Atomic Economic Synthesis of Layered Double Hydroxides Using Distiller Waste for Removal of Pb

Abstract

Two million tons per year of distiller waste had been produced by using the bischofite byproducts as raw materials to prepare Mg(OH)₂ through the ammonia method. The distiller waste restricted the development of potassium, lithium, and other resources in Qinghai salt lake in China. In this work, a new green synthesis route of CaMgAl-LDHs using distiller waste as raw materials through a 100% atomic economic reaction route was provided, and the full component of distiller waste was utilized without separation. Pure CaMgAl-LDHs was prepared at 90 °C for 180 min. A reaction mechanism of “dissolution–rapid nucleation–phase boundary reaction process” was revealed. The maximum removal capacity of Pb²⁺ by CaMgAl-LDHs reached 862.5 mg/g. This work realized the efficient utilization of distiller waste with complex components through an atomic economic reaction, providing a new idea for the high-value exploitation of waste resources and the green synthesis of inorganic functional materials.