Exam 14: Water Quality

Arrange the zones of the open sea in order of descending amount of light received, beginning with the zone which receives the most light.

Wastewater treatment sludge, after reduction to about 5% of its original volume by removal of water, can be disposed of by

Eutrophication is the

Groundwater (from wells), unlike surface water, can be contaminated while looking perfectly clear.

Groundwater (from wells) may contain

Mercury poisoning can occur from consuming fish which contain

Lead enters drinking water primarily from

The recovery zone of polluted natural waters is characterized by

Acids can enter natural waters due to

Lakes generally evolve naturally over time in the following manner.

Cold, clear lakes or streams with few nutrients and a relatively low abundance of life are referred to as

Water pollution can be

A "clean zone" of water has

Anaerobes are forms of life which

Sediment (soil particles) in natural waters can

The zone of the open sea having the most light is the

At very low dissolved oxygen (DO) levels in water, the septic zone, the forms of life are limited to

The amount of oxygen required to decompose a given quantity of organic material is known as the

Secondary sewage treatment is focused on

The rapid decrease of dissolved oxygen in the decomposition zone of water is known as