Calcium (Ca), phosphorus (P), and chitin are the main components of the exoskeleton of krill. Defluoridation of a solution of sodium fluoride (NaF) using calcium phosphate (Ca3(PO4)2) and chitin as defluoridation agents was studied. Orthogonal experiments were designed to find the optimum reaction conditions for defluoridation, to obtain the maximum defluoridation efficiency and fluoride removal capacity of calcium phosphate and chitin. At the same time, a comparison of the capacity of the two defluoridation agents was made. The results suggest that calcium phosphate has a far greater capability than chitin for the removal of fluoride (F) from water under similar reaction conditions. It is also suggested that Antarctic krill is likely to adsorb fluoride via compounds such as calcium phosphate, hydroxyapatite, and other compounds of Ca and P with the general form (Ca, X)x(PO4, HPO4, Y)y(OH, Z)z, in addition to chitin.
RESEARCH-ARTICLE
Comparison of the defluoridation efficiency of calcium phosphate and chitin in the exoskeleton of Antarctic krill

Vol. 23, Issue 3, pp. 149-154 (2012) • DOI
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1. School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China;
2. Advanced Lab for Eco-safety and Human health, Suzhou Institute of USTC, Suzhou 215123, China
2. Advanced Lab for Eco-safety and Human health, Suzhou Institute of USTC, Suzhou 215123, China
1 Boulton I C, Cooke J A, Johnson M S. Fluoride accumulation and toxicity in wild small mammals. Environ Pollut, 1994, 85(2): 161–167
2 Choubisa S L. Endemic fluorosis in Southern Rajasthan, India. Fluoride, 2001, 34(1): 61–70
3 Li Y M, Liang C K, Slemenda C W, et al. Effect of long-term exposure to fluoride in drinking water on risks of bone fractures. J Bone Mineral Res, 2001, 16(5): 932–939
4 Zhang H S, Xia W P, Cheng X H, et al. A study of fluoride anomaly in Antarctic krill. Antarctic Research, 1991, 3(4): 24–30
5 Sands M, Nicol S, McMinn A. Fluoride in Antarctic marine crustaceans. Mar Biol, 1998, 132(4): 591–598
6 Yin X B, Chen L A, Sun L G, et al. Why do penguins not develop skeletal fluorosis?. Fluoride, 2010, 43(2): 108–118
7 Zhu B Y, Wang X Y, Hu Q X. A study of fluoride in Antarctic krill. Antarctic Research, 1988, 1(1): 51–55
8 Zhang X G, Zhou A M, Lin X X, et al. Comparative study of chemical compositions of white shrimp head and shell. Modern Food Science and Technology, 2009, 25(3): 224–227
9 Xie Z Q, Sun L G. Fluoride content in bones of Adelie penguins and environmental media in Antarctica. Environ Geochem Health, 2003, 25(4): 483–490
10 Xiang J H. Antarctic krill and fluorine. Marine Science, 1985, 9(3): 57–59
11 Xu S Q, Wang J, Cheng B B, et al. Concentrations of Ca, P and Sr and characteristics of Ca/P and Ca/Sr in the bones of typical seabirds in the Antarctic. Journal of University of Science and Technology of China, 2007, 37(8): 995–1002
12 Brannon A C, Rao K R. Barium, strontium and calcium levels in the exoskeleton, hepatopancreas and abdominal muscle of the grass shrimp, Palaemonetes pugio: relation to molting and exposure to barite. Comparative Biochemistry and Physiology, 1979, 63(2): 261–274
13 Deshimaru O, Yone Y. Requirement of prawn for dietary minerals. Bulletin of the Japanese Society of Science Fisheries, 1978, 44(8): 907–910
14 Sun S, Yan X J. Active substances in the Antarctic krill. Chinese Journal of Polar Research, 2001, 13(3): 213–216
15 Zhu Y Y, Yin X B, Zhou S B. A preliminary study of selenium and mineral elements in Antarctic krill. Chinese Journal of Polar Research, 2010, 22(2): 135–140
16 Yang T, Kim C, Jho J, et al. Regulating fluoride uptake by calcium phosphate minerals with polymeric additives. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012, 401: 126–136
17 Chen F, Feng Z D, Lin C J. Effect of sodium fluoride solution on the hydrolysis of CaHPO4·2H2O and the solubility of its hydrolysate. Journal of Xiamen University (Natural Science), 2001, 40(1): 52–58
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