Reverse Osmosis (RO) is a separation approach that’s appropriate for a variety of purposes, particularly when salt and/or dissolved solids must be faraway from an answer. It is amongst the most typical types of water treatment.
According to Anelia Hough, water treatment marketing consultant at Allmech, leading South African producer of boilers and provider of water therapy components, there are several factors to be considered when deciding on an RO system: the customer’s capacity requirement (i.e. water usage), the daily production capability of the system, and the % rejection for specific contaminants within the source water.
“Beyond this, RO vegetation require proper maintenance and care to ensure they operate optimally and to increase their lifespan,” she says. “Aside from regular upkeep, the best way to protect a RO plant is by pre-treating water, which reduces the pressure on the RO membrane – a costly part. It also helps to avoid issues like scaling and bio-fouling.”
Common Issues with RO Plants
“Factors that can affect a RO system’s performance embody temperature, operating stress, back stress, the equilibrium effect/TDS creep, p.c restoration, and, after all, the RO membrane’s permeate manufacturing and percent rejection rankings,” says Hough.
The commonest issues in RO plants include:
• Fouling: occurs when contaminants accumulate on the membrane floor, effectively plugging the membrane. There are many contaminants in municipal feed water that are harmless for human consumption, however giant sufficient to rapidly foul (or plug) an RO system.
• Scaling: when particles are deposited on a membrane, inflicting it to plug. As certain dissolved compounds turn out to be extra concentrated, scaling can occur if these compounds exceed their solubility limits and precipitate on the membrane surface as scale. Scaling calculations are normally solely primarily based on the silicate concentration within the feed water.
• Biofouling: reduces precise membrane efficiency by way of microbial era in a biofilm that forms on the membrane surface.
• Chemical damage: on a RO membrane, this implies the next permeate circulate and poorer high quality permeate water. Dosing of oxidant brokers, such as chlorine or hypochlorite, can reduce efficiency and finally outcome in the failure of the RO membranes. Use of aggressive cleaners can even trigger chemical harm.
• Mechanical damage: can occur when a system is pressurised too quickly, damaging the RO membrane components. One of probably the most clears indicators of damages on a RO membrane is the lack of salt rejection capabilities. There can additionally be fairly often a rise of permeate flow rate.
Pre-treatment might help to avoid these issues, and Hough says there are various choices available.
Pre-treatment Options
“When choosing a pre-filter, users should all the time search for a verified efficiency rating subsequent to the micron measurement on the filter’s technical information 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 ideal for a pre-treatment course of to any reverse osmosis system serving to to make sure long life of the RO membrane elements. A nicely operated multimedia filter can take away particulates down to 20 microns. A multimedia filter that uses a coagulant addition can remove particulates all the way down to 10 microns.
• Micro Filtration: The filters used in microfiltration have a pore dimension of approximately 0.1 micron. Bacteria and suspended solids are the one factor that can be removed via microfiltration.
• Antiscalants and scale inhibitors: There are many chemical substances that can be used as antiscalants and dispersants to improve the operation of RO. Antiscalants are a household of chemical compounds designed to inhibit the formation and precipitation of crystallized mineral salts that form scale.
• Softening by ion trade: A water softener is a filtration system that removes hardness-causing calcium and magnesium minerals from water by way of a course of called ion exchange. Standard water softeners are cation trade gadgets. Cation exchange entails the alternative 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 includes a switch of electrons from the floor of the GAC to the residual chlorine or chloramines. The chlorine or chloramines end up as a chloride ion that’s not an oxidizer.
“It’s also important to wash the RO membrane often,” says Hough. “This includes low and high pH cleaners to remove contaminants from the membrane. We handle scaling with low pH cleaners and organics, whereas colloidal and biofouling are treated with a high pH cleaner.”
Allmech presents the whole range of pre-treatment and RO membrane upkeep solutions for RO crops, including filtration techniques, softeners, antiscalants, chemical substances and different consumables.
“At Allmech, we’re trying forward to growing this a part of our business in 2022 and beyond, leveraging our experience in all issues related to water therapy. ราคาเกจวัดแรงดัน have a boiler division and we stock a complete range of Runxin valves, so we’re well positioned to be a one-stop store for anyone needing a water therapy or boiler specialist, and we’re anticipating a busy yr forward,” Hough says.

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