Marine organic colloids (MOCs) cause serious membrane fouling in the process of seawater desalination. Hence, this study was designed to efficiently eliminate MOCs by biomineralization of forming calcium carbonate/phosphate precipitate. Results showed that crystal formed by calcium solution and carbonate dosage was calcite, while the precipitate of calcium solution with phosphate was similar to hydroxyapatite. MOCs in the solution were throughout involved in forming the calcite and hydroxyapatite precipitates. The removal rates of protein, acid polysaccharide and humic acid in the MOCs by forming hydroxyapatite approached 56.56 %, 86.07 % and 95.34 %, extremely higher than that of calcite. Finally, MOCs removal mechanism by the biomineralization was proposed, where calcium ions were firstly absorbed by functional groups of organic macromolecules in the solution, then the added carbonate or phosphate anions were attracted by calcium ion, and finally the crystal growth occurred with macromolecules as templates. The present results might provide a new idea for the engineers to solve the problem of membrane fouling and thus present promising application in desalination process.
