RSB TDS Figure for Potable Water/Drinking Water

What is the value of TDS for drinking water/potable water produced from seawater desalination plants, requested by the Regulation and Supervision Bureau in Emirate of Abu Dhabi?

Is it 300 ppm or 200 ppm or higher?

What is the break up of constituents, especially that of Chloride Ion, Calcium?

Taxonomy

• Standards & Quality
• Treatment Methods
• Quality
• Sea Water Desalinisation
• Water Quality Management
• Water Supply Regulation
• Water Regulation
• Total Dissolved Solids (TDS)

7 Answers

1. For drinking water, from a consumer acceptance point of view, maximum TDS in the range of 500 mg/L. Consider the need for corrosion control.

2. The majority of the TDS in the raw water will be chloride, which accounts for approximately 55% of the solids and it is this, which will dictate the level of TDS present in the water after it has been RO treated.  The remainder will be the sum of calcium, magnesium and sodium along with sulphate.  They used to have a limit of between 100-1000 ppm TDS although this may have altered.  The starting level is 44,000 ppm TDS of which chloride accounts for 24,000 ppm as chloride and 14,000 as sodium. For RO to reduce the TDS to 100 ppm it would reduce the chloride to 55 ppm while the sodium would be 32 ppm.  The level of 1000 would give 550 ppm of chloride and 320 ppm as sodium and the water would start to taste slightly salty and the water becomes more corrosive.  So it would be better to keep it

3. The TDS coming out of RO depends on what type of membrane is being used.The constituents will depend on quality of feed but potable water will be loosing its taste if TDS is more than 170.Howsoever minimum level must be 50ppm.Ca level near 70 ppm & Mg level near 30 ppm are considered good for human consumption.

4. In Thailand,  we try to control drinking water products should be contains TDS higher than 50 ppm but for my opinion I  measure rain water and TDS contains is around 500-600ppm Naturally.

5. Mesure the content of plant and insect content as we i DK has discovered that in the water

6. RO systems and thermal systems can easily achieve100 to 500 mg/L in product water. Depending upon factors like membrane type and operating conditions. Gulf water can be above 50,000 TDS so that makes it a bit more difficult. The WHO does not have a guideline for potable water but it suggests up to 600 mg/L as desirable for consumers.

   Joseph Cotruvo

7. The requirements of TDS for drinking water doesn't depend on the type of source water i.e., surface/sub-surface/sea water. The point is whether the output required is potable water or anything else.

   2 Comments

   1. I was referring to the output TDS and not the input TDS. It's true the source water TDS determines the treatment process flow.

   2. It definitely depends upon the source water because that determines the technology and the amount of energy required to meet a goal and the cost!!