Table 1 Physicochemical parameters monitoring in the Ocoa River, Villavicencio—Meta, Colombia

Temperature (°C)

22.24*

23.55*

27.57

28.75*

29.33

29.77

30.53

28.7

pH

4.84

5.19

4.41

5.33

5.23

6.52

5.21

5.95

Dissolve oxygen (mg/L)

6.54

7.34

4.42*

3.56*

5.67

3.29*

6.77

5.96

Alkalinity (mg/L)

17.1

17.1

28.5

19.95

65.55

45.6

22.8

22.8

Hardness (mg/L)

62.7

54.15

65.55

51.3

45.6

59.85

22.8

31.35

Total dissolved solids (g/L)

97.83

89.03

86.08

83.1

133.67

133.12

37.05

31.88

Conductivity (µS/cm)

71.54*

121.02*

105.06*

106.05*

86.21*

148.45*

44.4

52.75

Total ammonia (mg/L)

0.11

0.14

0.83*

1.03*

0.61*

1.8*

0.16

0.15

Water chemical analysis

Cadmium (mg Cd/L)

–

<LD

–

<LD

–

<LD

–

<LD

Mercury (µg Hg/L)

<LD

–

<LD

–

2.37

–

<LD

–

Surfactants (mg SAAM/L)

0.049

<LD

0.053

<LD

0.061

<LD

0.037

<LD

Total hydrocarbons (mg/L)

3.39

4.61

4.53

3.02

<LD

<LD

0.05

<LD