Which process is essential for removing nearly all bacteria and viruses from wastewater treatment?

Chlorination is the process that is essential for removing nearly all bacteria and viruses from wastewater treatment. This method involves adding chlorine or chlorine compounds to the wastewater, which acts as a strong disinfectant. Chlorine works effectively to kill harmful microorganisms by denaturing their proteins, damaging their membranes, and disrupting their metabolic processes. As a result, chlorination is widely used in wastewater treatment facilities to ensure that effluents are safe for discharge into the environment or for reuse.

Desalination, while significant in providing potable water from saline sources, is not designed specifically for the removal of bacteria and viruses from wastewater. Its primary goal is to separate salt from water, which does not directly address microbial contamination.

The option of relying on over 4 feet of loamy soil involves natural filtration processes where soil can adsorb and filter out some pathogens. However, this method is less reliable for achieving sanitary levels of disinfection compared to the targeted action of chlorination, which can effectively ensure that harmful microorganisms are eliminated before the water is safely released.

Therefore, chlorination stands out as the most effective and widely used method for the disinfection of wastewater, making it the correct choice for this question.