Real Sample Solutions Research Articles

Colorimetric and fluorescence detection of Pb2+ by fluorescein derivative

A simple and low cost method for rapid detection of Pb2+ was developed in this study using a simple fluorescent probe, biotin-4-fluorescein. The presence of Pb2+ induced the color change of fluorescein from yellow to pink which can be detected visually by naked eyes. The color change of biotin-4-fluorescein was not observed while testing with other metal ions, such as Fe3+, Cu2+, Ca2+, Co2+ and Cd2+, indicating the selectivity of fluorescein derivative with Pb2+. Moreover, the color change was observed at pH above 7.0, and the pink color got more intense when increasing pH. Adding EDTA, a chelating reagent, into the solution of biotin-4-fluorescein/Pb2+ resulted to the rebound of the color to the original color of free biotin-4-fluorescein. The fluorescence spectra of fluorescein decreased with increasing Pb2+concentration, and the quenching was enhanced at higher pH. The association constant (Ka) of 2.00 × 104 M−1 was calculated from the fluorescence spectra with the limit of detection (LOD) and the limit of quantitation (LOQ) of 1.38 × 10−5 M (2.86 ppm) and 4.61 × 10−5 M (9.55 ppm), respectively. Job’s plot analysis indicated 2:1 ratio of binding interaction. Pb2+ in untreated wastewater was quantified for 24.99 ppm using this method. This quick analysis can be beneficial for the application of lead detection in real sample solutions, such as wastewater from industrial factories.

Enhanced photocatalytic performance of ternary g-C3N4/UiO-66/Ag3VO4 composite for methylene blue degradation under visible light irradiation

Anovel Ag3VO4/UiO-66/g-C3N4-based photocatalystwassynthesized using the solvothermal approach and characterized using XRD, SEM, FTIR, PL, and UV–Vis DRS. The photodegradation capacityof each componentwas tested using aqueous solutions of methylene blue (MB) and real sample solutions. It was found that the ternary composites (g-C3N4/UiO-66/Ag3VO4, 1 wt%, 5 wt%, 10 wt%, and 15 wt% g-C3N4) demonstrated higher degradation efficiency than the single and binary constituentsowing to beneficial interactions in the composite, which favor successful interfacial charge transfer and improve photogeneratede--h+pair separations. The influence of various experimental factors such as pH, initial dye amount, photocatalyst dose, and scavengers on MB degradation was examined. At optimal conditions of pH 6, catalyst load of 60 mg, and initialdye content of 10 ppm, the percent photodegradation of MB under irradiation with visible light (indoorsystem) was 99.35 %, while in the outdoor system,it was 99.5 % in 240 min. The selected photocatalyst was also applied for the degradation of real sewage sample solution, which was found to be 80.2 % under indoor and 89 % under outdoor experimental undertakings. After five cycles, the potential of the photocatalystremained substantial, indicating remarkable reusability. The scavenging experiment suggested that the principal active species were found to be superoxide (O2•) and hydroxide radicals (•OH). Thus, the composite g-C3N4/UiO-66/Ag3VO4 could be a promising option for industrial effluent removalapplications, particularly in the purification of organic dye-containing wastewater.

Sensing of Gunshot Residue components from real sample using Fluorescence Resonance Energy Transfer

The present work represents a Fluorescence Resonance Energy Transfer (FRET) based sensing method for detecting Gunshot Residue (GSR) components. Two laser dyes Acf and RhB have been used as donor and acceptor respectively in the FRET pair. The real sample was collected after test firing in a forensic science laboratory. On the other hand, a standard GSR solution has been prepared in the laboratory. For the preparation of standard GSR solutions, we used the water solutions of the salts BaCl2, SbCl3, and Pb(NO3)2. The FRET efficiency was measured between Acf and RhB to sense the presence of GSR components (Pb+2, Ba+2, and Sb+3) in both real sample and standard solution by mixing the salts in aqueous solution. It has been observed that the FRET efficiency systematically decreases in the presence of GSR components. To amplify the FRET efficiency of the dye pair, inorganic clay dispersion (laponite) was used. The enhancement in FRET efficiency represents a better sensitivity of the proposed sensor. The current sensor is useful for the quantification of concentrations of the GSR components in a real sample.

Electrochemical Detection of Dopamine at a Novel Poly(2,4,6‐trihydroxybenzaldehyde) Film Modified Electrode

AbstractIn this study, a novel electrodeposition of poly(2,4,6‐trihydroxybenzaldehyde) on bare glassy carbon electrode for dopamine detection was reported. 2,4,6‐trihydroxybenzaldehyde and the electrodeposited poly(2,4,6‐trihydroxybenzaldehyde) were characterized using Fourier transform‐infrared spectroscopy, UV‐visible spectroscopy, and scanning electron microscopy. The bare electrode modified with the optimum amount of 2,4,6‐trihydroxybenzaldehyde (PTGCE) was used for dopamine electroanalysis. The linear dynamic range and the limit of detection of DA at PTGCE were 0.70‐19.48 μM and 19.48–53.30 μM, and 0.64 μM, respectively. The modified electrode showed outstanding discriminatory dopamine detection in the presence of uric acid and ascorbic acid due to a dopamine‐uric acid and a dopamine‐ascorbic acid peak‐to‐peak separation of 160 mV and 200 mV, respectively. The proposed sensor showed considerable reproducibility of dopamine current response and excellent % dopamine recovery of 99.70 % from the real sample solution.

Development of a fabric phase sorptive extraction method using ethylenediamine tetra-acetic acid modifier for quantitative determination and elimination of Pb2+, Cu2+ and Zn2+ cations in real sample solutions

A novel and simple fabric phase sorptive extraction technique based on using ethylenediamine tetra-acetic acid (EDTA-FPSE), was used for selective solid phase extraction of Pb2+, Cu2+ and Zn2+ cations followed by using inductively coupled plasma-optical emission spectrometry (ICP-OES). Then, the synthesized adsorbent was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-Ray (EDX) analysis. The effect of some parameters including pH of the sample solution, extraction time, sample solution volume and the type and concentration of desorbent solution was investigated and they were optimized in details. Under the optimum experimental conditions, the limits of detection (LOD) were found to be: 0.062, 0.032 and 0.036 µg/L for Pb2+, Cu2+ and Zn2+cations, respectively and the limits of quantification (LOQ) were equal to 0.18, 0.1 and 0.12 µg/L for Pb2+, Cu2+ and Zn2+cations, correspondingly. Also, the reusability of the synthesized EDTA based on fabric phase sorptive adsorbent, showed that for these metal cations, it could be used for at least 12 adsorption/desorption cycles. Adsorption mechanism was evaluated by different isotherm models and based on the obtained results, the adsorption of Pb2+, Cu2+ and Zn2+ cations is followed by Langmuir isotherm model with a maximum adsorption capacity of 92.60, 75.76 and 101.10 mg g−1 for Pb2+, Cu2+ and Zn2+cations, respectively. Finally, the selective behavior, high recovery percentage (more than 90 %), simple extraction procedure (easily separation of adsorbent from solution), makes the EDTA based on fabric phase sorptive extraction (EDTA-FPSE) technique as an unique technique for solid phase extraction of these heavy metal cations in different real sample solutions.

Optical detection of uric acid based on a citric acid functionalized copper-doped biochar nanozyme.

Uric acid is the end product of purine metabolism and is a key biomarker for various diseases. Under normal conditions, there is a balance between its production and excretion. Its higher concentration can cause inflammation and severe pain, which makes it necessary to monitor its level for the diagnosis, management, and treatment of various pathological conditions. The current work reports on the synthesis of a copper-doped biochar (Cu@BC) nanocomposite and its functionalization with citric acid. The synthesis of the mimic enzyme was confirmed through various spectroscopic techniques. The nanozyme catalyzes hydrogen peroxide to oxidize tetramethylbenzidine (TMB) with an optical change from colorless to blue-green. This optical transformation was confirmed through a UV-vis spectrophotometer, which gave an expected λ max of 652 nm characteristic of TMBoxi. The incorporation of uric acid into this reaction mixture resulted in the reduction of TMBoxi to TMBred, accompanied by an optical change from blue-green to colorless, which was again confirmed with a UV-vis spectrophotometer. The fabricated sensor's performance was finely-tuned to report on its various key components. The best response was achieved at 2 mg of the nanozyme, pH 6, time 150 seconds, TMB, and hydrogen peroxide 0.9 and 1.5 mM, respectively. Under the above-mentioned optimized conditions, the fabricated sensor detected uric acid in the range of 1-90 μM with limits of detection and quantification of 0.17 and 0.58 μM, respectively, with an R 2 of 0.997. The proposed sensor was highly selective and successfully detected uric acid in real sample solutions.

Coprecipitation of Trace Propineb in Water and Food with Separation-Preconcentration Using Cu(II)-8-Hydroxyquinoline (8HQ) Precipitate

A new coprecipitation procedure was improved for preconcentration-separation and detection of trace propineb. In order to coprecipitate propineb, 8-hydroxyquinoline (8HQ) and copper (II) were used as a precipitating agent and a carrier element, respectively. Using the stoichiometric relationship with zinc, propineb was determined. The critical parameters on the quantitative recoveries of analyte such as pH, mass of precipitating agent, mass of carrier element, and sample volume were studied. The influences of the matrix components were also tested. The preconcentration factor was 80. The limit of detection (LOD), and the limit of quantification (LOQ) for propineb were 0.114 mg L−1 and 0.38 mg L−1, respectively. Copper(II)-8-hydroxyquinoline coprecipitation was applied to determine propineb in vegetable and fruit samples from Kayseri-Turkey with satisfactory results. Flame atomic absorption spectrometry (FAAS) was utilized for measurements of model and real sample solutions.

Amine-functionalized biochar: Highly re-useable and green alternative for heparin recovery from porcine intestinal mucosa

Heparin is an invaluable pharmaceutical ingredient typically recovered from bovine lung or porcine intestinal mucosa by a complex and costly multi-step process. The design of an efficient environmentally improved adsorbent that has high adsorption capacity and high thermal and chemical stability to withstand the harsh steps of the heparin recovery process is essential. In addition, the importance of having the right functional groups on the surface of the material when designing an adsorbent is highlighted. Herein we describe the use of APTES-functionalized biochar (N-Char) as an efficient and sustainable adsorbent to recover heparin from a porcine intestinal mucosa sample. Results demonstrate that the N-Char can recover as much as 60% (∼31 mg g−1) of heparin from a real sample solution (Porcine intestinal mucosa) under optimized conditions with anticoagulant potency of 59 ± 3 U per gram of mucosa, compared to 51 ± 2 U per gram for the heparin recovered via the commercial resin Amberlite FPA98 Cl. Functionalized biochar demonstrates high stability throughout five recycling adsorption/desorption rounds, indicating excellent re-usability.

Synthesis and Characterization of CeO2/Ag3PO4 p-n Heterojunction Photocatalyst: Its Photocatalytic Activity for the Degradation of Alizarin Yellow Dye

Novel single and binary photocatalysts were synthesized by coprecipitation method. The crystal structure, surface area, morphology, bandgap energy, functional groups, and optical properties were characterized using XRD, BET, SEM-EDX, UV/vis, FTIR, and PL instruments, respectively. Aqueous solutions of the model contaminant alizarin yellow (AY) dye and real wastewater sample solutions were used to evaluate the photocatalytic activity of single and binary nanocomposite. We found that the photocatalytic activity of CeO2/Ag3PO4 binary nanocomposite is higher than that of their individual counterparts. We investigated the effects of operating parameters such as pH, initial dye concentration, and photocatalytic loading on AY dye degradation. Under optimal conditions, the binary system showed an efficiency of 96.99%. The binary photocatalyst showed relatively higher AY photolysis efficiencies than actual wastewater, about 96.56% and 57.76%, respectively. The actions of various scavengers suggest that ·O2 and ·OH scavengers play an important role in AY decomposition. When the reusability of the photocatalyst was tested, only a reduction of about 20% was observed after four consecutive runs. The degradation of AY follows pseudo-first-order kinetics for newly synthesized nanocomposite. This result indicates that the binary nanocomposite can serve as an excellent medium for electron transport.

Synthesis of photoluminescent composite based on graphene quantum dot@ZIF-11: A novel sensor for extremely efficient nano-molar detection of CN–

This report proposes a simple and very high sensitive photoluminescence sensor for the detection of fatal cyanide ion using a novel composite made from graphene quantum dots (GQDs) as luminescence quantum materials which was encapsulated successfully in zeolitic imidazolate framework)ZIF-11(as a stable porous carrier. Characterization methods such as TGA, TEM, SEM, XRD and IR have been utilized to identify the species. The detection method is based on the significant PL quenching signal of GQDs@ZIF-11 composite by increasing the concentration of cyanide ion. This sensor detected the CN– with wide linear range LDR (0.15 to 30 μM), 0.95 % RSD and excellent limit of detection (LOD) of 14.5 nM. Interference study carried out in the presence of 19 different ions with good sensitivity toward cyanide ion. Also the study was performed on two real cyanide sample solutions which were extracted from apple seeds and bitter almonds. The good selectivity, high sensitivity, stability and wide linear response range made the sensor reliable and valuable compared to other previous ones.

Zeolite supported CdS/TiO2/CeO2 composite: Synthesis, characterization and photocatalytic activity for methylene blue dye degradation

A novel ternary composite CdS/TiO2/CeO2 and its zeolite-support were synthesized and characterized using XRD, SEM, UV–Vis DRS and PL spectroscopy. The photocatalytic performance of the synthesized nanocomposites was investigated using an aqueous solution of Methylene Blue (MB) dye and a real sewage sample solution.The photocatalytic activity of the zeolite-supported composite was superior to the naked CdS/TiO2/CeO2, binary, and single counter constituents. The effect of operational parameters on MB dye degradation was evaluated, and a significant photodegradation was recorded by a zeolite-supported CdS/TiO2/CeO2 composite. The supported composite showed significantly higher performance on the discoloration of MB (99.9%) than the real sewage sample solution (78.7%) based on the optimized parameters. The recyclability study of the spent photocatalyst exhibited 86.0% degradation of MB after four consecutive cycles, indicating the stability of the composite. Based on the findings, this research offers insight into a new and efficient visible-light-driven photocatalyst for the degradation of organic dyes in wastewater.

(Digital Presentation) Dopamine Detection at Green Carbon Quantum Dots Based Electrochemical Sensor

This work describes the fabrication and application of a sensor based on green carbon quantum dots/copper oxide nanocomposite for dopamine (DA) detection. The characterization of the copper oxide nanoparticles (CuO NPs), green carbon quantum dots prepared from banana peels (gCQDs), and their composite (gCQDs/CuO) was effected through Fourier Transform infrared spectroscopy (FT-IR), UV-visible spectroscopy, X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and thermogravimetric analysis. The comparative cyclic voltammogram of the CuO NPs modified glassy carbon electrode (GCE) (CuO/gCQDs), gCQDs modified GCE (gCQDs/GCE), and the nanocomposite modified GCE (gCQDs/CuO/GCE) shows that the composite modified GCE has the best electrocatalytic activity towards DA detection. The Nyquist plot of electrochemical impedance spectroscopy (EIS) data revealed that the composite modified GCE possesses the lowest charge transfer resistance (Rct). Using the square wave voltammetry (SWV), this sensor offered a limit of detection (LoD) of 25.41 µM over a linear range of 50-200 µM. The real sample analysis of DA in dopamine hydrochloride injection shows that the proposed sensor is capable of 94.8 % DA recovery from the real sample solution. The sensor also offered selective DA detection in the presence of ascorbic acid (AA).

Sensitivity and intrinsic limit of detection improvement in a photonic refractive-index sensor

In this work, we study the bulk refractive index (RI) sensitivity (S) and intrinsic limit of detection (ILOD) of a micro racetrack resonator (MRR) based RI-sensor. Sensing measurements are performed with solutions of sodium chloride (NaCl)-water. The sensing device includes an array of multiple silicon-oxy-nitride (SiON) MRRs, fibre-coupled to a vertical-cavity surface-emitting laser (VCSEL) operating at 850 nm. We particularly choose 850 nm for sensing measurement, since the water absorption coefficient at this wavelength is three orders of magnitude lower than at 1550 nm (another conventional wavelength in biosensing). Different concentrations of NaCl–water solutions (spanning from 0.0% to 1.8% weight/weight), are flowed on top of the MRR surface in the cladding layer. Measuring of whispering gallery mode (WGM) resonance wavelength shifts in NaCl–water solutions, confirming a S and ILOD of 31.66 nm/RIU and 5.98×10−4 RIU, respectively. Furthermore, with exact engineering of the physical parameters of the system, the best S and ILOD of 325.85 nm/RIU and 6.14×10−5 RIU are found, respectively. The ILOD parameter delineates the minimum amount of RI or correspondingly minimum concentration of a biological solution, which can be detected by a RI-sensor. In this regard, this device can find applications in the exact measurement of NaCl in real biological sample solutions.

Synthesis, characterization and electrochemical sensors application of MnO2 nanoparticles

The prepared MnO2 nanoparticles were characterized through electronic spectroscopy. The band gap value of nanoparticles is 3.12 eV. The stretching vibration band of nanoparticles of MnO2 at 631 cm−1 can be assigned to Mn–O. The manganese oxide nano flower–like structure, proved through atomic force microscopy (AFM) photographic studies. The MnO2 morphology was confirmed uniform coating on the electrode surface. Glassy carbon electrode (GCE) was modified with manganese oxide nanoparticles to enhance the electrocatalytic activity of the redox behavior of ascorbic acid. The oxide nano flower modified electrode is used as fresh voltammetric determination of ascorbic acid. The results of voltammetric behavior are satisfactory in the electro oxidation of ascorbic acid, and exhibit considerable improvement compared to glassy carbon electrode. Under the optimized experimental conditions, the modified electrode exhibit better linear dynamic range from 50 μg/L to 500 μg/L with lower limit of detection 30 μg/L for the stripping voltammetric determination of ascorbic acid. The real sample solution of ascorbic acid was successfully applied for accurate determination of trace amounts on nanomaterials modified electrode.

Synthesis and characterization of CdS/UiO-66/Ag3PO4 nanocomposite for photocatalytic degradation of methyl orange under visible light irradiation

Single, binary and ternary nanomaterials were synthesized by precipitation, solvothermal, simple solution and impregnation methods to serve as photocatalysts. The crystal structure, morphology, band gap energy, functional groups and optical properties of these materials were characterized by XRD, SEM-EDX, UV-Vis, FTIR, and PL instrumental techniques, respectively. Photocatalaytic degradation performances of all the as-synthesized photocatalysts were investigated under visible light irradiation using MO as a model organic pollutant. The photocatalytic degradation performances of all the photocatalysts were evaluated on aqueous solution of the model pollutant dye as well as on a real sewage sample solution collected from Bahir Dar Textile Share Company. Results suggested that the optimized ternary nanocomposite photocatalyst exhibited a relatively higher efficiency towards the photodegradation of both the methyl orange (MO) dye solution (90%) and the real sewage sample solution (71.2%). The effect of operational parameters such as pH (4), initial dye concentration (10 mg/L) and photocatalyst load (0.2 g/L) in MO dye degradation were investigated by using the ternary CdS/UiO-66/Ag3PO4 (R4) nanocomposite.
 
 KEY WORDS: Metal-organic frameworks, Nanocomposite, Ternary system, Photocatalysts, Methyl orange
 
 Bull. Chem. Soc. Ethiop. 2020, 34(3), 571-588.
 DOI: https://dx.doi.org/10.4314/bcse.v34i3.12

Enhanced photocatalytic activity of p-n-n heterojunctions ternary composite Cu2O/ZnO/Ag3PO4 under visible light irradiation

In this work, a ternary composite Cu2O/ZnO/Ag3PO4 with p-n-n heterojunctions was prepared via co-precipitation method. Single and binary counterparts were also prepared under similar conditions for comparison. The as-obtained photocatalytic materials were characterized by AAS, XRD, SEM-EDX, Uv–vis, PL, FTIR and BET techniques. Presence of the three oxide components in the composite was confirmed from AAS, XRD and EDX analyses. The calculated band gap of the composite (2.15 eV) demonstrated how formation of hetrojunction influenced the band gap of the host semiconductor ZnO (3.18 eV). Photocatalytic degradation activity of the composite under visible light irradiation was evaluated in aqueous solution comprising a model dye pollutant methyl orange (MO) and on a real sewage sample solution collected from Bahir Dar Textile Share Company. The ternary composite, Cu2O/ZnO/Ag3PO4, has shown relatively higher photodegradation efficiency on both Methyl orange (MO) (81.1 %) solution and textile effluent (78.2 %) compared with its single and binary congeners. This clearly indicates that the multiple heterojunction created a condition that favors the enhancement of MO dye degradation. The ternary heterojunction showed prolonged delay of electron-hole recombination, which is responsible for its highest photocatalytic efficiency as confirmed from results obtained from PL and trapping experiment.

Bio-Electrochemical Analysis of L-Ascorbic Acid Concentration in between Glaucoma/Cataract Patients Aqueous Humor

Glaucoma is the second leading causes of vision loss in the world after cataract and irreversible, particularly among the elderly, several years past, most of the molecular mechanisms leading to primary open angle glaucoma (POAG) are still unknown, however scientists discovered ascorbic acid (AA) concentration is reduced in cataract and glaucomatous patients aqueous humor compared with healthy eyes.For understand relationship between AA concentration and glaucoma, we try to develop a simple, sensitive and accurate sensor device for detection in AA . Electrochemical sensor featured with short analytical time, low cost, high sensitivity compared with other methods, in this work, a new electrochemical aptamer sensor for detecting AA was fabricated based on AA specific aptamer linked with polydopmine (PD) layer and immobilized on screen printed carbon electrode (SPCE). Cyclic voltammetry (CV) was used to investigate AA concentration dropped on modified electrode .Both analyze real human aqueous humor sample or commercial AA solution , aptamer electrode performed a good accuracy compared with high performance liquid chromatography (HPLC).

A novel electrochemical sensor based on carbon nanotubes array for selective detection of dopamine or uric acid

A novel single-walled carbon nanotubes array-modified glassy carbon electrode (SWCNTs array-GCE) has been fabricated through a simple electrochemical technique. Benefitting from their vertically aligned configuration on the electrode surface, the modified single-walled carbon nanotubes can be used more efficiently in comparison with other modified method. The as-fabricated SWCNTs array-GCE can separate the anodic oxidation potential of dopamine (DA), uric acid (UA) and ascorbic acid (AA) with well-defined peak separation in the presence of each other, and thus employs as a new electrochemical sensor for selective determination of DA and UA. It can make a further improvement of the electrocatalytic ability of the electrode to perform an acetone pretreatment to SWCNTs array-GCE before electrochemical detection, which has been confirmed by atomic force microscope and electrochemical impedance spectroscopic measurements. Especially, unlike other carbon nanotubes-based electrode at which only two redox pairs are observed for dopamine oxidations, a third two-electron oxidation of 5,6-dihydroxyindole to indole-5,6-quinone can be clearly observed at acetone-pretreated SWCNTs array-GCE, showing the excellent electrocatalytic performance of as-fabricated electrode toward dopamine. The practicability of SWCNTs array-GCE was evaluated for the selective detection of DA and UA in real sample solutions of human serum and urine. It revealed acceptable recovery results in the range of 94–104%, indicating that it might be a promising platform for further biosensor development.

Removal of Methylene Blue Dye from Water using Ecofriendly Waste Product (Eggshell) as an Adsorbent and Using the Optimum Adsorption Conditions with Real Water Sample from Tigris River

Environmental pollution is a worldwide issue that affects the human being health, water pollution is one of the causes of this phenomenon. Dyes represent the raw materials in many industries such as textile, paper, plastic and leather industries as well as they considered as toxic water pollutants. The adsorption method is one of the most effective methods for removing dyes from polluted water. In this search, ecofriendly food waste (eggshell) was used as an adsorbent for removing methylene blue dye (MB) from waste water. In this research, eggshell morphology was studied using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX). The stability of the eggshell adsorbent was tested by Thermal Gravimetric Analysis (TGA). Whereas checking with various MB dye concentration for eggshell the maximum adsorption was noticed at (8ppm) and this concentration was used for further optimization. MB solutions was prepared at pH 7.2 and at 21℃ same conditions as in Tigris River water which was used to compare the activity of the eggshells adsorbent using analytical standard MB solutions and on the other hand using real sample solutions. The results show that using eggshells adsorbent with standards solution and real sample solutions of MB provide the same general trends with respect to MB removal. Consequently, using eggshell as an ecofriendly adsorbent was successfully tested to be used with both MB analytical standard solutions and real river MB solutions.

Evaluation of Clay Soil Efficacy Carrying Zero-Valent Iron Nanoparticles to Remove Nitrate From Aqueous Solutions

Evaluation of nitrate removal from water resources by using clay soil adsorbent with zero-valent iron nanoparticles as reduction factor was the objective of this study. The optimal parameters such as pH, contact time, amount of adsorbent and various nitrate concentrations were then determined and adsorption isotherm coefficients were calculated based on optimum conditions. The optimal parameters in real solution samples were then analyzed. Physical features of adsorption column were determined using SEM and TEM tests. Data analysis was performed using descriptive statistics. At pH 3, contact time of 80 min, the amount of adsorbent 10 g/L and nitrate concentrations of 50 mg/L; maximum nitrate removal rate 99% was achieved. This amount was 95% in real solution. Nitrate uptake absorption was conducted using the Freundlich isotherm model. Regarding removal efficiency of 95%, clay soil modified by zero-valent iron nanoparticles had high capacity to remove nitrates from water. This method is thus recommended.