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 8

Morphologic analysis of heavy metals in sediment.

Number	Heavy metals	Proportion of various forms %				Morphological distribution order
		A (weak acid-extractable form)	B; (reducible form)	C; (oxidizable form)	D; (residual form)
N19-2	Cr(VI)					D > C > B > A
	As					D > B > A > C
	Cd					D > A > B > C
	Pb					D > B > A > C
S20-1	Cr(VI)					D > C > B > A
	As					D > B > A > C
	Cd					D > A > B > C
	Pb					D > B > A > C
N21-1	Cr(VI)					D > C > B > A
	As					D > A > B > C
	Cd					D > A > B > C
	Pb					D > B > A > C
N21-2	Cr(VI)					D > C > B > A
	As					D > B > C > A
	Cd					D > A > C > B
	Pb					D > B > C > A

Note: the data are the mean standard deviation.