scholarly journals Coke-Based Carbon Sorbent: Results of Gold Extraction in Laboratory and Pilot Tests

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 508 ◽  
Author(s):  
Svetlana Yefremova ◽  
Alma Terlikbayeva ◽  
Abdurassul Zharmenov ◽  
Askhat Kablanbekov ◽  
Lara Bunchuk ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Noble Metals ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Exchange Capacity ◽  
Carbon Sorbent ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Gold Extraction ◽  
Dynamic Exchange

Coke-based carbon sorbent (CBCS) was produced using special coke fines with the following characteristics: ash, 4.5%; iodine adsorption capacity, 52%; specific surface area, 600 m2 g−1; and total pore volume, 0.4 cm3 g−1. Gold adsorption from real production cyanide solutions in batch and column laboratory experiments was studied. The optimum adsorbent/solution ratio was 0.2 g/20 cm3. Sorption equilibrium occurred after 60 min of phase-time contact. The CBCS maximum adsorption capacity for gold was found to be 1.2 mg g−1. Both the Langmiur and Freundlich isotherm models confirmed that gold adsorption by CBCS proceeds favorably, but the Freundlich isotherm best describes the adsorption equilibrium. The CBCS dynamic exchange capacity (100 g t−1) and full dynamic exchange capacity (4600 g t−1) for gold were determined in column tests. It was revealed using SEM that adsorbate was retained in sorbent pores. The possibility of completely eluting gold from CBCS was demonstrated. A CBCS pilot test to recover gold from 200 dm3 of the cyanide solution containing (mg dm−3) 2.6 Au, 0.42 Ag, and 490 Cu was carried out. The total amount of noble metals (Au + Ag) adsorbed was 99.99% and gold ions was 94%. The CBCS maximum adsorption capacity for gold reached 2900 g t−1.

scholarly journals Adsorption of Mn2+ from Aqueous Solution Using Manganese Oxide-Coated Hollow Polymethylmethacrylate Microspheres (MHPM)

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dhiraj Dutta ◽  
Jyoti Prasad Borah ◽  
Amrit Puzari
Keyword(s):  
Aqueous Solution ◽  
Manganese Oxide ◽  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Coated Sand

Results of investigation on adsorption of Mn2+ from aqueous solution by manganese oxide-coated hollow polymethylmethacrylate microspheres (MHPM) are reported here. This is the first report on Mn-coated hollow polymer as a substitute for widely used materials like green sand or MN-coated sand. Hollow polymethylmethacrylate (HPM) was prepared by using a literature procedure. Manganese oxide (MnO) was coated on the surface of HPM (MHPM) by using the electroless plating technique. The HPM and MHPM were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Optical and scanning micrographs were used to monitor the surface properties of the coated layer which revealed the presence of MnO on the surface of HPM. TGA showed the presence of 4-5% of MnO in MHPM. Adsorption isotherm studies were carried out as a function of pH, initial ion concentration, and contact time, to determine the adsorption efficiency for removal of Mn2+ from contaminated water by the synthesized MHPM. The isotherm results showed that the maximum adsorption capacity of MnO-coated HPM to remove manganese contaminants from water is 8.373 mg/g. The obtained R 2 values of Langmuir isotherm and Freundlich isotherm models were 1 and 0.87, respectively. Therefore, R 2 magnitude confirmed that the Langmuir model is best suited for Mn2+ adsorption by a monolayer of MHPM adsorbent. The material developed shows higher adsorption capacity even at a higher concentration of solute ions, which is not usually observed with similar materials of this kind. Overall findings indicate that MHPM is a very potential lightweight adsorbent for removal of Mn2+ from the aqueous solution because of its low density and high surface area.

Investigation of adsorption capacity of N-carboxymethyl chitosan for Pb(II) ions

2013 ◽  
Vol 68 (8) ◽  
pp. 1873-1879 ◽  
Author(s):  
Chongxia Wang ◽  
Qingping Song ◽  
Jiangang Gao
Keyword(s):  
Adsorption Capacity ◽  
Ph Value ◽  
Chloroacetic Acid ◽  
Freundlich Isotherm ◽  
Carboxymethyl Chitosan ◽  
Langmuir Model ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
First Order

N-carboxymethyl chitosan (NCMC) was prepared by reacting chitosan (CTS) with chloroacetic acid and characterized by 13C-NMR spectroscopy to confirm that carboxymethylation occurred only in the amino groups. The adsorption properties of CTS, NCMC and O-carboxymethyl chitosan (OCMC) towards Pb(II) ions were evaluated and the order of the adsorption capacity was as follows: NCMC > OCMC > CTS. The effects of initial pH value (2.0–5.5) of the solutions and contact time (5–120 min) on adsorption of Pb(II) were investigated and the kinetic data were evaluated using the pseudo-first-order and pseudo-second-order models. Kinetics study showed that the adsorption process followed second-order kinetics rather than the first-order one. Furthermore, the experimental equilibrium data of Pb(II) on the NCMC were analyzed using the Langmuir and Freundlich isotherm models and the results indicated that the Langmuir model gave a better fit than the Freundlich equation and the maximum adsorption capacity obtained from the Langmuir model was 421.9 mg g−1.

scholarly journals Development of Natural Cation Exchanger for the Treatment of Lead ions from Aqueous Solution

2013 ◽  
Vol 29 ◽  
pp. 34-43
Author(s):  
Puspa Lal Homagai
Keyword(s):  
Adsorption Capacity ◽  
Sugarcane Bagasse ◽  
Active Sites ◽  
Freundlich Isotherm ◽  
Saccharum Officinarum ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Fast Kinetics ◽  
Pseudo Second Order

Cellulose, hemicelluloses and lignin are the main constituents found in sugarcane (Saccharum officinarum) bagasse having many surface active sites containing hydroxyl and/or phenolic groups which are effective for chemical modification. The biowaste was first charred with concentrated sulphuric acid and then the charred aminated sugarcane bagasse (CASB) was prepared by reduction followed by oxidation. The developed bio-sorbent was characterized by SEM, TGA/DTA, FTIR and elemental analysis. Batch adsorption methods were carried out to determine Pb+2 sorption capacities at different pH ranges and sorbate concentrations. The maximum adsorption capacity for Pb+2 was found to be 323 mg g-1 with an efficiency of 98% at pH 4.The experimental data showed a good fit to Langmuir isotherm as compared to Freundlich isotherm models. The kinetics was best fitted with the pseudo-second order model. The adsorption equilibrium was attained within 20 min. The high adsorption capacity and fast kinetics results of the charred aminated sugarcane bagasse indicated that it might be potential adsorbent for the removal of lead from contaminated water. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9235Journal of Nepal Chemical SocietyVol. 29, 2012Page: 34-43Uploaded date : 12/3/2013

Parametric and adsorption kinetic studies of methylene blue removal from simulated textile water using durian (Durio zibethinus murray) skin

2015 ◽  
Vol 72 (6) ◽  
pp. 896-907 ◽  
Author(s):  
S. M. Anisuzzaman ◽  
Collin G. Joseph ◽  
D. Krishnaiah ◽  
A. Bono ◽  
L. C. Ooi
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Durio Zibethinus

In this study, durian (Durio zibethinus Murray) skin was examined for its ability to remove methylene blue (MB) dye from simulated textile wastewater. Adsorption equilibrium and kinetics of MB removal from aqueous solutions at different parametric conditions such as different initial concentrations (2–10 mg/L), biosorbent dosages (0.3–0.7 g) and pH solution (4–9) onto durian skin were studied using batch adsorption. The amount of MB adsorbed increased from 3.45 to 17.31 mg/g with the increase in initial concentration of MB dye; whereas biosorbent dosage increased from 1.08 to 2.47 mg/g. Maximum dye adsorption capacity of the durian skin was found to increase from 3.78 to 6.40 mg/g, with increasing solution pH. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich isotherm models. The sorption equilibrium was best described by the Freundlich isotherm model with maximum adsorption capacity of 7.23 mg/g and this was due to the heterogeneous nature of the durian skin surface. Kinetic studies indicated that the sorption of MB dye tended to follow the pseudo second-order kinetic model with promising correlation of 0.9836 < R2 < 0.9918.

Adsorptive Removal of Drimarene Brilliant Blue by Thermo Stable, Eco-friendly Graphene Oxide Reinforced Polyvinyl Alcohols Hydrogels With High Reusability Potential

2021 ◽  
Author(s):  
Adeel Mustafa ◽  
Nazia Yaqoob ◽  
Maheen Almas ◽  
Shagufta Kamal ◽  
Khalid Mahmood Zia ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Thermo Gravimetric Analysis ◽  
Freundlich Isotherm ◽  
Brilliant Blue ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Pseudo Second Order

Abstract In this study graphene oxide (GO) reinforced polyvinyl alcohol (PVA) composites hydrogels were synthesized and used as efficient adsorbents for Drimarene Brilliant Blue K-4BL. GO nanoparticles (NPs) were synthesized by modified Hummer’s method. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), Thermo-gravimetric analysis (TGA), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed homogeneous dispersion of reinforcement in the synthesized composites. Moreover thermal stability of the composites was significantly enhanced by the addition of graphene oxide nanoparticles. The synthesized composites were used for the removal of Drimarene brilliant Blue from model waste water. The effect of pH, content of GONPs and initial concentration of Drimarene Brilliant Blue K-4BL on the adsorption capacity of synthesized GO/PVA composites were investigated. The equilibrium isothermal data were studied by applying Langmuir and Freundlich isotherm models. Results demonstrated that the adsorption process is well described by the Langmuir adsorption isotherm. According to the Langmuir model, maximum adsorption capacity i.e. 32mg/g was obtained at 0.7% GO/PVA composite. From the kinetic study it was concluded that pseudo-second-order model is the best fitted. Synthesized composites showed excellent reusability (almost 95 %) for the adsorption of Drimarene Brilliant Blue K-4BL after four successive cycles of adsorption and desorption. Thus, the GO/PVA composites demonstrated a great potential in terms of cost effectiveness, efficiency and reusability for the removal of Drimarene Brilliant Blue K-4BL dye.

Removal of Pb(II) Ions from Aqueous Solutions by Spherical Nanocomposites Synthesized Through Immobilization of Paecilomyces lilacinus in Silica Nanoparticles Coated with Ca-Alginate

2020 ◽  
Vol 20 (3) ◽  
pp. 1907-1916
Author(s):  
Xiaofang Ruan ◽  
Ruyi Li ◽  
Zhexu Ding ◽  
Jun Luo ◽  
Qilin Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Silica Nanoparticles ◽  
Adsorption Capacity ◽  
High Efficiency ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Alginate Beads ◽  
Paecilomyces Lilacinus ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity

In the present study, a novel microbial nanocomposite “Paecilomyces lilacinus-silica nanoparticlescalcium-alginate beads” (P. lilacinus-SN-Cal-Alg) were synthesized and their high efficiency for removing Pb(II) ions was demonstrated in aqueous solution. P. lilacinus-SN-Cal-Alg beads before and after the adsorption of Pb(II) were characterized by FT-IR, SEM-EDS, and XPS analyses. The adsorption capacity of Pb(II) by P. lilacinus-SN-Cal-Alg beads was analyzed in aqueous solution. For comparison, the adsorption capacity of Pb(II) by another type of microbial composites, namely, P. lilacinus-Cal-Alg beads, without addition of silica nanoparticles, was also studied in parallel. Lastly, the equilibrium data in adsorption process were examined by both Langmuir and Freundlich isotherm models to evaluate adsorption mechanism. The results showed that an excellent removal efficiency of Pb(II) in aqueous solution (85.54%) was obtained at initial concentration of 200 mg/L by using the P. lilacinus-SN-Cal-Alg beads. Meanwhile, they exhibited the better adsorption capacity for Pb(II) than P. lilacinus-Cal-Alg beads. The adsorption process by P. lilacinus-SN-Cal-Alg beads was best described by the Langmuir model indicating that monolayer adsorption of Pb(II) ions takes place on the beads surfaces and showed that its maximum adsorption capacity was 282.49 mg/g.

scholarly journals Activated carbon from mustard stalk biomass: Synthesis, characterization and application in wastewater treatment

2021 ◽  
pp. 10-10
Author(s):  
Kalpana Patidar ◽  
Manish Vashishtha
Keyword(s):  
Activated Carbon ◽  
Chemical Activation ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Isotherm Study ◽  
Adsorption Rates

Present work is focused on the preparation of mustard stalk activated carbon (MSAC) using chemical activation with H3PO4 and exploring its properties for its use in dye removal from wastewater. Adsorption variable (dosage, contact time, and solution pH), pore structure, morphology, surface functional groups, equilibrium kinetics, and isotherm study for removal of methylene blue (MB) using MSAC were investigated. The present study showed that an adsorption dosage of 0.2 g L-1 and pH 8 can be considered as optimum for the MB removal. SEM result showed that pore of MSAC was larger than the pore of the mustard stalk (MS). BET surface area and total pore volume of MSAC were found as 510 m2 g-1 and 0.33 cm3 g-1, respectively. Equilibrium adsorption data were examined by Langmuir and Freundlich isotherm models. Better correspondence to the Langmuir model with a maximum adsorption capacity of 212.76 mg g-1 (MB onto MSAC) was obtained. Dimensionless factor, RL revealed favourable nature of the sorption in the MSAC - MB system. Adsorption rates were found to conform to the pseudo-second-order kinetics with good correlation. These results show that the MSAC could be used as a renewable and economical alternative to commercial AC in the removal of MB dye from wastewater.

scholarly journals Selective recovery of platinum from spent autocatalyst solution by thiourea modified magnetic biocarbons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shao-Yi Lo ◽  
Wahid Dianbudiyanto ◽  
Shou-Heng Liu
Keyword(s):  
Adsorption Capacity ◽  
Noble Metals ◽  
Freundlich Isotherm ◽  
Platinum Group Metals ◽  
Rapid Decline ◽  
Maximum Adsorption Capacity ◽  
Mixed Solution ◽  
Batch Tests ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm

AbstractThe precious platinum group metals distributed in urban industrial products should be recycled because of their rapid decline in the contents through excessive mining. In this work, thiourea modified magnetic biocarbons are prepared via an energy-efficient microwave-assisted activation and assessed as potential adsorbents to recover platinum ions (i.e., Pt(IV)) from dilute waste solution. The physicochemical properties of prepared biocarbons are characterized by a series of spectroscopic and analytic instruments. The adsorption performance of biocarbons is carried out by using batch tests. Consequently, the maximum adsorption capacity of Pt(IV) observed for adsorbents is ca. 42.8 mg g−1 at pH = 2 and 328 K. Both adsorption kinetics and isotherm data of Pt(IV) on the adsorbents are fitted better with non-linear pseudo second-order model and Freundlich isotherm, respectively. Moreover, the thermodynamic parameters suggest that the Pt(IV) adsorption is endothermic and spontaneous. Most importantly, the adsorbents exhibit high selectivity toward Pt(IV) adsorption and preserve ca. 96.9% of adsorption capacity after six cyclic runs. After adsorption, the regeneration of the prepared adsorbents can be effectively attained by using 1 M thiourea/2% HCl mixed solution as an eluent. Combined the data from Fourier transform infrared and X-ray photoelectron spectroscopies, the mechanisms for Pt(IV) adsorption are governed by Pt–S bond between Pt(IV) and thiourea as well as the electrostatic attraction between anionic PtCl62− and cationic functional groups of adsorbents. The superior Pt(IV) recovery and sustainable features allow the thiourea modified magnetic biocarbon as a potential adsorbent to recycle noble metals from spent autocatalyst solution.

scholarly journals Characteristics of Heavy Metals Adsorption Cu, Pb and Cd Using Synthetics Zeolite Zsm-5

2016 ◽  
Vol 20 (2) ◽  
pp. 77 ◽  
Author(s):  
. Priyadi ◽  
. Iskandar ◽  
. Suwardi ◽  
Rino Rakhmata Mukti
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Negative Charge ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Heavy Metal Adsorption ◽  
Batch System ◽  
Adsorption Data

It is generally known that zeolite has potential for heavy metal adsorption. The  objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system with heavy metals of Cu2+, Pb2+ and Cd2+ in various concentrations (50, 100, 150, 200 and 250 ppm) with contact times 30, 60, 90, 120 and 250 minutes. Adsorption data was calculated by Langmuir and Freundlich isotherm. The results showed that the maximum adsorption capacity of zeolite ZSM-5 against heavy metals of Pb2+, Cu2+, and Cd2+, were 74.07, 69.93 and 60.24 mg g-1, respectively. These indicated that synthetic zeolite ZSM-5 had potential to adsorb heavy metals. The results also suggested that the adsorption capacity was affected by the pore size of zeolite, negative charge of zeolite, diameter of hydrated and electronegative ion.

scholarly journals Fly Ash Coated with Magnetic Materials: Improved Adsorbent for Cu (II) Removal from Wastewater

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Maria Harja ◽  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Dumitru Daniel Herea ◽  
...  
Keyword(s):  
Fly Ash ◽  
Adsorption Capacity ◽  
Copper Ions ◽  
Synthetic Wastewater ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Copper Adsorption ◽  
X Ray

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.

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