scholarly journals Biosorption of Cadmium by Fucus spiralis

2004 ◽  
Vol 1 (3) ◽  
pp. 180 ◽  
Author(s):  
Manuel Esteban Sastre de Vicente ◽  
Roberto Herrero ◽  
Pablo Lodeiro ◽  
Bruno Cordero

Environmental Context. Conventional processes for the removal of heavy metals from wastewaters generally involves chemical precipitation of metals (changing the pH) followed by a period to allow the metal precipitates to settle and be separated. These processes are inefficient when the metals are at a low concentration and still demand handling and disposal of toxic metal sludges. An alternative method for heavy metal removal is adsorption onto a biological material, biosorption. The biological materials, including agricultural byproducts, bacteria, fungi, yeast, and algae, all which take up heavy metals in substantial quantities, are relatively inexpensive, widely available, and from renewable sources. However, biological materials are complex and the active mechanisms often unclear. Abstract. Cadmium biosorption properties of nonliving, dried brown marine macroalga Fucus spiralis from Galician coast (northwest Spain) have been investigated. The biosorption capacity of the alga strongly depends on solution pH; the uptake is almost negligible at pH ≤ 2 and reaches a plateau at around pH 4.0. Cadmium biosorption kinetics by F. spiralis is relatively fast, with 90% of total adsorption taking place in less than one hour. A pseudo second order mechanism has been proved to be able to predict the kinetic behaviour of the biosorption process. The effect of initial cadmium ion concentration, alga dose, solution pH, and temperature on the biosorption kinetics has been studied. The Langmuir, Freundlich, Langmuir–Freundlich, and Tóth isotherms were used to fit the experimental data and to find out the adsorption parameters. Acid–base properties of the alga have been studied potentiometrically in order to calculate the number of acidic groups and the apparent pK value by using Katchalsky model. The pK obtained is comparable with typical values associated to the ionization of carboxyl groups of alginates, supporting the implication of these groups in the biosorption process.

2021 ◽  
Vol 5 (1) ◽  
pp. 18-25
Author(s):  
Ali Mohammed Salih ◽  
Craig Williams ◽  
Polla Khanaqa

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.


Author(s):  
Irene W. Maina ◽  
Morlu G. F. Stevens ◽  
Bareki S. Batlokwa

Aims: To employ valorized waste materials from Tilapia ruweti scales for removal of heavy metals from areas with major boating activities and high numbers of jetties at the Okavango delta, Botswana. Study Design: Biowaste materials were Identified, valorized and then optimized for adsorption and removal of boating and jetty pollutants from profiled Okavango Delta surface water samples. Place and Duration of Study: Okavango Delta, Maun and Botswana International University of Science and Technology, Palapye, Botswana between March 2017 and September 2018. Methodology: Tilapia ruweti scales were collected from Sehithwa, Maun while water samples were collected from areas with jetties and major boating activities at Shakawe, Mboma Island and Xakanaxa. The concentration of Zn, Cu, Ni, Co, Pb and Cd at all the sampling sites were accurately determined using micro-plasma atomic emission spectroscopy (MPAES). The fish scales were pulverized and valorized by subjecting them to 12.7% vinegar. Minitab 14 software was used as a modeling tool to provide multivariate optimized parameters that affect sorption studies that included initial ion concentration, sorbent dose, contact time and solution pH. The valorized waste materials were then utilized for removal of the selected heavy metals. Results: The optimized adsorption parameters that included contact time, solution pH, sorbent dose and initial ion concentration were ≤ 88.63 min, ≤ 8.75, ≤ 84.29 mg and ≤ 28.44 mg/L respectively. The valorized Tilapia ruweti waste displayed high removal efficiencies toward removing the selected ions from the Okavango Delta surface water samples up to 94.21% with %RSD < 2 for n = 3 (triplicate). Conclusion: The valorized Tilapia ruweti scales were recommended as a cheap, simple and an effective method for remediation of boating pollution at the Okavango delta and other recreational areas.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Rajaa Bassam ◽  
Achraf El hallaoui ◽  
Marouane El Alouani ◽  
Maissara Jabrane ◽  
El Hassan El Khattabi ◽  
...  

The aim of this study is the valorization of the Moroccan clays (QC-MC and QC-MT) from the Middle Atlas region as adsorbents for the treatment of water contaminated by cadmium Cd (II) ions. The physicochemical properties of natural clays are characterized by ICP-MS, XRD, FTIR, and SEM techniques. The adsorption process is investigated as a function of adsorbent mass, solution pH, contact time, temperature, and initial Cd (II) ion concentration. The kinetic investigation shows that the adsorption equilibrium of Cd (II) ions by both natural clays is reached after 30 min for QC-MT and 45 min for QC-MC and fits well to a pseudo-second-order kinetic model. The isotherm study is best fitted by a Freundlich model, with the maximum adsorption capacity determined by the linear form of the Freundlich isotherm being 4.23 mg/g for QC-MC and 5.85 mg/g for QC-MT at 25°C. The cadmium adsorption process was thermodynamically spontaneous and exothermic. The regeneration process showed that these natural clays had excellent recycling capacity. Characterization of the Moroccan natural clays before and after the adsorption process through FTIR, SEM, XRD, and EDX techniques confirmed the Cd (II) ion adsorption on the surfaces of both natural clay adsorbents. Overall, the high adsorption capacity of both natural clays for Cd (II) ions removal compared to other adsorbents motioned in the literature indicated that these two natural adsorbents are excellent candidates for heavy metal removal from aqueous environments.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wanqi Zhang ◽  
Yuhong An ◽  
Shujing Li ◽  
Zhechen Liu ◽  
Zhangjing Chen ◽  
...  

Abstract Thiol-lignocellulose sodium bentonite (TLSB) nanocomposites can effectively remove heavy metals from aqueous solutions. TLSB was formed by using –SH group-modified lignocellulose as a raw material, which was intercalated into the interlayers of hierarchical sodium bentonite. Characterization of TLSB was then performed with BET, FTIR, XRD, TGA, PZC, SEM, and TEM analyses. The results indicated that thiol-lignocellulose molecules may have different influences on the physicochemical properties of sodium bentonite, and an intercalated–exfoliated structure was successfully formed. The TLSB nanocomposite was subsequently investigated to validate its adsorption and desorption capacities for the zinc subgroup ions Zn(II), Cd(II) and Hg(II). The optimum adsorption parameters were determined based on the TLSB nanocomposite dosage, concentration of zinc subgroup ions, solution pH, adsorption temperature and adsorption time. The results revealed that the maximum adsorption capacity onto TLSB was 357.29 mg/g for Zn(II), 458.32 mg/g for Cd(II) and 208.12 mg/g for Hg(II). The adsorption kinetics were explained by the pseudo-second-order model, and the adsorption isotherm conformed to the Langmuir model, implying that the dominant chemical adsorption mechanism on TLSB is monolayer coverage. Thermodynamic studies suggested that the adsorption is spontaneous and endothermic. Desorption and regeneration experiments revealed that TLSB could be desorbed with HCl to recover Zn(II) and Cd(II) and with HNO3 to recover Hg(II) after several consecutive adsorption/desorption cycles. The adsorption mechanism was investigated through FTIR, EDX and SEM, which demonstrated that the introduction of thiol groups improved the adsorption capacity. All of these results suggested that TLSB is an eco-friendly and sustainable adsorbent for the extraction of Zn(II), Cd(II) and Hg(II) ions in aqueous media.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 780
Author(s):  
Concepcion Pla ◽  
David Benavente ◽  
Javier Valdes-Abellan ◽  
Antonio Jodar-Abellan

Heavy-metal sources in urban environments include automobile exhaust, fuel combustion, tires, road asphalt, weathering of building materials, and/or industrial activities. The presence of heavy metals in urban stormwaters constitutes a potential risk for water resources and aquatic life. Results from the present study demonstrated the effectiveness of two different lightweight aggregates (LWAs), Arlita and Filtralite, to remove heavy metals (Ni, Cu, Zn, Cd, and Pb) present in aqueous solutions. These materials were selected because they previously showed great results for water treatment and because of their physicochemical properties. The removal efficiency of the studied materials was evaluated with batch tests containing solutions contaminated with heavy metals (with individual and multiple contaminants) at different concentrations mixed with the LWA particles. Filtralite showed a better performance in heavy metal removal than Arlita: higher adsorption capacity for all metals, and lower release of metals from contaminated particles into washing water. The average removal capacities in tests developed with solutions containing individual contaminants for Arlita and Filtralite were 76% and 90%, respectively, although the values varied across the different contaminants. Metal elimination by LWAs was more effective with individual contaminated solutions than with multielemental ones. The analysis of the adsorption curves, the mineral precipitation on the LWA surface, and the geochemical modeling confirmed that two different mechanisms are responsible for the heavy-metal removal. First, the rough surface of the LWA presents sorbing surface sites of the forming minerals, resulting in the ion-exchange reactions of metal ions. Second, the LWA–water interaction causes an increase in solution pH, which triggers the precipitation and coprecipitation of the metals in the form of oxide and hydroxides. The study confirms that the use of Arlita and especially Filtralite present promising potential to remove heavy metals from urban stormwaters.


2013 ◽  
Vol 69 (9) ◽  
pp. 1775-1787 ◽  
Author(s):  
Vahid Javanbakht ◽  
Seyed Amir Alavi ◽  
Hamid Zilouei

Release and distribution of heavy metals through industrial wastewaters has adverse affects on the environment via contamination of surface- and ground-water resources. Biosorption of heavy metals from aqueous solutions has been proved to be very promising, offering significant advantages such as low cost, availability, profitability, ease of operation, and high efficiency, especially when dealing with low concentrations. Residual biomasses of industrial microorganisms including bacteria, algae, fungi, and yeast have been found to be capable of efficiently accumulating heavy metals as biosorbent. This paper presents and investigates major mechanisms of biosorption and most of the functional groups involved. The biosorption process includes the following mechanisms: transport across cell membrane, complexation, ion exchange, precipitation, and physical adsorption. In order to understand how metals bind to the biomass, it is essential to identify the functional groups responsible for metal binding. Most of these groups have been characterized on the cell walls. The biosorbent contains a variety of functional sites including carboxyl, imidazole, sulfydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide, and hydroxyl moieties that are responsible for metal adsorption. These could be helpful to improve biosorbents through modification of surface reactive sites via surface grafting and/or exchange of functional groups.


2016 ◽  
Vol 75 (3) ◽  
pp. 587-597 ◽  
Author(s):  
Qian Zhang ◽  
Bing Lin ◽  
Junming Hong ◽  
Chang-Tang Chang

This study focuses on the effectiveness of zeolite (10% CF-Z [0.5]) hydrothermally synthesized from waste quartz sand and calcium fluoride (CF) for ammonium ion and heavy metal removal. Zeolite was characterized through powder X-ray diffraction, Fourier-transform infrared spectroscopy, micromeritics N2 adsorption/desorption analysis, and field emission scanning electron microscopy. The effects of CF addition, Si/Al ratio, initial ammonium concentration, solution pH, and temperature on the adsorption of ammonium on 10% CF-Z (0.5) were further examined. Results showed that 10% CF-Z (0.5) was a single-phase zeolite A with cubic-shaped crystals and 10% CF-Z (0.5) efficiently adsorbs ammonium and heavy metals. For instance, 91% ammonium (10 mg L−1) and 93% lead (10 mg L−1) are removed. The adsorption isotherm, kinetics, and thermodynamics of ammonium adsorption on 10% CF-Z (0.5) were also theoretically analyzed. The adsorption isotherm of ammonium and lead on 10% CF-Z (0.5) in single systems indicated that Freundlich model provides the best fit for the equilibrium data, whereas pseudo-second-order model best describes the adsorption kinetics. The adsorption degree of ions on 10% CF-Z (0.5) in mixed systems exhibits the following pattern: lead &gt; ammonium &gt; cadmium &gt; chromium.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Waheed Ali Khoso ◽  
Noor Haleem ◽  
Muhammad Anwar Baig ◽  
Yousuf Jamal

AbstractThe heavy metals, such as Cr(VI), Pb(II) and Cd(II), in aqueous solutions are toxic even at trace levels and have caused adverse health impacts on human beings. Hence the removal of these heavy metals from the aqueous environment is important to protect biodiversity, hydrosphere ecosystems, and human beings. In this study, magnetic Nickel-Ferrite Nanoparticles (NFNs) were synthesized by co-precipitation method and characterized using X-Ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS) and Field Emission Scanning Electronic Microscopy (FE-SEM) techniques in order to confirm the crystalline structure, composition and morphology of the NFN’s, these were then used as adsorbent for the removal of Cr(VI), Pb(II) and Cd(II) from wastewater. The adsorption parameters under study were pH, dose and contact time. The values for optimum removal through batch-adsorption were investigated at different parameters (pH 3–7, dose: 10, 20, 30, 40 and 50 mg and contact time: 30, 60, 90, and 120 min). Removal efficiencies of Cr(VI), Pb(II) and Cd(II) were obtained 89%, 79% and 87% respectively under optimal conditions. It was found that the kinetics followed the pseudo second order model for the removal of heavy metals using Nickel ferrite nanoparticles.


2016 ◽  
Vol 73 (12) ◽  
pp. 2921-2928 ◽  
Author(s):  
Marla C. Maniquiz-Redillas ◽  
Lee-Hyung Kim

Abstract In this research, an infiltration trench equipped with an extensive pretreatment and filter bed consisting of woodchip, sand and gravel was utilized as a low impact development technique to manage stormwater runoff from a highly impervious road with particular emphasis on heavy metal removal. Findings revealed that the major factors influencing the removal of heavy metals were the concentration of the particulate matters and heavy metals in runoff, runoff volume and flow rates. The reduction of heavy metals was enhanced by sedimentation of particulates through pretreatment. Fine particles (&lt;2 mm) had the most significant amount of heavy metals, thus, enhanced adsorption and filtration using various filter media were important design considerations. Sediment was most highly attached on the surface area of woodchip than to other filter media like sand, gravel and geotextile. It is suggested that maintenance must be performed after the end of the winter season wherein high sediment rate was observed to maintain the efficiency of the treatment system.


2013 ◽  
Vol 779-780 ◽  
pp. 1674-1677 ◽  
Author(s):  
Dan Lian Huang ◽  
Guang Ming Zeng ◽  
Piao Xu ◽  
Cui Lai ◽  
Mei Hua Zhao ◽  
...  

Immobilized microbe technologies are expected to be effectively used in wastewater treatment. Removal of heavy-metals from wastewater by immobilized Phanerochaete chrysosporium (Pc) with Ca-alginate and iron oxide magnetic nanoparticles (MNPs) was studied. The results showed that a biosorbent as Pc immobilized by Ca-alginate and iron oxide magnetic nanoparticles was successfully developed. And the iron oxide magnetic nanoparticles played an important role in the increase of biosorption capacity of Pc. Energy dispersive spectrometer (EDS) analysis confirmed that metal ions adsorbed to the surface of the biosorbents were partly transmitted to the interior of biosorbents, mainly embedded with iron oxide nanoparticles and Ca-alginate. Moreover, it was found that MNPs-Ca-alginate immobilized Pc showed a good affinity to various heavy metals, such as Pb(II), Zn(II), Cd(II) or Mg(II) and so on. The results proved the high efficiency of the biosorbents for heavy-metal removal and its potential application in the treatment of metal-containing wastewater.


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