• • • • 反渗透 Reverse Osmosis 纳滤 Nanofiltroation 超滤 Ultra Filtration 微滤 Micro Filtration
进水 Feed Water
垂直过滤
Direct Filtration
产品水 Product Water
垂直过滤 Direct Filtration
Determined at 200 psi, 25% recovery, pH 7.8 on de-chlorinated city feed water with TFC membrane
Things to Remember 应记住的事项 Rejection Increases with Increasing
不均匀/不对称膜 Asymmetric Membrane
醋酸纤维素 Cellulose Acetate
屏障层
Barrier Layer
支持 Support
分级的密度 Graded-density cellulose acetate
薄膜合成物聚酰胺膜
Thin Film Composite Polyamide Membrane
2
Strong Solution
H2O H2O
纯水 Pure Water
Osmotic Pressure, PO,P
平衡 Equilibrium
反渗透 Reverse Osmosis
Applied Pressure, PF 渗透水压力 Permeate Pressure, PP
Osmotic HO Pressure, PO,F 2
Cations (Positive Charge - missing electrons)
离子 Ions
• 丢失或得到一个电子的离子= 单价的 Ions missing or having one electron = monovalent
• 丢失或得到二个电子的离子= 二价的
Ions missing or having two electrons = divalent
脱盐率随下列变化
• • • •
Degree of dissociation电离程度 Ionic charge离子电荷 Molecular weight分子量 Degree of molecular branching分子结
构
How small is small?
Inches 39.37 3.94 .39 .04 .004 .000,4 .000,04 .000,008 Meter 1 .1 .01 .001 .000,1 .000,01 .000,001 .000,000,2 5 x 10 -9 4 x 10 -10 Micrometer 1,000,000 100,000 10,000 1,000 100 10 1 .1 .005 UF .000,4 RO
离子的相关渗透率 Relative Permeation Rates of Ions
• 一价的 Monovalent = 1 x 10-5 cm/sec 快
• 二价的 Divalent
• 三价的 Trivalent
= 1 x 10-6 cm/sec
= 1 x 10-7 cm/sec 慢
典型离子脱出率
水中的杂质 Impurities in Water
• 离子类的 Ionic
水中的杂质 Impurities in Water
阳离子 Ca+2 Mg+2 Na+ K+ Fe+3 Mn+2 Al3+ NH4+ 阴离子 ClNO3SO42HCO3CO32SiO2 PO43-
• 离子的 Ionic
水中的杂质 Impurities in Water
• 丢失或得到三个电子的离子= 三价的
Ions missing or having three electrons = trivalent
离子 Ions
• 单价的 Monovalent: NaCl Na+ + Cl• 二价的 Divalent : CaSO4 Ca2+ + SO42• 三价的 Trivalent : Na3PO4 3Na+ + PO43-
渗透压 Osmotic Pressure
• 100 ppm Salt 1 PSI Osmotic Pressure
• 1000 ppm NaCl • 1000 ppm NaHCO3 • 1000 ppm Sucrose • 35,000 ppm Seawater = 11.4 psi = 12.8 psi = 1.5 psi = 374 psi
• 微粒的 Particulate
水中的杂质 Impurities in Water
• Ionic
• Non Ionic
• Particulate
• 气体类 Gases
水中的杂质 Impurities in Water
• Ionic
• Non Ionic
• 二氧化碳Carbon Dioxide
• 氧 Oxygen
浓水 Concentrate
横流过滤 Cross Flow Filtration
膜表面 Membrane Surface
渗透水Permeate
浓差极化
Concentration Polarization
横流过滤
Cross Flow Filtration
Things to Remember
需求记住的事项
• 进水速度必须能保证固体杂质的移动
Water velocity of the feed must be sufficient to keep the solids moving.
• 低流速会引起膜表面淤塞
Low water velocity will allow the membrane surface to “foul.”
溶液中的离子 Ions in Solution
•
• •
化合物在水中电离
Compounds dissolve in water to form charged ions 阴离子 （负电 荷– 得到电子） Anions (Negative Charge - extra electrons) 阳离子 （正电 – 丢失电子）
• Ionic
• Non Ionic
• 微粒的 Particulate
Impurities in Water
• Ionic
• Non Ionic
•固体悬浮物Suspended Solids
•胶质物 Colloidal Material
•微生物 Microbiological 细菌 Bacteria 滤过性微生物/病毒Virus 热原物质 Pyrogens 藻类 Algae
• Particulate
• 气体类 Gases
• 氯 Chlorine
• 氮 Nitrogen • 硫化氢 Hydrogen Sulfide
反渗透可去除：Reverse Osmosis Removes
• 离子类Ionic
• 非离子类Non 不去除 Ionic
• 微粒的 Particulate
气体类 Not Gases !
Strong Solution
H2O H2O
Pure Water
Osmotic Pressure, PO,P
纯水水流 Pure Water Flow
净推动压Net Driving Pressure （NDP）
进水 Feed
Applied Pressure, PF
渗透水
Permeate
Permeate Pressure, PP Osmotic Pressure, PO,F Osmotic Pressure, PO,P
聚酰胺超薄 屏障层
Polyamide Ultra-thin Barrier Layer
0.2 micron 40 micron
多微孔聚砜
Microporous Polysulfone
120 微米 micron
Compaction is not an issue
强化纤维 Reinforcing Fabric
• 反渗透 Reverse Osmosis 溶解的固体杂质 Dissolved Solids • 纳滤 Nanofiltration 二价离子 Divalent Ions (Ca & Mg) • 超滤 Ultrafiltration 有机物和胶体 Organics & Colloids • 微滤 Microfiltration 固体悬浮物 Suspended Solids
• 较高的水回收率（更高的水利用率）意味着较低 的水流速 Higher water recoveries (greater water utilization) means lower water velocity.
过滤型谱 The Filtration Spectrum
横流过滤
Cross Flow Filtration
1 Angstrom = 1 * 10 -10 m
Salt Rejection
Membrane
H2 ClNa+
Na
+
膜孔径 Membrane Pore Channel
反渗透 Reverse Osmosis
膜 Membranes
第一个RO膜
First RO Membrane
ROGA

Module #1
反渗透 Reverse Osmosis
基本原理 FUNDAMENTALS
过滤类型 Types of Filtration