scholarly journals New composite sorbent for speciation analysis of soluble chromium in textiles

2019 ◽  
Vol 17 (1) ◽  
pp. 1095-1104
Author(s):  
Penka Vasileva ◽  
Ivanka Dakova ◽  
Tanya Yordanova ◽  
Irina Karadjova

AbstractMicrometer-sized silica spheres coated with a layer of Cr(VI) imprinted methylimidazolium ionic liquid were synthesized and applied for fast and selective determination of leachable Cr(VI) in fabrics. The silica cores were synthesized via original seeded growth procedure. Formation of ionic liquid layer onto their surface was simultaneously combined with CrO42− imprinting. The sorbent characterization was accomplished by SEM/ EDS, elemental microanalysis, and thermogravimetry. Excellent separation of Cr(VI) from Cr(III) was achieved at pH 3 for 10 minutes in a batch mode. A mixture of ascorbic and nitric acids was found to be the most efficient eluent. The adsorption equilibrium data were best represented by the Langmuir isotherm model. The sorbent was applied for quantification of Cr(VI) in textile extracts in accordance with international standard ISO105-E04. The analytical procedure developed (LOD 0.015 μg/g (measured by ETAAS), RSD 3−8% for concentration levels of Cr(VI) 0.015-0.5 μg/g) completely meets the requirements of the international textile regulations.

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1540
Author(s):  
Muhammad Ahmad ◽  
Tehseen Nawaz ◽  
Mohammad Mujahid Alam ◽  
Yasir Abbas ◽  
Shafqat Ali ◽  
...  

The development of excellent drug adsorbents and clarifying the interaction mechanisms between adsorbents and adsorbates are greatly desired for a clean environment. Herein, we report that a reduced graphene oxide modified sheeted polyphosphazene (rGO/poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol)) defined as PZS on rGO was used to remove the tetracycline (TC) drug from an aqueous solution. Compared to PZS microspheres, the adsorption capacity of sheeted PZS@rGO exhibited a high adsorption capacity of 496 mg/g. The adsorption equilibrium data well obeyed the Langmuir isotherm model, and the kinetics isotherm was fitted to the pseudo-second-order model. Thermodynamic analysis showed that the adsorption of TC was an exothermic, spontaneous process. Furthermore, we highlighted the importance of the surface modification of PZS by the introduction of rGO, which tremendously increased the surface area necessary for high adsorption. Along with high surface area, electrostatic attractions, H-bonding, π-π stacking and Lewis acid-base interactions were involved in the high adsorption capacity of PZS@rGO. Furthermore, we also proposed the mechanism of TC adsorption via PZS@rGO.


2001 ◽  
Vol 84 (2) ◽  
pp. 368-375 ◽  
Author(s):  
Mohammed Rizk ◽  
Fathalla Belal ◽  
Fawiza Ibrahim ◽  
Soad Ahmed ◽  
Zeinab A Sheribah

Abstract A derivative UV-spectrophotometric analytical procedure was developed for determination of three 4-quinolone antibacterials: norfloxacin (NFX), ciprofloxacin (CFX), and sparfloxacin (SFX). The method depends on the complexation of Cu(II) with the studied compounds in aqueous medium. A third order, measurement was applied for their quantification. A linear correlation was established between the amplitude of the peak and concentration for all the studied drugs in the range of 15–80, 35–120, and 200–700 ng/mL, with minimum detectability (S/N = 2) of 1.0, 1.3, and 5.1 ng/mL for NFX, CFX, and SFX, respectively. The method was successfully applied for accurate, sensitive, and selective determination of the studied drugs in bulk and tablets formulation with average percentage recoveries of 99.22 ± 0.55 to 100.33 ± 1.60. The results obtained were favorably compared with those of the reference method. The method was also used to determine sparfloxacin in spiked human plasma and urine. The results obtained were satisfactory, accurate, and precise.


2018 ◽  
Vol 6 (48) ◽  
pp. 8214-8220 ◽  
Author(s):  
Quan Li ◽  
Kaite Peng ◽  
Yanzhen Lu ◽  
Aoxin Li ◽  
Fenfang Che ◽  
...  

Label-free fluorescent ionic liquid-functionalized silicon nanoparticles with tunable amphiphilicity for highly sensitive and selective detection of Hg2+ were synthesized.


Carbon ◽  
2003 ◽  
Vol 41 (3) ◽  
pp. 585-588 ◽  
Author(s):  
Li Ming ◽  
Gu Anzhong ◽  
Lu Xuesheng ◽  
Wang Rongshun

2018 ◽  
Vol 156 ◽  
pp. 03014
Author(s):  
Sudarat Sertsing ◽  
Thanaphat Chukeaw ◽  
Sitthiphong Pengpanich ◽  
Bawornpong Pornchuti

In this study, silica aerogel was synthesized by drying at atmospheric pressure and modified further with aminopropyl triethoxysilane (APTES). The amine-functionalized silica aerogel was investigated as an adsorbent for removal of nickel and chromium ions. The effect of contact time, solution pH, and initial solution concentration were studied. The equilibrium was achieved within 60 min. The optimum pH was found to be 4. Adsorption equilibrium data were agreed fairly well with Langmuir isotherm model. Adsorption capacities for nickel and chromium ions were found to be 40.32 mg/g and 46.08 mg/g, respectively.


2021 ◽  
Author(s):  
C Donga ◽  
S Mishra ◽  
A Aziz ◽  
L Ndlovu ◽  
A Kuvarega ◽  
...  

Abstract (3-aminopropyl) triethoxysilane (APTES) modified magnetic graphene oxide was synthesized and applied in the adsorption of three heavy metals, Pb(II), Cd(II) and Ni(II) from aqueous solution. An approach to prepare magnetic GO was adopted by using (3-aminopropyl) triethoxysilane (APTES) as a functionalizing agent on magnetic nanosilica coupled with GO to form the Fe3O4@SiO2-NH2/GO nanocomposite. FT-IR, XRD, BET, UV, VSM, SAXS, SEM and TEM were used to characterize the synthesized nanoadsorbents. Batch adsorption studies were conducted to investigate the effect of solution pH, initial metal ion concentration, adsorbent dosage and contact time. The maximum equilibrium time was found to be 30 min for Pb(II), Cd(II) and 60 min for Ni(II). The kinetics studies showed that the adsorption of Pb(II), Cd(II) and Ni(II) onto Fe3O4@SiO2-NH2/GO followed the pseudo-second-order kinetics. All the adsorption equilibrium data were well fitted to Langmuir isotherm model and maximum monolayer adsorption capacity for Pb(II), Cd(II) and Ni(II) were 13.46, 18.58 and 13.52 mgg-1, respectively. The Fe3O4@SiO2-NH2/GO adsorbents were reused for at least 7 cycles without the leaching of mineral core, showing the enhanced stability and potential application of Fe3O4@SiO2-NH2/GO adsorbents in water/wastewater treatment.


2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Mohd Ismid Mohd Said ◽  
Shaikhah Sabri ◽  
Shamila Azman

Contamination of metals in aquatic environment is a worldwide problem because of its toxicity and capability to accumulate in biological chain, as well as persistence in the natural environment. Therefore various expensive technologies have been applied to treat metal-polluted water. In Malaysia there are abundance of banana species available which could provide cheap, low cost and environmental friendly bio-materials. Preliminary study was conducted on two species of banana i.e. Musa balbisiana (Nipah) and Musa acuminata (Kapas). The banana peels were washed, dried and grounded into various range of particle sizes (0.20–1.18 mm). The ability of the adsorbents were determined by agitation of 1.0 g banana peel and 100 ml of cadmium standard solution at the concentration of 100 mg/L. Musa balbisiana showed the highest removal of cadmium at 89.58% from the initial concentration compared to Musa acuminate with the particle size of 0.30-0.60 mm. Adsorption equilibrium data are well described by Langmuir isotherm model. The result also shows that different species have different capabilities to adsorb metal. Hence, their potential as bio-adsorbent could be further be examined for metal removal from wastewater.


Sign in / Sign up

Export Citation Format

Share Document