Table 1.
Physicochemical parameters monitoring in the Ocoa River, Villavicencio—Meta, Colombia
| Water physicochemical parameters | Site 1 | Site 2 | Site 3 | Reference | ||||
|---|---|---|---|---|---|---|---|---|
| Rainy | Dry | Rainy | Dry | Rainy | Dry | Rainy | Dry | |
| 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 |
DL detectable limit. Site 1 (Nacimiento, before entering the city), site 2 (Centauros, where sewage from the city is dumped), site 3 (Caño Seco, after the city and close to a landfill) and reference site (R)
* For the same season of year, asterisks indicate statistical significant differences (p < 0.05) between the reference site and the monitoring sites. Site 1 (Nacimiento), site 2 (Centauros), site 3 (Caño Seco) and reference site (R)