Synthesis of nano-sized hydrocalumite from a Gastropod shell for aqua system phosphate removal

Using Ca Fe layered double hydroxide transformation to optimise phosphate removal from waste waters

“…As discussed later in this work, the maximal TPRC of Ca-Fe LDH will be estimated to be as high as  110 mg P-PO4 g -1 , a value much higher than the removal capacity reported in homogeneous batch dispersion for other minerals such as ferrihydrite { 26 mg P-PO4 g -1 (Ruby et al, 2016)}, steel slag (up to  2.4 mg PO4 g -1 (Barca et al, 2012) or hydroxyapatite (0.3 mg P-PO4 g -1 (Bellier et al, 2006)). Maximal phosphate removal capacities {qe (Max) } of the same order of magnitude than the TPRC were in fact However, for both Ca-Al LDH and Ca-Fe LDH, the reported values of qe (Max) varied in a relatively broad range between  46 and  179 mg P-PO4 decrease of intensity and a general broadening of the LDH X-ray diffraction (XRD) peaks were observed (Ashekuzzaman et al, 2014;Oladoja et al, 2014). The synthesis of Ca-Fe LDH was reported to lead to a higher degree of crystallinity in comparison to Mg-Al LDH, i.e.…”

A critical review of the applicability of Avrami fractional kinetic equation in adsorption-based water treatment studies

“…It decreases with the increase in initial sorbate concentrations as a rule, which is a commonly known fact related to the interpretation of k S as a time-scaling factor (obviously, the higher the initial sorbate concentration value is, the longer the time required to reach equilibrium becomes) [21][22][23]. Despite the widely reported dependency of k S values on the initial sorbate concentration, reports of systems for which k S is independent of initial solute concentration have also been reported [24][25][26][27][28][29][30][31][32][33]. The reported conflicting trends in the relationship between k S and the initial sorbate concentrations was explicated via a theoretical analysis of kinetic models of sorption by Azizian et al [34] that for the system that obeys the pseudo-second-order kinetic model, their observed rate constant is a complex function of the initial concentration of solute.…”

Thermally-treated MgO/nanocrystalline cellulose immobilized onto a Santa Barbara-16 mesoporous SiO2 template for the sequestration of antibiotics from polluted water

“…The low adsorption of AMP on the MNCS adsorbents below pH 6.0 is due to charge–charge repulsion between the cationic AMP molecules and the positively charged surface of the adsorbents. 1,57,58 This is because AMP molecules exist in the cationic form at pH below the isoelectric point of ca. 5.46; 59 meanwhile, at these pH levels, the surface of the adsorbents with average pHPZC of ca.…”