胶州湾海水淤泥密度指数影响因素研究

Influencing factors of seawater silt density index in Jiaozhou Bay

超滤+反渗透组合的双膜法在海水淡化中已经得到广泛应用,然而反渗透膜的污染问题严重影响了正常生产。淤泥密度指数(SDI)已经成为评价反渗透进水水质的主要指标。通过对超滤出水水质进行检测分析并对反渗透膜主要污染物进行分析,探讨目前胶州湾海水淡化过程中反渗透进水SDI的影响因素及各因素影响程度,结果表明:微生物作为自然水体中广泛存在的生物,其随季节和温度变化造成的总量变化是影响SDI的最主要因素;水体中的硫酸盐以及Si、Al、Fe胶体是造成膜污染的主要无机污染物;此外,浊度与水样的SDI没有相关关系,也不能在反渗透过程中对水质情况进行有效衡量。最后,针对影响SDI的微生物因素的研究以及膜表面无机胶体的清洗提出未来发展方向。

The combination of ultrafiltration and reverse osmosis has been widely used in seawater desalination,but the pollution of reverse osmosis membrane has seriously affected the normal production.Silt density index(SDI)has become the main index for evaluating reverse osmosis inlet water quality.By detecting and analyzing the water quality of ultrafiltration effluent and analyzing the main pollutants in the reverse osmosis membrane,this study explored the influencing factors and the degree of influence of various factors on the SDI of reverse osmosis inflow seawater desalination process in Jiaozhou Bay.The results showed that,as the widely existing organisms in natural water,the total amount change of microorganisms with the season and temperature was the most important factor affecting SDI.Sulfate and Si,Al,Fe colloids in water were the main inorganic pollutants that caused membrane pollution.In addition,turbidity had no correlation with SDI of water samples,and could not be used to effectively measure water quality in reverse osmosis process.Finally,future development directions were proposed for the study of microbial factors that affect SDI and the cleaning of inorganic colloids on membrane surfaces.