Phosphorus elimination from aqueous solution using ‘zirconium loaded okara’ as a biosorbent

Abstract

This work deals with the capture of phosphorus from aqueous solutions by biosorption onto zirconium loaded okara (ZLO). The batch-mode experiments were conducted to examine the effect of pH, biosorbent dose, initial phosphorus concentration, contact time, and temperature on the process. It was found that, the adsorption was most favored in the pH range of 2-6. The optimal doses for the adsorption, at initial phosphorus concentrations of 5, 10, 25, 50mg/L were 2, 3, 7, 10g/L, respectively. The maximum adsorption capacity of ZLO was approximately 44.13mg PO4/g at 298K. The phosphate removal was rapid, reaching 95% in 30min. Freundlich model best fitted the equilibrium data, while Pseudo-second order model satisfactorily described the kinetic results. Thermodynamic analysis revealed feasible, spontaneous, and endothermic nature of the process. The research would be beneficial for developing a promising, eco-friendly phosphorus biosorbent from a plentiful AWB - okara.

Adsorption of phosphate from aqueous solutions and sewage using zirconium loaded okara (ZLO): Fixed-bed column study

“…As a result, pH 3 was chosen as the optimal pH for phosphorus adsorption on ZLO column. These findings agreed well with those of the batch adsorption tests reported in the previous paper (Nguyen et al, 2014c). It can be explained by the electrostatic interaction between anionic phosphates species with cationic functional groups on the surface of ZLO.…”

“…The idea of developing ZLO into phosphorus adsorbent is based on the formation of active binding sites for anions by loading okara with Zr(IV) solution. In the previous batch study, ZLO was proven to be a promising phosphorus adsorbent, due to high efficiency, selectivity and reusability (Nguyen et al, 2014c).…”

“…Zirconium was found to be an excellent loading metal in many studies performed by Biswas (2008); Mallampati and Valiyaveettil (2013); Nguyen et al, 2014b;Ohura et al (2011), etc. However, the high-cost remains a challenge, limiting the use of zirconium compounds for this purpose (Nguyen et al, 2014c;Ren et al, 2012).…”

Removal of antibiotics (sulfamethazine, tetracycline and chloramphenicol) from aqueous solution by raw and nitrogen plasma modified steel shavings

“…The ΔH° values of SMT and TC adsorption were positive, while a negative ΔH° of the CP adsorption was achieved. These results specified that the adsorption of SMT and TC was endothermic in nature whereas exothermic was the nature of CP adsorption (Nguyen et al, 2014). The outcomes in Table 5 show that the values of ΔS° in most cases of antibiotics elimination by the adsorbents were positive.…”

Phosphate Adsorption on Zirconium-Loaded Activated Carbon, and its Application for Phosphate Recovery from Deep Seawater

“…Zirconium-loaded materials with high phosphate affinities have therefore been prepared. Such materials are prepared by loading zirconium onto materials such as activated carbon (AC) [32], resin [33], wheat straw [34], orange waste gel [35], [36], and okara [37], [38].…”