N-doped mesoporous H3PO4–pyrocarbon from seaweed and melamine for batch adsorption of the endocrine disruptor bisphenol A

Abstract

N-doped mesoporous activated pyrocarbons from alkali-treated seaweed were prepared via pyrolysis with H3PO4 impregnation and subsequent modification with melamine at different loading ratios of 0:5, 0.5:5, 0.75:5, 1:5, 2:5, and 3:5 g/g. The activated seaweed pyrocarbon with a melamine doping ratio of 0.75:5 (TSWP–M0.75) achieved an enhanced bisphenol A (BPA) adsorption removalfrom 59.22% to 91.48%, confirming that nitrogen functionalities were successfully introduced onto the adsorbent’s surface. TSWP–M0.75 exhibited a maximum BPA capacity of 270.581 mg/g at 30 °C and an equilibrium time of 1 h (Rpseudo-second-order2 > 0.99), which were attributed to its surface heterogeneity structure of 0.25 cm3/g mesoporosity and 412.80 m2/g BET surface area. Freundlich isotherm (RFreundlich2 > 0.92) was applied to the design of a single-stage adsorber to predict the required TSWP–M0.75 amount for the treatment of industrial effluents containing BPA.