Final answer:
The process wastewater goes through in treatment facilities includes primary, secondary, and tertiary treatments to remove solids, decompose organic matter, and filter out contaminants, with disinfection as a crucial final step. Therefore, correct option is d.
Step-by-step explanation:
Wastewater Treatment Process
Wastewater treatment facilities utilize a multi-step process to clean the wastewater before it can be released back into the environment or reused for other purposes. The primary phase involves the removal of solids, where wastewater is stored in a basin, allowing solids to settle and lighter substances to rise, which are then removed.
Secondary treatment is a biological process where aerobic bacteria decompose organic solids. The final step, tertiary treatment, includes additional filtration to remove remaining contaminants and nutrients. Moreover, disinfection methods such as chlorine, ozone, ultraviolet light, or bleach are used to eliminate harmful microorganisms.
Throughout this process, features like bar screens and filtration through sand and rocks are utilized to remove large debris, reduce turbidity, and decrease organic matter content. Advanced treatments might also incorporate chemical processes to further cleanse the water.
The efficiency of the treatment depends on numerous factors including the volume of wastewater, the nature of the contaminants present, and the intended use of the treated water.