Survey and Risk Assessment of Contaminants in Soil from a Nitrogenous Fertilizer Plant Located in North China

Table 6

Sample analysis results.

Variable	Pollutant concentration (mg/kg)			Screening value (mg/kg)	Control value (mg/kg)	Detection rate (%)	Overstandard rate (%)	Maximum ratio
	Max	Mean	Min
Cu	6590.00	107.82	5.94	2000	8000	100	1.81	3.30
NH3-N	3951.00	445.19	0.14	1549	—	100	10.16	2.55
TPH	16263.00	129.19	<3.00	826	5000	30.70	1.81	19.69
Fluoride	1150	424.94	127.00	1050	—	100	0.23	1.10

NH₃-N, ammonia-nitrogen; TPH, total petroleum hydrocarbons.