Shrimp shells-derived biochar for efficient adsorption of pb2+ in aqueous solutions

Abstract

Oxidation modification is an important technique for the development of novel adsorbents and has attracted considerable interest in recent years. A new and efficient Pb(II) adsorbent was developed in this study using simple and cost-effective protocols. Shrimp shell biochar (SSC) was obtained by pyrolysis of abandoned shrimp shells and subsequently treated with mixed acid to obtain modified biochar (SSC-M). The structure and adsorption properties of SSC and SSC-M were investigated for Pb(II) adsorption using a variety of characterisation methods. Both SSC and SSC-M exhibited excellent aqueous Pb(II) adsorption capacities and achieved maximum adsorption capacities of 94.16 and 156.48 mg g–1 at the optimal condition, respectively. The adsorption of lead ions by SSC and SSC-M followed a pseudo-second-order kinetics model and a monolayer adsorption process. Moreover, the prominent adsorption performance of SSC-M for Pb(II) was mainly attributed to electrostatic interactions and surface complexation. SSC-M can be a promising and affordable adsorbent for Pb(II) ions owing to its significant adsorption capacity.