Environmental Engineering Lab Final

increased DO concentration, decrease CO, and reduce taste and odor of gases dissolved in the water.

In water treatment systems, aeration may be performed for a variety of purposes, list three:

False

National primary drinking water regulations are non-enforceable guidelines for contaminants that may cause cosmetic and aesthetic effects in drinking water.

False

National secondary drinking regulations are legally enforceable standards that apply to public water systems.

True

The activated sludge process is a type of wastewater treatment process for treating sewage or industrial wastewaters using aeration and biological floc.

Boiling water, by Clarks Method, and Gan's Permutit method

Mention and describe (at least 3) methods to remove hardness in water.

PM, CO, and VOCs

Mention at least three parameters that should be monitored/controlled for Indoor Air Quality, and mention strategies to keep them within an acceptable range.

temperature and DO

Mention two parameters affected by suspended solids in water.

detention time and suitable shaped chamber or vessel

Mention two process performance considerations needed in order to get an efficient flocculation.

mobile, stationary, area, and natural

Air quality contaminants sources include:

True

An important characteristic of particulate matter(PM) is the size of the individual particles, because size determines how easily the particles interact with our bodies when they enter our lungs.

increase

As the water temperature decreases, the amount of dissolved oxygen in the water ___________.

decreases

As the water warms, the amount of dissolved oxygen in the water __________.

True

Besides efficient removal of turbidity and color, coagulation with alum and ferric chloride or ferric sulfate is also widely used for removal of heavy metal ions from water.

True

Change in the solubility of nutrients and heavy metals is an effect of pH change in the water.

When limestone and dolomite dissolve in water, one half of the molecule is calcium or magnesium (the "hardness") and the other half is the carbonate (the "alkalinity")

Describe the relationship between alkalinity and hardness in water.

gravity aerators, spray aerators, and diffused air aerators

Describe three types of aerators that are commonly used in water and wastewater treatment.

electrostatic and intermolecular

During coagulation process, when two colloidal particles approach each other, they are subjected to two major types of forces: ___________ forces.

Chlorides and Sulfates cause a gain in compressive strength & pH causes deterioration of the structure.

Explain how Chloride, pH, and Sulfates affect structural concrete.

Permanent hardness of water is caused by chlorides in the form of calcium (Ca) and magnesium (Mg) in water, and hardness of the water can not be removed by boiling. Permanent hardness can be removed by the demineralization method or softening the water.

Explain permanent hardness

Temporary hardness occurs when soluble salts of calcium (Ca) and magnesium (Mg) are present in water, and hardness can be removed by boiling the water.

Explain temporary hardness

concentration of salts, temperature, mixing process, pH range, and alkalinity.

Factors affecting coagulation efficiency are:

impellor speed, water temperature, bubble size, and surface area in direct contact with the atmosphere

Factors affecting the transfer rate of oxygen between water and the atmosphere, includes:

protect the waste water treatment plant equipment

In a WWTP, the preliminary treatment is intended to:

True

In a municipal wastewater treatment, the objective of the primary treatment is the removal of settleable organic/inorganic solids by sedimentation, and the removal of materials that will float by skimming.

True

In a wastewater treatment plant the tertiary treatment is used to accomplish the final cleaning process.

degrade the organic material by using biological treatment

In a wastewater treatment plant, the secondary treatment is intended to:

aeration and microorganisms

In an activated sludge process, wastewater is treated using ___________.

False

In reaeration tanks, bubble size matters. It is okay to be said that bubbles of bigger size with maximized surface area, allow a better oxygen transfer rate.

True

One of the aeration purpose in the water treatment is to oxidize iron and manganese from their soluble states causing them to precipitate.

False

One of the aeration purpose in water treatment is to create a floc of good size (0.1-0.3mm), density, and toughness for later removal in the sedimentation and filtration purposes.

True

One of the aeration purposes in water treatment is to remove volatile organic compounds (VOCs).

True

Shifting of pH beyond 5 to 10 upsets the aerobic treatment of the wastewater.

False

TSS are filterable solids that pass through a filter with a pore size of 2.0 mircon.

True

The EPA's primary drinking water regulations are enforceable under the law.

True

The EPA's secondary drinking water standards are non-enforceable.

temperature

The amount of oxygen the water can hold depends primarily on the ________________ of the water.

True

The chief limitation of the COD test is its inability to differentiate between biologically degradable and biologically inert organic material.

Coagulation, Flocculation, Sedimentation, and Filtration

The treatment operations specifically aimed at removing turbidity by:

trivalent cation, insoluble at neutral pH, and non toxic

Three key properties of a coagulant are:

turbidity, odor, and color

Three qualitative analyses that define water quality are:

sedimentation, oxidation, and clarification

Three treatments/operations specifically aimed at removing turbidity are:

ozone, CO, NO2, SO2, PM2.5, PM10, and lead

USEPA uses six criteria as indicators of air quality. Mention at least three of the "criteria pollutants" __________, ______________, and ____________.

False

VSS represents the fixed inorganic fraction of solids in a water sample.

True

VSS represents the organic fraction of solids in a water sample.

Use of water as a cooling agent in industrial plants, runoff from paved surfaces, and natural causes.

What are the main causes of thermal pollution?

Major cations causing hardness are calcium and magnesium (Ca2+ and Mg2+). Other ions which lead to hardness are Mn2+, Fe2+, and Al3+.

What are the principal cations causing hardness in water and the major anions associated with them?

decrease in DO that affects aquatic life

What is the main consequences in thermal pollution?

False

When water is warm/hot the hydrogen and oxygen molecules are bound much closer together. Since they are held so close this allows them to hold more oxygen compared to cold water.

COD

__________ is defined as: the amount of oxygen required to oxidize organic and inorganic matter in wastewater.

Total Dissolved Solids

__________ refer to any organic matter or inorganic salts that have dissolved in a water system.

Coagulation

_____________ is a chemical process to promote aggregation of colloidal material.

Flocculation

______________ process involves a slow mixing process to enlarge large, strong aggregates to be formed.