Final answer:
Chlorination is the least effective method for eliminating Cryptosporidium from drinking water, as the parasite's cyst stage is resistant to chlorine. Methods like reverse osmosis, boiling, and using special filters are effective. However, chlorination is essential for reducing many other pathogens in water.
Step-by-step explanation:
All of the following are appropriate means of eliminating Cryptosporidium from drinking water except:
- reverse osmosis
- boiling the water
- chlorination
- using a special filter
Among the methods listed, chlorination is the least effective at eliminating Cryptosporidium. This protozoan parasite has a cyst stage that can resist the chlorination process typically used in municipal water treatments. On the other hand, reverse osmosis, boiling the water, and using special filters are effective at removing or destroying Cryptosporidium from drinking water.
Chlorination, while being a common method for disinfecting water, may not completely remove all hardy organisms such as Cryptosporidium. The cyst stage of this parasite can survive cold temperatures and is less susceptible to chlorine treatment. Nonetheless, chlorination does play a significant role in reducing many other pathogenic microbes in drinking water and is a widely used disinfection method.
For comprehensive water treatment and ensuring safety from Cryptosporidium, combined methods including filtration and ultraviolet disinfection are often recommended, in addition to chlorine-based treatments, to ensure that these resistant cysts are effectively removed or inactivated.