Adsorption of Cadmium on Gel Combustion Derived Nano ZnO

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Venkatesham V ◽  
Madhu G.M ◽  
Satyanarayana S V ◽  
Preetham H S
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Surface Area ◽  
Heavy Metal Ions ◽  
Cadmium Concentration ◽  
Nano Zno ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Gel Combustion ◽  
Cd Adsorption

Large amount of heavy metal ions disposed in wastewater by various industries causes environmental pollution and toxicity in waste water. Many naturally available materials were used as adsorbents for the removal of heavy metal ions, but they are not effective because of low surface area. Novel nano materials are used as adsorbents in the removal of metal ions to treat potable water. In the present work nano sized large surface area (80.425 m2/g) Zinc Oxide (ZnO) was synthesized by gel combustion method and used as an adsorbent for the removal of cadmium (II) (Cd2+) from aqueous solution. The nano ZnO and Cd adsorbed ZnO were characterized by XRD, the additional Cd peaks in XRD pattern confirms the Cd adsorption. SEM analysis confirmed the adsorption of Cd2+ by change in the morphology of adsorbent. Percentage purity of the element and the presence of the Cd were characterized by EDAX. Adsorption of Cd2+ on ZnO was confirmed by varying parameters like initial concentration, pH and adsorbent dosage. Cadmium concentration in the solution was analyzed using Atomic Absorption Spectrometer (AAS). Increase in the initial concentration of Cd solution, decreases the percentage of adsorption, where as increase in the adsorbent dosage and pH of the solution increases the adsorption of Cd2+ on ZnO. Synthesized nano ZnO shows maximum of 95% Cd adsorption at lower initial concentration. Experimental data fits Langmuir and Freundlich adsorption isotherm models.

scholarly journals Study on Adsorption Properties of Loess Calcareous Nodules to Heavy Metalions In Aqueous-solution

2021 ◽  
Author(s):  
Qi Li ◽  
Li Yanan ◽  
Xiaoxiao Shu
Keyword(s):  
Heavy Metal ◽  
Particle Size ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Adsorption Rate ◽  
Obvious Effect ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Adsorption Rates

Abstract Using calcareous calcareous tuberculosis as adsorbent and heavy metal ions (Cu2+, Zn2+, Cd2+ and Pb2+) as adsorbents, different particle size, adsorption time, pH, adsorbent dosage and initial concentration of heavy metals were studied by single heavy metal adsorption test. And the influence of temperature and other factors on the adsorption of heavy metal ions by calcareous nodules, and determine the optimal conditions for the adsorption of heavy metal ions by calcareous nodules. The results show that the adsorption rates of Cu2+, Zn2+ and Pb2+ decrease gradually with the increase of particle size, but have no obvious effect on Cd2+. With the increase of adsorption time, adsorbent dosage and temperature, the adsorption rates of Cu2+, Zn2+, Cd2+ and Pb2+ gradually increase. The adsorption rate of Cu2+, Zn2+ and Cd2+ decreased gradually with the increase of the initial concentration of heavy metal ions, while the adsorption rate of Pb2+ increased first and then decreased. With the increase of pH, the adsorption rate of Cd2+ increased first and then increased slowly. The adsorption rates of Cu2+, Zn2+ and Pb2+ increased first and then decreased. The adsorption capacity of calcareous nodules to four heavy metal ions is in the order of Pb2+＞Zn2+＞Cu2+＞Cd2+. When the particle size is 0.25 mm, the adsorption time is 120 min, and the dosage is 0.6 g, the calcareous nodules are Pb2+, Zn2+, Cu2+. And Cd2+ can achieve better adsorption, and the adsorption rate can reach 83.33%, 77.78%, 73.81% and 81.93% of its maximum adsorption rate, respectively. The optimal adsorption pH of calcareous nodules to Pb2+, Zn2+, Cu2+ and Cd2+ was 7, 6, 5 and 8, respectively, and the optimal temperature was 50 °C.

scholarly journals Adsorption Features of Loess Calcareous Nodules to Heavy-Metal Ions in Aqueous Solution

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1314
Author(s):  
Qi Li ◽  
Yanan Li
Keyword(s):  
Heavy Metal ◽  
Particle Size ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Heavy Metal Ions ◽  
Adsorption Rate ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Adsorption Rates

This paper explores the use of calcareous tuberculosis as an adsorbent and heavy-metal ions (Cu2+, Zn2+, Cd2+, and Pb2+) as adsorbates, and the influence of varying levels of particle size, adsorption time, pH, adsorbent dosage, and initial concentration of heavy metals is studied through an experiment of single heavy-metal adsorption. In addition, the impact of the temperature and other factors on the adsorption of heavy-metal ions by calcareous nodules is analyzed to identify the optimal conditions for the adsorption of heavy-metal ions by calcareous nodules. As shown by the research findings, the adsorption rates of Cu2+, Zn2+, and Pb2+ gradually declined with the increase in particle size, with no evident effect on Cd2+. In the meantime, with further increases in factors such as the adsorption time, adsorbent dosage, and temperature, the adsorption rates of Cu2+, Zn2+, Cd2+, and Pb2+ experienced gradual increases. The adsorption rates of Cu2+, Zn2+, and Cd2+ gradually declined with the increase in initial concentration of heavy-metal ions, whereas the adsorption rate of Pb2+ experience increased first and then declined. As the pH increased, the adsorption rate of Cd2+ experience increased first and then declined at a slow pace. The adsorption rates of Cu2+, Zn2+, and Pb2+ increased first and then decreased. The adsorption capacity of calcareous nodules toward the four heavy-metal ions was in the order of Pb2+ > Zn2+ > Cu2+ > Cd2+. When the particle size was set to 0.25 mm, the adsorption time was set to 120 min, and the dosage was set to 0.6 g, the calcareous nodules included Pb2+, Zn2+, and Cu2+. Moreover, Cd2+ was able to achieve stronger adsorption capacity, with the adsorption rate able to reach 83.33%, 77.78%, 73.81%, and 81.93% of its maximum level. Therefore, as the particle size of the heavy-metal ions decreased, the adsorption capacity generally became stronger. As the adsorption time increased, the temperature and the amount of adsorbent also increased. The optimal pH value for the adsorption of calcareous nodules toward Pb2+, Zn2+, Cu2+, and Cd2+ was found to be 7, 6, 5, and 8, respectively, and the optimal temperature was 50 °C. In summary, calcareous nodules are a natural, low-cost, and effective adsorbent.

Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Date Palm ◽  
Operating Conditions ◽  
Initial Concentration ◽  
Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

Synthesis of graphene oxide/ polyvinyl alcohol (GO/PVA) composite film as an adsorbent

2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Thu Le Dieu ◽  
Hoang Tran Vinh
Keyword(s):  
Waste Water ◽  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Composite Film ◽  
Heavy Metal Ions ◽  
Precipitation Method ◽  
Initial Concentration ◽  
Ft Ir ◽  
Co Precipitation

In this study, heavy metal ions or organic in the aqueous solution are removed by adsorbent without filtration or centrifugation as well as incorporate magnetic materials into the adsorbent. A composite film GO/PVA from PVA and self – synthesized GO by co - precipitation method has synthesized successfully. This composite was characterized by XRD, SEM, FT-IR to evaluate the properties of this material. The results showed that there was an interaction between GO and PVA so we have tested the adsorption capacity of this composite with Co(II) ions and the obtained efficiency of this process was 99.5% with the initial concentration of solution is 20 mg.L-1. This film is completely capable of removing heavy metal ions from waste water.

scholarly journals Modification of Salix americana willow bark for removal of heavy metal ions from aqueous solutions

2014 ◽  
Vol 16 (4) ◽  
pp. 41-44
Author(s):  
Iwona Rypińska ◽  
Marta Biegańska
Keyword(s):  
Heavy Metal ◽  
Nitric Acid ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Practical Application ◽  
Initial Concentration ◽  
Willow Bark ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

Abstract Salix americana willow bark is a waste arising in the process of wicker decortication that so far has not found any practical application. The bark can adsorb metal ions, because in its composition among others are phenolic groups which may be involved in the removal of metal ions from water solutions. The results of sorption of copper(II) and zinc(II) on modified willow bark of Salix americana were presented. The bark was modified with nitric and sulfuric acids at concentrations ranging from 5 to 15%. The best adsorption results were obtained using 15% nitric acid for modification. Adsorption of metal ions from aqueous solutions at concentrations raging from 20 to 100 mg/dm3 was studied. It was found that an increase in the initial concentration of copper(II) and zinc(II) resulted in an increase in their adsorption on the modified cortex.

Bio-inspired surface-functionalization of graphene oxide for the adsorption of organic dyes and heavy metal ions with a superhigh capacity

2014 ◽  
Vol 2 (14) ◽  
pp. 5034-5040 ◽  
Author(s):  
Zhihui Dong ◽  
Dong Wang ◽  
Xia Liu ◽  
Xianfeng Pei ◽  
Liwei Chen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Graphene Oxide ◽  
Synergistic Effect ◽  
Metal Ions ◽  
Surface Area ◽  
Surface Functionalization ◽  
Heavy Metal Ions ◽  
Organic Dyes ◽  
High Surface ◽  
High Surface Area

By utilizing the synergistic effect of poly-dopamine (PD) with functional groups and graphene oxide (GO) with a high surface area, a series of sub-nano thick PD layer coated GO (PD/GO) composites were fabricated and used for effectively decontaminating wastewater.

scholarly journals SYNTHESIS Mg-Al HYDROTALCITE FOR ADSORPTION OF Pb2+ IN WATER

2018 ◽  
Vol 127 (1A) ◽  
pp. 15
Author(s):  
Ngô Minh Đức
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Surface Area ◽  
Heavy Metal Ions ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Loading Capacity ◽  
Capillary Diameter ◽  
Adsorption Experiment ◽  
Co Precipitation

Hydrotalcite was synthesized using the co-precipitation method with  the Mg/Al molar ratio of 3.0 and then  calcined at 450 °C, for 5 h. The obtained solid was characterized by XRD, BET. As seen from results of physical characterization, the synthesized Hydrotalcite material owns large surface area of  309.3 m<sup>2</sup>/g, mean capillary diameter of 11.52 nm. Hydrotalcite application as adsorbent of heavy metal ions. The results of adsorption experiment for Pb<sup>2+</sup> in water showed that the absorption equilibrium was attained after 90 minutes at pH = 5 with maximum adsorption loading capacity of 144.93 mg/g. The synthesized adsorbent could be regenerated with HNO<sub>3</sub> (1M) solution

scholarly journals PEMANFAATAN LIMBAH CANGKANG KERANG BULU SEBAGAI ADSORBEN UNTUK MENJERAP LOGAM KADMIUM (II) DAN TIMBAL (II)

2015 ◽  
Vol 4 (3) ◽  
pp. 40-45
Author(s):  
Akhmad Anugerah S ◽  
Iriany
Keyword(s):  
Heavy Metal ◽  
Moisture Content ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Heavy Metal Ions ◽  
Thermal Activation ◽  
Freundlich Isotherm ◽  
Shell Size ◽  
Activation Temperature

Adsorbent from fur shells could be used to adsorb heavy metal ions such, as Cd (II) and Pb (II). This is shown by the research of adsorption using the fur shells. This research was aimed to characterize the fur shells. Variables in this research were the activation temperature and concentration of the metal solution. This research was begun with reduction of the shell size to 140  mesh, then thermal activation at temperature 110ᴼC, 500ᴼC and 800ᴼC in the furnace. After that adsorbent was characterized using BET, measured its density, moisture content and ash, the adsorption capacity of the adsorbent was tested by using solution of Cd (II) and Pb (II), and then the concentration of the remaining solution was measured by AAS. The result showed that activated adsorbent  at temperatures 110ᴼC, 500ᴼC and 800ᴼC had surface area of 725.43; 807.94; and 803.822 m2/g. Density was inversely proportional to the activation temperature, the value of moisture content and ash obtained were in accordance to SNI. Activated adsorbent at 500ᴼC suitabled with  the Freundlich Isotherm.

Removal of Heavy Metals from Wastewater of Textile Industry Using Polymeric Nano-Adsorbent

2019 ◽  
Vol 7 (1) ◽  
pp. 10-18
Author(s):  
Ahmad Naveed ◽  
Najaf Ali ◽  
Muhammad Ashraf ◽  
Hafiz Miqdad Masood
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Human Health ◽  
Retention Time ◽  
Textile Industry ◽  
Heavy Metal Ions ◽  
Electrostatic Force ◽  
Human Society ◽  
Aquatic Life ◽  
Adsorbent Dosage

Wastewater of textile industry having impurities and heavy metal ions cause problems in human society that can endanger the human health through food chain. Adsorption of heavy metal ions before draining makes wastewater safe for aquatic life and human health. Now a day’s adsorption of heavy metal through polymeric nano adsorbents is the emerging technology which is more efficient than conventional adsorbents like activated carbon. The pH 9.0 gave maximum 96% sorption of Co at 1.0 g/L adsorbent dosage, due to increased electrostatic force of attraction produced by the negative charge at the surface of sorbent which is favorable for adsorbing cationic species. In the beginning of15 minute retention time, metal ions adsorption was rapid due to availability of more number of adsorptive sites but further increase of retention time decreased the sorption capacity due to partial desorption that may occur due to the charge density and diameter of hydrated ions. Similarly in case of Cu, the maximum sorption was 95% at 7.0 pH using 1.0 g/L adsorbent dosage.

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