CHS 330 quiz 6

Which of the following statements is true regarding the purpose for water purification? To take out suspended particles. To remove pathogens To protect public health All of the above

All of the above

!!! Which of the following statement is accurate about water availability? Although the majority of the earth's surface is water, most of this water is ocean water that is not readily useable for human use. Around 2.5% of water on earth is freshwater and all of it is readily usable by for human use. The readily accessible fresh water comes from polar ice and glaciers. Although only a very small fraction of the world's total water supply is available for human use, this water supply is distributed evenly where humans live.

Although the majority of the earth's surface is water, most of this water is ocean water that is not readily useable for human use.

Which of the following statements is true about microplastics? They are naturally formed harmless substances but can affect the taste of drinking water. They exist in the water cycle and drinking water is the only way for human exposure to them. It is estimated that on average, the weekly exposure to them is about as much as the weight of a plastic credit card. Personal care products is the major source of microplastics in the oceans.

It is estimated that on average, the weekly exposure to them is about as much as the weight of a plastic credit card.

Which of the following statement is NOT true about nutrients in wastewater? Many of which come from human activities It is good for the ecosystem as it acts like fertilizers to the creatures in natural water systems It can cause eutrophication When people talk about these nutrients, they are primarily referring to N and P

It is good for the ecosystem as it acts like fertilizers to the creatures in natural water systems

Which of the following is NOT belong to the main sources of drinking water Lakes Rivers Oceans Groundwater

Oceans

What is the largest household/residential water usage in the United States? Leaks in the water lines Outdoor use Toilets Clothes washing

Outdoor use

!!! Which of the following processes is not directly for wastewater treatment but for treatment of the byproduct? Sludge processing Primary treatment Secondary treatment Tertiary treatment

Sludge processing

Which of the following statements is NOT a stage for water treatment? Coagulation Sedimentation Filtration Tertiary treatment

Tertiary treatment

Which of the following statements is correct regarding the global water cycle? The water cycle is complex and involves many processes that can carry water over long distances. Groundwater has its own processes and is isolated from the rest of the water cycle. Living creatures are not actively participating in the water cycle. The water in oceans are not readily drinkable and evaporation from water in oceans is also not readily drinkable in the water cycle

The water cycle is complex and involves many processes that can carry water over long distances.

Which of the following statements is NOT true about the objectives of wastewater treatment? To remove pathogens To remove organic matter To remove suspended solids To make the treated water drinkable by public

To make the treated water drinkable by public

True or false: disinfection of drinking water is very important and has little side effect for all of the water supplies in the United States

false

True or false: In the United States, domestic water use takes up a small fraction of total water use.

true