A city council is debating between two potential water purification systems: reverse osmosis and ion exchange. They would like to choose the option that generates less waste. Which of these statements correctly describes the waste generated by the two technologies?

Question

A. Reverse osmosis produces waste water with high concentrations of pollutants while ion exchange produces resin with bound pollutants.
B. Reverse osmosis produces resin with bound pollutants while ion exchange produces thin membranes with high concentrations of pollutants.
C. Reverse osmosis produces resin with bound pollutants while ion exchange produces waste water with high concentrations of pollutants.
D. Reverse osmosis produces thin membranes with high concentrations of pollutants while ion exchange produces resin with bound pollutants.

Answer 1

The correct statement that describes the waste generated by reverse osmosis and ion exchange is:

A. Reverse osmosis produces waste water with high concentrations of pollutants while ion exchange produces resin with bound pollutants.

Here's the reasoning:

• Reverse osmosis (RO) works by forcing water through a semi-permeable membrane that allows only water molecules to pass while blocking larger molecules and impurities, leading to the generation of waste water that has a higher concentration of pollutants.

• Ion exchange (IE) involves exchanging ions within a resin material; the pollutants are bound to the resin, which can become saturated over time and will also need to be regenerated or disposed of.

Thus, Option A accurately describes the waste by highlighting the nature of the waste generated by both technologies.