真空膜蒸馏处理循环冷却水的试验研究

RESEARCH ON VACUUM MEMBRANE DISTILLATION FOR CIRCULATING COOLING WATER

基于提高循环冷却水的处理效率,并探寻新的电去离子预处理工艺,利用自制中空纤维膜组件,考察了真空膜蒸馏过程参数对产水水质的影响。结果表明,在试验范围内,料液流量(7.21～18.98 L/h)、热侧温度(52℃～73℃)、冷侧真空度(0.055～0.087MPa)对产水水质影响不大,电导率在5μS/cm以下,总硬度小于1 mg/L(以CaCO3计),UV254在0.02～0.04之间,TOC在0.05～0.5 mg/L之间,去除率分别达到99.8%、99.85%、93.71%、99.65%,可以达到电去离子的进水水质要求;预软化可以提高出水水质;浓缩倍数增大到20倍,电导率由1.72μS/cm上升到3.73μS/cm,Ca2+浓度、UV254、TOC等指标变化不大,采用真空膜蒸馏可望实现循环冷却水的零排放。

With the purpose of improving the recovery of circulating cooling water, in this pa- per,vacuum membrane distillation（VMD） experiments were carried out with homemade hollow fiber membrane module.The influences of operation parameters on the effluent water quality were investigated,at the same time to search a new pretreatment technology electricity for electrodeionization（EDI）.The results showed that in the test range, flow（7.21-18.98 L/h）,tem- perature in the hot side（52~C^73~C）and vacuum of the cold side（0.055-0.087 MPa）have little effect on the effluent water quality,the conductivity of output water is lower than 5 /z S/cm, total hardness remains less than lmg/L,UV254 is between 0.02-0.04,TOC remains between 0.05-0.5 mg/L,the removal rate achieved 99.8%,99.85%,93.71%,99.65% respectively which can meet the requirement for EDI＇s feed water quality ;pre-softening can improve the effluent water＇s quality;when the circulating cooling water was concentrated 20 times,the conductivity just increase from 1.72 IxS/cm to 3.73 p^S/cm ,and other indexs such as Ca2＋,UV254,TOC changed little,so using vacuum membrane distillation may make zero release of circulatingcooling water come true.