Effects of Sediment Dredging on Nutrient Release and Eutrophication in the Gate-Controlled Estuary of Northern Taihu Lake

Table 1

Nutrient concentrations in the dredged and undredged regions.

Sampling site/season		Dredged region				Undredged region
		Spring	Summer	Autumn	Winter	Spring	Summer	Autumn	Winter
Surface water (mg/L)	TN	1.33 ± 0.49	1.42 ± 0.94	1.15 ± 0.40	1.56 ± 0.64	1.78 ± 0.64	2.29 ± 0.56	1.38 ± 0.06	1.81 ± 0.36
	TP	0.07 ± 0.02	0.10 ± 0.82	0.07 ± 0.04	0.08 ± 0.08	0.11 ± 0.07	0.16 ± 0.03	0.07 ± 0.01	0.06 ± 0.02
	NH4^+-N	0.52 ± 0.24	0.41 ± 0.06	0.24 ± 0.16	0.19 ± 0.09	0.67 ± 0.60	0.85 ± 0.51	0.31 ± 0.11	0.11 ± 0.02
	NO3^−-N	0.22 ± 0.13	0.09 ± 0.004	0.12 ± 0.06	0.33 ± 0.24	0.27 ± 0.06	0.09 ± 0.02	0.20 ± 0.03	0.40 ± 0.10
	TOC	19.79 ± 0.84	13.20 ± 1.24	16.82 ± 1.28	15.70 ± 1.46	15.98 ± 1.85	12.07 ± 0.87	15.23 ± 1.99	14.31 ± 2.49
Surface sediment (g/kg)	TN	2.99 ± 1.52	4.29 ± 0.89	3.19 ± 1.52	4.04 ± 1.11	4.39 ± 1.62	4.27 ± 0.74	5.58 ± 2.30	6.04 ± 2.02
	TP	0.16 ± 0.07	0.15 ± 0.01	0.15 ± 0.01	0.15 ± 0.02	0.16 ± 0.04	0.19 ± 0.04	0.17 ± 0.06	0.19 ± 0.12
	TOC	29.89 ± 15.23	42.94 ± 8.91	31.88 ± 15.17	40.43 ± 11.06	43.94 ± 16.25	42.68 ± 7.38	55.77 ± 22.99	60.44 ± 20.21