%0 Dataset
%T Data set of hardness removal rate of nanofiltration in Tianjin Jinhai Lake (July September 2020)
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/7bfba711-0505-43fc-b294-1d9076def3eb
%W NCDC
%R 10.12072/ncdc.MDBW.db0020.2021
%A Du runhong
%K Nanofiltration;calcium ion;magnesium ion
%X After precision filtration ultrafiltration pretreatment of Jinhai lake water, the pretreated water is pumped into the desalination system equipped with different numbers of nanofiltration membranes by high-pressure pump (crn3-29, Grundfos). The nanofiltration membrane adopts commercial polyamide 4040 roll membrane module (vnf2, Guiyang times Wharton Co., Ltd.). After the pressure and flow rate are stable for half an hour, the produced water samples are collected, the content of calcium and magnesium ions is measured by a third-party detection organization, and the removal rate of calcium and magnesium is calculated. The operating pressure is 1.3 MPa, the salt content of influent is 7.5 g / L, the water temperature is 30 ± 2 ℃, the influent flow is 2 m3 / h, and the number of membrane modules is 6-8.  The content of calcium and magnesium ions is determined according to the standard test methods for drinking water (GB / T 15452-2009). The measurement is accurate to two decimal places. The removal rates of calcium ion and magnesium ion by nanofiltration desalination system are greater than 98.45% and 98.72% respectively, reaching the assessment index of the assignment.