Ability of Hydroxyapatite Synthesized from Waste Oyster Shells to Remove Fluoride Ions

作者：Terasaka Sota; Kamitakahara Masanobu^*; Yokoi Taishi; Matsubara Hideaki

来源：Materials Transactions, 2015, 56(9): 1509-1512.

DOI：10.2320/matertrans.M2015149

• environmental purification material
• hydroxyapatite
• oyster shell
• fluoride ion

Calcium carbonates, the main component of seashell waste, can be converted to hydroxyapatite (HA) via phosphate solution treatment. HA can remove F- from water, as recommended by the World Health Organization (WHO), and HA particles of small sizes and/or large amounts are expected to remove F- more effectively. To control the size and amount of synthesized HA, oyster shells were treated in the (NH4)(2)HPO4 solution whose pH value was adjusted to 10 at 4-120 degrees C for 24h. The HA particle size and amount increased with increasing reaction temperature. The samples' abilities to remove F- were evaluated by immersing them in F--containing solutions. The sample treated at 30 degrees C removed F- the most effectively, achieving a F- concentration below 1.5 mg center dot dm(-3), which is the level recommended by the WHO. The HA surface area is important in F- removal.

• 出版日期2015-9