DTRO vs Spiral Wound RO: Performance Comparison in Tough Wastewater

Two technologies that are often used to treat difficult wastewater are Disc Tube Reverse Osmosis (DTRO) and Spiral Wound Reverse Osmosis (SWRO). Both systems use reverse osmosis, but the DTRO module has some unique benefits in tough situations. DTRO is great at dealing with wastewaters that have a lot of particles and fouling. It gets rid of more contaminants while keeping the membrane from getting too dirty. Its unique disc-stack design lets it work at higher pressures and makes it easier to clean. This makes it perfect for treating landfill leachate and industrial effluents with high chemical oxygen demand (COD). SWRO systems, on the other hand, are more often utilized to clean water in less demanding situations. This article will go into detail about the main distinctions between these technologies so you can choose the one that best meets your challenging wastewater treatment demands.

Spiral Wound vs. DTRO: Design and Operation Structure of the RO DTRO Module

The DTRO module has a special disc-stack setup. Inside a cylindrical pressure vessel, several membrane discs are stacked on top of each other and separated by spacers. This design makes small flow channels between the discs, which makes for a lot of turbulence and little chance of fouling. The feed water goes into the module from the center and flows out via the membrane discs in a radial pattern. The permeate is collected at the edges, while the concentrate leaves at the bottom.

Spiral Wound RO Style

Flat sheet membranes are wrapped around a central permeate collection tube in spiral wound RO modules. Water that is fed into the module flows axially, while permeate spirals inward to the collection tube. This design is small and inexpensive for many uses, although it may be more likely to get dirty in tough wastewater situations.

Different Ways of Working

Compared to regular spiral wound systems, which work at 30 to 60 bar, DTRO systems can work at much higher pressures (up to 120 bar). This lets DTRO deal with higher TDS levels and get better recovery rates in challenging wastewater situations. Also, the disc-stack construction of DTRO makes it easy to clean and replace membranes, which cuts down on downtime and maintenance expenses.

How well it works in tough wastewater situations？

How well does it remove contaminants?

When it comes to wastewater with a lot of particles and contaminants, DTRO modules work better at getting rid of them:

• Salt Rejection: More than 99% of most dissolved ions
• COD Removal: Works well on wastewater with COD levels up to 25,000 mg/L. Heavy Metal Removal: >95% rejection of metals like lithium, nickel, and cobalt.
• Removal of Organic Compounds: Very good at getting rid of complicated organic molecules that are typically encountered in industrial waste.

Spiral wound RO systems work well for many water treatment jobs, but they may not always work well in these tough conditions since they are more likely to get dirty and have limits on how much pressure they can handle.

Resistance to fouling

There are various ways that the DTRO module design naturally resists fouling:

• High turbulence in restricted flow channels stops particles from settling down.
• Changes in the direction of flow happen often, which makes it hard for the fouling layer to form.
• Anti-fouling membrane coatings improve performance over time.
• Higher operating pressures assist fight osmotic pressure in waters with a lot of TDS.

Even while spiral wrapped systems have certain anti-fouling properties, they tend to work worse in applications where fouling is common. This could mean that you have to clean more often and that the membranes might not last as long.

Rates of Recovery

In difficult wastewater applications, DTRO systems may recover 50–70% of the water, which is much greater than what standard spiral wound systems can do in the same conditions. This higher recovery means that there is less waste and possibly lower disposal costs for concentrated streams.

Uses and Costs to Think About

Best Uses for DTRO

DTRO technology works really well in a number of tough situations for treating wastewater:

• Landfill Leachate: Effectively removes high levels of COD, ammonia, and dissolved solids
• Waste from factories: Dealing with high-TDS wastewater from the chemical, petrochemical, and mining industries
• Zero Liquid Discharge (ZLD) Systems: Concentration of wastewater streams for additional treatment or evaporation.
• Produced Water Treatment: Dealing with water from oil and gas activities that has a lot of salt and oil in it

Using Spiral Wound RO

The primary choice for spiral wound RO is still:

• Making drinking water for cities
• Desalination of seawater (with the right pretreatment)
• Process water for the food and drink industry
• Making water that is safe for use in medicine
• Comparing Costs

Even though the initial prices of DTRO systems may be higher than those of similar spiral wrapped systems, there are a number of reasons why they can save money in the long run when used in severe wastewater situations:

• Better fouling resistance means that membranes need to be replaced less often.
• Less use of chemicals for cleaning and upkeep
• Energy savings from better recovery rates and more effective use
• Less time spent on cleaning and maintenance tasks

When looking at the total cost of ownership for difficult wastewater treatment projects, DTRO often turns out to be the more cost-effective option throughout the life of the system.

Conclusion

DTRO technology has a lot of benefits over standard spiral wound RO systems when it comes to treating difficult wastewater. The DTRO module's unique design makes it work better in situations with a lot of fouling and high TDS, making it perfect for tough jobs like treating landfill leachate and processing industrial effluent. Spiral wound RO is still a good choice for many water filtration needs because it is cheap, but DTRO works better when regular systems have trouble.

DTRO systems can save money over time and work better in tough wastewater treatment situations by removing more contaminants, being less likely to get dirty, and using less energy. DTRO technology is a significant instrument in the water treatment toolset since enterprises are facing stricter environmental rules and the need for better water management.

Are you having trouble with challenging wastewater treatment in your field? Guangdong Morui Environmental Technology Co., Ltd. is an expert in cutting-edge water treatment systems, such as DTRO systems. Our knowledgeable staff can help you figure out if DTRO is the best option for your needs, whether you work in manufacturing, food and drink production, medicines, or municipal water treatment.

We make our own membranes and have a network of factories that process equipment. This lets us offer personalized, high-quality solutions with full support. Guangdong Morui is your trusted partner for excellent water treatment, from the first consultation to the installation, commissioning, and continuing maintenance.

FAQs

Q1: How long does a DTRO membrane usually last compared to a spiral wound RO membrane in difficult wastewater situations?

A: In tough wastewater conditions, DTRO membranes usually survive two to three times longer than spiral wrapped membranes. In these cases, spiral wound membranes may need to be replaced every 1 to 2 years, but DTRO membranes can often keep working for 3 to 5 years or longer. The DTRO module lasts longer since it is better at resisting fouling and can handle higher working pressures.

Q2: How much energy does DTRO use compared to spiral wound RO for treating wastewater with high TDS?

A: When processing high-TDS wastewaters, DTRO systems usually use 20–30% less energy than spiral wound RO systems. The main reason for this increase in efficiency is that the DTRO module can work at greater recovery rates, which means that less water needs to be processed. The disc-stack design also helps with mass transfer, which makes it easier to reject salt at lower applied pressures.

Q3: Is it possible to add DTRO modules to spiral wound RO systems that are already in use?

A: Many existing spiral wound RO systems can be modified to use DTRO technology, but it's not as easy as just plugging it in and playing. This refit usually means changing the membrane vessels, changing the pipes, and maybe even upgrading the high-pressure pumps to handle the increased working pressures of the DTRO module. You need to do a full engineering study to find out if this kind of improvement is possible and cost-effective for your system.

High-Performance DTRO Modules for Tough Wastewater Treatment | Morui

Discover Guangdong Morui's cutting-edge DTRO modules created exclusively for difficult wastewater applications. Our innovative disc tube reverse osmosis system offers improved performance in high-fouling and high-TDS conditions, giving exceptional pollutant removal and energy efficiency. Whether you're dealing with landfill leachate, industrial effluents, or looking for zero liquid discharge, our DTRO solutions can help you accomplish your water treatment goals.

Contact our professional team today to learn how Morui's DTRO modules may revolutionize your challenging wastewater treatment operations. Email us at benson@guangdongmorui.com for a personalized consultation and take the first step towards more effective, economical wastewater management.

References

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2. Chen, X., & Wang, Y. (2022). Advancements in Disc Tube Reverse Osmosis for High-TDS Wastewater Applications. Desalination, 518, 115257.

3. López-Rodríguez, J., et al. (2021). Energy Efficiency in Membrane-Based Wastewater Treatment: A Review of DTRO and SWRO Systems. Water Research, 189, 116584.

4. Patel, S. K., & Jiang, L. (2023). Fouling Mitigation Strategies in Advanced Reverse Osmosis Technologies for Tough Wastewater Treatment. Separation and Purification Technology, 302, 121952.

5. Zhang, M., et al. (2022). Techno-Economic Assessment of DTRO vs. Conventional RO in Landfill Leachate Treatment. Environmental Technology & Innovation, 25, 102277.

6. Thompson, J., & Lee, K. P. (2023). Membrane Technology Advancements for Zero Liquid Discharge Systems: Focus on DTRO Applications. Journal of Water Process Engineering, 51, 103354.