scholarly journals Using amine-functionalized magnetite hollow nanospheres (AMHNs) as adsorbents for heavy metal ions

2017 ◽  
Vol 76 (2) ◽  
pp. 452-458 ◽  
Author(s):  
Sen Lin ◽  
Lili Liu ◽  
Yong Yang ◽  
Wei Zhang ◽  
Meng Xu ◽  
...  

In this paper, the amine-functionalized magnetite hollow nanospheres (AMHNs), prepared through a facile one-pot synthesis, were used as heavy metal ion adsorbents, whose morphology and physicochemical features were exploring by transmission electron microscopy, vibrating sample magnetometer, X-ray diffraction and Fourier-transform infrared analyses. Its adsorption performances for Pb2+, Cu2+, Zn2+, Ni2+ and Cd2+ were studied in detail. The adsorption increased with the increase of initial pH value of the solution and could be obviously affected by ionic strength. Also, the adsorption kinetics and isotherms were studied. The adsorption processes for Pb2+, Cu2+, Zn2+, Ni2+ and Cd2+ could all reach equilibrium in 60 min and be described well by the Langmuir thermodynamics model. The saturated adsorption capacities for Pb2+, Cu2+, Zn2+, Ni2+ and Cd2+ were 0.66, 0.47, 0.45, 0.38 and 0.26 mmol/g, respectively. In addition, the competitive adsorption showed the AMHNs had higher affinity to Pb2+ than to other heavy metal ions.

2019 ◽  
Vol 80 (8) ◽  
pp. 1407-1412 ◽  
Author(s):  
Rue Chiramba ◽  
Gratitude Charis ◽  
Nonhlanhla Fungura ◽  
Gwiranai Danha ◽  
Tirivaviri Mamvura

Abstract Contamination of water bodies by heavy metal ions is a challenge many developing nations like Zimbabwe face, with negative environmental and socio-economic repercussions. Treating affected bodies usually requires a costly consignment of chemicals and activated carbon. This research investigates the possible use of an abundant waste resource – poultry feathers – to make activated carbon for heavy metal ion removal. Poultry consumption in this nation generates more than five million tonnes of feathers a year, with very few uses of this by-product. This research was carried out to evaluate the effectiveness of activated carbon synthesized from poultry feathers with sodium hydroxide as the activating agent. It was tested for removing heavy metal ions from waste water at Lake Chivero and the experimental work done showed that it had a removal efficiency as high as 97%, with a high affinity for lead ions as compared with chromium ions. Upon characterization, the activated carbon showed an iodine number of 520 mg and it worked best at a pH value of 8. The efficiency removal also increased with increasing adsorbent concentration as well as contact time up to a period where these factors ceased to be the limiting factors of the reaction.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1037 ◽  
Author(s):  
Baobin Wang ◽  
Miao Ran ◽  
Guigan Fang ◽  
Ting Wu ◽  
Yonghao Ni

The pentose/furfural industrial manufacturing process uses corn cob residue as a raw material, where such a process yields significant amount of lignin-rich residue (LCR) at the end, which is commonly disposed by burning. In this study, the conversion of LCR to biochars (BCs), and their subsequent applications for heavy metal ion removal, were investigated. The BCs were prepared through hydrothermal carbonization and post-activation, using either ZnCl2 or H3PO4 treatment. The as-prepared activated BCs were characterized using N2 adsorption–desorption isotherms, XRD, FT-IR, SEM and TEM, and their performance in removing heavy metal ions (Pb2+, Cu2+, Cd2+) from aqueous solutions was assessed. The ZnCl2-activated BCs (BC-ZnCl2) exhibit a higher adsorption capacity than the H3PO4-activated BCs (BC-H3PO4), mainly due to the differences in their chemical/physical characteristics. The related adsorption kinetics and isotherms were analyzed.


2002 ◽  
Vol 20 (7) ◽  
pp. 607-617 ◽  
Author(s):  
Adil Denizli ◽  
Bora Garipcan ◽  
Sibel Emir ◽  
Süleyman Patir ◽  
Ridvan Say

Details of the adsorption performance of poly(2-hydroxyethylmethacrylate–methacrylamidocysteine) [p(HEMA–MAC)] beads towards the removal of heavy metal ions from aqueous solution were studied. The metal-complexing ligand and/or co-monomer MAC was newly synthesized from methylacrylochloride and cysteine. Spherical beads of average size 150–200 mm were obtained by the radical suspension polymerization of MAC and HEMA conducted in an aqueous dispersion. The p(HEMA–MAC) beads obtained had a specific surface area of 18.9 m2/g. p(HEMA–MAC) beads were characterized by swelling studies, FT-IR spectroscopy and elemental analysis. Such beads with a swelling ratio of 72%, and containing 3.9 mmol MAC/g, were used for heavy metal removal studies. The adsorption capacities of the beads for selected metal ions, i.e. CdII, AsIII, CrIII, HgII and PbII, were investigated in aqueous media containing different amounts of these ions (10–750 mg/l) and at different pH values (3.0–7.0). The adsorption rate was fast in all cases. The maximum adsorption capacities of the p(HEMA–MAC) beads were 1058.2 mg/g for CdII, 123.4 mg/g for AsIII, 199.6 mg/g for CrIII, 639.1 mg/g for PbII and 1018.6 mg/g for HgII. On a molar basis, the following affinity order was observed: CdII > HgII > CrIII > PbII >AsIII. The adsorption capacity of the MAC-incorporated beads was affected significantly by the pH value of the aqueous medium. The adsorption of heavy metal ions from artificial wastewater was also studied. In this case, the adsorption capacities were 52.2 mg/g for CdII, 23.1 mg/g for CrIII, 83.4 mg/g for HgII, 62.6 mg/g for PbII and 11.1 mg/g for AsIII at an initial metal ion concentration of 0.5 mmol/l. The chelating beads could be regenerated easily with a higher effectiveness by 0.1 M HNO3. These features make p(HEMA–MAC) beads potential candidates for heavy metal ion removal at high capacity.


Author(s):  
Yunyun Gui ◽  
Yihe Wang ◽  
Chiyang He ◽  
Zhouqing Tan ◽  
Lingfeng Gao ◽  
...  

Novel multi-optical signal channel gold nanoclusters (MS-AuNCs) with CL and FL properties were designed and prepared by a one-pot method. Then the CL and FL spectra of MS-AuNCs were applied to the sensing array for heavy metal ion differentiation.


2019 ◽  
Vol 11 (19) ◽  
pp. 5186 ◽  
Author(s):  
Jing Qian ◽  
Tianjiao Yang ◽  
Weiping Zhang ◽  
Yuchen Lei ◽  
Chengli Zhang ◽  
...  

NH2-Fe2O3 and NH2-Fe2O3/chitosan (NH2-Fe2O3/CS) with excellent physical properties and high adsorption capacities for several heavy metal ions were synthesized using a one-pot hydrothermal method. The materials were characterized by scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Physicochemical properties were determined by the Fourier transform infrared spectra (FTIR) and nitrogen adsorption analysis (Brunauer–Emmett–Teller (BET) method). The results of the characterization studies show that the material is uniformly dispersed and has good crystallinity and well-defined porous particles. The material is mesoporous, and the particles have a specific surface area of 55.41–233.03 m2·g−1, a total pore volume of 0.24–0.54 cm3·g−1, and a diameter of 3.83–17.56 nm. Additional results demonstrate that NH2-Fe2O3 and NH2-Fe2O3/CS are effective adsorbents for the removal of heavy metal ions from solution. In a ternary system, the order of their selective adsorption was determined to be Pb(II) > Cu(II) > Cd(II), and the adsorption rate of Pb(II) was much higher than that of Cu(II) and Cd (II). The metal ion adsorption capacity of NH2-Fe2O3 and NH2-Fe2O3/CS makes them promising adsorbents for wastewater cleanup.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 685
Author(s):  
Ai-Huei Chiou ◽  
Jun-Luo Wei ◽  
Ssu-Han Chen

A novel surface-enhanced Raman scattering (SERS)-based probe to capture heavy metal ion (Zn2+) by bovine serum albumin (BSA) using Si-nanowire (SiNW) arrays with silver nanoparticles (AgNPs) was developed. A layer with AgNPs was deposited on the SiNW surface by RF magnetron sputtering for enhancement of SERS signals. Using a high-resolution transmission electron microscope (HRTEM), the observation reveals that the AgNP layer with depths of 30–75 nm was successfully deposited on SiNW arrays. The Ag peaks in EDS and XRD spectra of SiNW arrays confirmed the presence of Ag particles on SiNW arrays. The WCA observations showed a high affinity of the Ag–SiNW arrays immobilized with BSA (water contact angle (WCA) = 87.1°) and ZnSO4 (WCA = 8.8°). The results of FTIR analysis illustrate that the conjugate bonds exist between zinc sulfate (ZnSO4) and –OH groups/–NH groups of BSA. The resulting SiNWs/Ag NPs composite interfaces showed large Raman scattering enhancement for the capture of heavy metal ions by BSA with a detection of 0.1 μM. BSA and ZnSO4 conjugations, illustrating specific SERS spectra with high sensitivity, which suggests great promise in developing label-free biosensors.


2013 ◽  
Vol 773 ◽  
pp. 283-288
Author(s):  
Xing Zou ◽  
Xiang Quan Chen ◽  
Hai Chao Xie ◽  
Xiao Dan Qiu

The manganese sulfate solution leached from low-grade pyrolusite with pyrite and H2SO4 contains heavy metal ions of high concentration, influencing the quality of the final products of manganese compounds and causing manganese ions not to be electrolyzed. The present study was focused on the separation of Co, Ni and Zn ions from the leached solution with BaS. By controlling the pH value at 5.0-6.5, temperature at 50-60°C, reaction time at 15 min and mixing velocity at 78 rpm, the heavy metal ions could be separated effectively. Under the above optimized conditions, the ion concentration of Co, Ni, and Zn in the solution was reduced to 0.06 mg.L-1, 0.27mg.L-1 and 0.01mg.L-1, and the separation efficiency was 99.72%, 99.18% and 99.9% respectively. The obtained pure solution meets the demands of manganese electrowinning.


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