Comparative Analysis of Desalination Effectiveness: Reverse Osmosis vs. Electrodialysis for Brackish Water


Desalination of brackish water is a crucial endeavor for ensuring a sustainable and safe water supply. This article provides a comprehensive analysis of the desalination effectiveness of two prominent methods: reverse osmosis and electrodialysis. Understanding their respective capabilities and outcomes is essential for making informed decisions in water treatment.

Desalination Effectiveness of Reverse Osmosis:

1. High Ion Removal Rates:

The reverse osmosis system demonstrates superior removal rates for divalent and multivalent cations and anions compared to monovalent ions. The table below illustrates the impressive removal percentages for various ions:

Removal Rate (%)100.098.899.598.596.5
Removal Rate (%)98.496.496.094.7

2. Effective Removal of Inorganic Salts:

The reverse osmosis system achieves removal rates of 96% to 100% for soluble total solids, total hardness, iron, manganese, calcium, magnesium, potassium, sodium, sulfate, chloride, and silica in challenging SO4·Cl2Na·Mg and SO4·Cl2Na brackish waters. Key indicators such as total hardness, chloride, sulfate, and dissolved solids consistently exceed 98%, surpassing both national and international water quality standards.

3. Toxic Element Removal:

The reverse osmosis system effectively removes harmful elements such as fluoride (96%) and hexavalent chromium (92.5%), ensuring the production of safe and potable water.

4. Pollutant and Toxicological Indicator Removal:

While the removal rates for pollutants and toxicological indicators such as chemical oxygen demand, NH3-N, NO2-N, NO3-N, and arsenic range from 40% to 83%, these percentages are satisfactory given the lower initial concentrations in the source water. The system easily meets the standards for drinking water quality.

5. Microbial Content Removal:

Brackish water exhibits variations in microbial content. The reverse osmosis system significantly improves the removal rates for total bacteria counts, rising from 44.6% to an impressive 93.2%.

Comparative Analysis with Electrodialysis:

The comparative effectiveness of reverse osmosis and electrodialysis reveals that reverse osmosis consistently outperforms electrodialysis in desalination rates and water purity. The energy consumption and water usage in reverse osmosis are lower than those in electrodialysis, making it a more sustainable and efficient option.


Adopting reverse osmosis for desalination of brackish water has proven to be a highly effective and adaptable solution. The system’s desalination rates consistently exceed 96%, ensuring water quality compliance with national standards. The integrated nature of reverse osmosis systems, along with their compact structure, minimal footprint, and stable performance, positions them as a rational and effective choice for desalinating brackish water.

This analysis highlights the significance of choosing the right desalination method and underscores the remarkable capabilities of reverse osmosis in addressing the challenges posed by brackish water sources.

Xi’an CHIWATEC Water Treatment Technology is a high-tech enterprise specialized in various water processing devices. Aside from these individual products, which cover a number of types and series, we can also help with related comprehensive engineering projects. Thanks to our hard work and dedication upon our founding, we are now one of the fastest-developing water treatment equipment manufacturers in Western China.

Further reading

brine water desalination system

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