In this work,we employed waste activated sludge (WAS) as carbon source to prepare ul-trahigh specific surface area (SSA) biopolymers-based carbons (BBCs) through alkali (KOH)treatment coupled to pyrolysis strategy.Before the pyrolysis process,the involvement of KOH made a great recovery of soluble biopolymers from WAS,resulting in highly-efficient catalytic pyrolysis.The Brunner-Emmett-Teller and pore volume of BBCs prepared at 800℃(BBC8oo) reached the maximum at 2633.89 m2·g-1 and 2.919 m3·g-1,respectively.X-ray pho-toelectron spectroscopy suggested that aromatic carbon in the form of C=C was the dom-inant fraction of C element in BBCs.The N element in BBCs were composed of pyrrolic ni-trogen and pyridinic nitrogen at 700℃,while a new graphitic nitrogen appeared over 800℃.As a refractory pollutant of wastewater treatment plants,tetracycline (TC) was selected to evaluate adsorption performance of BBCs.The adsorption behavior of BBCs towards TC was conformed to the pseudo-second-order kinetic and the Langmuir models,signifying that chemisorption of monolayers was dominant in TC adsorption.The adsorption capacity of BBC800 reached the maximum at 877.19 mg·g-1 for 90 min at 298 K.Thermodynamic anal-ysis indicated that the adsorption process was endothermic and spontaneous.Hydrogen bonding and π-π stacking interaction were mainly responsible for TC adsorption,and inter-facial diffusion was the main rate-control step in adsorption process.The presence of sol-uble microbial products (SMPs) enhanced TC removal.This work provided a novel strategy to prepare bio-carbon with ultrahigh SSA using WAS for highly-efficient removal of organic pollutants.