Influence of B₂O₃ on Phosphate Ion Released from SiO₂-B₂O₃-P₂O₅-Na₂CO₃ Glass in Synthetic Seawater

Abstract

Phosphates have been receiving important attention in various fields and one of the fundamental sources of nutrients required to be used as source of nutrients for plankton growth. The objective of this study is to determine the effect of boron oxide on phosphate ion released from the system SiO2-B2O3-P2O5-Na2CO3 glasses. The compositions of this glass system [wt%: (55-x)% SiO2- (15+x)% B2O3- 5% P2O5- 25% Na2CO3] where 15≤x≤40 % have been prepared with the different amount of B2O3 (30-55wt%) and P2O5 with Na2CO3 were fixed. The glass has been prepared by melting in the alumina crucible within 2 h of soaking time at 1300 °C in the furnace and cooled to room temperature. The obtained glass samples were crushed and sieved at mean size of 2 mm – 4 mm. The dissolution studies were determined through the immersion of the glass samples in 50 mL synthetic seawater for 30 days under static condition. The results were obtained and analyzed using Discrete Auto Analyzer. Fourier Transform Infrared (FTIR) with Attenuated Total Reflectance (ATR) method was used to determine the functional group sample of glasses and the glass phase was characterized by X-Ray diffraction (XRD) techniques. Dissolution studies showed that, the concentration of phosphate ion released decreased with increasing B2O3 content whilst, increased with immersion time. The obtained experimental data indicated that, the optimum concentration of phosphate ion (10.27 ppm) was achieved at 35 wt% of B2O3 at week three.