矿泉水技术改造一

消除圣水峪矿泉水中沉淀物的技术改造实验分析（一）纳滤膜过滤的应用摘要：由于圣水峪矿泉水的原水中的暂时硬度达到220mg/L，会产生沉淀。简单的超滤不可能去除无机盐，反渗透膜有会把绝大部分无机盐去除，所以使用纳滤膜来做实验，分析纳滤膜对总硬度及阳离子Ca2+、Mg2+、Sr2+和阴离子HCO-、3F-的去除效果和规律。1实验装置与实验方法1.1实验装置纳滤膜实验装置由济宁新格瑞水处理有限公司提供，纳滤膜采用美国陶氏NF270-400型膜一只，实际运行压力在0.5〜0.9MPa之间不等。1.2实验方法进水采用超滤后水，进膜压力为0.5MPa-0.9MPa之间，从0.5MPa开始，稳定运行两小时后依次升高0.1MPa，每个压力下稳定运行1小时后品控部取样，以后每小时取一次样品，每个压力取样两次，同时取纳滤前水样做对比实验。品控部对每个样品进行PH值、电导率、总硬度、总碱度、钙、镁、重碳酸盐的检验。同时把超滤水和0.7MPa进膜压力的纳滤后水样送检，检测锶和氟的含量。2结果和讨论2.1纳滤膜对矿物质的去除效果纳滤膜对不同地区水中矿物质总量均有相当的去除作用，但去除率（用电导率表示）不稳定，去除率集中在50%左右，并随进膜的压力升高而升高，随原水电导率的增加，离子去除率总体呈降低趋势，如表1所示。表1纳滤膜对水中矿物质的去除效果

井号项目0.5MPa0.6MPa0.7MPa0.8MPa0.9MPa新井电导率us/cm超滤水705709708702695692693696699697纳滤水370364353351338339328325322323去除率47.548.750.150.051.451.052.753.353.953.6老井电导率us/cm超滤水722733733728725730730730730731纳滤水482408376376354353346346340340去除率33.344.348.748.151.251.652.652.653.453.5有关资料表明，截留率与浓度的这种相关性与道南平衡和迁移离子的屏蔽作用有关。进料溶液中的离子浓度越高，其在膜微孔中的浓度也越高，因此最终在渗透物中的浓度也越高。同时，对负电荷的纳滤膜孔壁，正离子被富集在孔壁附近，使得孔内负的固定离子受到这种富集分布的屏蔽。这样，随着进料浓度的增加，电荷屏蔽作用增强，更多的阴离子可能从膜中透过，导致膜的截留率下降。2.2纳滤膜对总硬度及阳离子的去除效果纳滤膜对水中总硬度及钙离子、镁离子的去除效果见表2。井号项目0.5MPa0.6MPa0.7MPa0.8MPa0.9MPa新井总硬度mg/L超滤水360.3354.3348.3350.3348.3338.3346.3348.3348.3342.3纳滤水146.8146.8154.1156.1154.1154.1140.1146.1138.1136.1去除率59.358.655.855.455，854，459.558.160.460.2钙mg/L超滤水101.8105100.296.296.595.7100.298.697.0103.4纳滤水44.944.142.544.140.144.144.143.338.542.5去除率55.958.057.654.258.453.956.056.060.358.9镁mg/L超滤水27.724.325.324.320.122.027.222.424.325.3纳滤水11.711.712.612.611.210.79.7210.211.211.2去除率57.851.950.248.244.351.464.354.553.955.7老井总硬度us/cm超滤水346.3364.3350.3348.3358.3340.3342.3344.3362.3346.3纳滤水160.1162.1156.1148.1142.1146.1140.1138.1144.1140.1去除率53.855.555.457.560.357.159.159.960.259.5钙mg/L超滤水108.2109.8106.6110.6115.4107.4109.0125.1113.0121.0纳滤水65.071.357.051.343.348.155.348.942.543.3去除率40.035.146.553.662.555.249.360.162.464.2镁mg/L超滤水18.519.018.017.016.519.015.611.815.117.0纳滤水11.27.33.276.17.55.1――5.17.96.5去除率39.561.671.864.154.573.2一一56.847.761.8纳滤膜对总硬度和对阳离子的去除率波动很大，特别是镁比钙、总硬度的去除率波动更大，从33%〜73.2%不等。纳滤膜对总硬度、钙离子的去除率大部分在50%〜60%、40%〜60%之间，且随着进压得升高而有升高的趋势。2.3纳滤膜对总碱度及阴离子的去除效果纳滤膜对总碱度、碳酸氢根离子的去除效果见表3。井号项目0.5MPa0.6MPa0.7MPa0.8MPa0.9MPa新井总碱度mg/L超滤水220.1224.9210.5215.3215.3224.9229.6224.8210.5215.3纳滤水110.0114.8110.0100.5100.595.795.795.7100.595.7去除率50.049.047.753.353.357.457.357.452.355.6HCO-3mg/L超滤水268.3274.2256.7262.5262.5274.2256.7274.2256.7262.5纳滤水134.2140.0134.2122.5122.5116.7116.7116.7122.5116.7去除率50.048.947.753.353.357.454.557.452.355.5老井总碱度us/cm超滤水210.5215.3220.1210.5215.3215.3210.5208.1212.9210.5纳滤水153.1114.8100.5100.586.190.990.986.186.190.9去除率27.346.754.352.360.057.856.858.659.656.8HCO-3mg/L超滤水256.7262.5268.3256.7262.5262.5256.7253.4259.6256.7纳滤水186.7140.0122.5122.5105.0110.8110.8105.0105.0110.8去除率27.346.754.352.360.057.856.858.659.656.8纳滤膜对总碱度、碳酸氢根离子有较好的去除率，但去除率与进水中相应离子的浓度大小之间无明显差异，但随进膜的压力的升高，去除率有上升的趋势。同一水样和同一压力条件下，总碱度、碳酸氢根离子的去除率基本一样，纳滤膜对总碱度、碳酸氢根离子的去除率在45%-60%之间在。2.4纳滤膜对PH值的影响纳滤膜对PH值的影响，结果见表4。井号项目0.5MPa0.6MPa0.7MPa0.8MPa0.9MPa新井PH值超滤水7.567.887.847.937.937.937.867.887.877.88纳滤水7.587.497.487.467.457.457.437.467.427.43降低-0.020.390.360.470.480.480.430.420.450.45老井PH值超滤水7.797.857.867.837.887.847.877.847.867.81纳滤水7.767.797.647.637.627.617.587.567.577.56降低0.030.060.220.20.260.230.290.280.290.25纳滤膜对PH值有一定的降低，但降低幅度较小且不稳定。2.5纳滤膜对锶和氟离子的去除效果由于实验室不能进行锶和氟的检验，需送检。取0.7MPa压力下纳滤水和原水，两口井都取样，总共四个样送检。结果见表5。项目新井老井原水纳滤水去除率原水纳滤水去除率锶3.971.8952.4%1.100.5153.7%氟0.940.4947.9%0.490.2353.1%在0.7MPa压力下，纳滤对锶的去除率在50%以上；对氟的去除率不稳定且随着含量增大而降低。这次送检的结果，其中新井的锶、氟与以前的检验结果差异较大，这次的样品是在连续抽水48小时以后所取的样品。我认为，有必要连续抽水直到水质稳定。3结论纳滤膜操作压力低，对高电价位的离子的去除率高，对分子质量大离子去除率高，是一种适合于饮用水生产中采用的膜过滤技术。纳滤膜对水中矿物质总量、总硬度、钙