In this study, the adsorption behaviors and mechanisms of Pb(II) and Zn(II) by animal-derived biochar (ADB) in single and binary metal systems were comparatively investigated. ADB contains considerable amounts of Ca/P components and is mainly composed of hydroxyapatite (HAP), which plays an important role in the adsorption of Pb(II) and Zn(II). The maximum adsorption capacities of Pb(II) and Zn(II) on ADB were in the order of Zn(II)-single (3.23 mmol g) > Pb(II)-single (2.74 mmol g) ≈ Pb(II)-binary (2.71 mmol g) > Zn(II)-binary (2.31 mmol g). In the single metal system, approximately 99.9% of the adsorbed Pb(II) existed as Pb(PO)Cl, while the dominant adsorption mechanism of Zn(II) was cation exchange, followed by precipitation, accounting for 78.0%-80.6% and 19.4%-21.5% of the adsorption capacity, respectively. These findings were verified by X-ray diffraction refinement, X-ray photoelectron spectroscopy, metal speciation modeling, and Ca(II) exchange experiment. In the binary metal system, the proportion and form of Pb(II) precipitate remained unchanged. However, the binding of Zn(II) to ADB was completely dependent on the cation exchange with Ca(II), and no remarkable Zn(II) precipitation was observed. Phosphate released from HAP preferentially precipitated with Pb(II) than with Zn(II) when they coexisted. Consequently, Pb(II) competition may alter the Zn(II) adsorption mechanism on ADB. Nonetheless, ADB could serve as an efficient biochar for the simultaneous immobilization of Pb(II) and Zn(II) via different mechanisms.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.scitotenv.2019.136395 | DOI Listing |
J Hazard Mater
January 2025
School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.
A carbon-magnetic modified sepiolite nanocomposite (γ-FeO/SiO-Mg(OH)@BC) was synthesized using a hydrothermal method, consisting of γ-FeO, activated sludge biochar (BC), and alkali-modified sepiolite. Its ability to remove heavy metals such as Sb(V), Pb(II), Cd(II), and Zn(II) was investigated through adsorption experiments. Using response surface optimization, the optimal adsorption conditions were determined: adsorption time = 3.
View Article and Find Full Text PDFAnal Chem
January 2025
Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens 157 71, Greece.
This work describes fully integrated multifolding electrochemical paper-based devices (ePADs) for enhanced multiplexed voltammetric determination of heavy metals (Zn(II), Cd(II), and Pb(II)) using tunable passive preconcentration. The paper devices integrate five circular sample preconcentration layers and a 3-electrode electrochemical cell. The hydrophobic barriers of the devices are drawn by pen-plotting with hydrophobic ink, while the electrodes are deposited by screen-printing.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Inorganic Chemistry, Shahid Beheshti University, Tehran, 19839 69411, Iran.
Five metal dithiocarbamate complexes [M(PTHIQDTC)] [where PTHIQDTC is (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline dithiocarbamate anion and M is Ni(II) (1), Sn(II) (2), Hg(II) (3), Pb(II) (4) and Zn(II) (5)] were synthesized from the reaction of MX (X is Cl for 1-3 and OAc for 4-5) with ligand of triethylammonium (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline dithiocarbamate [EtNH][PTHIQDTC] in methanolic solution at room temperature. The five complexes were characterized by IR, H andC NMR, mass spectrometry, elemental analysis and TGA analysis. Recrystallization of [Zn(PTHIQDTC)] (5) in dimethylsulfoxide (DMSO) converts 5 to [Zn(PTHIQDTC)(DMSO)] (6).
View Article and Find Full Text PDFSci Total Environ
December 2024
College of Life Science, College of Marine Science and Engineering, Nanjing Normal University, Nanjing 210023, China. Electronic address:
The study of the competitive and selective immobilization properties and mechanisms of pollutants immobilized by metastable biogenic monohydrocalcite is of great importance for the assessment of the eco-environmental effects and applications of hydrated calcite at the Earth's poles. Microbial culture technology was used to induce the synthesis of biogenic monohydrocalcite (BMHC), and mineral characterization, batch adsorption experiments and chemical analyses were further used to investigate the sequestration characteristics, action mechanism, and environmental effects of BMHC on Pb(II)-Ni(II)-Zn(II)-methylene blue (MB) compound pollution. The results show that BMHC is an organic-inorganic mineral composite (about 3.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
November 2024
Department of Biology, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran.
This work investigates the use of Aspergillus brasiliensis, this particular species of Aspergillus, as a biosorbent for the first time. It is employed to biosorption Zn(II), Cd(II), and Pb(II) and combines the biosorption experiments with electrochemical measurements for in situ analysis. For the experiments, a batch system was employed with the dead biomass.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!