Based on the CPCB guidelines, the range of pH for surface water should be between 6.5 and 8.5. The pH exceeding the range might affect aquatic life, especially the adult fishes, as it may cause damage to the outer part including gills and eyes.
An adequate supply of oxygen in dissolved form is essential for the survival of aquatic life. Hence, DO is considered as an indicator of aquatic health. Concentration of DO also determines the changes made by abiotic or biotic organisms and hence measurement of DO is essential. A rapid fall in the DO levels indicates high organic pollution in the river.
Temperature of the surface water.
Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.
Electrical conductivity (EC) is the amount of ions present in the water. It also indicates the amount of total dissolved solids and both of these are positively correlated i.e. more dissolved solid indicates more electrical conductivity. If the water is used for drinking and other domestic uses high EC can cause the laxative effect, however since drinking water is also a source of major ions in the human body and hence low EC might cause deficiency of ions.
Common sources are agricultural run-off, industrial wastes.
Common sources are agricultural runoff, industrial wastes and sewages
CDOM are a mixture of colored organic compounds essential for the biochemical cycle in the freshwater. These are also called yellow substances. They control the nutrient availability, light penetration and ecosystem productivity. High CDOM inhibits the growth of phytoplankton resulting in decrease in DO.
Chlorophyll-a is the photosynthetic pigment responsible for the green color of the plant leaves and algal biomass. The concentration of Chlorophyll-a directly indicates the amount of photosynthetic community or algae in the water. Existence of chlorophyll-a concentration in phytoplankton and the phytoplankton spectra reflectance is related to the optical activity of the pigment, the composition and appearance of the algal cells.
The protein in the cell wall of microbes has similar fluoresces like amino acids i.e. “Tryptophan” and hence tryptophan like fluorescence is used to measure the microbial health, fecal coliform concentration and BOD of surface water.