WATER QUALITY PARAMETERS TEMPERATURE Temperature of a waterway

WATER QUALITY PARAMETERS

TEMPERATURE � Temperature of a waterway is significant because it affects the amount of dissolved oxygen in the water. � The amount of oxygen that will dissolve in water increases as temperature decreases. � Water at O C will hold up to 14. 6 mg/l of oxygen, while at 30 C it will hold only up to 7. 6 mg/L.

TEMPERATURE � Temperature also affects, � the metabolic rate of aquatic animals, � rates of development, � Rate of reproduction, and � the sensitivity of organisms to toxins, parasites and disease. � Temperature ranges for plants and animals can be affected by manmade structures such as dams and weirs and releases of water from them.

How Water Temperature Increases? � It happens Due to � summer season, � Industry effluents and run off, � Deforestation, � Turbidity in water, � Algae growth.

SALINITY � A measure of the dissolved salts in the water. � measured as either TDS (Total Dissolved Solids), which measures the amount of dissolved salts in the water, � or as EC (Electrical Conductivity), which is the property of a substance which enables it to serve as a channel or medium for electricity. � Saline water is good conductor of electricity. � EC can be converted to TDS and vice versa.

SOURCES OF SALINITY � include � urban and rural run-off containing salt, � fertilisers and � Organic matter. � Land use issues related to high levels of salinity include � the resultant rise in the water table, excessive irrigation, groundwater seepage and runoff containing dissolved solids from industry, sewage, agriculture etc.

EFFECTS OF SALINITY � salinity that is beyond the normal range for any species of organism will cause health problems or even death to that organism. � Water containing a TDS level of over 500 mg/L is unsuitable for irrigation of many plants and tastes unpleasant to drink.

TURBIDITY � Turbidity is a measure of the ability of light to pass through water, that is, a measure of the water’s cloudiness. � Measuring cloudiness gives an estimate of suspended solids in the water. � Turbidity is measured in Nephelometric Turbidity Units (NTU’s).

HOW DO TURBIDITY LEVELS RISE? � Higher turbidity can be caused by human activity like cutting trees and removing vegetation next to a body of water. � Trees provide shade to keep the water cooler, and trees and other plants help block mud and soil from washing into the water.

TURBIDITY EFFECTS � High turbidity affects submerged plants by preventing sufficient light from reaching them for photosynthesis. � High turbidity also has the capacity to significantly increase water temperature. � Though high turbidity is often a sign of poor water quality and land management, crystal clear water does not always guarantee healthy water. � Extremely clear water can signify very acidic conditions or high levels of salinity.

p. H � At extremely high or low p. H levels, the water becomes unsuitable for most organisms. � Young fish and insects are also very sensitive to changes in p. H. � Most aquatic organisms adapt to a specific p. H level and may die if the p. H of the water changes even slightly.

p. H � p. H can vary from its normal levels (6. 5 to 8. 2) due to pollution from automobiles and coal-burning power plants. � These sources of pollution help to form acid rain. � Acid forms when chemicals in the air combine with moisture in the atmosphere. � It falls to earth as acid rain or snow. � A ph range of 6. 5 – 8 is optimal for freshwater. � A range of 8 – 9 is optimal for sea water.

DISSOLVED OXYGEN (DO) � The amount of oxygen in water, to a degree, shows its overall health. � That is, if oxygen levels are high, one can guess that pollution levels in the water are low. � Conversely, the body of water is not of optimal health.

BIOCHEMICAL OXYGEN DEMAND (BOD) � When organic matter decomposes, microorganisms (such as bacteria and fungi) feed upon this decaying material and eventually the matter becomes oxidized. � Biochemical oxygen demand, or BOD, measures the amount of oxygen consumed by microorganisms in the process of decomposing organic matter in stream water. � The harder the microorganisms work, the more oxygen they use, and the higher the measure of BOD, leaving less oxygen for other life in the water.

BOD EFFECTS �A high BOD measure harms stream health in the same ways as low dissolved oxygen: aquatic organisms become stressed, suffocate, and die. � The few organisms that can survive with less oxygen, like carp and sewage worms, will increase in number.

HOW DO BOD LEVELS RISE? � As more organic matter enters a stream, the BOD will rise. � Organic � leaves matter may include and woody debris; � dead plants and animals; � animal manure; � effluents from mills, � and food-processing plants; etc.

WATER HARDNESS � � Water hardness in the water is of two types, 1. Permanent water hardness is attributed to the presence of sulfates and chlorides of calcium and magnesium. � The permanent hardness can only be removed by chemical means. � 2. Temporary water hardness is attributed to the presence of bicarbonates of calcium and magnesium. � The temporary hardness can be removed by boiling the water.

NITROGEN AND PHOSPHOROUS � Phosphorus/Nitrogen enters the water � Plants take up them and grow too much � Plants (algae) die and sink to the bottom � Bacteria at the bottom decompose the dead plants, using up oxygen in the process � Oxygen levels drop, killing fish or aquatic insects � They both continues to enter the water � The cycle continues

OIL AND GREASE � This includes all oils, fats and waxes, such as kerosene and lubricating oils. � Oil and grease causes unsightly films on open water bodies and negatively affects aquatic life. � It forms a layer on surface of water and does not allow the oxygen to be dissolved in water. � It also blocks sewerage lines and pipes and results in blockage of waste water disposal and treatment.

COLOR IN WATER � algae may impart a green, brown or even reddish color to the water. � Red and brown colors are due to iron; � black � and is due to manganese or organic matter; yellow to dissolved organic matter.

REFERENCES � WATER QUALITY PARAMETERS & INDICATORS � Water Quality Parameters � http: //greenactivist. wordpress. com/2012/02/29/ water-quality-parameters/