反渗透海水淡化水后处理技术

POST-TREATMENT TECHNIQUE OF REVERSE OSMOSIS(RO)-DESALINATED SEAWATER

采用溶解白云石法对反渗透海水淡化水进行矿化,研究了温度、pH、白云石粒径、固液接触时间等因素对矿化反应的影响,选择合适的碱对出水pH、总碱度和碳酸钙沉淀势进行调节。结果表明,反应塔出水钙镁离子含量随温度和接触时间的增大而增大,随pH、白云石粒径的增大而减小。在优化的条件下,产水钙镁离子含量为分别为82.75mg/L(以CaCO3计)和19.25mg/L,pH为7.80,碱度为95.28mg/L(以CaCO3计),碳酸钙沉淀势为1.22mg/L(以CaCO3计)。产水水质稳定,不具有腐蚀性。

RO-desalinated seawater was mineralized by dissolving dolomite. The effect of temperature, pH, dolomite particle size, contact time on mineralized reaction was investigated systematically. The pH, total alkalinity and calcium carbonate precipitation potential （CCPP） of product water were adjusted by adding different alkalis. The results showed that mass concentration of Ca2＋ and Mg2＋ in water increased with an increase of temperature and contact time, while decreased with the decrease ofpH and dolomite particle size. Under the optimization condition, the product water was stable and non-corrosive with 82.75 mg,/L of Ca2＋ （as CaCO3）, 19.25 mg/L ofMg2＋, pH being 7.80, 95.28 mg/L of alkalinity （as CaCO3） and 1.22 mg/L of CCPP （as CaCO3）.