Essay on Turbidity: Turbidity and Secchi Disk Measures

Submitted By jamesflame123
Words: 581
Pages: 3
Open Document
INTRODUCTION
Turbidity is caused by suspended solid matter that scatters light passing throughout the water. Too much turbidity in the water causes gill damage in fish and makes it difficult for them to find food. There are three different ways to measure turbidity. The secchi disk, a 20cm circle that is divided into quarters, which are alternately black and white. It is attached to a rope and lowered into the water and the units of measurement are centimeters, which are marked on the rope. The spectrophotometer or Colorimeter is a machine that measures the amount of light that can pass through a sample of water in a clear 10 mL tube. The turbidity test kit involves two 50 ml granulated cylinders, distilled water, Standard Turbidity Reagent, and stirring rod.LIGHT

Turbidity is very significant to life in the bay or any other body of water. SAV’s (Submerged Aquatic Vegetation) similar to land plants need light to carryout photosynthesis, the process through which plants make food. If there is no light, there is no photosynthesis, leading to a decline in SAV’s. SAV’s are the start of many food chains. They are eaten by small fish, which are in turn eaten by larger fish, and these eaten by bigger fish, some of which are caught and eaten by humans. Light can reach twice as far as a secchi disk measures. For example if the secchi disk measurement is 30cm, the light can reach a depth of 60cm.

CLARITY vs. TURBIDITY

It is thought that clarity and turbidity are too different and cannot be compared. In Water Quality Monitoring they can be used interchangeably, provided that the method used is indicated. The secchi disk is used if the bottom of the body of water is not visible, and the turbidity test or Colorimeter used if the bottom of the body of water is visible. The secchi disk measures clarity, how far down an object is visible. The Colorimeter and test kit measure turbidity, the cloudiness of the water.

SECCHI DISK

The secchi disk is a 20cm black and white disk that measures clarity. It is attached to a rope that is marked every 5cm alternating black and yellow markings. It is lowered
Show More

Related Documents: Essay on Turbidity: Turbidity and Secchi Disk Measures

Turbidity and Formazin Turbidity Unit Essay

most widely used measurement unit for turbidity is the Formazin Turbidity Unit (FTU). ISO refers to its units as FNU (Formazin Nephelometric Units). There are several practical ways of checking water quality, the most direct being some measure of attenuation (that is, reduction in strength) of light as it passes through a sample column of water. The alternatively used Jackson Candle method (units: Jackson Turbidity Unit or JTU) is essentially the inverse measure of the length of a column of water…

Words 480 - Pages 2