[Characteristics and comparative study of a new drinking-water defluoridation adsorbent Bio-F].
To evaluate the application potentiality pf a new type drinking-water defluoridation adsorbent Bio-F, comparative study on the defluoridation characteristics of common adsorbents activated alumina (AA), bone char (BC), activated clinoptilolite (AC) with Bio-F was conducted. The defluoridation characteristics under different conditions, such as particle diameter, pH, retention time, fluorine concentration, regeneration stability, were investigated by continuous-flow column experiments and static tests. The defluoridation efficiency of high fluoride underground water by four types of adsorbents was also compared. The results showed that F(-) adsorption kinetics of Bio-F fitted the Lagergren First-order equation (R2 = 0.9580). F(-) adsorption by Bio-F was found to fit the Langmuir adsorption isotherm (R2 = 0.9992). The results indicated that the static defluoridation capacity (DC) of Bio-F was 4.0883 mg x g(-1), which was about 1.8 folds and 5.8 folds of those of AA and AC respectively. DC of all four adsorbents was positively correlated with F(-) concentration and negatively correlated with particle size. High concentration of CO3(2-) and HCO3(-) reduced the DC of Bio-F (p < 0.05), while high concentration of Ca2+, NO3(-), HPO4(2-) favored defluoridation by Bio-F (p < 0.001). The optimal retention time of Bio-F was 3-4 min, which was less than that of AC (20 min) and AA (11 min). The DC of Bio-F remained relatively stable in pH 4.0-9.0 and in regeneration since the DC variation was not more than 15%. The above results indicated that Bio-F was superior to AA, BC and AC in drinking-water defluoridation.
Zhu
Chi
C
Hubei Key Laboratory of Urban Aquatic Environmental Ecology, Central China Normal University, Wuhan 430079, China. zhuchi126@126.com
Zhao
Liang-Yuan
LY
Yuan
Heng
H
Yang
Han-Ying
HY
Li
Ang
A
Wang
Peng
P
Yang
Shao
S
D000327:Adsorption; D005458:Fluoride Poisoning / Q000517:prevention & control; D005459:Fluorides / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*
D014874:Water Pollutants, Chemical; D005459:Fluorides