5 Major Differences between RO and EDI Water Systems

Water is the heart of the human body, 50-65 % on average, although when looking at infants the percentage is typically around 75-78%. Water intake is mostly recommended since most body processes require it to facilitate optimal body functioning. Hard water contains much of dissolved minerals and the process of water purification comes from understanding the difference between RO and EDI water filteration systems.

5 Major Difference between RO and EDI Water Systems

Reverse Osmosis Water System

1.  How RO Works

RO system uses strong pressure gradient to drive water through the semi-permeable membrane while removing impurities, thus leaving water purified.
The system uses water line valve, which fits onto the cold water supply line. This valve has a tube which attaches to inlet RO pre-filter side. This is the water source of the RO system.
The water has to enter into the RO Pre-filter first. The sediment and the carbon filters are the more that one type of pre-filters. These filters prevent RO membrane by removing the sand silt, dirt and other sediments which could damage the system by clogging.
The system has an RO Membrane. This membrane is semi-permeable designed to remove a wide range of both aesthetic and health-related contaminants. Water is passed through the membrane and then pressurized into a storage tank where treated water is stored.

Post filters are used to treat water from the water storage tank before it comes out through the RO faucet. This is usually a carbon filter which helps on removing bad odor and bad taste from the water, hence given the name polishing post filtration filter.

2.  Reverse Osmosis System Components

Drain line, check valve, flow restrictor, storage tank, faucet, automatic shut off valve, post filters, pre-filters, and RO membrane.
3.  Application of RO system is used in power plant boiler feeds, whole house water treatment system, and commercial water plant purification systems.
4.  Advantages of RO system; It improves water taste, has simple maintenance since it is easy to replace parts and clean the system. Help save money, by producing highly purified water better than bottled water, and removes impurities in water using carbon filters to filter chlorine and chloramines.
5.  Disadvantages of RO system, first, it used too much space, second it consumes much energy, lastly, it is expensive in parts maintenance and replacement.

The Electrodeionization (EDI) Water System

This is a high water purifying production method which combines membrane separation and ion exchange processes. The process combines semi-impermeable membrane and ion exchange media technology which enable high-efficiency demineralization process.
In this technology, electrodialysis uses electric current and ion exchange and resin to remove ionized species from water. The semi-permeable membrane is ion based on the charge, flows electric current to reduce the ions based on their charge. This removes ionic impurities leaving a purified water product.

1. How EDI Works

The EDI has a basic structure of the deionization chamber. This chamber has ion exchange resin, packed between a cationic exchange membrane and an anionic exchange membrane. This means that only ions are passed through the membrane while the water is blocked.
The water again is passed through the resin filled the diluting compartment, for several processes to continue. Strong ions are removed out of the feed stream by the mixed bed resins containing the cation and anion selective membranes while being exchanged for H+ and OH- ions. These ions bound here migrate to a separate chamber under the influence of an externally applied electric field. The produced H+ and OH- ions are necessary for maintaining the resins in their regenerated state while ions in the separation chamber are flushed out as waste.

2. EDI Components

Resin, ion exchange media, electric current, semi-impermeable membranes, oppositely charged electrodes, concentrate spacer, anion membrane, dilute spacer, and cation membrane.
3. Applications of EDI is Used in the recycling of residual water in the food and beverages industry, microchip rinse water, and power plant boiler feed water. Moreover, its performance is very reliable since it provides high purity water production.
4. The advantages of EDI water system are simple, use little space, produced constant water flow which is highly purified, safe and reliable plus causes no pollution, it consumes lower power, its cost effective in operation and maintenance, and requires less supervision by an operator.
5. The disadvantages of the EDI system are that first, it requires a pretreatment purification to have pure water below hardness. This is because clogging can occur due to the calcium carbonate limiting its operations. Second, Carbon dioxide penetrates through the system, dissociating and raising the conductivity of water. Another strip gas method is attached to manage CO2.

In conclusion, specifying the difference between RO and EDI water systems is relevant to water purification methods that are qualifying the use of pure water. The choice of a water purifying system depends on which one is suitable to serve the required needs. Sustainable water is the ultimate goal of all industrial water filtration systems for future water storage and uses for all generations.