纳滤和反渗透技术在高含盐地下水中的应用及比较研究

Application and comparison of nanofiltration and reverse osmosis technology in high salinity groundwater

J市地下水无机盐污染物超标,常规工艺难以有效处理。为保障居民用水品质,开展以纳滤和反渗透为核心的膜分离技术中试和扩展小试研究。结果表明:使用超滤作为预处理工艺能有效保证纳滤和反渗透工艺的进水水质;纳滤和反渗透工艺能有效去除水中的TDS、总硬度、硫酸盐、氟化物、UV_(254)和DOC,除氟化物外去除率均在95%以上,且纳滤和反渗透工艺运行稳定,投加阻垢剂后无明显膜污染;为提高经济性,可将处理水与原水掺混供水,掺混比为38%,掺混后供水水质达标;通过技术经济分析,结合当地水质情况,纳滤工艺更适合作为改造的核心工艺。

The inorganic salt pollutants in groundwater in J City exceed the standard,and the conventional process is difficult to effectively treat.In order to protect the water quality,a membrane separation technology with nanofiltration(NF)and reverse osmosis(RO)is used for pilot-scale research and extended bench-scale research.The results show that the pretreatment using ultrafiltration can effectively ensure the influent water quality of the NF and RO.The NF and RO can effectively remove TDS,total hardness,sulfate,fluoride,UV254 and DOC in water,and the removal rates are above 95%except for fluoride.There is no obvious membrane fouling after adding scale inhibitor.In order to improve economy,treatment water can be mixed with raw water,and the blending ratio is 38%.After mixing,the water quality meet the standard.For the location conditions,the NF is more suitable as the process of the update through technical and economic comparison.