Distinguished Ni(II) Capture with Rapid and Superior Capability Using Biochar: Behavior and Mechanism

Abstract

Batch experiments were used to study the interaction mechanism of Ni(II) with biochar as a function of solution pH, contact time, initial concentrations, reaction temperature, and the addition of humic compounds. The results indicate that Ni(II) can be interacted with biochar by a compound mechanism under different environmental conditions. It is suggested that outer-sphere surface complexes at low pH are transformed into inner-sphere surface complexes and surface precipitates are formed at pH 8.89 or 10.18. The combined macroscopic and microscopic insights provide additional details regarding the mobility, fate, and risk of Ni(II) in a practical aquatic environment, as well as the natural purification of metals in ecological environments.