Table 2 Significant processes affecting water quality (modified from Bartram et al., 1996)
From: Impact of land uses on water quality in Malaysia: a review
Category | Parameters | Significant process within water body | Water body |
|---|---|---|---|
• Physical | Temperature, electrical conductivity (EC), total suspended solids (TSS), turbidity, total dissolved solids (TDS), etc. | Gas exchange with atmosphere | Mostly rivers and lakes |
Volatilization | Mostly rivers and lakes | ||
Adsorption/desorption | All water bodies | ||
Heating and cooling | Mostly rivers and lakes | ||
Diffusion | Lakes and groundwater | ||
• Chemical | Heavy metals, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), nitrate, etc. | Photodegradation | Lakes and rivers |
Acid-base reactions | All water bodies | ||
Redox reactions | All water bodies | ||
Dissolution of particles | All water bodies | ||
Precipitation of minerals | All water bodies | ||
Ionic exchange | Groundwater | ||
• Biological | Escherichia coli (E. coli), Ephemeroptera, Trichoptera, Coliform bacteria, sea urchin, etc. | Primary production | Surface waters |
Microbial die-off and growth | All water bodies | ||
Decomposition of organic matter | Mostly rivers and lakes | ||
Bioaccumulation | Mostly rivers and lakes | ||
• Hydrological | Water level, depth (m), velocity (m/s), flow direction, discharge, etc. | Dilution | All water bodies |
Evaporation | Surface waters | ||
Percolation and leaching | Groundwater | ||
Suspension and settling | Surface waters |