|Fang, June - University Of Florida|
|Gao, Bin - University Of Florida|
|Zimmerman, Andrew - University Of Florida|
|Chen, Jianjun - University Of Florida|
Submitted to: RSC Advances
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2016
Publication Date: 3/1/2016
Citation: Fang, J., Gao, B., Zimmerman, A.R., Ro, K.S., Chen, J. 2016. Physically (CO2) activated hydrochars from hickory and peanut hull: preparation, characterization, and sorption of methylene blue, lead, copper, and cadmium. Royal Society of Chemistry Advances. 65:24906-24911.
Interpretive Summary: Hydrochar is a carbonaceous solid obtained from hydrothermal carbonization of biomass. Hydrochars made from hickory and peanut hull were physically activated with carbon dioxide to increase surface area. Although 28-54% of the hydrochar mass was lost during the high temperature activation process, the resulting activated hydrochars showed excellent aqueous sorption capacity toward organic compounds and heavy metals such as methylene blue, lead, copper, and cadmium. This study suggested that the activated hydrochar could be used to clean water as other commercial activated charcoals.
Technical Abstract: The effects of carbon dioxide activation temperature (600-900 degree Celsius °C) and time (1 and 2 h) on the physicochemical and sorptive characteristics of hickory and peanut hull hydrochars were investigated. The extent of burn-off increased with increasing activation times and temperatures, and ranged from 34-54% and 28-50% for activated hydrochars (AHCs), respectively. Surface area and pore volume of the AHCs also increased with activation time and temperature and were much higher than those of their corresponding non-activated parent hydrochars. In general, the physical activation improved the ability of all AHCs to sorb methylene blue, lead (Pb2+), copper (Cu2+), and cadmium (Cd2+) from aqueous solutions. AHCs created at 900°C had the best sorption ability and the highest sorption rate was usually observed in 900°C 2 h AHCs. The sorption of methylene blue and the three heavy metals was strongly correlated with AHC surface area, suggesting that the adsorption occurred via site-specific interactions.