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1

Efficient solidification of Pb2+ by activated tungsten tailings and cement

Cheng Hao, Kuang Jingzhong, Zhu Luping, Yuan Weiquan, Huang Zheyu, Yang Yiqiang

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 2

art. no. 162618

EN

The preparation of cementing admixture from tailings and co-solidification of Pb2+ with cement is a green way to realize the resource utilization of tailings and treatment of the lead-containing wastewater. In this paper, the tungsten tailings were activated in different ways, and the mechanical properties of the tungsten tailings-cement solidified body with different activation systems and the solidification behavior of Pb2+ were studied. The phase and microstructure of the hydrated product were characterized by XRD, FT-IR, SEM and EDS. The results showed that the curing effect of Pb2+ was obviously different of different activation systems, and the curing effect of the solidified body of the ternary composite activation system (TCAS) was the best, second only to the pure cement system (PCS). Different activation methods have a significant impact on the mechanical properties of the solidified body. With the increase of the Pb2+ content, the compressive strength of the solidified body gradually decreased, the Pb2+ leaching concentration gradually increased; with the extension of the curing age, the compressive strength gradually increased, and the Pb2+ leaching concentration gradually decreased. In particular, the compressive strength of the 28d solidified body was 31.43 MPa and the leaching concentration of Pb2+ was only 0.38 mg/L when the Pb2+ content was 5%. The phase, microstructure and EDS results of the hydration products showed that Pb2+ was mainly solidified in the C-S-H gel.

2

Structure and properties of polyacrylonitrile/polystyrene and carbon nanoparticle-based nanocomposite foams

Kausar A.

Advances in Materials Science

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2019

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Vol. 19, nr 1(59)

5--20

EN

In this study, novel polyacrylonitrile/polystyrene (PAN/PS) blend has been prepared and reinforced with carbon nanoparticle to form polyacrylonitrile/polystyrene/carbon nanoparticle (PAN/PS/CNP) nanocomposite foam. Acid-functional carbon nanoparticle (0.1-3 wt.%) was used as nano-reinforcement for PAN/PS blend matrix. 2’-azobisisobutyronitrile was employed as foaming agent. The PAN/PS/CNP nanocomposite foams have been tested for structure, morphology, mechanical properties, thermal stability, non-flammability, water uptake, and toxic ion removal. Field-emission scanning electron microscopy and transmission electron microscopy exposed unique nanocellular morphology owing to physical interaction between the matrix and functional CNP. PAN/PS/CNP 0.1 Foam with 0.1 wt.% nanofiller had compression strength, modulus, and foam density of 41.8 MPa, 22.3 GPa, and 0.9 mgcm−3, respectively. Nanofiller loading of 3wt.% (PAN/PS/CNP 3 Foam) considerably enhanced the compression strength, modulus, and foam density as 68.2 MPa, 37.7 GPa, and 1.9 mgcm−3, respectively. CNP reinforcement also enhanced the initial weight loss and maximum decomposition temperature of PAN/PS/CNP 3 Foam to 541 and 574 ºC, relative to neat foam (T0 = 411 ºC; T10 = 459 ºC). Nanocomposite foams have also shown excellent flame retardancy as V-0 rating and high char yield of up to 57% were attained. Due to hydrophilic nature of functional carbon nanoparticle, water absorption capacity of 3 wt.% nanocomposite foam was 30% higher than that of pristine foam. Moreover, novel foams were also tested for the removal of toxic Pb2+ ions. PAN/PS/CNP 3 Foam has shown much higher ion removal capacity (166 mg/g) and efficiency (99 %) than that of PAN/PS foam having removal capacity and efficiency of 90 mg/g and 45 %, respectively.

3

Recognition of Environmentally Important Ions

Łukasik N., Wagner-Wysiecka E., Hubscher-Bruder V., Michel S., Bocheńska M.

Logistyka

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2013

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nr 4

EN

The synthesis and binding properties of N,N’-bis(2-naphthyl)pyridine-2,6-dicarboxyamide are described. The ion binding ability in solution has been tested by UV-Vis spectrophotometry and liquid-liquid extraction of metal picrates from water into dichloromethane. Among studies ions spectral changes of ligand solution in acetonitrile were observed in the presence of Pb2+, Cu2+, and F- ions. The stability constants (logβ) and the stoichiometry of formed complexes were determined.

PL

Artykuł przedstawia syntezę i właściwości kompleksujące receptora jonów, będącego amidową pochodną kwasu pirydyno-2,6-dikarboksylowego. Badania prowadzone były przy użyciu spektrofotometrii UV-Vis oraz metod ekstrakcyjnych.

4

Sorption of lead(II) on copper(II) and nickel-potassium hexacyanoferrates and magnetite-loaded resin from inorganic acid solutions

Kubica B.

Nukleonika

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2010

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Vol. 55, No. 2

163-168

EN

The sorption of Pb2+ on the composite sorbent obtained by incorporating of copper(II)-potassium hexacyanoferrate or nickel(II)-potassium hexacyanoferrate and magnetite into sulphonated phenolic resin was studied. The sorption kinetics were performed in hydrochloric, nitric and sulphuric acid solutions in the concentrations range from 10-4 molźdm-3 to 1 molźdm-3. The distribution coefficients for the lead(II) sorption on the sorbents in these conditions were determined. The highest Kd values, more than 1000 cm3źg-1, were obtained for composite sorbents CuNCFM from HCl, HNO3 and H2SO4 (range concentration 10-4-10-2) and for CuNCF and NiNCF from HCl (range concentration 10-4-10-2). Also, the lead(II) sorption on the magnetite-loaded resin was performed.

5

Influence of pH on concentration of Pb2+ ions in bulk precipitation and throughfall

Kram K.J.

Chemia i Inżynieria Ekologiczna

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2005

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Vol. 12, nr 12

1375-1380

EN

Studies were performed on H+ and Pb2+ input in hulk precipitation and throughfall of 5 forest ecosystems of Kampinoski National Park. There were stands with following dominant trees: pine, birch, false acacia, alder, and oak. The studies were carried out during the growing seasons (April-October) 1998-2000. Results of that studies showed strict correlation between acidity of rainfalls (bulk precipitation and throughfali) and concentration of lead ions - the higher concentration of H+ (lower pH) the higher concentration of Pb2+. Besides concentrations of lead in throughfall were higher then in hulk precipitation with similar acidity.

PL

W trakcie sezonu wegetacyjnego (kwiecień-październik) w latach 1998-2000 na terenie Kampinoskiego Parku Narodowego przeprowadzono badania składu chemicznego opadów atmosferycznych. Badania te były prowadzone zarówno na terenie otwartym, jak i pod koronami drzew 5 różnych drzewostanów. Były to drzewostany, w których dominującym gatunkiem drzew były: sosna, brzoza, robinia, olsza i dąb. Wyniki tych badań wykazały, że stężenie jonów ołowiu (Pb2+) zarówno w wodach deszczowych, jak i podkoronowych było ściśle związane z kwasowością tych wód - przy wyższym stężeniu H+ (mniejsze pH) wyższe było stężenie jonów ołowiu. Przy czym przy podobnej kwasowości zaobserwowano większe stężenia jonów ołowiu w wodach podkoronowych niż w wodach deszczowych.

6

Cyclic Voltammetric Study of the Complexation of Pb2+ Ions by Dibenzopyridino-18-crown-6 in Some Nitriles

Chojnacka-Kalinowska G., Kalinowski M.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 9

1605-1610

EN

A cyclic voltammetric study of the interaction of Pb2+ ions with dibenzopyridino-18-crown-6 in acetonitrile, propionitrile, butyronitrile, benzyl cyanide and benzonitrile has been carried out at various temperatures. Stability constants of the resulting 1:1 complexes were found to decrease with increasing DN, the solvent donor number. The enthalpy and entropy of complexation were calculated from the temperature dependence of the stability constants; the complexes were enthalpy stabilized, but entropy destabilized in all the solvents under study. The relationships DeltaHo vs. DN and DeltaSo vs. DN were found.

7

Effect of Pb(II) Ions on Mortality of the IJs of Steinernema Feltiae Filipjev and Heterorhabditis Megidis Poinar

Jarmuł J., Kamionek M.

Chemia i Inżynieria Ekologiczna

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2000

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Vol. 7, nr 10

1023-1029

EN

An effect of lead nitrate on H. megidis and S. feltiae was studied. Changes: in the invasive properties of IJs exposed to Pb (II) ions; in the sexual structure of a nematode population developing in the host insect, and in viability of larvae migrating from the dead insect to the external environment were adopted as criteria of this effect. We used lead concentrations of 40, 100, 500 1000. and 5000 ppm Pb and an initial dose of 50 IJs per 1 G. melonella larvae. Preliminary results demonstrated that the presence of heavy metal ions affects the reproductive abilities of nematodes. S.feltiae totally loses its reproductive abilities with the increasing concentration of Pb+2 ions since almost all giant males die. H. megidis preserves its growth capabilities but the second generation is decimated before it attains the invasive stage.

PL

Badano wpływ azotanu ołowiu Pb(NO3)2 na H. megidis i S. feltiae. Jako kryteria oceny tego wpływu przyjęto zmiany: w inwazyjności IJs poddanych działaniu jonów Pb (II); w strukturze płciowej populacji nicieni rozwijającej się wewnątrz owada żywicielskiego oraz w żywotności larw migrujących z martwego owada do środowiska zewnętrznego. Zastosowano stężenia:40, 100, 500, 1000, 5000 ppm ołowiu oraz dawkę inicjalną 50 IJs na 1 larwę G. melonella. Na podstawie wstępnych wyników stwierdzono, że obecność jonów metali ciężkich w środowisku powoduje spadek inwazyjności larw inwazyjnych S. feltiae. Zależy on od stężenia jonów Pb2+.