Magnetic Composite Lignin Colloids Prepared with a Convenient Patching Method for Generally Treating Heterogeneous Oily Wastewater

Abstract The key to the efficient use of biomass resources is the rational design and preparation of lignin‐based fine chemicals. In this investigation, the colloidal self‐assembly structure formed by lignin in good solvents is used as the module, magnetic Fe 3 O 4 nanoparticles are taken as the carrier, and magnetic composite lignin nanoparticles are prepared in batches by a rapid and convenient surficial grafting (patching) process. The varying amphiphilicity and wettability of lignin are influenced by the various types of wetting solvents. Its wetting behavior can be regulated to achieve oil–water separation in different adsorption or/and emulsification processes. This study provides a novel tool for industrial oil–water separation and, thus, general oily wastewater treatment.