Question 1

Deep disposal wells for toxic liquid wastes must never extend down to the water table.

Accepted Answer

The answer of Deep disposal wells for toxic liquid wastes...

Question 2

The time it takes for half the atoms of the isotope to decay is called as the half-life period.

Accepted Answer

The statement is true.

Question 3

Chlorination of some drinking water,if carelessly done,can lead to production of small quantities of toxic chlorinated hydrocarbons.

Accepted Answer

Chlorination of drinking water can lead to the formation of small quantities of toxic chlorinated hydrocarbons such as trihalomethanes (THMs) if not done properly.

Question 4

Ocean disposal of dredge spoils may cause water-turbidity problems and release toxic metals into seawater.

Accepted Answer

Ocean disposal of dredge spoils can cause water-turbidity problems because the sediment plume can spread and reduce visibility in the water. In addition, dredge spoils may contain toxic metals that can be released into seawater, which can be harmful to marine organisms and human health if they enter the food chain. Therefore, it is important to properly manage dredge spoils and consider alternative disposal methods to minimize their environmental impact.

Question 5

One concern with respect to expanding "Superfund" through a tax on disposers of toxic wastes is that such a practice might encourage more illicit waste dumping.

Accepted Answer

The concern mentioned suggests that if a tax is imposed on disposers of toxic wastes, they may resort to illicit waste dumping to avoid the tax. Therefore, option A is correct.

Question 6

The classification of radioactive wastes as high-level or low-level is very accurate.

Accepted Answer

The classification of radioactive wastes into high-level or low-level categories is somewhat arbitrary and can vary by country and regulatory framework, making it not always very accurate or consistent.

Question 7

The appeal of the Yucca Mountain disposal site is that it is in an area where no earthquakes have occurred for approximately 10,000 years.

Accepted Answer

Yucca Mountain, located in Nevada, is in a seismically active region where earthquakes have occurred, raising concerns about its suitability for nuclear waste disposal.

Question 8

Consuming products in and recycling of glass is better than consuming products in and recycling aluminum because less energy is needed to re-melt glass bottles compared to that which is needed to re-melt aluminum.

Accepted Answer

Glass has a lower melting point than aluminum and requires less energy to re-melt, making it a more energy-efficient material to recycle.

Question 9

Liquid wastes can be incinerated in specially designed equipment,with most toxic organic compounds destroyed in the process.

Accepted Answer

Incineration of liquid wastes is a highly effective and widely used method of waste management. It involves burning the waste in specially designed equipment at high temperatures, typically between 800-1200°C. This process can destroy most toxic organic compounds present in the waste, including hazardous chemicals, pathogens, and heavy metals. However, it is important to note that incineration can also release harmful emissions, such as dioxins and other pollutants, into the air. Consequently, many countries have strict regulations and emission limits for incineration facilities to minimize the environmental impact.

Question 10

Recycled plastic is mixed with sawdust to make a product known as composite lumber.

Accepted Answer

Composite lumber is a material made from recycled plastic and wood fibers or sawdust.

Question 11

Steel is in such demand that it is all readily recycled.

Accepted Answer

While steel is highly recyclable and in demand, not all steel gets recycled due to various factors such as collection and sorting challenges, contamination, and economic considerations.

Question 12

"Waste exchanges" are international agreements that allow each nation to specialize in certain types of waste disposal with a group of cooperating nations,so each can engage in the types of disposal for which its geology is most suitable.

Accepted Answer

Waste exchanges are platforms or programs where companies can offer and exchange waste materials that may be useful to others, typically to reduce waste and promote recycling, rather than international agreements on waste disposal specialization.

Question 13

A leaching field is the area around a landfill into which leachate percolates.

Accepted Answer

A leaching field, also known as a drain field, is part of a septic system that removes contaminants and impurities from the liquid that emerges from the septic tank.

Question 14

The Hanford (Washington)Reservation,where high-level liquid radioactive wastes are currently in storage is located near the Columbia River,upstream of Portland,Oregon.

Accepted Answer

This statement is true, as Hanford is located near the Columbia River upstream of Portland, Oregon and contains high-level liquid radioactive waste.

Question 15

Once water has been contaminated with sewage,it is impossible to restore it to drinking-water quality.

Accepted Answer

While it can be difficult and expensive to restore water contaminated with sewage to drinking water quality, it is not always impossible. Advanced treatment processes such as reverse osmosis, advanced oxidation, and ultrafiltration can be used to effectively remove contaminants and restore the water to a safe level for drinking. However, these treatment methods may not be available or feasible in all situations.

Question 16

The basic assumption behind the dilute-and-disperse philosophy of liquid-waste disposal is that even potentially harmful substances pose no threat if sufficiently diluted.

Accepted Answer

The basic assumption behind the dilute-and-disperse philosophy of liquid-waste disposal is indeed that even potentially harmful substances pose no threat if sufficiently diluted.

Question 17

Glass bottles or aluminum cans may be recycled into similar new bottles and cans; recycled plastic objects generally can't be remanufactured back into the same objects.

Accepted Answer

Glass and aluminum can be recycled into similar new products, but plastic is often downcycled into lower quality products as it cannot be remanufactured into the same object.

Question 18

Because there is still disagreement about the best methods to use,no high-level radioactive wastes have been consigned to permanent disposal sites,anywhere in the world.

Accepted Answer

While some countries have constructed permanent disposal sites for high-level radioactive waste, there is still ongoing debate and disagreement over the most effective methods for disposal. Therefore, no high-level radioactive wastes have been consigned to permanent disposal sites anywhere in the world.

Quiz 16: Waste Disposal