Chemical Activation of Biochar with H3PO4 - A Comparison between Two Reactor Types

Abstract

As the use of medicine increases worldwide, more and more drugs are found in wastewaters. It is now known that wastewater is a main pathway to enter the environment. Even state-of-the-art WWTPs are not able to remove these organic micropollutants (OMPs), or only to a limited extent. Therefore, an additional treatment step can be required and activated powdered carbon (APC) could be a possible solution. In this work, phosphoric acid is used for chemical impregnation and further activation. Two reactor approaches were used, a standard tubular (TR) and a fluidized bed reactor (FBR). Reaction times (RT) vary between 0.5 and 2/1 h at 700 to 1000 °C. For comparison, various parameters were carried out, such as specific surface area (SSA), total carbon (TC), yield and pore size distribution. The new FBR achieved higher SSA (1354.19 m2g-1) and a better pore distribution while using less impregnation agent (IA), lower temperatures and a shorter RT.