Equilibrium and kinetic behavior on cadmium and lead removal by using synthetic polymer

Abstract

It is known that synthetic polymer plays a big role in various applications. One of its potentials is to remove heavy metal ions through single batch adsorption. Adsorption behavior and mechanism of synthetic polymer are the two main focuses in this research. The synthetic polymer of Poly(AN-co-AA) has been successfully polymerized, modified with hydroxylamine hydrochloride and removed Cd 2+ and Pb 2+ . The poly(AN-co-AA) and amidoxime (AO) modified poly(AN-co-AA) were characterized by Fourier Transform Infrared Analysis (FTIR), microanalysis, Scanning Electron Microscopy (SEM) and Thermogravimetry (TGA). At pH 9, the percentage removal for Cd 2+ (90%) and Pb 2+ (98%) were the highest with adsorbent dosage at 4 gL −1 and 8 g L −1 , respectively. The experimental data for Cd 2+ (20 mg g −1 ) and Pb 2+ (125 mg g −1 ) were fitted well by Sips and Freundlich isotherms model, respectively. The adsorption rate for both Cd 2+ and Pb 2+ were stated by using Lagergren pseudo-first order.

Tetrasodium iminodisuccinate as a biodegradable complexing agent for remediating metal‐contaminated soil

“…To control the removal efficiency, the equilibrium constant between the washing agent and potentially toxic metals can be changed by adjusting the pH value. [ 44 ] Figure 3A shows the Cu, Cd, and Pb removal efficiencies under different pH conditions; Cu, Pb, and Cd removal efficiencies decreased from 90.1% to 70.1%, from 75.1% to 60.2%, and from 81.2% to 36.4%, respectively, with an increase in pH from 3 to 11. Only a minimal change in the Pb removal efficiency occurred with increasing pH, which indicates that Pb was less affected by pH in soil washing with IDS.…”

“…To control the removal efficiency, the equilibrium constant between the washing agent and potentially toxic metals can be changed by adjusting the pH value. [44] Figure 3A affected by pH in soil washing with IDS. However, pH significantly affected Cd removal, for which the removal efficiency decreased from 81.2% to 50.2% as the pH increased from 3 to 10, and sharply dropped to 36.4% with a further increase in pH to 11.…”

The feature of migration and deoxygenation of radionuclides U(Ⅵ) on genetically recombined bacteria W1

“…Langmuir model assumes that the adsorbed substance is uniformly adsorbed on the binding site on the surface in a single layer, while the empirical Freundlich isotherm describes the process of substance was absorbed into multilayer heterogeneous surfaces (Martins et al, 2017). Regarding Sips, it has the characteristics of both models (Zahri et al, 2017). Through the least-squares method, equations (3, 4, 5) were created non-linear regression curves: where qe (mmol Uranium g −1 ) is the bacterial strains adsorption capacity at equilibrium, Qmax (mmol Uranium g −1 ) is the maximum adsorption capacity, Ceq (mmol•L −1 ) is the Uranium concentration at equilibrium, KL (L•mg −1 ), KF (mmol 1-N •L N •g −1 ) and KS (L•mg −1 ) are the adsorption constants related with the adsorption capacity (qe) of the adsorbent at equilibrium, and N (=1/n) is a unitless parameter usually associated with the adsorption intensity in Freundlich model.…”

Exploring the Potential of Aerated Concrete and Clay Bricks from Construction and Demolition Waste as Adsorbents for Pb(II) Removal from Aqueous Solutions

“…Various adsorbents have been tested and utilized for removing lead, both in laboratory settings and in practical industrial applications [13][14][15]. However, certain adsorbents such as synthetic polymers, nanoparticles, and carbon nanotubes, despite exhibiting high efficiency in lead removal, have not been extensively adopted due to their high cost [16][17][18]. Thus, substantial efforts have been made to identify potential low-cost adsorbents for the removal of lead.…”