Abstract
In this work, a bimetallic Ni/La nanoparticle-laded biosorbent was fabricated from pomegranate fibers by solvothermal synthesis method. The material exhibited a high-efficient phosphate removal capability. The results of the characterization analysis showed that the surface of pomegranate fibers was rough and evenly coated with Ni and La after modification, and the specific surface area of Ni-La@Peel increased to 50.20 m2/g, providing a large number of adsorption sites for phosphate removal. The maximum phosphate removal rate of adsorbent was higher than 97% in a wide pH range (3.7–10.8). The maximum adsorption capacities of Ni-La@Peel were 226.55 mg-P/g and 220.31 mg-P/g under alkaline and acidic conditions, respectively, as calculated using the Langmuir model. Meanwhile, all the results were consistent with the Langmuir isothermal (R2 = 0.99) and kinetic pseudo-second order models (R2 = 0.99), indicating that the phosphate removal mechanism of Ni-La@Peel was mainly related to homogeneous chemisorption. Experimental results showed that in the presence of other anions, such as chloride, sulfate, nitrate, bromide and fluoride, the adsorption capacity of phosphate was only reduced by about 10% compared to the blank sample individually. In addition, the phosphate removal efficiency of Ni-La@Peel remained 82.05% at 7th adsorption-desorption cycle. These findings show that Ni-La@Peel is a promising material for purification of phosphate-containing wastewater.
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•Nickel/lanthanum hydroxides fabricated with pomegranate peel was prepared.•Phosphate uptake occurred by pore filled, electrostatic interaction and precipitation.•Maximum P removal efficiency of biosorbent was over 96% in a wide range of pH.•Enhanced phosphate removal was achieved 226.55 mg/g by the bimetallic bioadsorbent.•Phosphate adsorption efficiency with co-existing anions was reduced less than 10%.