Phosphate adsorption from sewage sludge filtrate using zinc–aluminum layered double hydroxides

Abstract

a b s t r a c tA series of layered double hydroxides (LDHs) with different metal cations were synthesized to remove phosphate in waste sludge filtrate from a municipal wastewater treatment plant for phosphorus recovery and to help control eutrophication. The highest phosphate adsorption capacity was obtained by using Zn-Al-2-300, that is LDHs with Zn/Al molar ratio of 2 and calcined at 300 • C for 4 h. Circumneutral and mildly alkaline waters appeared suitable for the possible application of Zn-Al LDHs due to the amphoteric nature of aluminum hydroxide. Phosphate adsorption from the sludge filtrate by the LDHs followed pseudo-second-order kinetics, and the adsorption capacity at equilibrium was determined to be ∼50 mg P/g. Adsorption isotherms showed that phosphate uptake in this study was an endothermic process and had a good fit with a Langmuir-type model. The absorbed phosphate can be effectively desorbed (more than 80%) from LDHs particles by a 5 wt% NaOH solution. The regeneration rate of used LDHs was ∼60% after six cycles of adsorption-desorption-regeneration.

Magnetic calcinated cobalt ferrite/magnesium aluminum hydrotalcite composite for enhanced adsorption of methyl orange

“…After calcination, the characteristic diffraction peaks of MgAl-LDH disappeared, suggesting that the layered structure of CoFe 2 O 4 /MgAl-LDH was destroyed, and MgAl-LDH was converted into magnesium and aluminum mixed oxides [31]. In the XRD patterns of CoFe 2 O 4 /MgAl-LDO after MO adsorption, the characteristic diffraction peaks of MgAl-LDH were detected again, indicating the reconstruction of the layered structure of the adsorbent [35]. …”

Influence of calcination on the adsorptive removal of phosphate by Zn–Al layered double hydroxides from excess sludge liquor

“…The phosphate adsorption capacity of LDHs varied significantly due to their great diversity in metal precursors, intercalated anions, and preparation methods [21,25,26]. A great number of studies were performed to explore the influencing factors of the adsorption capability of LDHs [27].…”

Desalination Behavior of Calcined Hydrotalcite From Seawater for Preparation of Agricultural Cultivation Solution Using Natural Zeolite

“…2;2014 4 reconstruction of their original structure (Pavlovic et al, 2005). Anion contaminants removed from the solution by CHT have been reported and shown to have high removal capacity for acids (Vreysen & Maes, 2008;Yang, Song, & Qian, 2010, 2013, heavy metal ions (Goswamee et al, 1998;Yang et al, 2005), pesticides (Inachio et al, 2001;You, Zhao, & Vance, 2002;Legrouri et al, 2005;Li et al, 2005;Cardoso & Valim, 2006), dyes (Zhu et al, 2005;Gaini et al, 2009;Asouhidou et al, 2011), halogens (Lv et al, 2006;Lv & Luo, 2007), phosphates (Shin et al, 1996;Chitrakar et al, 2005;Das et al, 2006;Cheng et al, 2009), surfactants (Pavan, Crepaldi, & Valim, 2000) and thiocyanate (Li et al, 2008), but there have been no studies of the treatment of seawater using CHT. Natural zeolite is generally associated with grassy volcanic rock in natural deposits,, and is available in large quantities at low cost (Tominaga, 2001).…”