Design of a renewable hydroxyapatite-biocarbon composite for the removal of uranium(VI) with high-efficiency adsorption performance

Abstract

The hydroxyapatite-loaded swine manure derived-biocarbon was successfully prepared by pyrolysis method for the adsorption of uranium(VI). The results of the adsorption experiments displayed that the adsorption behaviors for uranium(VI) of biocarbon did almost not depend on the interfering ions except Al3+, Ca2+ and CO32−, showing the high selectivity of the composites for uranium(VI). The maximum static and dynamic removal capacity of the hydroxyapatite-biocarbon composites to uranium(VI) were 834.8 and 782.8 mg/g (pH = 3, m/V = 0.1 g/L and T = 298 K), far exceeding other reported biocarbon and hydroxyapatite materials, which indicated that the hydroxyapatite-biocarbon composites possessed an application potential in adsorption. After five cycles of adsorption–desorption processes, the removal efficiency of the hydroxyapatite-biocarbon composite for uranium(VI) was 93.2% (Ci = 5 mg/L, pH = 3, m/V = 0.1 g/L and T = 298 K), revealing that the composite had excellent stability and reusability. Moreover, the capture mechanisms of the hydroxyapatite-biocarbon composite for uranium(VI) included ion exchange and complexation, which was ascribed to the ample active adsorption sites (–OH and PO43−). Therefore, the hydroxyapatite-loaded swine manure derived-biocarbon would be a potential material to effectually separate uranium(VI) from solution. Graphical abstract

Enhancing Fluoride Removal from Wastewater using Aluminum-Yttria-Amended Sludge Biochar

“…Conversely, under acidic conditions, they become protonated and positively charged. The modi ed sludge biochar exhibits a high zero-charge-point and strong acid-base buffering properties due to the formation of numerous amorphous bimetallic oxides with a positive charge, as well as good dispersion of biochar support (Liao et al 2022).…”

“…The XPS results show the increase of metal oxides on the surface of the adsorbent after adsorption and the complexation reaction with uorine ions, which nally presents in the form of complexed uorides. Due to the inherent uorophilic nature of the aluminum-yttrium as well as the dispersing effect of sludge biochar (Liao et al 2022), the adsorbent exhibits excellent acid-base suitability and predominantly multilayer inhomogeneous adsorption (Jing et al 2020;Kim et al 2020).…”

“…A signi cant decline in removal e ciency was observed when the pH exceeded 9. Due to the dispersion action of biochar(Liao et al 2022), which fully exposed more active sites and increased its applicability over a larger pH range, the Al/Y-CSBC adsorbent had an adsorption capability of more than 90% uoride removal in the range of solution pH = 5 ~ 9.…”

Study of the effect of uranium recovery at Hap/Fe2O3 composite and Fe2O3 interfaces on the parameters of the electrical double layer

“…3 However, there are many different modifications of hydroxyapatite, which were studied in uranium adsorption processes, but obtaining these composites is more complex than synthesizing Hap/Fe 2 O 3 . 39–49…”

“…3 However, there are many different modications of hydroxyapatite, which were studied in uranium adsorption processes, but obtaining these composites is more complex than synthesizing Hap/Fe 2 O 3 . [39][40][41][42][43][44][45][46][47][48][49] The aim of this study was the characterization of surface properties to determine and compare the nanostructure of electrical double layers on the surfaces of a synthetic composite Hap/Fe 2 O 3 as well as commercially available iron oxide formed in the solution of a basic electrolyte and those containing additionally inorganic ions U(VI). The parameters characterizing the surface and diffusion parts of the edl were determined by the use of the potentiometric titration method and electrophoretic mobility measurements.…”