Characteristics of selective fluoride adsorption by biocarbon-Mg/Al layered double hydroxides composites from protein solutions: kinetics and equilibrium isotherms study.
In the study, two novel applied biocarbon-Mg/Al layered double hydroxides composites (CPLDH and CPLDH-Ca) were successfully prepared and characterized by TEM, ICP-AES, XFS, EDS, FTIR, XRD, BET and pHpzc. The fluoride removal efficiency (RF) and protein recovery ratio (RP) of the adsorbents were studied in protein systems of lysozyme (LSZ) and bovine serum albumin (BSA). The results showed that the CPLDH-Ca presented remarkable performance for selective fluoride removal from protein solution. It reached the maximum RF of 92.1% and 94.8% at the CPLDH-Ca dose of 2.0g/L in LSZ and BSA system, respectively. The RP in both systems of LSZ and BSA were more than 90%. Additionally, the RP of CPLDH-Ca increased with the increase of ionic strengths, and it almost can be 100% with more than 93% RF. Fluoride adsorption by the CPLDH-Ca with different initial fluoride concentrations was found to obey the mixed surface reaction and diffusion controlled adsorption kinetic model, and the overall reaction rate is probably controlled by intra-particle diffusion, boundary layer diffusion and reaction process. The adsorption isotherms of fluoride in BSA system fit the Langmuir-Freundlich model well. The BSA has synergistic effect on fluoride adsorption and the degree increased with the increase of the initial BSA concentration.
Department of Chemistry, Dalian University of Technology, Dalian 116023, PR China. Electronic address: chmawv@yahoo.com.
Wei
W
Ma
Department of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
Tengfei
T
Lv
Department of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
Xiaoyan
X
Song
Department of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
Zihong
Z
Cheng
Department of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
Shibo
S
Duan
Department of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
Gang
G
Xin
Dalian Ocean Fishery Group of Corporations, Dalian 116023, PR China.
Fujun
F
Liu
Dalian Ocean Fishery Group of Corporations, Dalian 116023, PR China.
Decong
D
Pan
D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D000818:Animals; D002244:Carbon / Q000737:chemistry*; D005459:Fluorides / Q000302:isolation & purification*; D005506:Food Contamination; D059022:Food Safety; D008276:Magnesium Hydroxide / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008892:Milk / Q000737:chemistry / Q000592:standards; D009113:Muramidase / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D013054:Spectrophotometry, Atomic; D013499:Surface Properties; D014961:X-Ray Diffraction
D012996:Solutions; C010467:hydrotalcite; D012710:Serum Albumin, Bovine; D000536:Aluminum Hydroxide; D002244:Carbon; D009113:Muramidase; D008276:Magnesium Hydroxide; D005459:Fluorides
Biocarbon–Mg/Al layered double hydroxides composites; Equilibrium isotherms; Fluoride selective adsorption; Kinetics; Protein solution