Reverse Osmosis (RO) is a separation approach that’s appropriate for a wide range of functions, particularly when salt and/or dissolved solids have to be removed from an answer. It is among the most common forms of water treatment.
According to Anelia Hough, water treatment advisor at Allmech, leading South African producer of boilers and supplier of water remedy elements, there are a quantity of elements to be considered when deciding on an RO system: the customer’s capability requirement (i.e. water usage), the daily manufacturing capability of the system, and the p.c rejection for specific contaminants in the source water.
“Beyond this, RO plants require proper maintenance and care to make sure they function optimally and to increase their lifespan,” she says. “Aside from regular maintenance, the best way to guard a RO plant is by pre-treating water, which reduces the pressure on the RO membrane – a expensive part. It also helps to avoid issues like scaling and bio-fouling.”
Common Issues with RO Plants
“Factors that may affect a RO system’s efficiency embody temperature, operating strain, again stress, the equilibrium effect/TDS creep, p.c restoration, and, of course, the RO membrane’s permeate production and p.c rejection rankings,” says Hough.
The most common issues in RO vegetation include:
• Fouling: happens when contaminants accumulate on the membrane surface, effectively plugging the membrane. There are many contaminants in municipal feed water which are harmless for human consumption, but giant sufficient to rapidly foul (or plug) an RO system.
• Scaling: when particles are deposited on a membrane, causing it to plug. As certain dissolved compounds turn out to be extra concentrated, scaling can happen if these compounds exceed their solubility limits and precipitate on the membrane surface as scale. Scaling calculations are often solely primarily based on the silicate focus in the feed water.
• Biofouling: reduces actual membrane performance via microbial technology in a biofilm that varieties on the membrane floor.
• Chemical harm: on a RO membrane, this means a better permeate move and poorer quality permeate water. Dosing of oxidant brokers, such as chlorine or hypochlorite, can cut back efficiency and in the end result within the failure of the RO membranes. Use of aggressive cleaners also can cause chemical injury.
• Mechanical harm: can occur when a system is pressurised too quickly, damaging the RO membrane parts. One of the most clears signs of damages on a RO membrane is the shortage of salt rejection capabilities. There can be very often a rise of permeate circulate rate.
Pre-treatment may help to keep away from these issues, and Hough says there are numerous options available.
Pre-treatment Options
“When selecting a pre-filter, customers should all the time look for a verified effectivity ranking subsequent to the micron measurement on the filter’s technical knowledge sheet,” says Hough.
• Multi Media Filtration: A multi-media filter is used to assist prevent fouling of a RO system. This type of sediment filtration is good for a pre-treatment process to any reverse osmosis system helping to make sure lengthy life of the RO membrane parts. A well operated multimedia filter can take away particulates down to 20 microns. A multimedia filter that uses a coagulant addition can remove particulates down to 10 microns.
• Micro Filtration: The filters used in microfiltration have a pore size of approximately zero.1 micron. Bacteria and suspended solids are the one factor that can be removed through microfiltration.
• Antiscalants and scale inhibitors: There are many chemical compounds that can be utilized as antiscalants and dispersants to improve the operation of RO. Antiscalants are a family of chemical compounds designed to inhibit the formation and precipitation of crystallized mineral salts that type scale.
• Softening by ion change: A water softener is a filtration system that removes hardness-causing calcium and magnesium minerals from water by way of a course of referred to as ion exchange. Standard water softeners are cation exchange devices. Cation change involves the substitute of the hardness ions with non-hardness ions.
• Granular Activated Carbon (GAC) Filtration: Activated carbon removes residual chlorine and chloramines by a chemical reaction that involves a transfer of electrons from the floor of the GAC to the residual chlorine or chloramines. The chlorine or chloramines find yourself as a chloride ion that is not an oxidizer.
“It’s also necessary to scrub the RO membrane regularly,” says Hough. “This entails low and high pH cleaners to remove contaminants from the membrane. We address scaling with low pH cleaners and organics, whereas colloidal and biofouling are treated with a high pH cleaner.”
Allmech offers the complete vary of pre-treatment and RO membrane maintenance solutions for RO vegetation, together with filtration methods, softeners, antiscalants, chemical substances and different consumables.
“At ความหมายของเครื่องวัดความดัน , we’re wanting ahead to growing this a part of our enterprise in 2022 and past, leveraging our expertise in all things associated to water therapy. We even have a boiler division and we inventory a complete range of Runxin valves, so we’re properly positioned to be a one-stop store for anyone needing a water therapy or boiler specialist, and we’re anticipating a busy year ahead,” Hough says.

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