Kinetics of Chromium Ion Removal from Tannery Wastes Using Amberlite IRA-400 Cl− and its Hybrids

Magnesium oxide nanoparticles (MgO-NPs) were synthesized using the fungal strain Aspergillus terreus S1 to overcome the disadvantages of chemical and physical methods. The factors affecting the biosynthesis process were optimized as follows: concentration of Mg(NO3)2·6H2O precursor (3 mM), contact time (36 min), pH (8), and incubation temperature (35 °C). The characterization of biosynthesized MgO-NPs was accomplished using UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy—energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS). Data confirmed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with a size range of 8.0–38.0 nm at a maximum surface plasmon resonance of 280 nm. The biological activities of biosynthesized MgO-NPs including antimicrobial activity, biotreatment of tanning effluent, and chromium ion removal were investigated. The highest growth inhibition of pathogenic Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans was achieved at 200 μg mL–1 of MgO-NPs. The biosynthesized MgO-NPs exhibited high efficacy to decolorize the tanning effluent (96.8 ± 1.7% after 150 min at 1.0 µg mL–1) and greatly decrease chemical parameters including total suspended solids (TSS), total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), and conductivity with percentages of 98.04, 98.3, 89.1, 97.2, and 97.7%, respectively. Further, the biosynthesized MgO-NPs showed a strong potential to remove chromium ions from the tanning effluent, from 835.3 mg L–1 to 21.0 mg L–1, with a removal percentage of 97.5%.

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Thermogravimetric Analysis and Pyrolysis Kinetics of Tannery Wastes in an Inert Atmosphere

Journal of the American Leather Chemists Association ◽

10.34314/jalca.v115i4.3798 ◽

2020 ◽

Vol 115 (4) ◽

pp. 123-131

Author(s):

Lan Luo ◽

Cheng-Kung Liiu ◽

Eleanor Brown ◽

Fang Wang ◽

Yadi Hu ◽

...

Keyword(s):

Reaction Model ◽

Inert Atmosphere ◽

Single Step ◽

Industrial Wastes ◽

Future Application ◽

Pyrolysis Kinetics ◽

Heating Rates ◽

Renewable Chemicals ◽

Tannery Wastes ◽

Kinetics Of

Industrial wastes generated from tanneries contain large quantities of water-insoluble proteins, which may be used for the production of composite materials, renewable chemicals and energy. In this work, the pyrolysis kinetics of powdered sheep fur wastes (SFW) was studied by thermogravimetry (TG) at different heating rates from room temperature to 600°C in nitrogen atmosphere. TG results revealed that there are three stages in this process. The overall apparent activation energy (E) in the main pyrolysis stage was determined to be 275.6 kJ mol-1 by modified Kissinger-Akahira-Sunose (MKAS) method. Because the pyrolysis of SFW could not be described by a single-step reaction, the experimental DTG curve of SFW was deconvoluted into three individual peaks followed by reconstruction of TG curves corresponding to three pseudo components. The average values of E obtained for these pseudo components are 234.7 kJ mol-1, 176.4 kJ mol-1, and 186.2 kJ mol-1, respectively. Generalized master-plots method indicated that the SFW pyrolysis may follow the random nucleation and growth mechanism (Avrami-Erofeev model). Reaction model functions f(?) for these pseudo components could be expressed as: f(?)=3.1(1-?)[-ln(1-?)]0.67; f(?)=3.6(1-?)[-ln(1-?)]0.72, and f(?)=3.9(1-?)[-ln(1-?)]0.74, respectively. These results may provide insight for further studies as well as for future application of pyrolysis technology for tannery wastes.

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Preparation of Zn-Doped Biochar from Sewage Sludge for Chromium Ion Removal

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2018.15392 ◽

2018 ◽

Vol 18 (8) ◽

pp. 5520-5527 ◽

Cited By ~ 5

Author(s):

Nhat-Thien Nguyen ◽

Sung-Ying Lee ◽

Shiao-Shing Chen ◽

Nguyen-Cong Nguyen ◽

Chang-Tang Chang ◽

...

Keyword(s):

Sewage Sludge ◽

Chromium Ion ◽

Ion Removal

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Optimization of Chitosan Surface Response Methodology (Natural and Commercial) Used for Chromium Ion Removal from Wastewater across Different Parameters

Sustainability ◽

10.3390/su132313494 ◽

2021 ◽

Vol 13 (23) ◽

pp. 13494

Author(s):

Mai Sheta ◽

Basant Yousry ◽

Ahmed Zattot ◽

Nahla A. Taha

Keyword(s):

Freundlich Isotherm ◽

Isotherm Models ◽

Order Model ◽

Equilibrium Studies ◽

Sorption Behaviour ◽

Chromium Ion ◽

Ion Removal ◽

Shrimp Shell ◽

Different Types ◽

Pseudo Second Order

Chromium is one of the most significant metals used in the industry. There are many techniques for treating different types of industrial waste water that include chromium ion. In this study, the authors successfully adsorbed the chromium ion from alkaline aqueous solutions using different prepared types of chitosan as adsorbent materials. For the simultaneous sorption behaviour, the adsorption potential of the produced adsorbent was investigated for Cr+6 in a batch system. Natural chitosan was extracted from shrimp shell as it contains about 8–10% chitin which is used in the production of chitosan. The removal percentage of Cr+6 reached 99% after grafting natural and commercial chitosan at specific conditions. Several isotherm models have been used for mechanistic studies. The results indicated that the adsorption data for commercial chitosan is well-fitted by the Freundlich isotherm, Langmuir for commercial grafted, natural and natural grafted chitosan. Kinetic and equilibrium studies showed that the experimental data of Cr+6 were better described by the pseudo-first-order model for commercial chitosan and fitted the pseudo-second-order model for different types of chitosan used. Significantly, in order to scale this effective strategy on an industrial scale, response surface methodology (RSM) was used as a modelling tool to optimise process parameters such as ion concentrations, utilising Statistica Software.

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