In a world where access to fresh water is becoming an increasingly critical challenge, desalination water treatment plants (WTP) are another solution to providing accessible water to governments, businesses, and individuals worldwide. In this blog post, we’ll delve into the fascinating world of desalination, specifically reverse osmosis desalination, exploring its significance, applications, cost drivers, challenges, and the sustainable practices driving and developing this technology.
What is Desalination you ask?
Desalination is the process of taking salty water or seawater and turning it into the freshwater we rely on for drinking, agriculture, industry, and more. This transformation is achieved through various desalination techniques, such as reverse osmosis, distillation, and electrodialysis. It’s a game-changer in regions with scarce freshwater resources.
In places like South Africa, where water shortages are a constant concern, desalination has been highlighted as another viable water treatment solution. Although many of the points below relate to desalination as a whole, we will be speaking with an emphasis on reverse osmosis desalination.
Industry Sectors Benefitting from Desalination
Reverse osmosis desalination is incredibly versatile and caters to an array of industry sectors. Some of the most common applications include:
Municipal water supply
Desalination plays a crucial role in ensuring a reliable and sustainable source of drinking water for cities and communities, particularly during droughts or in areas where traditional sources of freshwater like rivers and lakes are insufficient.
Irrigation is essential for crop cultivation; desalinated water ensures a consistent water supply. It's particularly valuable for high-value crops and greenhouse agriculture where water quality is critical.
Water is essential for various mining processes, including ore processing, dust suppression, and worker consumption. Desalination provides a dependable source of water for mining operations, reducing the need to transport water over long distances.
These industries include petrochemicals, power generation, and food and beverage production. Desalination and other forms of water treatment also contribute to overall water efficiency by recycling and reusing treated water, thus saving on operational costs.
Encompassing hotels, resorts, and recreational facilities, this industry relies heavily on water for various operations and guest services. This often involves extensive water usage for activities such as pools, landscaping, and maintenance issues related to plumbing systems.
The Cost Puzzle
Now, let’s talk money. Although developments in desalination technologies and processes are driving down the cost of this form of water treatment, reverse osmosis desalination plants are still perceived to come with a high price tag, this isn’t always the case and will be quite specific to the individual or business and what value the treated water is to them.
In various industry sectors such as hospitality, mining, and agriculture, water plays a pivotal role in ensuring the efficient and profitable operation of businesses. In these sectors, the absence of a reliable water supply would render these businesses incapable of functioning effectively.
Understanding what drives the costs of this water treatment solution is essential as to why you should make a few considerations about reverse osmosis desalination water treatment.
Durability – “How the WTP is built”.
Ensuring the durability of a reverse osmosis desalination WTP is critical to its long-term performance and cost-effectiveness. Apart from the design being a vital aspect to the durability of the WTP, several other considerations play a crucial role in enhancing the durability of these facilities, below are a few of these key considerations:
Choice of materials: The choice of materials is a critical consideration, particularly in the context of reverse osmosis desalination, where operational pressures range from 30 to 60 bars. Given the corrosive properties of seawater, it is common practice to prioritize the use of materials such as stainless steel and other corrosion-resistant options for crucial components like piping, vessels, and structural elements. In some instances, a combination of materials is employed to optimize the longevity and cost-effectiveness of the Water Treatment Plant (WTP). For instance, Pumps made from duplex steel are chosen, given their high replacement cost, while 316 stainless steel may be used for piping, as its replacement cost is considerably lower than that of a pump.
Coatings and Linings: Protective coatings and linings can be applied to surfaces exposed to seawater to enhance their durability. These coatings act as a barrier between the aggressive elements in seawater and the underlying materials, reducing corrosion and scaling.
Environmental Factors: Understanding the local environmental conditions, including temperature, humidity, and wind exposure, is important for designing a plant that can withstand the specific challenges of the area.
By addressing these considerations, reverse osmosis desalination WTP can be designed and operated to withstand the challenges posed by seawater and other aggressive elements, ensuring their long-term durability and reliability. This is why you are always welcome to consult with us on any questions you may have.
Seawater Quality – “What goes inside”.
Seawater is tricky. It packs a punch with corrosive minerals, organic and microbial content that can affect some of the main components of the desalination plant such as the pumps, membranes, and vessels. These minerals and organic content can cause several problems:
Ions like chloride and sulphate, can promote corrosion of metallic components in the desalination system. This corrosion can weaken pipes, pumps, valves, and other equipment, leading to leaks, structural damage, and ultimately premature failure of the WTP.
Minerals like calcium and magnesium, when present in high concentrations, can lead to scaling. Scaling occurs when these minerals precipitate out of the water and form solid deposits on the surfaces of equipment and pipes.
The presence of organic and microbial content within seawater can promote fouling, which is the accumulation of organic and inorganic materials on membranes or other filtration components.
To address these challenges, reverse osmosis desalination plants employ various strategies, including pre-treatment processes to remove or reduce aggressive minerals and organic content as well as implement the use of anti-scaling and anti-fouling chemicals within the water treatment process. Water Purification Solutions offers anti-scaling and anti-fouling chemicals, simply give us a call for more information.
Maintenance – “Keeping the engine running”.
For desalination plants to be effective, regular maintenance and timely replacement of consumable components, are essential. Again, we would like to highlight the importance of choosing the right materials for the major components of your WTP such as the pumps and membranes as this will significantly drive down future maintenance costs of the WTP.
Delving a little deeper into maintenance of the reverse osmosis desalination plant, aspects include regular inspections, cleaning protocols, performance monitoring or for a more efficient option remote access and monitoring, ensuring the plant runs like a well-oiled machine, minimizing downtime and extending its life.
When it comes to the replacement of consumable components we generally speak about Filter Changes, Seals and Gaskets, Pressure Vessel Maintenance, and Sensor Calibration.
By adhering to a well-planned maintenance schedule and promptly replacing worn-out or fouled components, a reverse osmosis desalination WTP can run smoothly, efficiently, and cost-effectively, providing a reliable source of clean water for years to come. It’s the key to keeping the engine of your desalination plant running strong and ensuring the longevity of the system.
To sum up our cost puzzle, there are multiple factors to take into account, by understanding and managing the above will be key to keeping the overall costs in check.
Keeping sustainability in mind.
Historically, reverse osmosis desalination consumed a large amount of energy in order to operate the plant, but at Water Purification Solutions we don’t ignore sustainability, with ongoing technological advancements, power consumption can be reduced. Modern water treatment plants incorporate energy recovery solutions, like pressure exchangers and turbines, to capture and reuse the energy from brine discharge, this can halve, the power consumption of your water treatment plant. It’s like recycling energy and making the process eco-friendlier and more cost-effective.
Another way of reducing power consumption is by incorporating renewable energy resources such a solar power, this is particularly applicable in South Africa where we are exposed to a large amount of sunlight throughout the year.
We’re not here to hide any of the concerns listed by major players in the sustainability sector, you can read up on some of the concerns regarding desalination given within this UN Environment Programme article. If you have any questions, we will gladly discuss the concerns with you in order to put your mind at ease.
In a nutshell, reverse osmosis desalination water treatment is just one of the solutions offered by Water Purification Solutions to a world where clean water is accessible to all. By embracing these innovations, we’re not only securing our water resources but also improving the well-being of communities and industries worldwide. With a growing focus on sustainability, the desalination industry is paving the way for a brighter future, where clean water is within reach for everyone. If you want to dive deeper into all that is desalination we recommend you click through to the Science Direct website.
At Water Purification Solutions, we assist individuals and businesses with their water treatment needs and can walk you through the entire process from consultation, design, manufacturing, installation, and maintenance of various water treatment plants including desalination treatment plants.
Simply put, we’re here to provide access to clean water for all.