Reverse Osmosis (RO) is a separation method that’s appropriate for a variety of purposes, especially when salt and/or dissolved solids must be removed from an answer. It is one of the most typical forms of water treatment.
According to Anelia Hough, water remedy advisor at Allmech, main South African manufacturer of boilers and provider of water therapy parts, there are several factors to be considered when choosing an RO system: the customer’s capability requirement (i.e. water usage), the daily manufacturing capacity of the system, and the % rejection for specific contaminants within the source water.
“Beyond this, RO vegetation require correct maintenance and care to ensure they operate optimally and to extend their lifespan,” she says. “Aside from regular maintenance, the greatest way to guard a RO plant is by pre-treating water, which reduces the pressure on the RO membrane – a pricey element. 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 include temperature, operating stress, again strain, the equilibrium effect/TDS creep, percent restoration, and, after all, the RO membrane’s permeate production and p.c rejection scores,” says Hough.
The most typical issues in RO plants embody:
• Fouling: occurs when contaminants accumulate on the membrane surface, successfully plugging the membrane. There are many contaminants in municipal feed water which would possibly be harmless for human consumption, but massive enough to shortly foul (or plug) an RO system.
• Scaling: when particles are deposited on a membrane, inflicting it to plug. As sure dissolved compounds turn into extra concentrated, scaling can happen if these compounds exceed their solubility limits and precipitate on the membrane floor as scale. Scaling calculations are usually only primarily based on the silicate concentration within the feed water.
• Biofouling: reduces precise membrane performance by way of microbial era in a biofilm that types on the membrane floor.
• Chemical damage: on a RO membrane, this implies the next permeate move and poorer quality permeate water. Dosing of oxidant agents, such as chlorine or hypochlorite, can cut back efficiency and ultimately outcome in the failure of the RO membranes. Use of aggressive cleaners can also cause chemical damage.
• Mechanical injury: can occur when a system is pressurised too quickly, damaging the RO membrane elements. One of essentially the most clears indicators of damages on a RO membrane is the shortage of salt rejection capabilities. There is also fairly often a rise of permeate move rate.
Pre-treatment may help to keep away from these issues, and Hough says there are various choices obtainable.
Pre- เกจวัดแรงดันถังลม
“When deciding on a pre-filter, customers should always search for a verified efficiency score next to the micron size 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 kind of sediment filtration is right for a pre-treatment process to any reverse osmosis system serving to to make sure long life of the RO membrane elements. A well operated multimedia filter can remove particulates down to twenty microns. A multimedia filter that makes use of a coagulant addition can take away particulates all the method down to 10 microns.
• Micro Filtration: The filters used in microfiltration have a pore dimension of roughly zero.1 micron. Bacteria and suspended solids are the only component that could be eliminated by way of microfiltration.
• Antiscalants and scale inhibitors: There are many chemicals that can be used as antiscalants and dispersants to improve the operation of RO. Antiscalants are a household of chemical substances designed to inhibit the formation and precipitation of crystallized mineral salts that kind scale.
• Softening by ion exchange: 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 trade. Standard water softeners are cation exchange units. Cation trade includes 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 involves 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 no longer an oxidizer.
“It’s also essential to clean the RO membrane frequently,” 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 handled with a excessive pH cleaner.”
Allmech presents the complete vary of pre-treatment and RO membrane upkeep options for RO crops, together with filtration systems, softeners, antiscalants, chemicals and other consumables.
“At Allmech, we’re trying ahead to rising this a half of our enterprise in 2022 and past, leveraging our expertise in all issues related to water remedy. We also have a boiler division and we stock a complete range of Runxin valves, so we’re properly positioned to be a one-stop store for anybody needing a water remedy or boiler specialist, and we’re anticipating a busy 12 months forward,” Hough says.

Scroll to Top