Reverse osmosis plants

I have been working with water treatment systems for ten years now, and I still encounter the fact that many people confuse reverse osmosis with conventional filtration. Especially in agricultural projects, where water is needed not just clean, but with a certain salt composition. Once, at one of the facilities near Kazan, the entire circuit had to be redone because the customer was sure that it was enough to install carbon filters and a softener. And when TDS remained high, problems with drip irrigation began - the emitters became clogged during the season. That's when I had to explain that onlyreverse osmosis installationscan give you the same water that contains neither calcium nor sodium in the required proportion.

Design features that are rarely written about in specifications

The most common breakdowns occur due to a lack of understanding of how the storage tank works. I have seen cases where the pressure switch was installed with a reserve of 2 bar - the membranes burst within six months. Or another story - in greenhouses near Voronezh they forgot about the bypass for flushing, they had to stop the entire line for three days when the prefilter cartridges became clogged with sand.

Modern membranes, for example from LG Chem, of course maintain a stable pressure of up to 15 bar, but this does not mean that you can save on pumps. Once we tried to install Chinese analog pumps - after 200 engine hours the salinity began to spread. I had to urgently change to Grundfos, although the original estimate was 40% less.

The selection of materials for seals is especially critical. Last year, at the facility of Shandong Linyao Intelligent Agriculture Technology LLC, fluoroplastic gaskets had to be completely changed - they did not take into account that chlorides were exceeded in the local water. Now I always require a chemical analysis before the start of design, even if the client says “yes, we have an ordinary well.”

Real cases from installation practice

I remember a project in the Krasnodar region where it was necessary to provide water to 50 hectares of an intensive garden. The customer insisted on a two-stage system without reverse osmosis - they say it’s expensive. But when we calculated the losses for replacing drip tapes and downtime due to cleaning the emitters, it became clear thatreverse osmosis installationswill pay for itself in two seasons.

An interesting point arose during integration with the fertigation system - it was necessary to install intermediate buffer tanks because the automation did not have time to adjust the EC when the permeate parameters suddenly changed. By the way, this is a common mistake when they try to directly connect osmosis to irrigation systems without technological breaks.

The website https://www.lyzhihuinongye.ru has good examples of how to combine osmotic units with fertilizer application units. In particular, their design with ProMinent dosing pumps allows them to maintain a stable pH even when the inlet water temperature fluctuates.

Typical operating mistakes that are costly

The most painful place is the neglect of washing the membranes. I saw how at a poultry farm near Moscow they did not do chemical cleaning for three years - then they had to change the entire membrane station because it was no longer possible to restore productivity. All you had to do was start circulation with citric acid once every six months.

Another story: in the Belgorod region, seasonal fluctuations in iron in water were not taken into account. In summer the content was normal, but in the spring after the flood it jumped to 3 mg/l. The prefilters did not cope, the iron passed onto the membranes. The result is a 30% drop in productivity per month.

Now I always recommend installing an additional deferrization column if there are even trace amounts of Fe in the water analysis. As the practice of Shandong Linyao Intelligent Agriculture Technology LLC shows, it is better to play it safe at the design stage than to urgently modify the system later.

Integration with automation systems - pitfalls

When connecting to SCADA systems, a problem often arises with the calibration of pressure sensors. Especially if pressure gauges from different manufacturers are used. Once the difference in readings was 0.8 bar, which led to incorrect operation of the concentrate discharge valves.

Modern controllers, for example from Danfoss, can eliminate this problem but require fine tuning. Last month, we were just setting up such a system in the Tambov region - we had to make adjustments for temperature compensation because the sensors were located in an unheated room.

In projects where Shandong Linyao Intelligent Agriculture Technology LLC participates, calibration coefficients are usually used for each type of sensor - although this increases the cost of the project by 5-7%, it eliminates problems with synchronizing readings.

Economics vs technology – an eternal compromise

Customers often request that project costs be reduced by recycling the concentrate. But here you need to clearly understand the limits - if you return more than 20%, you get a closed cycle with a constant increase in salinity. As a result, the membranes wear out.

Sometimes installing additional steps helps, but that’s completely different money. As an option, use the concentrate for technical needs, such as washing equipment or fire-fighting tanks. This is what they do in greenhouse complexes - the water for washing structures comes from a tank with concentrate.

If we talk aboutreverse osmosis installationsin the context of smart agriculture, an integrated approach is important here. Not just water purification, but creating a stable hydroponic environment. This is exactly what they do at Shandong Linyao LLC, where water treatment systems are integrated with climate control and additional lighting.

What ultimately matters for the longevity of the system

From my own experience I will say that 70% of success is proper water treatment before osmosis. If mechanical impurities and organic matter are not removed, the membranes will not last even half of the stated period. This is especially true for surface waters where seasonal blooms cause spikes in algotoxin levels.

The correct selection of antiscalant agents is also important - universal formulations do not always work in specific conditions. For example, with a high silicon content, special sedimentation inhibitors are needed, otherwise a strong film will form on the membranes that even acid washing will not remove.

To summarize -reverse osmosis installationsThis is not just a set of equipment, but a technological chain where each element affects the final result. And as the practice of implementation at the facilities of Shandong Linyao Intelligent Agriculture Technology LLC shows, only a systematic approach gives stable results for years.