Phosphorylated wood designed as a biosorbent for effectively removing Ni2+ from wastewater

In this study, the chemical modification of paulownia wood is described, along with its utilization as a novel adsorbent for the adsorption of Ni2+ from simulated wastewater. A wood-based adsorbent was prepared by esterification using phosphoric acid, and the reaction conditions were optimized to realize an efficient process. The samples were systematically analyzed through various techniques, and the results showed that the phosphorylation of wood was successfully completed, as its phosphate group content was quantified as 2.94 mmol·g−1. The effects of pH, initial ion concentration, temperature, and time on the adsorption of Ni2+ by the samples were investigated. Under the optimum conditions, the maximum adsorption capacity of PEW was 130.2 mg·g−1. The adsorption of Ni2+ by PEW was a combination of physical and chemical adsorption, which was a spontaneous process. The coordination of Ni2+ by phosphate on PEW was the main adsorption mechanism. Overall, this research provides a facile and green method for preparing a wood-based adsorbent with low cost, high performance and easy recycling for heavy ion mediation.