Turbidity in Water: Knowledge and Awareness of its Causes, Consequences, and Control
Turbidity in this context can be described as cloudiness or haziness in water which may be attributed to particulate matters and dissolved substances. They can range from soil and silt to plankton, organic material, and various microorganisms. It is therefore important to understand the factors that cause turbidity, the consequences of turbidity, as well as the methods of managing turbidity to ensure high water quality in natural water sources, drinking water sources, and other industrial applications. In this article, the author discusses the topic of turbidity and tries to understand its meaning and its applications in different fields.
What is Turbidity?
Turbidity refers to the quality of water in terms of its clarity or the ability of light to pass through it. High turbidity is characterized by clouding or haziness of the water due to the occurrence of particles in the water while low turbidity implies that the water is clear. Turbidity is commonly expressed in Nephelometric Turbidity Units (NTU) with the help of a turbidimeter, indicating the scattering of light through the water sample.
Causes of Turbidity
Several factors contribute to the turbidity of water:
- Natural Erosion: Sediments are also brought into water bodies through erosion by either wind, rain, or runoff; these contribute to high turbidity levels. Other factors that causes turbidity is through natural disasters such as landslides and volcanic activities.
- Stormwater Runoff: This is especially so when there is intense rainfall or floods that can easily wash off top soils, sediments, debris and pollute rivers, lakes, or reservoirs in urban and agricultural areas. The accumulation of these particles leads to a rise in turbidity of the water.
- Human Activities: Activities such as construction, mining, deforestation, and agriculture can upset the soil and enhance sedimentation. Another source of pollutants is industrial effluent and wastewater, which can bring in suspended solids and organic materials.
- Algal Blooms: High levels of nutrients, especially nitrogen and phosphorus, may cause algal blooms. Because these algae are constantly reproducing and dying, the water becomes more cloudy as a result of this process.
- Aquatic Life: The motility of fish, zooplankton and other benthos may stir up sediment and organic matter, thus increasing water turbidity.
- Decaying Organic Matter: Fragmentation of plant material, leaves, and other organic matter to the water bodies is capable of increasing the water turbidity.
Effects of Turbidity
The presence of high turbidity levels in water can have several negative impacts:
- Health Risks: Turbidity can contain pathogenic organisms like bacteria, viruses, and parasites which are dangerous to human health. These pathogens are known to cause waterborne diseases including giardiasis, cryptosporidiosis, and gastroenteritis.
- Reduced Water Quality: Immediate water quality quality characteristics that are influenced by high turbidity include taste, odor, and appearance of drinking water. It can also hinder the disinfection process because it forms a barrier that protects the microorganisms from coming into contact with disinfectants such as chlorine.
- Ecological Impact: Higher levels of turbidity leads to reduced light penetration which negatively impacts the growth of plant life in the water bodies. This can affect the food chain and have adverse effects on fish and other animals in water bodies.
- Sedimentation: It results in sedimentation within water bodies thus altering the living conditions of the aquatic life forms and the fish are suffocated by the clogging of their gills. It also buries fish eggs and other organisms that inhabit the benthos of the water bodies.
- Industrial Processes: Low clarity may cause complications in operations that require clear water in industries like manufacturing, food processing industries, and power industries. This can promote scaling, fouling, or harm to equipment.
Measuring Turbidity
Turbidity is usually determined through the use of a turbidity meter or a nephelometer. These devices quantify the amount of light absorbed and scattered by particles in the water sample. The following methods are used to measure turbidity:
- Nephelometric Method: This method employs a nephelometer to determine the amount of light transmitted at an angle of 90 degrees. It gives exact and precise measurements of turbidity in NTU, which is useful for water purification plants.
- Secchi Disk: Turbidity can be measured in water bodies using a simple tool called a Secchi disk. It includes submerging a black and white disk in water and measuring the depth at which the disk is no longer distinguishable. This method presents a measure of water clarity that is not direct but comes with its own set of advantages.
- Formazin Calibration: Turbidity standards are suspension of particles in water such as Formazin which is often used in calibration of turbidity meters. It serves as a reference standard in the determination of turbidity since it will always give true results.
Managing and Reducing Turbidity
It becomes important that turbidity is well managed and reduced to the desired levels to maintain good water quality. Several strategies can be employed:
- Erosion Control: Measures like vegetation planting, contour farming, and terracing help to minimize the erosion of soils and sedimentation on water bodies.
- Stormwater Management: Measures such as constructing retention ponds, wetlands, and vegetative buffers can assist in trapping stormwater runoff and minimizing its turbidity.
- Best Agricultural Practices: Sustainable farming practices include cover crops, no-till, and riparian management practices can help reduce sediment and nutrient pollution.
- Wastewater Treatment: Implementing enhanced methods of eliminating particulate matter and organic pollutants in wastewater prior to discharge can help in minimizing water turbidity in the next water bodies.
- Algae Control: Both nutrient reduction strategies and algal control methods should be employed to prevent algal blooms and limit turbidity in water bodies.
- Filtration and Sedimentation: Filtration and sedimentation methods in water treatment plants can help to improve the quality of drinking water by removing suspended particles and lowering the turbidity levels.
- Regular Monitoring: The recommended method of monitoring turbidity is by periodically sampling water sources and drinking water to identify turbidity problems and act accordingly.
Conclusion
Turbidity is one of the most important indicators for water quality, which has a profound influence on human life, aquatic organisms, and water-related businesses. It is important to learn the factors that lead to water pollution, the impact of such pollution on the water, and ways of dealing with it to ensure availability of clean and safe water. Through proper control and reduction of turbidity, there is hope that the availability and quality of water can be maintained for the present and future generations.