Table 1. Concentrations of dissolved heavy metals (μg L⁻¹), pH, electric conductivity (μS cm⁻¹), dissolved oxygen (mg L⁻¹), and temperature (°C) in the Zhujiang River, China.

	Low flow season						High flow season						Drinking water guidelines			Source area of Yangtze Rivere
	Min	Max	Mean	SD	Median	K–S testa	Min	Max	Mean	SD	Median	K–S testa	Chinab	WHOc	US EPAd
V	1.51	3.00	2.11	0.32	2.13	0.758	1.96	3.53	2.66	0.36	2.59	0.469				0.23
Cr	2.51	12.00	6.78	1.79	6.85	0.864	1.82	14.96	7.45	2.84	7.52	0.709	50	50	100	0.26
Mn	0.15	267.33	8.47	39.99	0.45	0.000	0.11	134.49	5.84	17.95	0.40	0.000	100	400		2.53
Co	0.03	1.57	0.15	0.18	0.11	0.000	0.04	0.51	0.12	0.08	0.11	0.001	1,000			0.24
Ni	0.47	37.35	4.10	6.33	2.39	0.000	0.47	49.03	4.43	7.50	2.08	0.000	20	70		0.18
Cu	0.33	115.73	3.93	13.83	0.90	0.000	0.24	136.80	8.24	23.34	0.77	0.000	1,000	2,000	1,300	0.63
Mo	0.11	95.75	1.89	10.58	0.63	0.000	0.13	0.96	0.49	0.21	0.44	0.134	70			0.72
Cd	0.02	2.09	0.09	0.23	0.04	0.000	0.02	1.36	0.06	0.15	0.03	0.000	5	3	5	0.02
Ba	7.99	46.79	16.59	7.12	14.72	0.000	4.00	48.40	14.22	7.59	12.50	0.001	700	700	2,000
Pb	0.03	0.60	0.07	0.07	0.06	0.000	0.02	0.45	0.06	0.06	0.04	0.000	10	10	15	0.76
pH	7.0	8.8	7.9	0.4	7.9	0.546	6.4	8.4	7.7	0.4	7.7	0.659	6.5–8.5
EC	76.0	602.0	354.6	123.3	353.0	0.606	90.0	533.0	307.7	114.2	319.0	0.627
DO	6.1	11.8	8.7	1.0	8.8	0.976	4.9	12.4	7.5	1.3	7.3	0.316
T	10.2	26.6	16.4	2.7	16.8	0.096	18.0	36.0	26.5	4.2	27.3	0.425

Notes:

^aKolmogorov–Smirnov test.

^bChinese drinking water standards (GB 5749-2006).

^cWHO (2006) drinking water guidelines.

^dUS EPA (2003) drinking water standards.

^eZhang & Zhou (1992).