scholarly journals Removal Of Arsenic, Cadmium And Lead From Synthetic Stormwater By Two Low-Cost Adsorbents: A Kinetic And Equilibrium Study

Author(s):  
Jason David

The adsorption isotherms and kinetics of two low cost adsorbents, Ladybug Sand and Greensand, were determined from multi-solute batch experiments using prepared synthetic stormwater containing arsenic, cadmium and lead. The adsorption equilibrium data were fit to the Langmuir, Freundlich and Henry isotherms using both nonlinear and linear regression techniques. Kinetic data were obtained at two different stormwater concentrations. The kinetic curves were fit to the pseudo-first-order, pseudo-second-order and homogenous surface diffusion model (HSDM). A solution to the HSDM was achieved using the user-oriented numeric solution proposed by Zhang et al. (2009). From the fitted kinetic models the reaction constants, k1 and k2, as well as the surface diffusion coefficient (Ds) were determined. The maximum service lives of adsorbent columns comprised of Ladybug Sand or Greensand were calculated using the equilibrium column model (ECM) to evaluate the feasibility of the adsorbents for use in advanced stormwater treatment.

2021 ◽  
Author(s):  
Jason David

The adsorption isotherms and kinetics of two low cost adsorbents, Ladybug Sand and Greensand, were determined from multi-solute batch experiments using prepared synthetic stormwater containing arsenic, cadmium and lead. The adsorption equilibrium data were fit to the Langmuir, Freundlich and Henry isotherms using both nonlinear and linear regression techniques. Kinetic data were obtained at two different stormwater concentrations. The kinetic curves were fit to the pseudo-first-order, pseudo-second-order and homogenous surface diffusion model (HSDM). A solution to the HSDM was achieved using the user-oriented numeric solution proposed by Zhang et al. (2009). From the fitted kinetic models the reaction constants, k1 and k2, as well as the surface diffusion coefficient (Ds) were determined. The maximum service lives of adsorbent columns comprised of Ladybug Sand or Greensand were calculated using the equilibrium column model (ECM) to evaluate the feasibility of the adsorbents for use in advanced stormwater treatment.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.


2011 ◽  
Vol 354-355 ◽  
pp. 33-36
Author(s):  
Jian Yun Li ◽  
Quan Xian Hua ◽  
Jun Ling Niu ◽  
Jian Wei Tang ◽  
Ke Xu

The adsorption of copper in aqueous solutions by steel slag was studied in batch adsorption experiments. The adsorption equilibrium data fitted best with Langmuir and Freundlich equations. The adsorption was preferential type. A comparison of the kinetics models on the apparent adsorption rate showed that the adsorption system was best described by the pseudo-second-order kinetics. The adsorption rate was controlled by both liquid film diffusion and intraparticle dispersion.


2011 ◽  
Vol 183-185 ◽  
pp. 362-366 ◽  
Author(s):  
Jun Li ◽  
Ming Zhen Hu

Adsorption removal of a cationic dye, rhodamine B (RhB) from water onto rectorite and sepiolite was investigated. The rectorite and sepiolite were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Attempts were made to fit the isothermal data using Langmuir and Freundlich equations. The experimental results have demonstrated that the equilibrium data are fitted well by a Freundlich isotherm equation. Pseudo-first-order and pseudo-second-order models were considered to evaluate the rate parameters. The experimental data were well described by the pseudo-second-order kinetic model. The results indicate that the rectorite exhibited higher adsorption capacity for the removal of RhB than sepiolite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.


2016 ◽  
Vol 16 (4) ◽  
pp. 992-1001 ◽  
Author(s):  
Jasmina Nikić ◽  
Jasmina Agbaba ◽  
Malcolm Watson ◽  
Snežana Maletić ◽  
Jelena Molnar Jazić ◽  
...  

A series of Fe–Mn binary oxides with different Fe:Mn ratios (1:1, 3:1, 6:1, 9:1) were synthesized to investigate the optimal Fe:Mn ratio for the removal of As(III) and As(V). Batch experiments were performed to determine the rate of adsorption and equilibrium isotherms. Adsorption kinetics were well described by the pseudo-second-order kinetic model for both As(III) and As(V). The adsorption equilibrium data fitted well to Langmuir and Freundlich isotherms. The maximum As(V) sorption capacity was observed at an Fe:Mn ratio of 6:1 (65.0 mg/g), whereas maximum As(III) uptake was at Fe:Mn ratio 3:1 (46.9 mg/g). Arsenic levels in real water samples were reduced from 37 μg/l to below the EU Water Framework Directive limit (10 μg/L) after treatment with Fe–Mn adsorbents.


2021 ◽  
Vol 22 (2) ◽  
pp. 1-6
Author(s):  
Suondos K. A. Barno ◽  
Haider J. Mohamed ◽  
Siham M. Saeed ◽  
Mohammed J. Al-Ani ◽  
Ammar S. Abbas

The research discussed the possibility of adsorption of Brilliant Blue Dye (BBD) from wastewater using 13X zeolite adsorbent, which is considered a byproduct of the production process of potassium carbonate from Iraqi potash raw materials. The 13X zeolite adsorbent was prepared and characterized by X-ray diffraction that showed a clear match with the standard 13X zeolite. The crystallinity rate was 82.15% and the crystal zeolite size was 5.29 nm. The surface area and pore volume of the obtained 13X zeolite were estimated. The prepared 13X zeolite showed the ability to remove BBD contaminant from wastewater at concentrations 5 to 50 ppm and the removal reached 96.60% at the lower pollutant concentration. Adsorption measurements versus time showed 48.18% removal of the dye during just the first half-hour and the maximum removal closest to the removal at the equilibrium after one and half hour. Langmuir isotherm was described the adsorption equilibrium data with a maximum adsorption capacity of 93.46 mg/g and the kinetics data of the adsorption process was followed the pseudo-second-order.


2021 ◽  
Vol 51 (3) ◽  
pp. 185-192
Author(s):  
M. Seenuvasan ◽  
Carlin Geor Malar ◽  
S.B. Ron Carter ◽  
S. Praveen

The nano-sorbent was synthesized by the embedment of magnetite onto the biochar obtained from Cassia auriculata for the effective adsorption of Levafix blue (LB) dye. Different instrumental techniques revealed the properties of biochar and the nano-sorbent. It was very distinct that the nano-sorbent gained highly favorable properties to be an effectual bio-sorbent. The effect of contact time, initial dye concentration and nano-sorbent dosage on the removal of LB dye was examined. Also, out of the kinetics studies models, the best fit and highest R2 values (0.9873) showed that the adsorption followed pseudo-second-order kinetics. Langmuir, Freundlich and Temkin isotherm models were established for the adsorption equilibrium data and the Temkin model showed the best reliability with the experimental results with highest R2 value of 0.9915. The adsorption system was modelled using the Artificial Neural Network (ANN) for biochar and nano-sorbent. The developed well-trained neural structure suggested the high performance of nano-sorbent.    


2012 ◽  
Vol 27 ◽  
pp. 107-114
Author(s):  
Jagjit Kour ◽  
P. L. Homagai ◽  
M. R. Pokherel ◽  
K. N. Ghimire

The industrial discharge of heavy metals into waters' course is one of the major pollution problems affecting water quality. Therefore, they must be removed prior to their discharge into waste streams. An efficient and low-cost bioadsorbent has been investigated from Desmostachya bipinnata (Kush) by charring with concentrated sulphuric acid and functionalized with dimethylamine.It was characterised by SEM, FTIR and elemental analysis. The effect of pH, initial concentration and contact time of the metal solution was monitered by batch method. The maximum adsorption capacities were determined for Cd and Zn at their optimum pH 6. The equilibrium data were analysed using Langmuir and Freundlich isotherm models. Langmuir isotherm model fitted well and the rate of adsorption followed the pseudo second order kinetic equation.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6669 J. Nepal Chem. Soc., Vol. 27, 2011 107-114  


Author(s):  
Regina Obiageli Ajemba

The adsorption performance of modified Nkalagu bentonite in removing Congo red (CR) from solution was investigated. The raw bentonite was modified by three different physicochemical methods: thermal activation (TA), acid activation (AA), and combined acid and thermal activation (ATA). The Congo red adsorption increased with increase in contact time, initial dye concentration, adsorbent dosage, temperature, and pH change. The results of the kinetics analysis of the adsorption data revealed that adsorption follows pseudo second-order kinetics. Analysis of the equilibrium data showed that Langmuir isotherm provided a better fit to the data. Evaluation of the thermodynamic parameters revealed that adsorption process is spontaneous and endothermic. The results from this study suggest that a combination of thermal and acid activation is an effective modification method to improve adsorption capacity of bentonite and makes the bentonite as low-cost adsorbent for removal of water pollutants.


2009 ◽  
Vol 60 (2) ◽  
pp. 467-474 ◽  
Author(s):  
K. L. Lv ◽  
Y. L. Du ◽  
C. M. Wang

Carboxylated chitosan (CKCTS) was prepared for the removal of Cd(II), Pb(II), and Cu(II) from aqueous solutions. The effects of experimental parameters such as pH value, initial concentration, contact time and temperature on the adsorption were studied. From the results we can see that the adsorption capacities of Cd(II), Pb(II), and Cu(II) increase with increasing pH of the solution. The kinetic rates were best fitted to the pseudo-second-order model. The adsorption equilibrium data were fitted well with the Langmuir isotherm, which revealed that the maximum adsorption capacities for monolayer saturation of Cd(II), Pb(II), and Cu(II) were 0.555, 0.733 and 0.827 mmol/g, respectively. The adsorption was an exothermic process.


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