Polyurethane Foam Sorbent Research Articles

Adsorption–Desorption Process to Separate Dyes from Tanning Wastewaters

Wastewater production is a major environmental issue for the leather and textile industries: in a modern plant, several synthetic dyes are used in separated coloring batches whose wastewaters are usually mixed, diluted with other process water streams, and sent to a unique wastewater treatment plant. This includes specific physical and biochemical tertiary treatments to remove dyes efficiently. One of the main difficulties of these processes is the presence of multiple dyes, which cannot be treated with the same efficiency as a “wide-spectrum” process. This work explores the possibility of using conventional granular activated carbon (GAC) and a new polyurethane foam (PUF) for the adsorption of an acid red dye in the wastewater of a specific coloring batch of the tanning industry. The aim of this work is twofold: on the one hand, we aim to explore the performance of the new PUF sorbent; on the other hand, we aim to explore the possibility of using adsorption as an optimized pre-treatment for single-dye batches, which may take advantage of the presence of a single type of target dye and its higher concentration. The effluent is then sent to the wastewater treatment plant for further depuration.

Elimination of Terbinafine Hydrochloride Antifungal Drug Traces from Water, Pharmaceutical Formulations and Blood Plasma using Low-Cost Bio and Synthetic Sorbents

<p>:<strong> </strong>Chitosan (CS) biosorbent and polyurethane foam (PUF) synthetic sorbent have been utilized to eliminate terbinafine hydrochloride (TRB HCl) antifungal drug in its pure and pharmaceutical forms from both contaminated aqueous and biological media using a batch process. The experimental conditions for efficient removal of TRB HCl for both CS and PUF were optimized depending on various experimental parameters such as the pH of the solution, contact periods, initial TRB HCl concentration, and sorbents dosage in the solution.</p><p>SEM, FT-IR, and XRD characterizations were carried out to study the adsorption of a drug by both sorbents. The optimum conditions for removing TRB HCl by CS and PUF were achieved at a pH of 8.5 and a contact time of 60 min at 250 rpm, using 0.4 g for both sorbents. The measured spectrophotometric absorbance at λ<sub>max</sub> of TRB HCl was 242 nm. In addition, the zero-point charge (pHpzc) was determined for the studied sorbents. The pHpzc of the surface of sorbents has shown that electrostatic attraction is one of the mechanisms in TRB HCl sorption. The adsorption process was modeled using the pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion kinetic models. The results indicated that the adsorption of TRB HCl on CS and PUF does follow a pseudo-first-order type of reaction kinetics. The adsorption process was modeled using Langmuir and Freundlich isotherms. The adsorption data found that the Freundlich isotherm model was more suitable for the PUF sorbent, while the Langmuir isotherm model better fit the CS biosorbent.</p><p>Evaluation of the experimental data using the Langmuir equation revealed that the maximum adsorption capacities of PUF and CS were 2.807 and 1.2297 mg. g<sup>-1</sup>, respectively. The solution was also used to estimate TRB HCl in its pharmaceutical form, and the assessed recoveries were 97.25 and 98.437% for CS and PUF, respectively. The proposed procedure was validated for other complex mediums by removing TRB HCl from spiked human blood plasma.<em> In-silico</em> aquatic toxicity forecast of TRB HCl was also carried out.</p>

Impregnation of Activated Carbon in Polyurethane Foam for Enhanced Solvent and Oil Adsorption from Water

This study illustrates the modification of the Poly-Urethane Foam (PUF) prepared from the Tung Oil (TO) and later impregnating it with varying ratio (~ 1 to 5 w/w%) of Activated Carbon (AC) which enable this modified entity to act as an effective adsorbent for the solvent and oil removal from the water. After its modification, it was found that the PUF impregnated with 5 w/w% AC displayed an enhanced solvent and oil adsorption capacity. The reusability of the adsorbent was observed to decrease with increasing number of cycles. Furthermore, the adsorption conduct was calculated in a batch-type process and validated using equilibrium and kinetics study. Here, the surface-modified PUF sorbent was characterized employing Scanning Electron Microscopy (SEM) and Contact Angle (CA) wettability study. Our findings inferred that with increasing AC ratio in the foam, its pore size and CA increases thereby enhancing the adsorption capacity making this proposed study to be more expedient for sustainable environment safety.

Separation of nickel and cadmium from aqueous solutions by flow injection preconcentration onto cadion functionalized polyurethane foam

A simultaneous spectrophotometric method was developed for the rapid determination of the binary elements nickel and cadmium. Two polyurethane foam sorbents, cadion functionalized foam and untreated foam, were separately packed in two minicolumns and used for on-line preconcentration/separation. The two elements were separated/preconcentrated on the cadion- foam minicolumn, and then they were eluted by hydrochloric acid and mixed with a thiocyante stream before entering the untreated foam minicolumn. Nickel passed out to react with 4-(2-pyridylazo)-resorcinol reagent and measured spectrophotometrically at 498 nm. The adsorbed cadmium-thiocyanate on the untreated foam was further eluted by sodium hydroxide and identically detected. At a preconcentration time of 60 sec (100 µg L−1), the detection limit was 4.6 and 3.3 µg L−1 and the quantification limit was 15.3 and 11.0 µg L−1 for cadmium and nickel, respectively. The preconcentration factor was 5.0 and 11.0, respectively, and sampling frequency was 12 and 20 h−1. The accuracy was assessed using the BCR397R human hair and NIST 1577b bovine liver certified reference materials with a recovery of 92.0–94.2% (Relative standard deviation = 5.3–8.2%). The analysis of human urine and tap water samples demonstrated the applicability of the method and showed a relative recovery of 89.6 to106% (Relative standard deviation ≤ 9.4%).

Sorption behavior of selected chlorophenols onto polyurethane foam treated with iron(III): kinetics and thermodynamic study.

An efficient, selective, and inexpensive method for complete elimination of chlorophenols (CPs) from water has been established. The proposed procedure was based upon the use of n-tributyl phosphate (TBP)-plasticized iron(III) physically immobilized polyurethane foam (PUF) solid sorbent for complete removal of CPs from aqueous media at pH close to 0. The interaction of the complex ion [Fe(C6H5O)6]3- with protonated ether oxygen of the PUF sorbent forms ternary ion associate on/in the PUFs. The retention of 4-chlorophenol (4-C) and 2,4,6-trichlorophenol (TCP) by the TBP-treated iron(III)-immobilized PUF fitted well with the pseudo-second-order kinetic model with a rate constant (k) of 0.04 and 0.15 g (mg min)-1, respectively. The sorption of 4-CP was endothermic whereas the uptake of TCP was favorable at low temperature approving the exothermic and non-spontaneous characteristics of its uptake. The ΔS value for 4-CP reveals good affinity of the ion [Fe(C6H5O)6]3- towards the PUF sorbent.

A novel platform based on gold nanoparticles chemically impregnated polyurethane foam sorbent coupled ion chromatography for selective separation and trace determination of phosphate ions in water

The sorption characteristics of phosphate ions from aqueous molybdate solution of pH ≤ 2 onto malachite green (MG) impregnated thiophenol (TP) functionalized Au nanoparticles based polyurethane foam (PUF) solid platform (MG-AuNPs-treated PUF) was studied. Phosphate uptakes followed Langmuir and Freundlich models. Based on the retention profile, a dual mechanism involving a “weak base anion exchanger i.e. solvent extraction” and a “surface adsorption” of phosphate retention as complex ion associate {[MG]+.[H2PMo12O40]−}PUF is anticipated. Complete retention of phosphate at various concentrations (0.01–100.0 μg mL−1) onto the sorbent packed column at 3–5 mL min−1 flow rate was achieved. A highly sensitive strategy for enriching, quantitative recovery and trace determination of phosphate in water using the sorbent packed column was developed. Under the optimized parameters, a linear concentration range of 0.07–25 μg L−1 and limits of detection (LOD) and quantification (LOQ) of 0.02 and 0.07 μg L−1 phosphate were achieved, respectively. The proposed and reference methods for analysis of phosphate in water samples were subjected to statistical treatment (student's t and F tests) at 95% confidence with no significant difference indicating the precision and accuracy of the proposed assay. The settled sorbent in flow mode was robust sufficient to be reused for five times without significant decrease in its performance. The intraday repeatability and interday stability of the established sorbent packed column towards phosphate (10.0 μg L−1) determination was studied. An estimated coefficient of variation less than ±5% was achieved revealing the suitably of the modified PUFs in column mode. The established column enabled multiple enrichment of phosphate from water and expanded the range of phosphate level which can be determined in water.

X-Ray Fluorescence Determination of Trace Elements in Vitamin-Mineral Complexes and Medicinal Herbs Using Chemically Modified Polyurethane Foam Sorbents

In this paper we proposed the method of X-ray fluorescence (XRF) determination of some essential trace elements in medicinal herbs and vitamin-mineral complexes at the level of 100-101 mg/ml. To increase sensitivity and selectivity of the determination we simple and effective approach based on the extraction of metal ions from aqueous solutions with chemically modified polyurethane foam sorbents followed by direct XRF analysis. The conditions of sorption preconcentration of Co(II), Ni(II) and Zn(II) ions with modified sorbents were optimized. The proposed approach is used for the determination of trace elements in several kinds of medicinal herbs (coltsfoot leaves, nettle leaves and yarrow herb) and vitamin-mineral complexes («Alfavit», «Vitrum» and «Multi-tabs»).

Colorimetry and Indirect X-ray Fluorescence Determination of Active Ingredients in Tetracycline Hydrochloride Drug and Injection Solution of B12 Vitamin Using of Polyurethane Foam Sorbents

The simple and available technique of colorimetry and indirect X-ray fluorescence determination of tetracycline hydrochloride (in the form of colored complex with iron(III) ions) and cyanocobalamine (in the form of the colored thiocyanate complex with cobalt(II) ions) is offered. The analytes were separated from the accompanying components by sorption to polyurethane foam based on ethers. The conditions of sorption separation and measurement of analytical signal of these substances are optimized. The obtained results of tetracycline drugs and injection solution B12 vitamin are in satisfactory agreement with data declared by the manufacturer.

The retention profile of phosphate ions in aqueous media onto ion pairing immobilized polyurethane foam: Kinetics, sorption and chromatographic separation

A strategy for enriching, separating and determining the inorganic phosphate ions in water based on the use of polyurethane foam (PUFs) physically immobilized with some ion pairing or basic dyes has been reported. The retention of inorganic phosphate from the test aqueous solution containing molybdate ions onto untreated- and ion pairing reagent e.g. crystal violet (CV) or tetrabutylammoniumtetrafluoroborate (Bu4N+·BF4−) impregnated PUFs solid phase extractor was followed the order: unloaded<CV<Bu4N+·BF4− treated PUFs sorbent at pH3.5–4.5. The kinetics of analyte sorption onto Bu4N+·BF4− treated PUFs at optimized pH (pH3.4–4.5) was fast and followed first order rate equation with an overall rate constant of 0.062min−1. Film and intraparticle transport are the main factors controlling the rate of phosphate sorption onto the sorbent from solutions at pH=3.5–4.5. Phosphate uptake followed Langmuir and Freundlich isotherm models. Thus, a dual-mode sorption involving absorption related to “weak base anion exchanger” and an added component for “surface adsorption” is the most probable retention mechanism for phosphate uptake by Bu4N+·BF4− loaded PUFs sorbent. Chromatographic separation of phosphate by Bu4N+·BF4− treated PUFs packed column was carried out. The number (N) and the height equivalent to the theoretical plates (HETP), critical and breakthrough capacities were found equal 81±4, 0.13±0.02mm, 2.5±0.2 and 27.25±2.06mgg−1, respectively. These results suggested the use of the proposed Bu4N+·BF4− treated PUFs in packed column for separation of trace levels of phosphate in water. The retained phosphate were recovered quantitatively (102.6±2.4–106.2±3.2%) with NaOH (0.5molL−1) and analyzed. The proposed column was applied for separation and recovery of phosphate ions in waste- and seawater samples. The results were in good agreement with the spiked and expected phosphate concentrations at 95% confidence.

Kinetics and thermodynamic characteristics of cadmium(II) sorption from water using procaine hydrochloride physically impregnated polyurethane foam

A fast and selective method for cadmium(II) removal from water by procaine hydrochloride (PQ+·Cl−) immobilized polyurethane foam (PUFs) sorbent was developed. The method was based upon formation of [CdI4]−2aq in the test aqueous KI solution and subsequent extraction by PQ+·Cl− treated PUFs. The sorption of Cd2+ ions followed first order equation with an overall rate constant of 0.132±0.033min−1. The values of ΔH and ΔS were −41.54±0.9kJmol−1 and −144.58±3.1Jmol−1K−1, respectively with a correlation factor of 0.998. The thermodynamic parameters (ΔH, ΔS and ΔG) suggest that the sorption was spontaneous and exothermic process. The negative value of ΔS provides indication of moderate sorption of [CdI4]2− ion associate and ordering of the ionic charges without compensatory disordering of the sorbed species onto the sorbent. Cadmium(II) sorption is mainly dominated by absorption related to “solvent extraction” and an added component for “surface adsorption”. PQ+·Cl− treated PUFs packed column was also tested for preconcentration of trace concentrations of cadmium(II) species in various water samples. The retained Cd species were successfully recovered with dilute HNO3 (1.0molL−1) and subsequently analyzed by ICP–OES. Thus, the proposed sorbent packed column provides efficient removal of traces of cadmium(II) ions from water samples. The method could be extended for preconcentrate of trace and ultra trace cadmium species from large samples onto PUF packed column and subsequently analyzed. Indeed, the developed method could be satisfactorily applied to the determination of trace Cd ions in natural water.

Determination of trace metal ions in water and plant samples using polyurethane foam modified with 2-aminothiazole

2-Aminothiazole (AT) was covalently bonded to polyurethane foam (PUF) via –N=N–NH– group and used for preconcentration/separation of Ni(II), Zn(II), and Cd(II) from water, black tea, and plant leaves prior to flame atomic absorption spectrometry determination. The resulting AT–PUF sorbent was characterized by density measurement, elemental analysis, UV–vis, and IR spectroscopy. The optimum sorption of these elements was achieved at sample pH 5–6. The sorption capacity was found to be 461 ± 1.4, 341 ± 1.3, and 435 ± 2.4 μg g−1 and limit of detection (3σ) was 2.0, 3.0, and 3.0 μg L−1 for Ni(II), Zn(II), and Cd(II), respectively. The preconcentration factor was 100 for all elements. The developed method was successfully applied for determination of these elements in tap and lake water, spinach and parsley leaves, and black tea samples and the corresponding relative standard deviation values were less than 10%.

Total-reflection X-ray fluorescence determination of cobalt and mercury in water using preconcentration on a polyurethane foam sorbent

A technique for X-ray fluorescence determination of cobalt and mercury in water using static and dynamic concentration in the form of thiocyanate and iodate complexes on polyurethane foam sorbents based on ethers is suggested. The possibility of the measurement of the X-ray fluorescence signal of analytes in the total external reflection mode, both in eluates and directly in the sorbent phase, is considered. The suggested approach allows one to improve the sensitivity of cobalt and mercury determination in water by 2–4 orders of magnitude in comparison with the classical sorption X-ray fluorescence techniques.

Retention Profile and Selective Separation of Trace Concentrations of Phenols from Water onto Iron(III) Physically Loaded Polyurethane Foam Solid Sorbent: Kinetics and Thermodynamic Study

Phenols are included in the list of potential toxins for motor neurons. Thus, fast and selective method for removal of phenols has been developed. The method was based upon the extraction of iron (III) phenolate complex anions [Fe(phenolate)6]3- by tri-n-butylphosphine (TBP)-plasticized iron(III) immobilized polyurethane foam (PUF) from the test aqueous solution adjusted to pH≈1 followed by subsequent formation of ternary ion association complex of these species with the protonated urethane and/or ether linkages on the PUF solid phase extractor (SPE). The rate of removal of phenols from the aqueous solution by TBP plasticized iron (III) immobilized PUF were studied in batch conditions employing a series of kinetic models. Initially, phenols uptake onto plasticized iron (III) treated PUF was fast followed by kinetically pseudo-second order rate equation with an overall rate constant (k) of 0.014 and 0.018 g (mg min)-1 for phenol and 2-chlorophenol (2-CP), respectively. Endothermic nature of phenols sorption is governed by the positive value of ΔH where as the negative values of ΔG dictate that the uptake of the analyte onto the sorbent is spontaneous phenomena. The positive values of ΔS for both phenols may be indicative of moderate sorption step of the complex anion [Fe(C6H5O)6]3- and ordering of ionic charges with a compensatory disordering of the sorbed species onto the sorbents. PUF sorbent provides efficient removal of phenols traces from various water samples.

Quality control for sampling of PCDD/PCDF emissions from open combustion sources

Both long duration (>6h) and high temperature (up to 139°C) sampling efforts were conducted using ambient air sampling methods to determine if either high volume throughput or higher than ambient air sampling temperatures resulted in loss of target polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs) from a polyurethane foam (PUF) sorbent. Emissions from open burning of simulated military forward operating base waste were sampled using EPA Method TO-9A for 185min duration using a filter/PUF/PUF in series combination. After a 54m3 sample was collected, the sampler was removed from the combustion source and the second PUF was replaced with a fresh, clean PUF. An additional 6h of ambient air sampling (171m3) was conducted and the second PUF was analyzed to determine if the PCDD/PCDF transferred from the filter and the first PUF. Less than 4.4% of the initial PCDD/PCDF was lost to the second PUF. To assess the potential for blow off of PCDD/PCDF analytes during open air sampling, the mobility of spiked mono- to hepta-PCDD/PCDF standards across a PUF sorbent was evaluated from ambient air temperatures to 145°C with total volumes between 600L and 2400L. Lower molecular weight compounds and higher flow amounts increased release of the spiked standards consistent with vapor pressure values. At 600L total sampled volume, the release temperature for 1% of the tetra-CDD (the lowest chlorinated homologue with a toxic compound) was 87°C; increasing the volume fourfold reduced this temperature to 73°C.

Direct X-ray fluorescence detection of mercury on polyurethane foam sorbents

An improved method for conducting a sorption X-ray fluorescence analysis of mercury (II) in water with static and dynamic preconcentrations in the form of iodide complexes on polyurethane foam sorbents based on ethers has been proposed. It was shown that optimizing the conditions of measuring analytical signals enabled a significant (one order of magnitude or more) increase in the sensitivity of the detection of X-ray fluorescence and widening of the linear range of graduation dependence.

Fast and selective removal of trace concentrations of bismuth (III) from water onto procaine hydrochloride loaded polyurethane foams sorbent: Kinetics and thermodynamics of bismuth (III) study

Bismuth (III) species are included in the list of potential toxins for motor neurons. Thus, fast and selective method for removal of bismuth (III) species has been developed. The method was based upon the formation of tetraiodobismuthate [BiI 4] − aq in the test aqueous solution in the presence of KI-H 2SO 4 followed by subsequent extraction of [BiI 4] − aq by procaine hydrochloride (PQ +·Cl −) immobilized polyurethane foams (PUFs). The rate of removal of bismuth (III) ions from aqueous solution by procaine hydrochloride (PQ +·Cl −) immobilized polyurethane foams (PUFs) were studied in batch conditions employing Weber–Morris, Lagergren, Bhattacharya and Venkobachar, and Bt models. The rate of sorption of bismuth (III) was rapid initially within 5–15 min and reached a maximum in 30 min compared to other solid sorbent. Initially, the uptake of [BiI 4] − aq onto PQ +·Cl − loaded PUFs was fast followed by kinetically first–order sorption with an overall rate constant, k = 0.132 ± 0.033 min −1. Thus, film and intraparticle transport are the two steps that might be influence bismuth (III) sorption. The negative values of Δ G of the retention step of bismuth (III) dictate that the uptake of the analyte onto the used sorbent is spontaneous phenomena. Exothermic nature of bismuth (III) sorption is governed by the negative value of Δ H. The positive value of Δ S reflects the organized uptake of bismuth (III) on the used sorbent in a more random fashion. The PUFs offers unique advantages of [BiI 4] − aq retention over conventional solid sorbents in rapid and effective separation of trace concentration of bismuth (III) from aqueous media. Thus, the developed PQ +·Cl − treated PUFs sorbent could be packed in column for removal of bismuth (III) species from industrial wastewater.

Chemical Speciation of Chromium(III) and (VI) Using Phosphonium Cation Impregnated Polyurethane Foams Prior to Their Spectrometric Determination

Fast and selective sorptions of Cr(VI) species from aqueous media onto tetraphenylphosphonium bromide (TPP(+) · Br(-)) physically immobilized polyurethane foams (PUFs) sorbent were achieved. Based on the Scatchard model of binding sites of the PUFs and Langmuir and Dubinin-Radushkevich (D-R) adsorption models of Cr(VI) retention onto TPP(+) · Br(-) immobilized PUFs, a dual retention mechanism involving absorption related to "weak-base anion ion exchange" and an added component for "surface adsorption" was proposed. Thus, the TPP(+) · Br(-) loaded PUFs were successfully packed in column mode for preconcentration of trace and ultra trace concentrations of Cr(VI) as halochromates [CrO(3)C](-)(aq) from aqueous HCl media. The retained [CrOCl(3)](-)(aq) species were recovered with NaOH (1.0 mol L(-1)) and analyzed by flame atomic absorption spectrometry. Cr(III) species after oxidation to Cr(VI) with H(2)O(2) in aqueous KOH (1.0 mol L(-1)) were also retained and could be recovered by the proposed method. The limits of detection (LOD) and quantification (LOQ) of Cr(VI) were 0.04 and 0.13 µg L(-1), respectively. The chemical speciation of Cr(III, VI) species in various water samples at trace and ultra trace levels were carried out by TPP(+) · Br(-) loaded PUFs packed column. The enhancement factor and sensitivity factor of [CrO(3)C](-)(aq) sorption were 80.0 and 30.0, respectively.

X-ray fluorescence and atomic emission determination of cobalt in water using polyurethane foam sorbents

The conditions of analytical signal formation during direct X-ray fluorescence and arc atomic emission determination of metals using polyurethane foam sorbents were studied. A sorption spectroscopic technique of cobalt determination in water with preconcentration in the form of thiocyanate complexes based on simple ethers using polyurethane foam sorbents was developed. The linear calibration range was two orders of magnitude. With a cobalt concentration from 25 ml of water in the static mode, the lower limit of the metal content was 3 and 9 μg/l for X-ray fluorescence and atomic emission methods, respectively.

Solid phase preconcentration and determination of trace concentrations of total gold (I) and/or (III) in sea and wastewater by ion pairing impregnated polyurethane foam packed column prior flame atomic absorption spectrometry

A low cost solid-phase extraction based protocol for the preconcentration and subsequent determination of gold (I) and (III) in various complex matrices was developed. The method was based upon the use of the ion pairing reagent tetraheptylammonium bromide (THA +.Br −) immobilized polyurethane foams (PUFs) sorbent in packed column for retention of ultra trace concentrations of gold (III) from aqueous chloride medium of pH 3–4 at 5 mL min − 1 flow rate. The retained gold (III) species were recovered (98.5 ± 2.7) by thiourea–HCl at 5 mL min − 1 flow rate. Gold (I) ions after oxidation to gold (III) with Br 2 water–HCl were also retained onto the reagent packed PUFs column and recovered (96.5 ± 2.1). A linear plot of gold (III) concentration in the range 0.0–20 ng mL − 1 and a limit of detection of 0.06 ng mL − 1 were achieved. The method was applied satisfactorily (> 95%) for the analysis of total inorganic gold (I) and/or gold (III) ions in wastewater samples and anodic slime.

Thiazolidinone Steroids Impregnated Polyurethane Foams as a Solid Phase Extractant for the Extraction and Preconcentration of Cadmium(II) from Industrial Wastewater

Two new thiazolidinone steroids namely sulfadiazino‐imino‐ steroid (I) and 3‐sulfonamoyl‐phenyl‐spiro[4‐oxo‐thiazolidin‐2, 2`steroid] (II) were prepared and characterized from their molecular weight determination and spectroscopic measurements. Compound II were physically immobilized onto polyurethane foams (PUFs) for the preconcentration of cadmium(II) from acidic aqueous media containing iodide ions. The kinetics of the retention step of cadmium(II) from aqueous solutions by compound II treated PUFs was studied. Particle diffusion was the most probable operating mechanism and did not control the kinetics of cadmium(II) retention by compound II immobilized PUFs. A preconcentration / separation procedure is presented for the solid phase extraction of trace cadmium(II) from aqueous media as its ternary complex ion associate with compound II in industrial wastewater samples onto compound II treated PUFs prior to determination by flame atomic absorption spectrometry (FAAS). Compound II treated PUFs sorbent was successfully packed in glass column for complete extraction and / or determination of trace concentrations of cadmium(II) in wastewater samples with satisfactory recovery (95±2.6). The cyclic voltammetry of compound II showed two well defined irreversible redox couples and suggested its possible use as complexing agent in stripping voltammetric determination of trace concentrations of toxic metal ions in wastewater.