Reverse Osmosis (RO) is a separation technique that is appropriate for a variety of applications, especially when salt and/or dissolved solids have to be faraway from a solution. It is considered one of the most typical forms of water therapy.
According to Anelia Hough, water therapy advisor at Allmech, main South African manufacturer of boilers and supplier of water therapy components, there are a quantity of elements to be thought-about when choosing an RO system: the customer’s capability requirement (i.e. water usage), the daily production capability of the system, and the percent rejection for particular contaminants in the source water.
“Beyond this, RO crops require proper upkeep and care to ensure they operate optimally and to extend their lifespan,” she says. “Aside from regular maintenance, the finest way to guard a RO plant is by pre-treating water, which reduces the strain on the RO membrane – a expensive component. It also helps to avoid points like scaling and bio-fouling.”
Common Issues with RO Plants
“Factors that may affect a RO system’s efficiency embrace temperature, operating stress, back stress, the equilibrium effect/TDS creep, % restoration, and, in fact, the RO membrane’s permeate production and p.c rejection rankings,” says Hough.
The most common issues in RO plants embody:
• Fouling: occurs when contaminants accumulate on the membrane floor, effectively plugging the membrane. There are many contaminants in municipal feed water which would possibly be harmless for human consumption, however massive sufficient to shortly foul (or plug) an RO system.
• Scaling: when particles are deposited on a membrane, causing it to plug. As certain dissolved compounds become extra concentrated, scaling can happen if these compounds exceed their solubility limits and precipitate on the membrane surface as scale. Scaling calculations are usually only based mostly on the silicate focus in the feed water.
• Biofouling: reduces precise membrane efficiency through microbial generation in a biofilm that types on the membrane floor.
• Chemical harm: on a RO membrane, this implies a higher permeate move and poorer high quality permeate water. Dosing of oxidant agents, corresponding to chlorine or hypochlorite, can scale back performance and finally end result in the failure of the RO membranes. Use of aggressive cleaners can even cause chemical injury.
• Mechanical harm: can occur when a system is pressurised too rapidly, damaging the RO membrane components. One of the most clears signs of damages on a RO membrane is the shortage of salt rejection capabilities. There can be fairly often an increase of permeate circulate fee.
Pre-treatment might help to avoid these problems, and Hough says there are numerous options out there.
Pre-treatment Options
“When deciding on a pre-filter, users ought to always look for a verified effectivity ranking 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 forestall fouling of a RO system. This sort of sediment filtration is ideal for a pre-treatment course of to any reverse osmosis system helping to ensure long life of the RO membrane components. A properly operated multimedia filter can take away particulates down to twenty microns. เกจวัดแรงลม that makes use of a coagulant addition can remove particulates all the method down to 10 microns.
• Micro Filtration: The filters used in microfiltration have a pore size of roughly zero.1 micron. Bacteria and suspended solids are the one element that can be removed via microfiltration.
• Antiscalants and scale inhibitors: There are many chemical compounds that can be utilized as antiscalants and dispersants to enhance the operation of RO. Antiscalants are a family of chemicals designed to inhibit the formation and precipitation of crystallized mineral salts that kind scale.
• Softening by ion change: A water softener is a filtration system that removes hardness-causing calcium and magnesium minerals from water via a course of called ion change. Standard water softeners are cation trade devices. Cation change involves 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 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 no longer an oxidizer.
“It’s also important to scrub the RO membrane regularly,” says Hough. “This involves 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 presents the complete vary of pre-treatment and RO membrane upkeep options for RO crops, including filtration systems, softeners, antiscalants, chemicals and other consumables.
“At Allmech, we’re looking ahead to rising this part of our business in 2022 and past, leveraging our expertise in all things related to water therapy. We even have a boiler division and we inventory a comprehensive range of Runxin valves, so we’re well positioned to be a one-stop shop for anybody needing a water therapy or boiler specialist, and we’re expecting a busy year ahead,” Hough says.

Scroll to Top