Constraints for effective heavy metal removal from aqueous solutions through commercial biochar – Insights from real and synthetic case studies.
Аннотация
Biochar is demonstrated to bear the potential for heavy metal removal from aqueous solution. Nevertheless, to foster upscaling of biochar technologies, such potential should be supported by strong evidence tied to widely available materials. In this way, findings are more directly relevant for commercial applications.Nine commercial biochar produced in Europe (with a focus on Italy) from different feedstocks and production processes have been thoroughly characterized through conventional (e.g. Elemental Analysis, Surface Analysis, FT-IR, TGA-DTG) and novel (e.g. Reflectance Analysis, Micro-Raman Spectroscopy) techniques to survey relationships between biochar properties and observed phenomena. These materials have then been employed as sorbents in three successive case studies pertaining to 1) Free-flowing surface waters 2) High (mg/L) and low (µg/L) concentration wastewaters 3) Synthetic solutions. Results of performed sorption experiments give insight into constraints for effective use of commercial biochar as a sorbent for heavy metals.The study provides an assessment of commercial biochar’s potential for water treatment and its challenges. Future developments address additional research gaps and the need for overarching standardization efforts to extract value from biochar as a tool for sustainable development.