Removal of Cu, Zn, Pb, and Cr from Yangtze Estuary Using the Phragmites australis Artificial Floating Wetlands

Table 4

Pearson correlation coefficients between metal concentrations in the aboveground and underground tissues and water factors.

Tissues	Season	Metals	Water factors
			DO	SAL	TDS	SPC	ORP	PH
Aboveground	Spring	Cu	NS	NS	NS	NS	NS	NS	NS
		Zn	NS	NS	0.701	0.699	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	NS	NS	NS	NS	NS	NS	NS
	Summer	Cu	NS	−0.750	−0.675	−0.672	NS	NS	NS
		Zn	NS	−0.767	−0.680	−0.679	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	NS	NS	NS	NS	NS	NS	NS
	Autumn	Cu	NS	−0.778	NS	NS	NS	NS	NS
		Zn	NS	−0.787	NS	NS	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	−0.831	NS	0.835	0.836	0.744	−0.720	NS
	Winter	Cu	NS	−0.751	NS	NS	NS	NS	NS
		Zn	NS	−0.442	NS	NS	NS	NS	NS
		Pb	NS	−0.684	NS	NS	NS	NS	NS
		Cr	NS	0.668	NS	NS	NS	NS	NS
Underground	Spring	Cu	NS	NS	NS	NS	NS	NS	NS
		Zn	NS	NS	NS	NS	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	NS	NS	NS	NS	NS	NS	NS
	Summer	Cu	NS	NS	NS	NS	NS	NS	NS
		Zn	NS	NS	NS	NS	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	NS	NS	NS	NS	NS	NS	NS
	Autumn	Cu	NS	NS	NS	NS	NS	NS	NS
		Zn	NS	NS	NS	NS	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	0.534	NS	NS	NS	NS	NS	NS
	Winter	Cu	NS	NS	NS	NS	NS	NS	NS
		Zn	NS	NS	NS	NS	NS	NS	NS
		Pb	NS	NS	NS	NS	NS	NS	NS
		Cr	NS	NS	NS	NS	NS	NS	NS

NS: no significant correlation. Correlation is significant at the 0.05 level. Correlation is significant at the 0.01 level.