Electrodialysis Concentration
Overview
Electrodialysis concentration (EDC) is an electrochemical process that separates ionic components from aqueous solutions using ion-selective membranes and an applied electric field. Unlike reverse osmosis, EDC targets specific ions, making it ideal for applications requiring precise concentration control, such as brine treatment or lactose recovery in dairy. The technology originated in the 1950s and has evolved with improved membrane materials and system designs. Modern EDC systems are modular, allowing scalability for industrial needs, and are particularly valued for their low energy consumption compared to thermal evaporation methods.
Structure and Working Principle
A typical EDC system consists of alternating cation- and anion-exchange membranes stacked between electrodes, forming concentrate and diluate compartments. When DC voltage is applied, cations migrate toward the cathode through cation-exchange membranes, while anions move toward the anode via anion-exchange membranes, effectively concentrating ions in specific compartments. Key components include spacer gaskets to ensure flow distribution, electrodes (often titanium with platinum coating), and pumps for feed circulation. Advanced systems incorporate pulsed electric fields or polarity reversal to mitigate membrane scaling. The process operates at ambient temperature, preserving heat-sensitive compounds in food/pharma applications.
Key Features
Energy efficiency is a standout feature, with EDC consuming 1–2 kWh/m³ for brackish water, significantly lower than thermal methods. Selectivity allows targeted removal of monovalent ions (e.g., Na⁺, Cl⁻) while retaining divalent ions (Ca²⁺, SO₄²⁻), useful in mineral recovery. Modularity enables flexible capacity adjustments by adding/removing membrane pairs. Systems can achieve concentration factors up to 20% TDS (total dissolved solids), with some specialized configurations reaching 30%. Automation options include real-time conductivity monitoring and adaptive voltage control to optimize performance.
Application Areas
In wastewater treatment, EDC recovers acids/alkalis from industrial effluents, such as pickling liquors in steel plants. The food industry uses it to concentrate fruit juices without thermal degradation, preserving flavor and nutrients. Emerging applications include lithium extraction from brine and glycine recovery from pharmaceutical waste. Seawater desalination pre-concentration is another niche, where EDC reduces the load on downstream RO systems. In Japan, over 60% of table salt is produced using electrodialysis, showcasing its economic viability at scale.
Maintenance and Precautions
Membrane fouling is the primary operational challenge, requiring regular cleaning (e.g., acid/alkali washes every 200–500 hours). Pre-treatment like ultrafiltration removes colloids and organics. Electrode deterioration can occur in high-chloride environments, warranting periodic inspection. System shutdowns should include membrane flushing to prevent drying damage. For CIP (clean-in-place), use 0.1M HNO₃ for inorganic scaling and 0.1M NaOH for organic foulants. Operators must monitor current efficiency; a drop below 80% often indicates maintenance needs.
B2B Procurement Guide
When sourcing EDC systems, specify feedwater characteristics (ion composition, TDS, temperature) and desired concentrate/diluate purity. Membrane choice is critical: homogeneous membranes suit high-purity needs, while heterogeneous types offer cost savings for harsh conditions. Lead times for custom systems range from 12–24 weeks. Total cost analysis should include membrane replacement (every 5–7 years) and energy consumption. For large projects (>100 m³/day), consider vendors offering performance guarantees and onsite commissioning support.
Related Manufacturers
- 主营：微弧氧化电源、双脉冲电源、脉冲电源、电解电源、电镀电源、电泳电源、氧化电源、电絮凝电源、电催化氧化电源、污水处理电源、电镀铬电源、电解除垢机、次氯酸钠发生器电源、电解制氢电源、电解金属回收电源、电积铜电源、电解抛光电源、等离子抛光电源、直流电源、整流器电源、冷却塔吸垢机、同步整流器
- 主营：Mvr蒸发器、多效蒸发器、蒸发结晶器、蒸发浓缩系统、冷却结晶器、化工废水处理蒸发器、母液干化系统
- 主营：小医院、化妆品、软化水、光伏电缆、电镀涂装、导电玻璃、电子设备、浓缩设备、发电锅炉、水设备、软水器、金刚石、线路板、ro反渗透、水处理ro、医疗器械、蒸汽锅炉、汽车用品、蔬菜养殖、铭宇环保、反渗透edi、除锈设备、花卉养殖、芯片制造、超滤设备
- 主营：电渗析、电渗析设备、电渗析除盐、电渗析制酸碱、电渗析实验设备、电渗析实验装置、电渗析脱盐
- 主营：电渗析设备、电渗析脱盐设备、实验设备、反渗透装置
- 主营：反渗透设备、高盐废水处理设备、苦咸水淡化设备、电渗析设备、实验室电渗析、全自动电渗析设备、化工溶液浓缩分离装置、频繁倒极电渗析设备、电子级纯水设备、EDI高纯水设备、离子交换设备、软化水设备、海水淡化设备、EDI超纯水设备、高纯水设备、超滤设备、工业用水处理系统、反渗透RO纯水装置、节能减排系统、全自动超滤装置、抗污染UF超滤设备、净水装置、反渗透浓水回用设备、EDI模块集成、小型单级反渗透机
- 主营：离子交换树脂、大孔吸附树脂、水处理树脂、电渗析、螯合树脂、食品专用树脂、西药专用树脂、植物提取树脂、废水处理树脂、固定化酶载体、催化树脂、氯碱工业树脂、环保专用树脂、湿法冶金树脂、双极膜、离子交换膜
- 主营：提取设备、脱盐系统、提取过滤、浓缩设备、浓缩分离、浓缩机器、浓缩机低温、超滤膜浓缩、电渗析设备、中药浓缩机、牛奶浓缩机、机器过滤、低温牛奶、过滤设备、提取机器、滤膜过滤、脱盐设备、水处理设备、超滤膜纳滤、分离机低温、树脂再生废水、膜分离设备
- 主营：蒸发器、废水蒸发器、单效废水蒸发器、浓缩蒸发器、浓缩器、mvr蒸发器浓缩、mvr浓缩蒸发器、双效废水蒸发器、三效废水蒸发器、多效废水蒸发器、MVR蒸发器、MVR废水蒸发器、母液干化机、蒸发结晶器、降膜蒸发器、强制循环蒸发器、结晶器、挥发器、单效蒸发器、双效蒸发器、三效蒸发器、多效蒸发器、mvr蒸发结晶器、mvr强制循环蒸发器、mvr结晶蒸发器
- 主营：edi整机、中回水、定制edi、edi电子、水系统、小医院、edi平台、edi系统、化验室、edi资质、edi模块、阀单罐、阀双罐、阀三罐、水设备、净水器、小区中、玻璃水、纯净水、edi设备、尿素水、实验室、玻璃冲洗、制造设备、蒸汽锅炉
- 主营：硫酸铜、阴阳膜、废水处理、浓缩阳膜、电渗析膜、浓缩阴膜、电渗析极膜、电渗析阴膜、电渗析设备、电渗析装置、左旋肉碱、减盐酱油、酸回收膜、脱盐阳膜、离子交换膜、扩散渗析膜、扩散渗析器、扩散渗析装置、工业级双极膜、高选择透过阳膜
- 主营：电渗析、反渗透设备、纯净水设备、工业反渗透装置