CONCLUSION
1. Adsorption of phosphate on calcium carbonates increases as a function of temperature.
2. Adsorption goes through a maximum at pH of 8.4.
3. Adsorption capacity increases as salinity decreases in aqueous solution.
4. Both the adsorption and desorption of phosphate on carbonate particle surface are fast processes. Aragonite shows a faster initial uptake of phosphate than calcite, while calcite shows a more rapidly release of phosphate than aragonite.
5. Further experiments showed that the phosphate adsorption or desorption capacities of aragonite and calcite are almost the same if carbonate is in equilibrium with phosphate for a week.