Enhanced adsorption of methylene blue by citric acid modification of biochar derived from water hyacinth (Eichornia crassipes).
In this work, a novel potential adsorbent, citric acid (CA)-modified biochar, named as CAWB, was obtained from water hyacinth biomass by slow pyrolysis in a N2environment at 300 °C. The CA modification focused on enhancing the contaminants adsorption capacity of biochar pyrolyzed at relatively low temperature. Over 90 % of the total methylene blue (MB) could be removed at the first 60 min by CAWB, and the maximum MB adsorption capacity could reach to 395 mg g-1. The physicochemical properties of CAWB was examined by FTIR, XPS, SEM, and BET analysis. The results indicated that the additional carboxyl groups were introduced to the surface of CAWB via the esterification reaction with CA, which played a significant role in the adsorption of MB. Batch adsorption studies showed that the initial MB concentration, solution pH, background ionic strength, and temperature could affect the removal efficiency obviously. The adsorption process could be well described by the pseudo-second-order kinetic model and Langmuir isotherm. Thermodynamic analysis revealed that the MB adsorption onto CAWB was an endothermic and spontaneous process. The regeneration study revealed that CAWB still exhibited an excellent regeneration and adsorption performance after multiple cycle adsorptions. The adsorption experiments of actual dye wastewater by CAWB suggested that it had a great potential in environmental application.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Yan
Y
Xu
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China. liuyunguo2012@yeah.net.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China. liuyunguo2012@yeah.net.
Yunguo
Y
Liu
School of Metallurgy and Environmental, Central South University, Changsha, 410083, People's Republic of China. 15171352964@163.com.|School of Architecture and Art, Central South University, Changsha, 410082, People's Republic of China. 15171352964@163.com.
Shaobo
S
Liu
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Xiaofei
X
Tan
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Guangming
G
Zeng
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Wei
W
Zeng
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Yang
Y
Ding
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.
Weicheng
W
Cao
School of Architecture and Art, Central South University, Changsha, 410082, People's Republic of China.
Bohong
B
Zheng
D000327:Adsorption; D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry*; D031806:Eichhornia / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry* / Q000302:isolation & purification; D013696:Temperature; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification
D002606:Charcoal; D019343:Citric Acid; D008751:Methylene Blue; D062065:Wastewater; D014874:Water Pollutants, Chemical; C540010:biochar
Adsorption; Biochar; Citric acid; Dye wastewater; Modification; Water hyacinth