Effects of Environmental Factors on Nutrients Release at Sediment-Water Interface and Assessment of Trophic Status for a Typical Shallow Lake, Northwest China

Table 2

Physical and chemical characteristics of the water and sediments.

Items	Range	Mean	SD
Water Characteristics
pH	8.18–8.84	8.45	0.38
Temperature (°C) (September)	21.5–24.1	23.1	0.84
Dissolved oxygen (mg/L)	2.81–4.83	4.01	0.58
Chl-a (mg/L)	2.60–3.48	2.91	0.72
Total N (mg/L)	2.52–2.87	2.72	0.11
Total P (mg/L)	0.06–0.80	0.13	0.19
Salinity (g/kg)	0.23–0.44	0.33	0.16
Secchi (m)	0.35–1.10	0.81	0.32
CODMn (mg/L)	17.12–20.73	18.61	1.12
Electric conductivity (ms/cm)	8.19–9.78	9.14	0.53
Sediment characteristics
Water content (%)	45.4–71.3	63.6	11.7
Clay (%)	3.72–9.53	6.58	1.39
Silt (%)	62.6–86.1	76.1	9.38
Sand (%)	8.04–36.19	25.3	7.49
Organic carbon (g/kg)	6.84–23.5	14.9	8.61