Biomass based activated carbon obtained from sludge and sugarcane bagasse for removing lead ion from wastewater

•Bagasse modified municipal sewage sludge based adsorbent.•HNO3 modified adsorbent to promote its adsorb-ability of Pb2+.•The adsorption capacity of Pb2+ increases to more than 50mg/g. Sewage sludge and bagasse were used as raw materials to produce cheap and efficient adsorbent with great adsorption capacity of Pb2+. By pyrolysis at 800°C for 0.5h, the largest surface area (806.57m2/g) of the adsorbent was obtained, enriched with organic functional groups. The optimal conditions for production of the adsorbent and adsorption of Pb2+ were investigated. The results of adsorb-ability fitted the Langmuir isotherm and pseudo-second-order model well. The highest Pb2+ (at pH=4.0) adsorption capacity was achieved by treating with 60% (v/v) HNO3. This is a promising approach for metal removal from wastewater, as well as recycling sewage sludge and bagasse to ease their disposal pressure.