Layered double hydroxide loaded pinecone biochar as adsorbent for heavy metals and phosphate ion removal from water

This study modified pinecone biochar with a novel layered double hydroxide (LDH) to enhance its capacity to adsorb heavy metal and phosphate ions from water. The unmodified pinecone biochar demonstrated moderate adsorption capacities for Cu2+ (25.0 mg/g), Co2+ (24 mg/g), Pb2+ (22.9 mg/g), and phosphate (36.0 mg/g). However, after LDH modification, the LDH-biochar showed significantly improved adsorption capacities for Pb2+ (135.9 mg/g) and phosphate (160.8 mg/g) and a slight increase for Cu2+ (30.6 mg/g) and Co2+ (28.0 mg/g). The LDH layer enhances the adsorption of Pb2+ through ion exchange, phosphate through surface precipitation, and Cu2+ and Co2+ through surface complexation. The integration of LDH creates a multifaceted layer that utilizes various mechanisms to boost the biochar's adsorption capacity.

Automated summary

This study modified pinecone biochar with layered double hydroxide (LDH) to enhance its adsorption capacity for heavy metal and phosphate ions. The LDH-biochar showed significantly improved adsorption capacities for Pb2+ and phosphate, and a slight increase for Cu2+ and Co2+. The LDH layer enhanced the adsorption through various mechanisms.