scholarly journals Reactivity and Heavy Metal Removal Capacity of Calcium Alginate Beads Loaded with Ca–Al Layered Double Hydroxides

2019 ◽  
Vol 3 (1) ◽  
pp. 22 ◽  
Author(s):  
Andres Borgiallo ◽  
Ricardo Rojas
Keyword(s):  
Heavy Metal ◽  
Layered Double Hydroxides ◽  
Calcium Alginate ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Alginate Beads ◽  
Buffering Capacity ◽  
Uptake Capacity ◽  
Removal Capacity ◽  
Double Hydroxides

Layered double hydroxides (LDHs) present multiple applications due to their versatility and reactivity. Thus, Ca–Al LDHs with Friedel’s salt structure (HC) have been proposed as heavy metal scavengers due to their buffering capacity at basic pHs. Nevertheless, the control of the reactivity of LDHs such as HC is necessary to optimize their applications. Here, the reactivity of an HC prepared by a coprecipitation method was modified by its inclusion in calcium alginate (CaAlg) beads prepared by ionic gelation. The obtained beads (CaAlg/HC) showed good dispersion of the HC particles in the alginate matrix and were used to test the acid base reactivity and heavy metal uptake capacity compared with pure CaAlg beads and HC powder separately. The pH buffering capacity of CaAlg beads was enriched by the inclusion of HC that, in turn, was modulated in its reactivity. Thus, the HC dissolution times changed from mere seconds for the powder to tens of minutes when enclosed in the beads in a kinetic profile determined by the diffusive step. On the other hand, Cu2+ uptake capacity of CaAlg/HC beads combined the Cu(OH)2 precipitation capacity of HC with the complexation capacity of alginate, reaching good affinity and capacity for the obtained beads. Nevertheless, the precipitation of the hydroxide was produced outside the bead, which would induce the addition of an additional separation step to produce an acceptable Cu2+ elimination.

scholarly journals Heavy metal removal from wastewater using various adsorbents: a review

2016 ◽  
Vol 7 (4) ◽  
pp. 387-419 ◽  
Author(s):  
Renu ◽  
Madhu Agarwal ◽  
K. Singh
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Aquatic Ecosystems ◽  
Adsorption Process ◽  
Metal Removal ◽  
Low Cost ◽  
Heavy Metal Removal ◽  
Review Article ◽  
Removal Capacity ◽  
Removal Of Heavy Metals

Heavy metals are discharged into water from various industries. They can be toxic or carcinogenic in nature and can cause severe problems for humans and aquatic ecosystems. Thus, the removal of heavy metals from wastewater is a serious problem. The adsorption process is widely used for the removal of heavy metals from wastewater because of its low cost, availability and eco-friendly nature. Both commercial adsorbents and bioadsorbents are used for the removal of heavy metals from wastewater, with high removal capacity. This review article aims to compile scattered information on the different adsorbents that are used for heavy metal removal and to provide information on the commercially available and natural bioadsorbents used for removal of chromium, cadmium and copper, in particular.

Removal of Some Heavy Metals by Electrocoagulation

2012 ◽  
Vol 468-471 ◽  
pp. 2882-2890 ◽  
Author(s):  
R. H. Al Anbari ◽  
S. M. Alfatlawi ◽  
J. H. Albaidhani
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Removal Efficiency ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Efficient Treatment ◽  
Electrolytic Cells ◽  
Removal Capacity ◽  
Metals Removal ◽  
Working Parameters

Heavy metal removal by electrocoagulation using iron electrodes material was investigated in this paper. Several working parameters, such as pH, current density and heavy metal ions concentration were studied in an attempt to achieve a higher removal capacity. A simple and efficient treatment process for removal of heavy metals is essentially necessary. The performance of continuous flow electrocoagulation system, with reactor consists of a ladder series of twelve electrolytic cells, each cell containing stainless steel cathode and iron anode. The treatment of synthetic solutions containing Zn 2+,Cu 2+,Ni 2+,Cr 3+,Cd 2+ and Co 2+ ,has been investigated. Results showed that iron is very effective as sacrificial electrode material for heavy metals removal efficiency and cost points. Also it was concluded that the chromium has lower efficient removal as compared to zinc, copper and nickel. At the same time cadmium and cobalt have minimum removal efficiency.

The Effect of Cu Concentration on TiO2 Nanotubes for Low Concentration of Pb(II) Removal

2013 ◽  
Vol 756 ◽  
pp. 212-218
Author(s):  
Syazwani Mohd Zaki ◽  
Srimala Sreekantan
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Uv Light ◽  
Heavy Metal Removal ◽  
Alginate Beads ◽  
Human Beings ◽  
Wet Impregnation ◽  
Initial Concentration ◽  
Low Concentration ◽  
High Level

Lead (Pb) has been recognized to be acutely toxic to human beings and studies have shown that young children, infants and pregnant women are particularly at risk to unsafe Pb (II) level. Generally, high level of Pb(II) can be removed by using alginate beads. However, at low level, it is not possible to be removed by alginate. For that reason, low concentration (10 ppm) of Pb(II) removal by photocatalytic activity is explored in this work. Cu loaded TiO₂ nanotube was prepared by wet impregnation with different Cu concentration. The initial concentration of Cu involved were 0.01 M, 0.06 M and 0.1 M. For heavy metal removal, the initial concentration of Pb(II) solution used was 10 ppm. The remnant concentration of Pb(II) solution after irradiated under ultraviolet(UV) light was determined by using Atomic Absorption Spectroscopy (AAS). It was observed that the optimal condition of Cu loaded nanotube was at 0.01 M and it exhibited highest removal of Pb(II) with 50%. However, at high Cu concentration(> 0.06 M), it declined the performance of TiO₂ nanotubes for Pb(II) removal. The removal of Pb(II) obtained at 0.06 M and 0.01M was only 23.3% and 17.1%.

EPS production and bioremoval of heavy metals by mixed and pure bacterial cultures isolated from Ankara Stream

2015 ◽  
Vol 72 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
Nur Koçberber Kiliç ◽  
Güliz Kürkçü ◽  
Durna Kumruoğlu ◽  
Gönül Dönmez
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Mixed Cultures ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
Bacterial Cultures ◽  
Removal Capacity ◽  
Pure Cultures ◽  
Pure Bacterial Cultures

This study is focused on isolation of Ni(II), Cu(II) and Cr(VI) resistant bacteria to assess their exopolysaccharide (EPS) production and related bioremoval capacities. Mixed cultures had higher heavy metal removal capacity in media with molasses (MAS) than the control cultures lacking this carbon (AS) containing 50 mg/l of heavy metal. The yields were 32%, 75.7%, and 51.1% in MAS, while the corresponding values were 29%, 55.1%, and 34.5% in AS, respectively. Purification of the strains 1, 5 and 6 present in the mixed cultures decreased the bioremoval capacities of the mixed culture samples, although these strains produced higher EPS amounts in MAS agar. Strain 5 had the highest Cu(II) (69.1%) and Cr(VI) (43.1%) removal rates at 25 mg/l initial concentration of each pollutant with EPS amounts of 0.74 g/l and 1.05 g/l, respectively. This strain was identified as Stenotrophomonas maltophilia. The presented data show that especially mixed and also pure cultures of bacterial strains isolated from Ankara Stream could be assessed as potential bioremoval agents in the treatment of Cu(II) or Cr(VI) containing wastewaters.

Comparative Evaluation of Soluble and Insoluble Xanthate Process for Heavy Metal Removal from Wastewaters

1992 ◽  
Vol 26 (1-2) ◽  
pp. 237-246 ◽  
Author(s):  
V. Tare ◽  
S. Chaudhari ◽  
M. Jawed
Keyword(s):  
Heavy Metal ◽  
Comparative Evaluation ◽  
Corn Starch ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Soluble Starch ◽  
Aqueous Systems ◽  
Cadmium Removal ◽  
Removal Capacity ◽  
Ph Range

Insoluble (ISX) and soluble starch xanthate (SSX) were synthesized in the laboratory from corn starch, and were used for metal [Cd(II), Cu(II) and Cr(VI)] removal from aqueous systems. Results indicate that soluble as well as insoluble xanthate processes are capable of meeting various effluent disposal standards. Metal removal by both the processes is maximum in the pH range 4 to 5. Mechanism of Cu(I I)-xanthate and Cr(VI)-xanthate interaction is also discussed. From overall comparison of the two processes it appears that theinsoluble xanthate process has an edge over the solublexanthate process in terms of metal removal capacity, reliability and ease of operation, particularly for cadmium removal. However, soluble xanthate process appears to be relatively less expensive compared to insoluble xanthate.

scholarly journals New Type of Sodium Alginate-g-acrylamide Polyelectrolyte Obtained by Electron Beam Irradiation: Characterization and Study of Flocculation Efficacy and Heavy Metal Removal Capacity

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 234 ◽  
Author(s):  
Gabriela Craciun ◽  
Elena Manaila and Daniel Ighigeanu
Keyword(s):  
Heavy Metal ◽  
Electron Beam ◽  
Sodium Alginate ◽  
Electron Beam Irradiation ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Beam Irradiation ◽  
Kaolin Suspension ◽  
Ion Removal ◽  
Removal Capacity

The goals of the paper were first the obtainment and characterization of sodium alginate-g-acrylamide polyelectrolytes by electron beam irradiation in the range of 0.5 to 2 kGy, and second, the evaluation of flocculation efficacy and heavy metal removal capacity from aqueous solutions of known concentrations. Based on sodium alginate concentration, two types of grafted polymers were obtained. Physical, chemical, and structural investigations were performed. Flocculation studies under different stirring conditions on 0.5, 0.1 and 0.2% kaolin suspension were done. The removal capacity of Cu2+ and Cr6+ ions was also investigated. The acrylamide grafting ratio on sodium alginate backbone was found up to 2000% for samples containing 1% sodium alginate and up to 500% for samples containing 2% sodium alginate. Transmittances between 98 and 100% were obtained using, in the flocculation studies, polyelectrolytes containing 2% sodium alginate in concentrations of 0.5 and 1 ppm on kaolin suspension of 0.1 wt %. The polymer concentration was found critical for kaolin suspension of 0.05 and 0.1 wt %. Polymers containing 1% sodium alginate were efficient in Cr6+ ion removal, while those containing 2% in Cu2+ ion removal.

Evaluation of Heavy Metal Removal Capacity of Bioretention Systems

2015 ◽  
Vol 226 (11) ◽  
Author(s):  
Sezar Gülbaz ◽  
Cevza Melek Kazezyılmaz-Alhan ◽  
Nadim K. Copty
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Removal Capacity
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