Removal of Cd(ii) and Pb(ii) ions from natural water using a low-cost synthetic mineral: behavior and mechanisms

Abstract

A low-cost synthetic mineral (LCSM) was prepared by mechanochemical treatment of a solid-state mixture containing potassium feldspar, wollastonite, gypsum, limestone and dolomite powder at a molar ration of 1 : 1 : 1 : 6 : 3 and hydration process.

Variations in Cadmium Concentrations in Rice and Oxidation-Reduction Potential at the Soil Surface with Supplementation of Fermented Botanical Waste-based Amendment in Large-scale Farmland

“…In the Cd adsorption test using the batch method, the maximum adsorption amount of Cd to FBWA showed higher or comparable levels than those of the other amendments obtained from organic wastes in recent reports (Table S6 in the SI) 30, [39][40][41][42][43][44][45] .…”

Improvement of Manganese Feroxyhyte’s Surface Charge with Exchangeable Ca Ions to Maximize Cd and Pb Uptake from Water

“…The measurement of main surface charge properties was performed by determining the isoelectric point (IEP), the point of zero charge (PZC), and the (negative) charge density of each adsorbent, noting that the IEP determination requires the plotting of the corresponding zeta-potential curve. For this purpose, 50 mg/L suspension of finely powdered adsorbent was dispersed in an electrolyte solution (0.01 M NaNO 3 ) and this was equilibrated at various pH values (3)(4)(5)(6)(7)(8)(9)(10), by adding either HNO 3 or NaOH dilute solutions (see Figure S2). The electrophoretic velocity of charged particles was determined by a Rank Brothers Micro-electrophoresis Apparatus Mk II (Rank Brothers, Cambridge, UK).…”

“…The choice of an appropriate adsorbent type for the specific needs of water treatment is crucial. The major categories of examined adsorbents for the removal of heavy metals can be mainly categorized into: organic-based [7,8], inorganic [9], agricultural by-products [10], and ion-exchange resins [11]. Unfortunately, most studies have evaluated the efficiency of adsorbents by calculating the maximum adsorption capacity values (Q max ), which can only be obtained when applying considerably high initial concentrations of the examined pollutants (usually in the order of several mg/L).…”

“…It is worth noting that this approach practically results in most cases to residual concentrations that are significantly exceeding the respective DWRLs [4]. Consequently, the majority of relevant publications overlook the need to evaluate the efficiency of adsorbents by succeeding residual concentrations (C e ) efficiently below the current DWRLs, and to estimate their removal capacity at C e = DWRL (denoted as Q DWRL value) within a natural water matrix [7][8][9][10][11][12][13].…”

Characterization and adsorption properties of cross-linked yeast/β-cyclodextrin polymers for Pb(ii) and Cd(ii) adsorption

“…The initial concentration of metal ions ranged from 10-120 mg L À1 , the pH was adjusted to 5 for Pb(II) and pH 7 for Cd(II). The mixture was shaken at 120 rpm in a double thermostatic shaker at four different temperatures (25,30,35, and 40 C) for 25 min.…”