Stream Sanitation

Density inversely related to temperature attains maximum density at 4C.

True

Peak Dissolved Oxygen mid-day is due to

photosynthesis

Lowest Dissolved Oxygen near dawn is due to

Community Respiration

Oxic Oxygen Conditions

>4 mg/L, ideally want

Hypoxic Oxygen Conditions

<2 mg/L, stressful for all aerobic organism

Anoxic Oxygen Conditions

<0.06 mg/L, only aerobic microorganisms can survive

pH 6 is 10x more acidic as pH 7

True

0 - Acidic (Hydrochloric Acid), 3 - stomach Acid, 7 - Neutral, 10 - soap, 14 basic (sodium hydroxide)

Alkalinity and Acidity are measurements of the capacity of water to

neutralize acids and bases

Wastewater Treatment Process in Order

Preliminary Treatment, Primary Treatment, Secondary Treatment, Tertiary Treatment, Disinfection, Solids Treatment

Preliminary Treatment consists of

Screening, Grit Removal, Pre-aeration, Flow metering/sampling

Primary Treatment consists of

Sedimentation and floatation

Secondary Treatment consists of

Biological Treatment & Sedimentation

Tertiary Treatment consists of

Filtration and Chemical/biological treatment of nutrients

Disinfection

UV, Chlorination

Solids Treatment

Dewatering, Digestion and Disposal

Filtration

Physical removal of particulate matter through a porous membrane

Types of Filtration

Gravity Filters, High Rate filters and pressure filters

Mean Cell resident Time

An expression utilized to express the average time a microbe will spend in the activated sludge process

Nitrification

process that converts ammonia to nitrite and then nitrate

Purpose of Disinfection is to

destroy pathogenic microorganisms and prevent the spread of disease

Sterilization

Destruction of all microorganisms

Ultraviolet Light Disinfection

Alters DNA of bacterial cells exposed to it, penetrates bacteria cell walls

Sludge Digestion

made up primarily of raw and secondary sludge biomass from the bottom of clarifiers

Anerobic Sludge Digestion

Reduces solids from a sticky, smelly mixture to a mixture that is odor free