TREATING CONTAMINATED GROUNDWATER
Contaminated ground water is one of the important challenges that we will face in the future. Over half of the United States population depends on groundwater as their source for drinking water. Groundwater is also a major source of water for irrigation. It is in everyone’s interest to protect ground water and ensure its use for generations to come. Unfortunately, groundwater is susceptible to pollutants. Man-made products such as oil, gas and chemicals may get into the groundwater making it unfit for human consumption. Drinking contaminated ground water can have very serious health effects such as hepatitis, dysentery and various forms of cancer. Ground water can also harm wildlife and vegetation. Sources of groundwater contamination include: Industrial storage tanks which may corrode, crack and develop leaks. There are over ten million storage tanks buried in the United states alone. Septic systems are another source. If a septic system is improperly designed or maintained it may leak bacteria, viruses, household chemicals and other contaminates into the soil and groundwater. Hazardous waste spills is another common source. Landfills that are not designed with the proper barrier or have a damaged barrier between the landfill and ground are a major concern. Wide spread use of chemicals and road slate can also eventually end up in groundwater.
Contaminated groundwater must be treated. One of the most efficient ways of treating groundwater is through a process call air stripping. Air stripping is the process of moving air through contaminated groundwater or surface water in a treatment system. Air Stripping removes contaminates from the water. In an air scrubber air passing through contaminated water helps evaporate contaminates faster and more efficiently. After treating the water, the air and chemical vapors are collected, and the vapors are either removed or vented. Air stripping uses an air stripping column that contains a series of column internals including plastic random packing. The process forces air
through contaminated water and evaporates the contaminates. The most popular type of air stripper is a packed column air stripper which is a vertical tank filled with plastic random packing such as kempac’s Tri-Pack, plastic Pall Ring Packing or plastic Saddles. Contaminated water is pumped into the top of the column and sprayed over the plastic random packing material. The water trickles downward though the spaces between the plastic random packing. Air is blown into the bottom of the column. As the air rises through the column it flows across the packing and contaminated water. The plastic random packing provides an area for the air and contaminated water to mix and helps to increase the rate of evaporation. The air is collected at the top of the column and can be released or treated while the water is collected at the bottom of the column and where it can be tested. This process can take months or even years depending on contamination concentrations and the amount of water required to be treated.
Selecting the proper column internals is important when designing an air stripper. Kemflo manufactures three types of plastic random packing that should be considered when designing an air stripper. These packing include the Tri-Pack style, Pall Ring Packing and the Plastic Saddle. The Tri-Pack is available is 1”, 2” and 3.5”. The Pall Ring Packing is available in 1”, 2” and 3.5”. The Plastic Saddle packing is available in 1”, 2” and 3”. The Tri-Pack style is most commonly used plastic random packing in air stripping applications due to its unique design. The Tri-Pack is a spherical column packing that is constructed of a network of ribs, struts and drip rods. The Tri-Pack’s superior geometric shape and active surface area make it the ideal random packing for air stripping applications.
For more information about kemflo’s Kempac plastic random packing product line please visit our website at www.kempac-packing.com.