What is the distinctive feature of iodine when used for water purification?

The distinctive feature of iodine when used for water purification is that it requires different amounts for treatment based on the clarity of the water, and it also has the aspect of being a potent poison. When purifying water with iodine, it's essential to adjust the dosage to account for turbidity – the cloudiness of water – as higher levels of impurities may require more iodine to ensure effective disinfection. Iodine acts as a biocide to eliminate pathogens, but it's crucial to recognize its toxic properties, especially in higher concentrations.

Understanding this aspect of iodine purification highlights the importance of recognizing not only the method of purification but also the potential health risks involved. For clear water, less iodine can be used due to the lower presence of contaminants, while cloudy water necessitates a higher dosage to achieve the same level of purification. This fact underscores why careful attention to iodine usage is vital in ensuring safe drinking water without undue health risks.