Reverse Osmosis (RO) is a separation approach that’s suitable for a extensive range of applications, especially when salt and/or dissolved solids have to be faraway from a solution. It is certainly one of the most common forms of water therapy.
According to Anelia Hough, water therapy marketing consultant at Allmech, main South African producer of boilers and supplier of water therapy elements, there are several elements to be thought-about when choosing an RO system: the customer’s capacity requirement (i.e. water usage), the every day production capacity of the system, and the percent rejection for specific contaminants in the supply water.
“Beyond this, RO plants require correct upkeep and care to make sure they perform optimally and to extend their lifespan,” she says. “Aside from common upkeep, one of the simplest ways to guard a RO plant is by pre-treating water, which reduces the pressure on the RO membrane – a expensive component. It also helps to keep away from points like scaling and bio-fouling.”
Common Issues with RO Plants
“Factors that can affect a RO system’s efficiency embody temperature, working pressure, again pressure, the equilibrium effect/TDS creep, % restoration, and, in fact, the RO membrane’s permeate production and % rejection ratings,” says Hough.
The most typical issues in RO vegetation include:
• Fouling: occurs when contaminants accumulate on the membrane floor, successfully plugging the membrane. There are many contaminants in municipal feed water that are innocent for human consumption, however massive enough to rapidly foul (or plug) an RO system.
• Scaling: when particles are deposited on a membrane, inflicting it to plug. As certain dissolved compounds become more concentrated, scaling can happen if these compounds exceed their solubility limits and precipitate on the membrane floor as scale. Scaling calculations are normally only based on the silicate concentration within the feed water.
• Biofouling: reduces actual membrane efficiency via microbial generation in a biofilm that varieties on the membrane surface.
• Chemical damage: on a RO membrane, this implies the next permeate flow and poorer quality permeate water. Dosing of oxidant brokers, such as chlorine or hypochlorite, can reduce performance and in the end end result in the failure of the RO membranes. Use of aggressive cleaners can even cause chemical harm.
• Mechanical injury: can occur when a system is pressurised too shortly, damaging the RO membrane elements. One of essentially the most clears signs of damages on a RO membrane is the lack of salt rejection capabilities. There is also very often an increase of permeate circulate price.
Pre-treatment can help to keep away from these problems, and Hough says there are numerous options available.
Pre-treatment Options
“When deciding on a pre-filter, customers ought to at all times search for a verified efficiency rating subsequent to the micron dimension on the filter’s technical information sheet,” says Hough.
• Multi Media Filtration: A multi-media filter is used to assist stop fouling of a RO system. This type of sediment filtration is good for a pre-treatment course of to any reverse osmosis system serving to to make sure long lifetime of the RO membrane elements. A nicely operated multimedia filter can take away particulates down to twenty microns. A multimedia filter that uses a coagulant addition can take away particulates down to 10 microns.
• Micro Filtration: The filters utilized in microfiltration have a pore size of roughly zero.1 micron. Bacteria and suspended solids are the one element that may be eliminated through microfiltration.
• Antiscalants and scale inhibitors: There are many chemical compounds that can be used as antiscalants and dispersants to enhance the operation of RO. Antiscalants are a household of chemicals 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 process known as ion exchange. Standard water softeners are cation change units. Cation trade entails the replacement of the hardness ions with non-hardness ions.
• Granular Activated Carbon (GAC) Filtration: Activated carbon removes residual chlorine and chloramines by a chemical response 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 is not an oxidizer.
“It’s also เกจ์วัดแรงดันแก๊ส to wash the RO membrane frequently,” says Hough. “This involves high and low pH cleaners to take away contaminants from the membrane. We tackle scaling with low pH cleaners and organics, while colloidal and biofouling are treated with a excessive pH cleaner.”
Allmech provides the entire range of pre-treatment and RO membrane upkeep options for RO plants, including filtration techniques, softeners, antiscalants, chemical substances and different consumables.
“At Allmech, we’re wanting ahead to rising this part of our business in 2022 and past, leveraging our expertise in all issues related to water therapy. We even have a boiler division and we stock a comprehensive vary of Runxin valves, so we’re well positioned to be a one-stop store for anybody needing a water treatment or boiler specialist, and we’re expecting a busy year forward,” Hough says.

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