Application of iron-coated sand on the treatment of toxic metals

2004 ◽  
Vol 4 (5-6) ◽  
pp. 335-341 ◽  
Author(s):  
Jae-Kyu Yang ◽  
Yoon-Young Chang ◽  
Sung-Il Lee ◽  
Hyung-Jin Choi ◽  
Seung-Mok Lee

Iron-coated sand (ICS) prepared by using FeCl3 and Joomoonjin sand widely used in Korea was used in this study. In batch adsorption kinetics, As(V) adsorption onto ICS was completed within 20 minutes, while adsorption of Pb(II), Cd(II), and Cu(II) onto ICS was slower than that of As(V) and strongly depended on initial pH. At pH 3.5, ICS showed a selective adsorption of Pb(II) compared to Cd( II) and Cu(II) . However, above pH 4.5, near complete removal of Pb(II), Cd(II), and Cu(II) was observed through adsorption or precipitation depending on pH. As(V) adsorption onto ICS occurred through an anionic-type and followed a Langmuir-type adsorption behaviour. In column experiments, pH was identified as an important parameter in the breakthrough of As(V). As(V) breakthrough at pH 4.5 was much slower than at pH 9 due to a strong chemical bonding between As(V) and ICS as similar with batch adsorption behaviour. With variation of ICS amounts, the optimum amount of ICS at pH 4.5 was identified as 5.0 grams in this research. At this condition, ICS could be used to treat 200 mg of As(V) with 1 kg of ICS until 50 ppb of As(V) appeared in the effluent. In this research, as a new treatment system, ICS can be potentially used to treat As(V) and cationic heavy metals.

2015 ◽  
Vol 15 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Anis Shofiyani ◽  
Narsito Narsito ◽  
Sri Juari Santosa ◽  
Sri Noegrohati ◽  
Titin Anita Zahara ◽  
...  

Ionic-Imprinted Chitosan/Chlorella biomass sorbent (IICCb) has been synthesized for selective adsorption of Cd(II) adsorption. IICCb was prepared by coating Cd(II)-complexed-chitosan hydrogel on the biomass surface followed by cross-linking procedure. Cd(II)-imprinting ions were then eluted using Na2EDTA solution to provide a specific template for binding sites of Cd(II). Batch adsorption was carried out as function of initial pH, contact time, and initial concentration of the Cd(II) solution. Result showed that the optimum adsorption of Cd(II) was found at pH 4-6. Study of pseudo-second order kinetic showed that the adsorption of Cd(II) on IICCb went faster than that on Ionic-Imprinted Chitosan (IIC) or Non-Imprinted Ionic Chitosan/Chlorella sorbent (NIICCb). The maximum Cd(II) adsorption capacity as obtained from Langmuir adsorption isotherm was found to be 53.76 mg/g on IICCb, that was comparatively higher than that on IIC (44.44 mg/g) or on NIICCb (51.02 mg/g) adsorbent.


1997 ◽  
Vol 35 (7) ◽  
pp. 63-70 ◽  
Author(s):  
Shang-Lien Lo ◽  
Hung-Te Jeng ◽  
Chin-Hsing Lai

This study was conducted to develop a process for coating hydrated iron oxide on the surface of quartz sand to utilize the adsorbent properties of the coating and the filtration properties of the sand. Three coating parameters were investigated: pH, Fe concentration at which iron oxide was prepared, and the coating temperature. A Scanning Electron Microscope (SEM) and X-Ray Diffractometer (XRD) were used to observe the surface properties of the coated layer. Acid resistance was used to evaluate the attachment strength of the coated layer. Batch adsorption tests were performed to compare the effects of each coating parameter on the adsorption of heavy metals on the coated layer. Energy Dispersive Analysis of X-ray (EDAX) was used for characterizing metal adsorption sites on the iron-coated sand. The results indicated that the coated sand had more pores and higher specific surface area because of the attachment of iron oxide. The coated sand produced at higher pH(coating) had better adsorption efficiencies of metals but had worse acid resistance. A high-temperature coating process enhanced the stability of the oxide coatings. Comparing heavy metal removal by adsorption on iron-coated sand and chemical precipitation, adsorption was shown to be capable of removing heavy metals over a wider pH range and to much lower levels than precipitation. The results from EDAX analysis showed that copper ions were chemisorbed on the surface of iron-coated sand.


Author(s):  
Seroor Atalah Khaleefa Alia ◽  
Dr. Mohammed Ibrahimb ◽  
Hussein Ali Hussein

Adsorption is most commonly applied process for the removal of pollutants such as dyes and heavy metals ions from wastewater. The present work talks about preparing graphenic material attached sand grains called graphene sand composite (GSC) by using ordinary sugar as a carbon source. Physical morphology and chemical composition of GSC was examined by using (FTIR, SEM, EDAX and XRD). Efficiency of GSC in the adsorption of organic dyes from water was investigated using reactive green dye with different parameters such as (ph, temperature, contact time and dose). Adsorption isotherm was also studied and the results showed that the maximum adsorption capacity of dye is 28.98 mg/g. This fast, low-cost process can be used to manufacture commercial filters to treat contaminated water using appropriate engineering designs.


Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.


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.


2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.


2018 ◽  
Vol 332 ◽  
pp. 387-397 ◽  
Author(s):  
Jawad Ali ◽  
Huabin Wang ◽  
Jerosha Ifthikar ◽  
Aimal Khan ◽  
Ting Wang ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mulu Berhe Desta

Adsorption of heavy metals (Cr, Cd, Pb, Ni, and Cu) onto Activated Teff Straw (ATS) has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the low-cost adsorbent ATS for the removal of heavy metals from textile effluents. The influence of contact time, pH, Temperature, and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly, and the optimal removal efficiency was reached within about 1 hour. Further increase in contact time did not show significant change in equilibrium concentration; that is, the adsorption phase reached equilibrium. The adsorption isotherms could be fitted well by the Langmuir model. The value in the present investigation was less than one, indicating that the adsorption of the metal ion onto ATS is favorable. After treatment with ATS the levels of heavy metals were observed to decrease by 88% (Ni), 82.9% (Cd), 81.5% (Cu), 74.5% (Cr), and 68.9% (Pb). Results indicate that the freely abundant, locally available, low-cost adsorbent, Teff straw can be treated as economically viable for the removal of metal ions from textile effluents.


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