TURBIDITY SENSOR

Turbidity & Total Suspended Solids 

Total suspended solids (TSS) are particles that are larger than 2 microns found in the water column. Anything smaller than 2 microns which is generally average filter size is considered a dissolved solid. Most suspended solids are made up of inorganic materials, though bacteria and algae can also contribute to the total solids concentration. These solids include anything drifting or floating in the water, from sediment, silt and sand to plankton and algae. Organic particles from decomposing materials can also contribute to the TSS concentration. As algae, plants and animals decay, the decomposition process allows small organic particles to break away and enter the water column as suspended solids. Even chemical precipitates are considered a form of suspended solids. Total suspended solids are a significant factor in observing water clarity. The more solids present in the water, the less clear the water will be. Some suspended solids can settle out into sediment at the bottom of a body of water over a period of time. Heavier particles, such as gravel and sand, often settle out when they enter an area of low or no water flow. Although this settling improves water clarity, the increased silt can smother benthic organisms and eggs. The remaining particles that do not settle out are called colloidal or non-settleable solids.

Why to monitor TSS:

It is very important to monitor TSS because in addition to being a warning sign for pollution, suspended solids can harbor pathogens such as bacteria and protozoa. These microorganisms attach to the suspended particles, aiding in their transportation and hiding them from disinfectants. These pathogens can infect aquatic or human life if the sediment is not removed. High concentrations of suspended solids can cause many problems for human health and aquatic life. High TSS can block light from reaching submerged vegetation. As the amount of light passing through the water is reduced, photosynthesis slows down. Reduced rates of photosynthesis causes less dissolved oxygen to be released into the water by plants. If light is completely blocked from bottom dwelling plants, the plants will stop producing oxygen and will die. As the plants are decomposed, bacteria will use up even more oxygen from the water. High TSS can also cause an increase in surface water temperature, because the suspended particles absorb heat from sunlight. High TSS can cause problems for industrial use, because the solids may clog or scour pipes and machinery.