Which of the following is an example of the multi-barrier approach to water treatment?

The multi-barrier approach to water treatment involves using several methods and processes to ensure that water is made safe for consumption. This approach is effective because it addresses various potential contaminants at different stages of treatment, reducing the likelihood of any harmful substances remaining in the water.

In this instance, the combination of coagulation, sedimentation, filtration, and disinfection represents a comprehensive method of treating water. Each step plays a distinct role: coagulation helps to clump together and remove suspended particles; sedimentation allows these particles to settle out; filtration removes remaining solids and some pathogens; and disinfection targets microorganisms that could potentially cause illness.

Using a variety of methods ensures that water treatment is robust and more resilient to the presence of unforeseen contaminants, thereby increasing the safety and quality of the water provided to consumers. This holistic strategy contrasts with the other options, which rely solely on one treatment method, failing to adequately tackle the diverse range of potential water quality issues.