4AE3 U5 C3 Obj 4.pdf

Liquid and Solid Emissions • Chapter 3 Objective 4 List sources and effects of liquid and thermal pollution. Liquid Pollution The most abundant liquid on Earth is water. While nearly three quarters of the Earth’s surface is covered with water, only a small amount (about 0.01%) is fresh surface wat...

Liquid and Solid Emissions • Chapter 3 Objective 4 List sources and effects of liquid and thermal pollution. Liquid Pollution The most abundant liquid on Earth is water. While nearly three quarters of the Earth’s surface is covered with water, only a small amount (about 0.01%) is fresh surface water (lakes and streams). Water found in soil and rock formations is known as groundwater. Water consumption demands are met by using surface water and groundwater drawn from wells or springs. Plants and industrial operations use a tremendous amount of water. Water discharged from these plants is known as effluent. Water alone is not usually considered to be a contaminant. However, many of the thousands of materials suspended or dissolved in it are contaminants. When water is used for any purpose, it is usually of much lower quality when it is disposed. Potentially hazardous materials get into water either by direct dumping, or by various processes where water carries, cleans, or unintentionally dissolves a contaminant. When undesirable material is dissolved or suspended in water, the solution or mixture has the potential to be a liquid pollutant. In some cases, and only if properly controlled, there are hazardous materials that can be released without creating a problem. Challenges arise when materials are released in an uncontrolled manner, such as a spill or a leak. In an energy plant, there are many places where liquid wastes could originate such as: • Cooling tower blowdown • Boiler blowdown • Waste from boiler waterside or fireside cleaning • Ash handling slurries • Water treatment equipment • Plant floor drains • Flue gas scrubbers • Oil storage locations If these liquids are not handled properly, liquid pollution could result. Materials become pollutants when they begin to have adverse effects on other occupants of the ecosystem. The effects of pollutants vary considerably depending on: • The type and quantity of the pollutant. • The susceptibility of the local environment to the pollutant. • Other conditions that may accentuate or lessen the effects of the pollutant. When hazardous liquid spills occur, they could cause: • Fires or explosions. • Exposure of humans, animals, and plants to toxic fumes, vapours, or clouds. • Hazardous byproducts formed by reactions in the environment. Evidence of water pollution may show up as an unexpected increase or decrease in the population of one or more species. As well, sickness, deformity, and abnormal behaviour can occur in an otherwise normal population. Thousands of dead fish found along the banks of a river are an indicator of a hazardous spill. 4th Class Edition 3 • Part A 3-11