Potential Environmental Impact of Liquids

What is a liquid? Liquids are forms of matter which flow when subjected to a pressure difference.

Effects of Liquid Pollutants Depends on four factors: What is the pollutant? How much of it there is? What is it effecting? What other conditions complicate or attenuate the effects of the pollutant?

The oil spill as seen from space by a NASA satellite The oil spill as seen from space by a NASA satellite. Sunlight illuminated the lingering oil slick off the Mississippi Delta on May 24, 2010. The Moderate-Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image the same day. Oil smoothes the ocean surface, making the Sun’s reflection brighter near the centerline of the path of the satellite, and reducing the scattering of sunlight in other places. As a result, the oil slick is brighter than the surrounding water in some places (image center) and darker than the surrounding water in others (image lower right). The tip of the Mississippi Delta is surrounded by muddy water that appears light tan. Bright white ribbons of oil streak across this sediment-laden water. Tendrils of oil extend to the north and east of the main body of the slick. A small, dark plume along the edge of the slick, not far from the original location of the Deepwater Horizon rig, indicates a possible controlled burn of oil on the ocean surface. To the west of the bird’s-foot part of the delta, dark patches in the water may also be oil, but detecting a manmade oil slick in coastal areas can be even more complicated than detecting it in the open ocean. When oil slicks are visible in satellite images, it is because they have changed how the water reflects light, either by making the Sun’s reflection brighter or by dampening the scattering of sunlight, which makes the oily area darker. In coastal areas, however, similar changes in reflectivity can occur from differences in salinity (fresh versus salt water) and from naturally produced oils from plants. Michon Scott NASA's Earth Observatory NASA Goddard Space Flight Center"

Secondary effects of liquid pollutants Liquids present problems in some of the following ways when a spill occurs. Fire or explosion hazard Toxicity to humans, to animals, or to plant life Fumes, vapours or clouds carried from the spill Reactivity problems where hazardous by products can be formed.

Evidence of pollution Population decrease in one or more species Sickness or deformity, abnormal behaviour or sudden population increase “fish kill” – thousands of dead fish along the banks of a river.

Limiting the effects of uncontrolled releases of liquid pollutants Contain or immobilize the material and neutralize or lower its hazard potential.

Determining water contamination Biochemical Oxygen Demand Test (BOD) – environmental procedure for determining the extent to which oxygen within a sample can support microbial life. http://www.rpi.edu/dept/chem-eng/Biotech-Environ/Environmental/BOD/coda.htm

Determining water contamination Chemical oxygen Demand Test (COD)- predicts the oxygen requirement of the effluent and is used for monitoring and control of discharges, and for assessing treatment plant performance. http://www.palintest.com/media/uploads/137.pdf

Determining water contamination pH testing – can determine the amount of alkaline or acidic materials.

Determining water contamination Turbidity testing Turbidity is a measurement of how cloudy water appears. http://learnweb.harvard.edu/ent/gallery/pop4/Turbidity_MWRA.pdf

Determining water contamination Colour testing – indicates material dissolved in water.

Determining water contamination

Thermal pollution Thermal pollution is a presence of waste heat in the water which can cause undesirable changes in the natural environment. http://www.scribd.com/doc/50715677/87/Control-of-Thermal-Pollution

Preventive Measures pH control Effluents dumped into an existing stream should have similar pH value as the receiving water.

Preventive Measures Settling ponds Effluent is allowed to slowly flow through a quiet pond where particulate matter settles to the bottom and the clean effluent is dumped into the water course.

Preventive Measures Vacuum Filter

Preventive Measures

Preventive Measures Emulsions and floating pollutants

Disposal of hazardous liquids Landfill Deep well injection Encasement and burial at sea Incineration Each liquid must be handled according to information on current MSDS sheet.