Abstract 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.

中文翻译：

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海水淡化过程中生物矿化消除海洋有机胶体（MOCs）：机制和效率

摘要 海洋有机胶体（MOCs）在海水淡化过程中会造成严重的膜污染。因此，本研究旨在通过形成碳酸钙/磷酸盐沉淀物的生物矿化来有效消除 MOC。结果表明，钙溶液和碳酸盐加入形成的晶体为方解石，而钙溶液与磷酸盐的沉淀与羟基磷灰石相似。溶液中的 MOC 始终参与形成方解石和羟基磷灰石沉淀。通过形成羟基磷灰石对MOCs中蛋白质、酸性多糖和腐殖酸的去除率分别接近56.56%、86.07%和95.34%，远高于方解石。最后提出了生物矿化去除MOCs的机制，其中钙离子首先被溶液中有机大分子的官能团吸收，然后加入的碳酸根或磷酸根阴离子被钙离子吸引，最后以高分子为模板发生晶体生长。目前的结果可能为工程师解决膜污染问题提供新的思路，从而在海水淡化过程中具有广阔的应用前景。