Determination of NH₄⁺ in Environmental Water with Interfering Substances Using the Modified Nessler Method

Table 1

Examples of regulation on maximum allowable NH₄⁺ concentrations for different waters.

Type of sample	WHO	Korean legislation	EPA	European legislation
Drinking water	—	0.5 mg L^−1	—	0.5 mg L^−1
Surface water	<0.2 mg L^−1; (up to 0.3 mg L^−1 in anaerobic waters)	—	0.02 mg L^−1	1.5 mg L^−1
Wastewater	—	—	—	20 mg L^−1; (expressed as N total)