scholarly journals Adsorption of Pb(II) and Cd(II) by SquidOmmastrephes bartramiMelanin

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Shiguo Chen ◽  
Changhu Xue ◽  
Jingfeng Wang ◽  
Hui Feng ◽  
Yuming Wang ◽  
...  
Keyword(s):  
Functional Groups ◽  
Metal Binding ◽  
Metal Ion ◽  
Ion Concentration ◽  
Obvious Effect ◽  
Removal Of Heavy Metals ◽  
New Material ◽  
Amine Groups ◽  
Ir Analysis ◽  
Ph Range

The adsorption of Cd(II) and Pb(II) by squid melanin was investigated. At a metal ion concentration of 2 mM/L, the biosorption efficiency of melanin reached 95% for Cd(II) and Pb(II). The maximum content of bound Cd(II) and Pb(II) was 0.93 mM/g and 0.65 mM/g, respectively. Temperature had no obvious effect on the adsorption of the metals, and in a pH range of 4.0–7.0, the adsorption yield was high and stable. Macrosalts such as NaCl,MgCl2, andCaCl2had no obvious effect on the binding of Pb(II) but greatly diminished the adsorption of Cd(II), which indicated that different functional groups in squid melanin are responsible for their adsorption. IR analysis of metal ion-enriched squid melanin demonstrated that the possible functional groups responsible for metal binding were phenolic hydroxyl (OH), carboxyl (COOH), and amine groups (NH). This study reports a new material for the removal of heavy metals from low-strength wastewater.

Cadmium Biosorption on Vegetal Biomass

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Zineb Salem ◽  
Khedidja Allia
Keyword(s):  
Metal Ion ◽  
Low Cost ◽  
Cadmium Concentration ◽  
Biomass Concentration ◽  
Ion Concentration ◽  
Mixing Rate ◽  
Effective Removal ◽  
Removal Of Heavy Metals ◽  
Mixing Rates ◽  
Ph Range

Effective removal of heavy metals from wastewater is one of the most important environmental challenges facing the world. Various techniques are used to remove the metals. Biosorption has gained credibility in the last decade because of its good performance and low cost. The objective of this study is to explore the use of olive pits for cadmium wastewater removal. The effects of mixing rate, pH, particle size, biomass and initial concentration and equilibrium metal ion concentration are evaluated. Results indicate nearly linear uptake by the biomass with increasing initial cadmium concentration. Adsorption increases rapidly in the pH range of 3-9, then levels off. Cadmium concentration uptake increase with increasing biomass concentration until reaching 5 g/L. Mixing rates up to 250 rpm increase uptake, however, higher mixing rates result in a vortex that incorporated air into the mixture, this resulted in a decrease in uptake. The adsorption isotherm appears to follow the Langmuir model.

Chelating modified cellulose bearing pendant heterocyclic moiety for effective removal of heavy metals

2019 ◽  
Vol 80 (8) ◽  
pp. 1549-1561
Author(s):  
R. Saravanan ◽  
R. Mahalakshmi ◽  
M. S. Karthikeyan ◽  
L. Ravikumar
Keyword(s):  
Metal Ion ◽  
Ion Concentration ◽  
Batch Mode ◽  
Effective Removal ◽  
Removal Of Heavy Metals ◽  
Intra Particle Diffusion ◽  
Functional Factors ◽  
Pseudo Second Order ◽  
Heterocyclic Moiety ◽  
Maximum Removal

Abstract Cellulose bearing pendant Schiff base with heterocyclic chelating groups (CMC-Bz) was synthesized, which were fully characterized using various instrumental techniques such as solid state carbon-13 nuclear magnetic resonance (13C-NMR), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) spectra. The adsorption of toxic metals onto cellulosic material was tested in a batch mode operation. The adsorption functional factors such as pH, adsorbent dose, metal ion concentration, equilibrium time and temperature were experimentally optimized for the maximum removal of Cu(II) and Pb(II) ions. Adsorption isotherms were evaluated with Langmuir, Freundlich, Temkin and Redlich–Peterson isotherms. Kinetic parameters and equilibrium adsorption capacities were investigated for pseudo-first-order, pseudo-second-order and intra-particle diffusion models. Thermodynamic parameters and reusability were also evaluated.

Impact of pH on CdII partitioning between alginate gel and aqueous media

2009 ◽  
Vol 6 (4) ◽  
pp. 305 ◽  
Author(s):  
Erwin J. J. Kalis ◽  
Thomas A. Davis ◽  
Raewyn M. Town ◽  
Herman P. van Leeuwen
Keyword(s):  
Functional Groups ◽  
Metal Ion ◽  
Ion Concentration ◽  
Local Concentration ◽  
Relevant Parameter ◽  
Donnan Potential ◽  
Alginate Gel ◽  
Bulk Medium ◽  
Ph Dependent

Environmental context. Biogels, such as those in cell walls or biofilm matrices, generally comprise negative structural charge which leads to accumulation of positively charged species, e.g. metal ions. The magnitude of the effective charge, and hence the local chemical speciation within the gel phase, is pH dependent. In situ speciation measurements in biogels, such as the model alginate studied in this work, offer a better estimate of bioavailable concentrations than does analysis of the surrounding aqueous medium. Abstract. Many microorganisms exist in a biogel-mediated micro-environment such as a cell wall or a biofilm, in which local concentrations of ionic nutrients and pollutants differ from those in the surrounding bulk medium. The local concentration is the relevant parameter for considerations of bioavailability. These modified concentrations arise as a consequence of the negative charges within biogels which may induce a Donnan potential inside the biogel phase. For metals, the net effect on the speciation within the biogel, relative to the bulk medium, is an enhancement of the concentration of free cations. Since the structural charge in the biogel arises from protolytic functional groups, the Donnan potential is pH dependent. Here we apply in situ voltammetry to measure the free metal ion concentration inside alginate gel as a function of pH. In the pH range 3 to 7, the speciation of CdII within this model biogel can be explained by specific binding to carboxylic functional groups and electrostatic binding resulting from the Donnan potential.

scholarly journals Harmful Impacts of Heavy Metals and Utility of Biosorption Technique for Their Removal from Wastewater: A Review

2022 ◽  
Vol 8 (1) ◽  
pp. 1-17
Author(s):  
Ankita Negi ◽  
Rajesh Kumar ◽  
Sushil Kumar Joshi ◽  
Arpita Negi ◽  
Bhuvnesh Kumar ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Metal Ion ◽  
Membrane Filtration ◽  
Literature Survey ◽  
Ion Concentration ◽  
Aquatic Environments ◽  
Chelating Ligands ◽  
Commercial Use ◽  
Removal Of Heavy Metals ◽  
Traditional Approaches

The increasing number of efluents discharged from the source of water (urban, industrial, agricultural etc.), is resulting in a higher concentration of heavy metals in the source. Heavy metals have a density of over 5g/cm3 to the metals. These are toxic, mutagenic, carcinogenic and resistant in watery and non-aquatic environments and impact water and non-water bodies seriously by substituting the basic metals of the same function. The extraction from the wastewater can be done in numerous techniques for example using an ion replacement, membrane filtration, osmosis, etc. This study discusses the adverse effects of heavy metals on the human body, the benefits of biosorption over traditional approaches for removal of heavy metals, the different biosorbents used to extract heavy metals and concerning issues regarding its commercial use, offering a wider viewpoint for the diversity of biosorbents and utilization of biosorption technique. It is evident from the profound literature survey that pH, biosorbent particle size, contact time, initial metal ion concentration, presence of chelating ligands etc. are some factors that affect the rate and extent of biosorption. 

scholarly journals Trace metals in the open oceans: speciation modelling based on humic-type ligands

2011 ◽  
Vol 8 (3) ◽  
pp. 304 ◽  
Author(s):  
Anthony Stockdale ◽  
Edward Tipping ◽  
John Hamilton-Taylor ◽  
Stephen Lofts
Keyword(s):  
Trace Metals ◽  
Metal Binding ◽  
Metal Ion ◽  
Model Fitting ◽  
Organic Ligands ◽  
Ion Concentration ◽  
Detailed Knowledge ◽  
Soil Systems ◽  
Speciation Model ◽  
Speciation Modelling

Environmental contextSpeciation of trace metals in the oceans is typically explained by invoking the concept of metal binding to specific organic ligands. Here, using a speciation model widely used for freshwaters, we assess the extent to which non-specific humic-type ligands found in the ocean may explain chemical speciation of cationic metals. We found that the model can give good fits in some cases, and that experimental results do not give consistent variation from the model. This has implications for the way that the availability of trace elements is considered in ocean environments. AbstractThe speciation of trace metals in the oceans is typically explained by invoking the concept of metal binding to specific organic ligands, but a lack of detailed knowledge about the ligands has impeded the formulation of comprehensive models to predict speciation chemistry. The aim of our study was to shed further light on the possible role of humic-type ligands in trace metal complexation in the oceans by comparing published seawater (open ocean) speciation measurements with predictions obtained using a speciation model typically used for freshwater and soil systems (Windermere Humic Aqueous Model; WHAM). We show that in some cases, speciation of trace metals in seawater environments may be reasonably predicted using this model with its default parameter set, without any model fitting. The results support the idea that humic-type ligands may account for much of the observed organic binding at least in the cases of Fe, Cu and Pb. Although the model does not consistently provide agreement with the measured values, it provides a useful benchmark to compare different datasets and to examine variation in speciation as a result of varying levels of competing metal ion concentration and fulvic acid activity.

scholarly journals Kinetic Studies of Heavy Metal Removal from Industrial Wastewater by Using Natural Zeolite

2021 ◽  
Vol 5 (1) ◽  
pp. 18-25
Author(s):  
Ali Mohammed Salih ◽  
Craig Williams ◽  
Polla Khanaqa
Keyword(s):  
Heavy Metals ◽  
Natural Zeolite ◽  
Industrial Wastewater ◽  
Metal Ion ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Solution Concentration ◽  
Ion Concentration ◽  
Solution Ph ◽  
Removal Of Heavy Metals

The present work involves the study of the removal of Cu2+, Fe3+, Pb2+ and Zn2+ from synthetic metal solutions using natural zeolite. Laboratory experiments were used to investigate the efficiency of adsorbents in the uptake of heavy metals from industrial wastewater. The kinetic study was used to identify the effect of parameters that affect the rate of adsorption and evaluated their impact on the efficiency of the zeolite in the removal of heavy metals from industrial wastewater. Natural zeolite (clinoptilolite) as adsorbent contacted with multi-component synthetic solutions containing Cu2+, Fe3+, Pb2+ and Zn2+ ions without any pre-modifications and every hour 15 ml of the samples were filtered and taken for metal ion concentration analysis using the ICP-OES. The pH values were monitored and adjusted regularly. The results showed that the capacity of the adsorbents for the removal of heavy metals increased with a greater mass of absorbent, increased initial solution pH, increased agitation speed and higher solution concentration.

Nickel ion removal from aqueous solutions through the adsorption process: a review

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammadtaghi Vakili ◽  
Mohd Rafatullah ◽  
Jing Yuan ◽  
Haider M. Zwain ◽  
Amin Mojiri ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Adsorption Process ◽  
Negative Impact ◽  
Ion Concentration ◽  
Nickel Ion ◽  
Nickel Ions ◽  
Desorption Mechanism ◽  
Ph Range ◽  
Nickel Adsorption

AbstractRecently, removal of nickel ions has been gaining a lot of attention because of the negative impact of nickel ions on the environment. The aim of this review paper is to organize the scattered available information on removal of nickel ions from aqueous solutions through the adsorption process. Survey on investigated materials suggests that composite- and polymer-based adsorbents have the most effective capability for nickel adsorption. The composite material class, i.e. CaCO3-maltose, followed by biopolymer-based material showed the highest Ni(II) adsorption capacity of 769.23 and 500 mg/g, respectively. The importance of treatment parameters (i.e. pH, temperature, contact time, and metal ion concentration) is discussed, together with their effect on the underlying physicochemical phenomena, giving particular attention to the adsorption/desorption mechanism. It was ascertained that adsorption of nickel ions is pH dependent and the optimal pH range for adsorption of Ni(II) ions was in range of 6–8. In general, nickel adsorption is an endothermic and spontaneous process that mainly occurs by forming a monolayer on the adsorbent (experimental data are often fitted by Langmuir isotherms and pseudo-second-order kinetics). Regeneration (i.e. desorption) is also reviewed, suggesting that acidic eluents (e.g. HCl and HNO3) allow, in most of the cases, an efficacious spent adsorbent recovery. The percentage use of desorption agents followed the order of acids (77%) > chelators (8.5%) > alkalis (8%) > salts (4.5%) > water (2%). Helpful information about adsorption and desorption of nickel ions from aqueous solutions is provided.

Keratin Protein Nano-fiber for Removal of Heavy Metals and Contaminants

2001 ◽  
Vol 702 ◽  
Author(s):  
M. Misra ◽  
P. Kar ◽  
G. Priyadarshan ◽  
Carlo Licata
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Binding ◽  
Metal Uptake ◽  
Binding Capacity ◽  
Nano Fiber ◽  
Removal Of Heavy Metals ◽  
Wide Ph Range ◽  
As Adsorption ◽  
Ph Range

ABSTRACTKeratin protein fiber (AKF™) is a renewable source of biosorbent that can be used for filtration of heavy metal and nanosize contaminants. The major composition of keratin fiber is the structured protein micofibril, consisting of numerous nanosized pores. The combination of nanostructure and metal binding capacity protein sites make it an ideal material for removal of heavy metals from solutions. The mechanism of heavy metal uptake onto keratin protein involves a combination of several steps such as adsorption, precipitation, and ion exchange. Keratin protein has good tensile strength and is stable over a wide pH range.

Synthesis and applications of functionalized silsesquioxane polymers attached to organic and inorganic matrices

2008 ◽  
Vol 80 (7) ◽  
pp. 1593-1611 ◽  
Author(s):  
Yoshitaka Gushikem ◽  
Edilson V. Benvenutti ◽  
Yuriy V. Kholin
Keyword(s):  
Functional Groups ◽  
Metal Ion ◽  
Adsorption Process ◽  
Electrochemical Sensors ◽  
Water Soluble ◽  
Soluble Form ◽  
High Affinity ◽  
Insoluble Form ◽  
Amine Groups ◽  
Electroactive Species

Organofunctionalized silsesquioxane polymers obtained in a water-soluble form can be used to coat various substrates such as SiO2, SiO2/Al2O3, Al2O3, cellulose/Al2O3, and graphite or, when obtained in a water-insoluble form, can be used directly. These organofunctionalized silsesquioxanes can also be attached to poly(dimethylsiloxane) (PDMS) polymers. The functional groups constituted by neutral amine groups or cationic groups (pyridinium, 3- and 4-picolinium, or 1,4-diazabicyclo[2.2.2]octane (DABCO), mono- or -dicationic) have relatively high affinity for metal ion in ethanol solutions, as shown by their stability constants. Materials containing attached cationic functional groups have also been efficiently used to immobilize various electroactive species and to construct electrochemical sensors for analytical applications. This work discusses the preparation of silsesquioxane derivatives, their characterization as prepared and when dispersed on several substrates, and comments on some applications of these materials, with an emphasis on the metal adsorption process and manufacture of electrochemical sensors.

The Adsorption of Heavy Metal from Aqueous Solutions onto the Porous Biomorphic-Genetic Composite of Hydroxyapatite/Carbon with Eucalyptus and Bamboo Template

2015 ◽  
Vol 730 ◽  
pp. 260-264 ◽  
Author(s):  
Shuang Cao ◽  
Bin Huang ◽  
Zong Qiang Zhu ◽  
Yi Nian Zhu
Keyword(s):  
Heavy Metals ◽  
Metal Ion ◽  
Contaminated Water ◽  
Initial Concentration ◽  
Metal Ion Removal ◽  
Ion Removal ◽  
Adsorbed Amount ◽  
Removal Of Heavy Metals ◽  
New Material ◽  
Ammonia Leaching

This study used two types of plant, eucalyptus and bamboo, to produce sorbents for copper (II), cadmium (II), zinc (II), and lead (II) metal ion removal in a water bath shake. The porous biomorphic-genetic composite of hydroxyapatite/carbon with eucalyptus template (PBGC-Fe/C-E) and the porous biomorphic-genetic composite of hydroxyapatite/carbon with bamboo template (PBGC-Fe/C-B) were prepared using eucalyptus and bamboo as plant templates, and through various processes including ammonia leaching, cyclical impregnation using calcium hydroxide and diammonium solutions, and aerobic firing inside muffle furnaces. Tests were conducted on the HAP/C composites to observe their adsorption effects on Cu (II), Zn (II), Pb (II), and Cd (II). The results show that the prepared composites were able to adsorb heavy metals in water effectively. The results indicated that the adsorbed amount of PBGC-Fe/C-E were found to be 16.4371, 4.6725,24.5528, 17.0194 mg/1 for Cu (II), Zn (II), Pb (II) and Cd (II) ions at initial concentration of 50mg/L (25°C), respectively. The adsorbed amount of PBGC-Fe/C-B were found to be 10.5876, 3.9142,21.2463, 13.4721 mg/1 for Cu (II), Zn (II), Pb (II) and Cd (II) ions at initial concentration of 50mg/L (25°C), respectively. The prepared adsorbent is expected to be a new material for the removal of heavy metals from contaminated water.

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