sample pH, sorbent dosage, extraction time, ionic strength, and desorption condition (solvent type, volume, and time). Under the optimized experimental conditions, the method exhibited linearity in the concentration range 5-1000 ng mL-1 for triticonazole and 2-1000 ng mL-1 for diniconazole and tebuconazole. The limits of detection (LOD) for the three TFs werein the range 0.6-1.5 ng mL-1. The method demonstrated acceptable precision with intra-day and inter-day relative standard deviation (RSD) values of less than 6.5%. The enrichment factors ranged from 248 to 254. Finally, the method applicability was evaluated by determiningTFs in river water, rice paddy soil, and grape samples with recoveries in the range 90.5-106, indicating that the matrix effect was negligible in the proposed DMSPE procedure.

Usage of natural wastes from animal and plant origins as adsorbents for the removal of some toxic industrial dyes and heavy metals in aqueous media

It has always been crucial to have enough water available for survival and growth; hence it is necessary to purify polluted water for reuse. In this study, contaminated water is cleansed by the adsorption of three dyes Methylene blue (MB), Congo Red (CR), and Bromocersol Green (BCG), as well as two heavy metals, chromium (VI) and zinc (II) using a low-cost adsorbent like activated carbon gotten from treated sheep remnants and barely husks. H3PO4 acid-modified adsorbents were used in adsorption tests, which involved six different parameters (pH, contact time, adsorbent concentration, sorbent dosage, temperature, and stirring speed). The optimum pH values for the adsorption of Cr (VI), Zn (II), MB, CR, and BCG onto both adsorbents were 6, 7, 4, and 6, respectively, giving equilibrium adsorption capacity values of 1.617, 1.529, 15.388, 62.401, and 288.902 mg/g, respectively. The adsorption capacity of the activated carbon increases with increasing contact time till equilibrium is established, Adsorption isotherm study was evaluated using both the Langmuir and the Freundlich isotherms to confirm the effectiveness of adsorbents made from inexpensive wastes. Furthermore, the merits of using treated natural wastes from both plant and animal origins for water purification have been confirmed. This study supports the concepts of the environmental sustainability for the earth plant.

Role of starch in one pot fabrication of mesoporous gamma-alumina with excellent fluoride sorption capacity

Green synthesis of mesoporous γ-AƖ2O3, a cutting-edge material for sustainable application in medicine, engineering, energy, and water treatment, is still challenging. Our study used a one-pot strategy for facile synthesis of γ-AƖ2O3 by sol-gel method using starch from cassava waste. AƖ(OH)3 were bound to the O-H groups of the starch molecule to form the AƖ(OH)3-starch complex in a nano-network confined in starch polymer cages. Its calcination at 500 ℃ produced a mesoporous, highly crystalline water stable γ-AƖ2O3 with a pore size of 2.07 nm and an extensive BET surface area (215 cm2/g). Using the response surface methodology (RSM), the as-synthesized γ-AƖ2O3 was optimized for efficient fluoride removal from water. A central composite design (CCD) was used to study the effect of initial fluoride concentration, pH, contact time, and sorbent dose on fluoride removal efficiency and optimization of the process. The relative importance of the sorption process variables to the fluoride removal process was assessed using ANOVA. The quadratic model showed that the predicted response was significantly correlated with the experimental response (R2 = 0.9667), with sorbent dose and pH being the process's most influential factors. Optimum conditions for 93.6% fluoride removal efficiency were sorbent dose of 0.5 g, initial fluoride concentration of 10 mg/L, pH 7, and contact time of 137.5 min. A weakly acidic medium favored fluoride removal from water, while the presence of PO43- and HCO3- retarded the process. The sorption data fitted well in the Langmuir isotherm (0.9783) and pseudo-second-order kinetic model (0.9999), indicative of a chemisorption process. The maximum sorption capacity towards fluoride was 207.5 mg/g. A thermodynamic study indicated that the sorption process was spontaneous and endothermic, with increased randomness at the solid-solution interface. Sorption, desorption, sustainability, and leaching tests showed that the sorbent could be used for sustainable fluoride removal at 8.3 USD/1000 liters of safe drinking water.