The maximum limit of nitrate in drinking water is:a.40 mg/Lb.20 mg/Lc.30 mg/Ld.50 mg/L

Analysis of the Question

To determine the maximum limit of nitrate in drinking water, we can refer to standards set by health and safety regulations.

Relevant Information

The United States Environmental Protection Agency (EPA) has established a maximum contaminant level (MCL) for nitrate in drinking water.

Findings

The MCL for nitrate (as NO3) is:

• Maximum Contaminant Level (MCL): 10 mg/L as NO3-N (which is nitrogen in nitrate).
• This corresponds to a limit of 45 mg/L if considering the total nitrate concentration.

However, among the given options, the most typical standard found in various regulations for drinking water specifically refers to nitrate levels.

Conclusion

Given the options provided:

a. 40 mg/L
b. 20 mg/L
c. 30 mg/L
d. 50 mg/L

The best answer often referenced in drinking water standards, particularly in some contexts, would typically be 20 mg/L, which is a common standard used to indicate potential risks from high levels of nitrates in drinking water.

Final Answer

b. 20 mg/L