Adsorption of Malachite Green from Aqueous Phase by Tea Stalk Powder: Parameters, Kinetic, Isothermal, and Thermodynamic Studies
Xiyao Liu,
Yilin Wu,
Wenchang Zhao,
Zhuanrong Wu,
Hua Han,
Zhenbang Xie,
Murat Yilmaz,
Tzu-Hsing Ko
Affiliations
Xiyao Liu
Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, College of Chemistry and Materials, Ningde Normal University, Ningde city, China
Yilin Wu
College of Horticulture and Forestry Sciences, Huazhong Agriculture University, Wuhan city, Hubei, China
Wenchang Zhao
Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, College of Chemistry and Materials, Ningde Normal University, Ningde city, China
Zhuanrong Wu
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou city, Guangdong, China
Hua Han
Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, College of Chemistry and Materials, Ningde Normal University, Ningde city, China
Zhenbang Xie
Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, College of Chemistry and Materials, Ningde Normal University, Ningde city, China
Murat Yilmaz
Department of Chemistry and Chemical Processing Technologies, Bahçe Vocational School, Osmaniye Korkut Ata University, Osmaniye 80000, Türkiye
Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, College of Chemistry and Materials, Ningde Normal University, Ningde city, China
Decolorization of malachite green (MG) from the aqueous phase was investigated using tea stalk powder. The adsorption efficiency decreased with the initial MG concentration, ionic strength of the solution, and heavy metal content. A suitable initial MG concentration of up to 200 mg/L can be accepted because adsorption efficiency of more than 95% is achieved. Various adsorption kinetic models were used to fit the experimental data, and the data obtained was best explained by the pseudo second-order model. The adsorption capacities calculated with the pseudo second-order model at different initial MG concentrations ranging from 24.27 to 158.7 mg/g were very close to the experimental data. The Langmuir isotherm fitted well, and the thermodynamic investigation showed that the adsorption of MG by tea stalk powder was feasible, endothermic, and spontaneous. The regeneration/adsorption experiments indicated that the tea stalk powder remained more than 95% of efficiency after six cycles using NaOH as desorbent and thus could be used many times. In conclusion, tea stalk has considerable potential as a cost-effective adsorbent for the removal of MG.
