MEMBRANE SYSTEMS
In water treatment, membranes are barriers that allow water to pass through but stop unwanted substances from passing through with it. Technically, membranes filter out salts, pollutants, viruses and other particles from water like how our bodies cell walls function.
Water treatment plants purify waste water, groundwater and surface water using a variety of membrane types and methods to produce drinking and industrial water.
Ultra Filtration
Ultrafiltration (UF) is a purification method that uses an ultrafine membrane media to remove particulate debris from soluble chemicals The Ultra Filtration membrane considered is of hollow fiber type having a molecular cut off at 100,000 Daltosns. The Ultra Filtration process is a cross-flow type technology. The hollow fiber membrane allows water to pass through while rejecting (arresting) bacteria, particulate matter, colloids which is drained off. The membranes can be back flushed on a predetermined time or differential pressure. Generally, a recovery of 90% is obtained. There are UF membranes used in highly purified water generation in pharma and semiconductor industries. They have molecular cut off at 100,000 Daltosns.
Ultrafiltration is a system of hollow fiber membrane filtration that removes suspended solids, viruses, bacteria, endotoxins, and other pathogens from your feed water. It works on a simple principle – the pressure of the water itself pushes it through a series of semi-permeable membranes to filter out unwanted particles.
An ultrafiltration process first screens sand and other large particles of 10 microns or more. Next, it screens particles up to ~0.1 microns, which filters out most bacteria. Lastly, it filters viruses and other organic macro-molecules that are just 0.02 microns large.
Ultrafiltration is an excellent separation technology for desalination pretreatment, reverse osmosis pretreatment, and wastewater reclamation, as well as for producing potable water.
When used as a pretreatment for
reverse osmosis (RO) , UF also helps reduce fouling of the RO membranes, which can lead to:
- Reduced chemical cleaning frequency and consequently, lower operating costs and downtime.
- The potential to operate RO at higher flux, with fewer membranes and vessels, leading to lower capital cost for the RO system.
Reverse Osmosis Systems [Single and Double Pass]
Reverse Osmosis (RO) is a water purification process that uses a semi-permeable membrane to separate water molecules from other substances. RO is used in industrial operations for the manufacture of drinkable water because it has the ability to remove biological contaminants, primarily bacteria, as well as dissolved or suspended chemicals.
Reverse Osmosis Unit is the heart of the treatment scheme. It will reduce the Dissolved Salts from the raw water up to the remarkable level. A lot of bacteria are also removed in this process.
APK design Single stage & Two Stage RO System as raw water quality. In a single-pass system, the water passes over the RO membrane once and gets divided into the permeate water and the reject water stream.
In a two-stage RO system, the concentrate from the first stage becomes the feed water to the second stage. The permeate water that is collected from the first stage is combined with the permeate from the second stages. Additional stages increase the recovery of the system.
The feed water enters the RO system as a single stream and departs as either concentrate or permeate water in a one-stage RO system. The concentrate from the first stage provides the feed water for the second stage in a two-stage RO system. The permeate water collected in the first step is blended with the permeate water obtained in the second stage. Additional steps speed up the system’s recuperation.
Brackish Water RO Membranes
BW Brackish Water Desalination is a procedure for treating brackish water, which has higher saline levels than freshwater but lower levels than seawater. These membranes are designed to efficiently remove dissolved salts and other impurities from brackish water using the reverse osmosis process This technology uses modern filtration and purification techniques to eliminate contaminants from brackish water, making it appropriate for drinking, irrigation, and
industrial
usage. They are used in any industrial application that involves removing excess salt, metals, and other TDS from water.
Heat Sanitisable Reverse Osmosis
Heat-sanitisable reverse osmosis (HSRO) elements that deliver outstanding quality water with the added capability to withstand sanitization with hot water, eliminating the need for chemical sanitizers. HSRO membranes are designed for applications that require hygienic purified water. Purified water used in the pharmaceutical, medical, and biotechnology applications. Permeate polishing in food and dairy processes.
HSRO membranes combine heat sanitization, superior permeate quality, and high rejection rates, making them valuable in critical industries where purity and cleanliness are paramount.
Nano Filtration
Nanofiltration is a membrane filtration technology that includes nanometer-sized pores through which particles smaller than 10 nanometers pass. Nanofiltration membranes have pore diameters ranging from 1 to 10 nanometers, which are smaller than those used in microfiltration and ultrafiltration but slightly larger than those used in reverse osmosis. Polymer thin films are commonly used to construct membranes.
One of the primary benefits of using nanofiltration to soften water is that the process of keeping calcium and magnesium ions while passing smaller hydrated monovalent ions is achieved without the addition of extra sodium ions, as in ion exchangers.
It is used to soften, disinfect, and remove impurities from water, and to purify or separate chemicals such as pharmaceuticals.
Sea Water RO Membranes
Used for seawater desalination, these high productivity membranes are usually found on ships as well as land and sea-based desalination plants, creating drinkable water from seawater.
RO seawater desalination uses permeable membranes to remove dissolved solids while dividing the feed water into purified water and the rejected concentrated salts resulting in purified water with 99% less dissolved solids and salts. These seawater reverse osmosis systems are immensely powerful, with the capacity of purifying significantly high TDS water. Seawater RO systems are usable anywhere from yachts to municipalities. It’s important to choose the correct materials of construction to handle seawater as it is extremely corrosive.
Electro De Ionization [EDI]
Electro deionization (EDI) is a water treatment technology that utilizes DC power, ion exchange membranes, and ion exchange resin to deionize water. EDI is a continuous Electro-Deionization process. This is a 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.
