Efficient Separation of Heavy Metals by Magnetic Nanostructured Beads

This study reports the ability of magnetic alginate activated carbon (MAAC) beads to remove Cd(II), Hg(II), and Ni(II) from water in a mono-metal and ternary system. The adsorption capacity of the MAAC beads was highest in the mono-metal system. The removal efficiency of such metal ions falls in the range of 20–80% and it followed the order Cd(II) > Ni(II) > Hg(II). The model that best fitted in the ternary system was the Freundlich isotherm, while in the mono-system it was the Langmuir isotherm. The maximum Cd(II), Hg(II), and Ni(II) adsorption capacities calculated from the Freundlich isotherm in the mono-metal system were 7.09, 5.08, and 4.82 (mg/g) (mg/L)1/n, respectively. Lower adsorption capacity was observed in the ternary system due to the competition of metal ions for available adsorption sites. Desorption and reusability experiments demonstrated the MAAC beads could be used for at least five consecutive adsorption/desorption cycles. These findings suggest the practical use of the MAAC beads as efficient adsorbent for the removal of heavy metals from wastewater.

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Removal Mechanism and Effective Current of Electrocoagulation for Treating Wastewater Containing Ni(II), Cu(II), and Cr(VI)

Water ◽

10.3390/w12092614 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2614

Author(s):

Chien-Hung Huang ◽

Shan-Yi Shen ◽

Cheng-Di Dong ◽

Mohanraj Kumar ◽

Jih-Hsing Chang

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Metal Ions ◽

Adsorption Capacity ◽

Langmuir Isotherm ◽

Active Sites ◽

Freundlich Isotherm ◽

Removal Mechanism ◽

Adsorption Sites ◽

Effective Current

This study aims to clarify the removal mechanism and to calculate the effective current of electrocoagulation (i.e., EC) for treating wastewater containing Ni(II), Cu(II), and Cr(VI). The adsorption behavior of various heavy metals onto Al(OH)3 coagulant generated by the EC process was investigated and the estimating method of the corresponding current was established. Results indicate that adsorption of single Ni(II) and Cu(II) by Al(OH)3 coagulant can be simulated by the Langmuir isotherm, while Cr(VI) adsorption fits the Freundlich isotherm better. As treating single heavy metal of wastewater, the removal mechanism of the EC process is the adsorption reaction. Under the coexisting condition, the Ni(II) and Cu(II) will compete for the same active sites on the Al(OH)3 surface and Cu(II) suppresses Ni(II) adsorption. As treating the coexisting heavy metals, Ni(II) removal not only associates with adsorption but also with the coprecipitation. In contrast, Cr(VI) does not compete with other metal ions for the same type of adsorption sites. Whether single or coexisting conditions, the adsorption capacity of heavy metals onto Al(OH)3 coagulants can be used to compute the necessary current to effectively remove heavy metals in the EC system.

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Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

BioResources ◽

10.15376/biores.2.1.66-81 ◽

2007 ◽

Vol 2 (1) ◽

pp. 66-81

Author(s):

Miyoung Oh ◽

Mandla A. Tshabalala

Keyword(s):

Heavy Metals ◽

Metal Ions ◽

Adsorption Capacity ◽

Ponderosa Pine ◽

Metal Ion ◽

Value Added ◽

Freundlich Isotherm ◽

Toxic Heavy Metals ◽

Adsorption Affinity ◽

Column Adsorption

ark flour from ponderosa pine (Pinus ponderosa) was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(II), Zn(II), Cd(II), and Ni(II) under both equilibrium and dynamic adsorption conditions. The experimental data for Cd(II) and Zn(II) showed a better fit to the Langmuir than to the Freundlich isotherm. The Cu(II) data best fit the Freundlich isotherm, and the Ni(II) data fitted both Freundlich and Langmuir isotherms equally. According to the Freundlich constant KF, adsorption capacity of pelletized bark for the metal ions in aqueous solution, pH 5.1 ± 0.2, followed the order Cd(II) > Cu(II) > Zn(II) >> Ni(II); according to the Langmuir constant b, adsorption affinity followed the order Cd(II) >> Cu(II) ≈ Zn(II) >> Ni(II). Although data from dynamic column adsorption experiments did not show a good fit to the Thomas kinetic adsorption model, estimates of sorption affinity series of the metal ions on pelletized bark derived from this model were not consistent with the series derived from the Langmuir or Freundlich isotherms and followed the order Cu(II) > Zn(II) ≈ Cd(II) > Ni(II). According to the Thomas kinetic model, the theoretical maximum amounts of metal that can be sorbed on the pelletized bark in a column at influent concentration of ≈10 mg/L and flow rate = 5 mL/min were estimated to be 57, 53, 50, and 27 mg/g for copper, zinc, cadmium, and nickel, respectively. This study demonstrated the potential for converting low-cost bark residues to value-added sorbents using starting materials and chemicals derived from renewable resources. These sorbents can be applied in the removal of toxic heavy metals from waste streams with heavy metal ion concentrations of up to 100 mg/L in the case of Cu(II).

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Hydrazinolyzed cellulose-g-polymethyl acrylate as adsorbent for efficient removal of Cd(II) and Pb(II) ions from aqueous solution

Water Science & Technology ◽

10.2166/wst.2016.581 ◽

2016 ◽

Vol 75 (5) ◽

pp. 1051-1058 ◽

Cited By ~ 5

Author(s):

Qiujin Jia ◽

Wanting Zhang ◽

Dongping Li ◽

Yulong Liu ◽

Yuju Che ◽

...

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Physical Adsorption ◽

Freundlich Isotherm ◽

Isotherm Model ◽

Initial Ph ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Adsorption Desorption ◽

Efficient Adsorbent

Hydrazinolyzed cellulose-graft-polymethyl acrylate (Cell-g-PMA-HZ), an efficient adsorbent for removal of Cd(II) and Pb(II) from aqueous solution, has been prepared by ceric salt-initiated graft polymerization of methyl acrylate from microcrystalline cellulose surface and subsequent hydrazinolysis. The influences of initial pH, contact time, and temperature on adsorption capacity of Cell-g-PMA-HZ as well as adsorption equilibrium, kinetic and thermodynamic properties were examined in detail. As for Cd(II) adsorption, kinetic adsorption can be explained by pseudo-second-order, while adsorption isotherm fits well with Langmuir isotherm model, from which maximum equilibrium adsorption capacity can be derived as 235.85 mg g−1 at 28 °C. Further thermodynamic investigation indicated that adsorption of Cd(II) by adsorbent Cell-g-PMA-HZ is endothermic and spontaneous under studied conditions. On the other hand, isotherm of Pb(II) adsorption fits well with Freundlich isotherm model and is more likely to be a physical-adsorption-dominated process. Consecutive adsorption–desorption experiments showed that Cell-g-PMA-HZ is reusable with satisfactory adsorption capacity.

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Study on the Removal of Heavy Metals by Biomass

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.276 ◽

2013 ◽

Vol 634-638 ◽

pp. 276-279

Author(s):

Neng Zhou ◽

Zhen Zhou ◽

Yuan Qin ◽

Chu Jie Zeng

Keyword(s):

Heavy Metals ◽

Adsorption Capacity ◽

Contact Time ◽

Room Temperature ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Experimental Conditions ◽

Adsorption Time ◽

Removal Of Heavy Metals ◽

Efficient Adsorbent

In this paper, the adsorption of heavy metals by biomass, namely dry garlic stem, an environmentally-friendly and natural adsorbent, were studied．The efficiency of the adsorbent was studied under different experimental conditions by varying parameters such as pH, initial concentration and contact time using batch adsorption technique. The results show that at pH 5.50, room temperature, the adsorption time 90 min and the amount of garlic stem 0.5 g, Co2+ have the maximum adsorption capacity. The maximum adsorption capacity of the Co2+ on garlic stem is 14.9 mg/g. At pH 9.50, the adsorption time 90 min and the amount of garlic stem 0.7g, Cd2+ have the maximum adsorption at the same temperature. The maximum adsorption of the Cd2+ is 20.90 mg/g. At pH 10.0, the adsorption time 150 min and the amount of garlic stem 0.3g, Ni2+ have the maximum adsorption at the same temperature. The dry garlic stem is a efficient adsorbent in removing cobalt, cadmium and nickel from aqueous solution.

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Potential Use of Agro/Food Wastes as Biosorbents in the Removal of Heavy Metals

10.5772/intechopen.94175 ◽

2020 ◽

Author(s):

Faizan Ahmad ◽

Sadaf Zaidi

Keyword(s):

Heavy Metals ◽

Metal Ions ◽

Adsorption Capacity ◽

Membrane Filtration ◽

Toxic Metal ◽

Lead Ion ◽

Food Wastes ◽

Toxic Metal Ions ◽

Alternative Technologies ◽

Removal Of Heavy Metals

The production of large quantities of agro/food wastes from food processing industries and the release of pollutants in the form of heavy metals from various metallurgical industries are the grave problems of the society as well as serious threats to the environment. It is estimated that approximately one–third of all food that is produced goes to waste, meaning thereby that nearly 1.3 billion tonnes of agro/food wastes are generated per year. This readily available and large amount waste can be utilized for the removal of toxic metals obtained from metallurgical industries by converting it into the adsorbents. For example, mango peel showed adsorption capacity of 68.92 mg/g in removing cadmium II ions. Similarly, coconut waste showed a higher adsorption capacity of 285 and 263 mg/g in removing cadmium and lead ion, respectively. Biosorption and bioaccumulation are recommended as novel, efficient, eco-friendly, and less costly alternative technologies over the conventional methods such as ion exchange, chemical precipitation, and membrane filtration, etc. for the removal of toxic metal ions. Because of the presence of metal-binding functional groups, the industrial by-products, agro-wastes and microbial biomass are considered as the potential biosorbents. Thus they can be used for the removal of toxic metal ions. This chapter highlights the available information and methods on utilizing the agro/food waste for the eradication of toxic and heavy metal ions. Furthermore, this chapter also focuses on the sorption mechanisms of different adsorbents as well as their adsorbing capacities.

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Efficient Removal of Heavy Metals from Aqueous Solutions Using a Bionanocomposite of Eggshell/Ag-Fe

Catalysts ◽

10.3390/catal10070727 ◽

2020 ◽

Vol 10 (7) ◽

pp. 727

Author(s):

Verónica M. Alamillo-López ◽

Víctor Sánchez-Mendieta ◽

Oscar F. Olea-Mejía ◽

María G. González-Pedroza ◽

Raúl A. Morales-Luckie

Keyword(s):

Heavy Metals ◽

Adsorption Capacity ◽

Natural Material ◽

Efficient Removal ◽

Fe Nanoparticles ◽

Adsorption Data ◽

Removal Of Heavy Metals ◽

Heavy Metals Ions ◽

Efficient Adsorbent ◽

Adsorbent Materials

Eggshell and an easily synthesized bionanocomposite of eggshell with Ag-Fe nanoparticles demonstrated to be efficient adsorbent materials for the removal of lead, arsenic, and mercury from water. The natural material and the bionanocomposite were characterized by TEM and XRD. Ag-Fe nanoparticles vary from 1 to 100 nm in size. Equilibrium times of the adsorption systems were achieved between 4 and 8 h. The experimental adsorption data fitted the pseudo-second and Elovich models; therefore, the adsorption of heavy metals ions took place mainly by a chemical process. The adsorption capacity of eggshell in mg/g was 7.01 for As5+, 3.90 for Pb2+, and 1.51 for Hg2+, while the nanocomposite adsorption capacity was 17.7 for As5+, 27.8 for Pb2+ and 15.88 for Hg2+.

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Synthesis of Gelatin-Cellulose Nanocrystals Hydrogel Membrane For Removal of Cu (II) And Co (II) From Mining Processes Wastewater

10.21203/rs.3.rs-383692/v1 ◽

2021 ◽

Author(s):

John Kabuba ◽

Trésor Lukusa

Keyword(s):

Experimental Data ◽

Heavy Metals ◽

Metal Ions ◽

Cellulose Nanocrystals ◽

Contact Time ◽

Low Cost ◽

Freundlich Isotherm ◽

Particle Diffusion ◽

Hydrogel Membrane ◽

Removal Of Heavy Metals

Abstract This study describes the removal of Cu (II) and Co (II) ions from mining processes wastewater using synthesis of Gelatin-cellulose nanocrystals (CNCs) hydrogel membrane (GCHM). In a batch experiment, the influence of different parameters such as pH, contact time, temperature, and ratio of gelatin and CNCs was evaluated. Higher removal efficiency was obtained at ratio 3 ÷ 1 and at pH 5 and 7 for Cu (II) and Co (II), respectively, and a contact time of 120 mins and a temperature of 30°C. The experimental data fitted satisfactory to Freundlich isotherm model. The adsorption of metal ions has been fit by the particle diffusion model. The results revealed that gelatin and CNCs were identified as the low-cost and promising adsorption material for the removal of heavy metals from wastewater.

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Sawdust for the Removal of Heavy Metals from Water: A Review

Molecules ◽

10.3390/molecules26144318 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4318

Author(s):

Elie Meez ◽

Abbas Rahdar ◽

George Z. Kyzas

Keyword(s):

Heavy Metals ◽

Adsorption Mechanism ◽

Freundlich Isotherm ◽

Order Kinetic ◽

Suitable Material ◽

Removal Of Heavy Metals ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

And Control ◽

Environmental Agencies

The threat of the accumulation of heavy metals in wastewater is increasing, due to their abilities to inflict damage to human health, especially in the past decade. The world’s environmental agencies are trying to issue several regulations that allow the management and control of random disposals of heavy metals. Scientific studies have heavily focused on finding suitable materials and techniques for the purification of wastewaters, but most solutions have been rejected due to cost-related issues. Several potential materials for this objective have been found and have been compared to determine the most suitable material for the purification process. Sawdust, among all the materials investigated, shows high potential and very promising results. Sawdust has been shown to have a good structure suitable for water purification processes. Parameters affecting the adsorption mechanism of heavy metals into sawdust have been studied and it has been shown that pH, contact time and several other parameters could play a major role in improving the adsorption process. The adsorption was found to follow the Langmuir or Freundlich isotherm and a pseudo second-order kinetic model, meaning that the type of adsorption was a chemisorption. Sawdust has major advantages to be considered and is one of the most promising materials to solve the wastewater problem.

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Removal of Cd(II) from Water System Using Novel Biosorbent Derived from Persimmon Fallen Leaves

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1130.685 ◽

2015 ◽

Vol 1130 ◽

pp. 685-688

Author(s):

Rui Yi Fan ◽

Qing Ping Yi ◽

Qing Lin Zhang ◽

Zheng Rong Luo

Keyword(s):

Aqueous Solution ◽

Metal Ions ◽

Adsorption Capacity ◽

Water System ◽

Raw Material ◽

Batch Adsorption ◽

Diospyros Kaki ◽

Cadmium Metal ◽

Fallen Leaves ◽

Adsorption Desorption

A biosorbent was prepared by treating the persimmon (Diospyros kaki Thunb.) fallen leaves with sodium hydroxide (NaOH). The NaOH concentration and stirring period for the preparation of the biosorbent were adjusted to optimise the Cd(I) adsorption capacity of the biosorbents. Removal of highly toxic Cadmium metal ions from water system using the optimal biosorbent named ‘NPFL’ was investigated using a mimic industrial column. The result showed that NPFL could remove Cd(II) in large quantities from aqueous solution with coexisting metal ions. The raw material, NPFL and Cd(II) loaded NPFL were characterized by SEM-EDS. The reusability of NPFL was also studied by batch adsorption-desorption test.

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Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.789.176 ◽

2013 ◽

Vol 789 ◽

pp. 176-179 ◽

Cited By ~ 3

Author(s):

Eny Kusrini ◽

Nofrijon Sofyan ◽

Dwi Marta Nurjaya ◽

Santoso Santoso ◽

Dewi Tristantini

Keyword(s):

Heavy Metals ◽

Aqueous Solution ◽

Metal Ions ◽

Precipitation Method ◽

X Ray Diffraction ◽

X Ray ◽

Removal Of Heavy Metals ◽

Sem Micrograph ◽

Pseudo Second Order ◽

Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

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