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1

Biosorption of Pb(II) by the resistant Enterobacter sp. : Investigated by kinetics, equilibrium and thermodynamics

Liu Lei, Xia Mengya, Hao Jianwen, Xu Haoxi, Song Wencheng

Archives of Environmental Protection

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2021

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Vol. 47, no. 3

28--36

EN

The Pb(II)-resistant bacterium was isolated from heavy metal-contained soils and used as a biosorbent to remove Pb(II). The strain was identified as Enterobacter sp. based on the 16S rRNA sequence analysis. The effect of biosorption properties (pH value, Pb(II) concentration, bacterial concentration and temperature) on Pb(II) was investigated by batch experiments. Results of FTIR and XPS showed that the biosorption process mainly involved some oxygen-containing groups (-OH and -COOH groups). The experimental results and equilibrium data were fitted by pseudo-second-order kinetic model and Langmuir model, respectively. The experimental biosorption isotherms fitted the Langmuir model, and the maximum biosorption capacity was 40.75 mg/g at 298 K. The calculated ΔGо and ΔHо were –4.06 and 14.91(kJ/mol), respectively, which indicated that biosorption process was spontaneous and endothermic. Results show that Enterobacter sp. will be an efficient biosorbent for Pb(II) removal.

2

Halloysite composites with Fe3O4 particles: the effect of impregnation on the removal of aqueous Cd(II) and Pb(II)

Maziarz P., Matusik J.

Mineralogia

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2017

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Vol. 48, iss. 1/4

107--126

EN

In this study, halloysite-Fe3O4 composites were synthesized by a chemical-precipitation method to facilitate magnetic separation of the sorbents from aqueous solution. The research focused on the effect of Fe3O4 phase on the halloysite sorption properties. The X-ray diffraction (XRD) results confirmed successful deposition of Fe3O4 particles on a halloysite surface. They showed that the coating with Fe3O4 particles enhanced the halloysite adsorption affinity toward Cd(II) and Pb(II). The highest adsorption capacity was determined for the composites having 10% of the surface deposited with Fe3O4. In this case, the adsorption capacity for Cd(II) and Pb(II) was 33 and 112 mmol•kg-1, respectively. The point of zero charge (pHPZC) and desorption results indicated that the removal mechanism of metals is mainly related to chemisorption involving reaction with hydroxyls of either halloysite or Fe3O4 phase. The ion exchange is of limited importance due to the low cation exchange capacity (CEC) of halloysite - Fe3O4 composites.

3

Efficiency of Pb(II) and Mo(VI) removal by kaolinite impregnated with zero-valent iron particles

Rybka K., Suwała K., Maziarz P., Matusik J.

Mineralogia

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2017

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Vol. 48, iss. 1/4

71--86

EN

In this work, kaolinite modified with zero-valent iron was synthesized and used as a sorbent for Pb(II) and Mo(VI) removal from aqueous solutions. The obtained material was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The methods revealed successful modification by the Fe0 particles precipitation on the surface of well-ordered kaolinite. The sorption experiment results showed a significant increase of sorption capacity in relation to the raw kaolinite. The kaolinite with 25% content of Fe0 was found to be the best material for Pb(II) and Mo(VI) removal, resulting in approximately 500 mmol•kg-1 and 350 mmol•kg-1 sorption, respectively. The possible mechanisms responsible for metals’ removal were identified as reduction by Fe0 ‘core’ and adsorption on the iron hydroxides ‘shell’. The study indicated that the obtained material is capable of efficient Pb(II) and Mo(VI) removal and may be an interesting alternative to other methods used for heavy metals’ removal.

4

Removal of Pb(II) and Cd(II) ions from aqueous solutions with selected organic wastes

Bozecka A., Bozecki P., Sanak-Rydlewska S.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

380--396

EN

The authors investigated sorption of Pb(II) and Cd(II) ions from aqueous solutions on selected natural wastes: sunflower hulls, walnut shells and plum stones. The chemical and physical structure of the surface of these sorbents was determined using infrared spectrometry and scanning electron microscopy. The most favourable physicochemical parameters of the sorption processes were also defined. The sorption of Pb(II) and Cd(II) ions was described according to the Langmuir and Freundlich models. It has been shown that the adsorbents studied can be effectively used in removing heavy metals from aqueous solutions. The sunflower hulls have the highest sorption capacity for Pb(II) and Cd(II) ions. It is equal to 36.93 mg/g for the Pb(II) ions and 19.93 mg/g Cd(II) ions. The calculated values of thermodynamic functions indicate a spontaneous (ΔGº< 0) and exothermic (ΔHº< 0) nature of the sorption processes. A participation of ion exchange in these processes is significant. Desorption tests confirm that the adsorbed heavy metals can be recovered and the sorbent materials after regeneration can be reused.

5

Removal of Cu(II) and Pb(II) from aqueous solutions by lactic acid bacteria

Wierzba S.

Proceedings of ECOpole

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2015

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Vol. 9, No. 2

505--512

EN

The aim of the study was to compare the removal of Cu(II) and Pb(II) from aqueous solution by lactic acid bacteria (LAB). Effect of various process parameters, viz., initial metal ions concentration, pH, and contact time has been studied for the removal of copper and lead ions. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the metal ions by LAB biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The sorbent showed the maximum sorptive capacity amounting to be 11.07 and 10.51 mg · g–1 for Cu(II) and Pb(II) ions, respectively. The optimum conditions were pH 6.0 with equilibrium time of 40 min for both metal ions. The involvement of functional groups on the surface of dried biomass in biosorption process is also discussed.

PL

Celem pracy było porównanie zdolności usuwania Cu(II) i Pb(II) z roztworu wodnego przez bakterie kwasu mlekowego (LAB). Badano wpływ różnych parametrów, tj. stężenia jonów metali, pH i czas kontaktu, na proces usuwania jonów miedzi i ołowiu. Do opisu izoterm adsorpcji jonów metali przez biomasę LAB zastosowano modele Langmuira i Freundlicha. Uzyskane dane doświadczalne były lepiej dopasowane do modelu Langmuira niż Freundlicha. Sorbent wykazał maksymalną zdolność sorpcyjną, wynoszącą 11,07 i 10.51 mg · g–1 odpowiednio dla jonów Cu(II) i Pb(II). Optymalne warunki biosorpcji obu jonów metali wynosiły: pH 6,0 i czas równowagi 40 minut. Omówiono również udział grup funkcyjnych na powierzchni biomasy w procesie biosorpcji.

6

Performance of silica aerogels modified with amino functional groups in PB(II) and CD(II) removal from aqueous solutions

Faghihian H., Nourmoradi H., Shokouhi M.

Polish Journal of Chemical Technology

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2012

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Vol. 14, nr 1

50-56

EN

The adsorption behavior of Pb(II) and Cd(II) ions in aqueous solutions on silica aerogels modified with amino propyl triethoxysilane was investigated as a function of pH, contact time, adsorbate concentration and adsorbent dose. It was found that maximum adsorption of Pb(II) and Cd(II) ions occurs at pH 6.0 and pH 8.0, respectively. The optimum contact time to obtain equilibrium adsorption with the modified silica aerogel was experimentally found to be around 48h. Adsorption isotherms clearly indicated that the adsorption behavior of metals ions on the modified silica aerogels is fitted well with both the Langmuir and Freundlich isotherms. The maximum adsorption capacities of Pb(II) and Cd(II) on modified silica aerogel were found to be 45.45mg/g and 35.71mg/g, respectively. The results indicated that silica aerogels modified with amino functional groups can be used as an efficient adsorbent in the removal of metal ions such as Pb(II) and Cd(II) from aqueous solutions.

7

Adsorption of heavy metal ions at the Al2O3-SiO2/NaClO4 electrolyte interface

Skwarek E., Matysek-Nawrocka M., Janusz W., Zarko V. I., Gun'ko V. M.

Physicochemical Problems of Mineral Processing

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2008

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Vol. 42

153-164

EN

The study on adsorption of heavy metals (Cd(II), Ni(II) and Pb(II)) at the Al2O3-SiO2/electrolyte solution interface is presented in this paper. The influence of ionic strength, pH, background electrolyte (NaClO4) concentration and composition of metal oxide on adsorption of Cd(II), Ni(II) and Pb(II) from solution of initial concentration ranged from 1×10-6 to 1×10-3 mol/dm3 in the mentioned system was investigated. The adsorptions edge parameters (pH50% and pH10-90%) for different concentrations of electrolyte were presented. The adsorption measurements were complemented by the potentiometric titration of Al2O3-SiO2 suspensions and electrophoretic measurements. Charge reversal point (CR2) can be observed for solution concentration of 10-3 mol/dm3 as a result of Cd(II), Ni(II) and Pb(II) ions adsorption.

PL

Kadm, ołów i nikiel są toksycznymi metalami ciężkim, który stanowią wciąż poważne zagrożenie dla organizmów żywych. W środowisku naturalnym oraz w wielu procesach technologicznych mamy do czynienia ze skomplikowanymi układami gdzie występują obok siebie tlenki typu Al2O3-SiO2 oraz jony metali ciężkich. Przeprowadzono badania adsorpcji jonów niklu, kadmu i ołowiu dla różnych stężeń początkowych, w funkcji pH dla układów AS1, AS3, AS8/roztwór NaCl. Kształt krzywych adsorpcji w funkcji pH ma postać krawędzi adsorpcji. Wzrost stężenia początkowego jonów metali ciężkich, powoduje przesunięcie krawędzi w kierunku zasadowym skali pH. Wyznaczono charakterystyczne parametry krawędzi adsorpcji tj. pH50% i apH10-90%, w oparciu o zależność adsorpcji od pH stosując model TLM, obliczono równieS stałe reakcji adsorpcji jonów Ni(II), Cd(II), Pb(II) metodą optymalizacji numerycznej. Zależność gęstości ładunku powierzchniowego od pH w obecności jonów metali ciężkich, jest w dobrej korelacji z zależnością adsorpcji jonów Ni(II), Cd(II), Pb(II) od pH. Adsorpcja badanych jonów na powierzchni AS1, AS3, AS8 prowadzi do wzrostu stężenia grup ujemnie naładowanych.

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Transport jonów Zn(II) i Pb(II) przez polimerowe membrany inkluzyjne zawierające kwasy fosforoorganiczne w roli przenośników jonów

Ulewicz M., Gajda B.

Hutnik, Wiadomości Hutnicze

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2006

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Vol. 73, nr 7

317-321

PL

W pracy przedstawiono wyniki badań transportu jonów Zn(II) i Pb(II) przez polimerowe membrany inkluzyjne. W roli przenośnika jonów zastosowano kwas di(2-etyloheksylo)fosforowy oraz komercyjne przenośniki Cyanex 272, 302 i 302. Przedstawiono wpływ rodzaju i stężenia przenośnika, pH fazy zasilającej oraz stężenia kwasu w fazie odbierającej na efektywność i selektywność procesu transportu kationów.

EN

In this paper the facilitated transport of Zn(II) and Pb(II) ions through polymer inclusion membranes is presented. In membranes di(2-ethylhexyl)phosphoric acid (D2EHPA ) as well as commercial extractants, i.e. Cyanex 272, 301, and 302 were used as ion carrier. The infl uence of the carrier nature and concentration in the membrane phase and pH receiving phase, and concentration of HCl in receiving phase on cation transport selectivity end effi ciency has been shown.