INVESTIGATION OF CARBON ADSORPTION/ABSORPTION CAPABILITY OF BIOCHAR FROM EICHHORNIA CRASSIPES (WATER HYACINTH) GROWN UNDER ELEVATED CARBON DIOXIDE.

Abstract

Global warming is a pertinent issue that deserves immediate attention since its impacts are on both an individual and global scale. Many methods were proposed to minimise CO2 emission but few were available for reducing atmospheric CO2. The concept of adopting biochar for atmospheric CO2 removal is not new as it has been explored extensively over the past few years. Often, studies on biochar CO2 sorption used terrestrial plant biomasses. However, this study focuses on using aquatic plants, water hyacinths, pre-treated with different CO2 conditions before biochar production. This study involves a two-stage experiment. In the first stage of the experiment, water hyacinths were exposed to elevated CO2 (20,000ppm) and ambient CO2 (400-500ppm) condition to form two types of biomass. In the subsequent stage, both types of biomasses were converted to biochar at 400⁰C. They then underwent CO2 sorption test at 1000ppm CO2 concentration and SEM. Results from CO2 sorption test revealed that biochar produced from water hyacinths subjected to elevated CO2 level exhibit better CO2 sorption ability. However, the reason for this better performance was not due to porosity, as seen from SEM. Based on a comparison with biochar produced from mung beans, water hyacinth-derived biochar fared poorer in adsorbing CO2. Nonetheless, this study has concluded that biochar produced from water hyacinths were still able to adsorb CO2 and was able to remove more CO2 when the plant was pre-treated with high CO2 level.