Risk Assessment and Prediction of Heavy Metal Pollution in Groundwater and River Sediment: A Case Study of a Typical Agricultural Irrigation Area in Northeast China

Table 4

Contents of heavy metals in sediment of Hun River (ppm).

Number	Thickness (cm)	Cr(VI)	As	Cd	Pb
N10-1	0–26
N10-2	26–40
N11-1	0–25
N11-2	25–45
N11-3	45–50
N12-1	0–50
N13-1-1	0–5
N13-1-2	5–30
N13-2-1	0–15
N13-2-2	15–40
N13-2-3	40–64
N14-1	0–23
N14-2	23–30
N14-3	30–40
N14-4	40–50
N16-1	0–26
N16-2	26–50
N17	0–32
N18	0–28
N19-1	0–5
N19-2	5–25
N20-1	0–29
N21-1	0–5
N21-2	5–26
N24-1	Surface layer
S14-1	Surface layer
S16-1	Surface layer
S19-1	0–44
S19-2	0–44
S20-1	0–13
S20-2	13–22
Background value		60	15	0.5	35

Note: the data are the mean ± standard deviation.