Introduction

Total Dissolved Solids (TDS) is a parameter that measures the concentration of dissolved ions in water. High levels of TDS in drinking water can affect its taste and quality, leading to several health hazards. Therefore, it is necessary to reduce TDS in water treatment plants to ensure safe drinking water for human consumption. In this article, we will discuss how to reduce TDS in water treatment plants.

Understanding TDS in Water

Before discussing how to reduce TDS in water treatment plants, it is important to understand what TDS is and its sources. TDS is the measurement of the inorganic and organic substances present in water. These substances include minerals, salts, metals, and other dissolved particles. TDS is generated from natural sources such as runoff water from mountains, soil erosion, industrial and agricultural activities, and human activities. High TDS levels in water can cause hardness, scaling, corrosion, and significant harm to human health.

Methods to Reduce TDS in Water Treatment Plants

There are various methods to reduce TDS in water treatment plants. These methods include:

Reverse Osmosis

Reverse Osmosis (RO) is one of the most common and effective methods used to reduce TDS in water treatment plants. In RO, a semi-permeable membrane is used to remove dissolved impurities from the water. The water is passed through a membrane under pressure, which separates impurities from pure water. The pure water is collected on one side of the membrane, and impurities are discharged on the other side. RO can remove up to 90% of TDS from water.

Demineralization

Demineralization is another method used to remove TDS from water treatment plants. In this process, the water is passed through a series of cationic and anionic exchangers to remove ionized particles. Demineralization can remove TDS up to 99% from water. However, demineralization is a costly and complex process.

Electrodialysis

Electrodialysis is a process that uses an electric current to remove ions from the water. In this process, the water is passed through a series of ion exchange membranes. The cations and anions present in water migrate to their respective electrodes, where they are removed. Electrodialysis can remove up to 80-90% of TDS from water.

Nanofiltration

Nanofiltration is a process that uses a semi-permeable membrane to remove TDS from water. The membrane used in nanofiltration has a smaller pore size than ultrafiltration but larger than RO membrane. This process can remove up to 70-80% of TDS from water.

Ion Exchange

Ion exchange is a method used to remove TDS from water in a water treatment plant. In this process, the water is passed through a resin column containing sodium ions that remove cations and replace them with sodium ions. This process can remove up to 90-95% of TDS from water.

Conclusion

In conclusion, TDS is an essential parameter to measure the water quality in a water treatment plant. High TDS levels can affect the water's taste, quality, and health. Therefore, it is vital to reduce TDS in water treatment plants. Various methods, such as reverse osmosis, demineralization, electrodialysis, nanofiltration, and ion exchange, can be used to reduce TDS from water. Water treatment plants should select the appropriate method based on their water quality and treatment requirements.