Final Exam Review

Question 1

Activated sludge

Answer 1

Primary effluent mixed with settled solids. Air is bubbled through water and microbes introduced. Water goes to second clarifier, microbes flocc and sink. Portion of sludge sent to digester.

Question 2

Bioretention system

Answer 2

Combination of settling, filtration, and bioaccumulation processes.
To slow and detain runoff to have a form of biologically active treatment.

Question 3

Combination inlet

Answer 3

Combination of curb and gutter inlets. May be lowered to increase hydraulic flow, is clogged the least.

Question 4

Created-treatment wetland

Answer 4

Made to detain and treat storm water, not made for habitats. Have high pollutant removal of nutrients and dissolved pollutants through settling, filtration, and biouptake.

Question 5

Curb inlet

Answer 5

Opening on edge of a curb, no grate, less than 6 inches high. Potential safety hazard, no road obstruction.

Question 6

Detention basin

Answer 6

Holds storm water temporarily. Fills during or after rainfall, dry most of the time.

Question 7

Disinfection

Answer 7

Last process in secondary treatment, destroys or inactivates any pathogens left. Chlorination or UV light - excess chlorine can enter receiving waters, UV scrambles pathogens DNA.

Question 8

Flood hazard area

Answer 8

Portion of floodplain inundated by 100 year flood.

Question 9

Floodplain

Answer 9

Area where water in streams overflows its banks and inundates low-lying land

Question 10

Garbage

Answer 10

Putrescible (rots) or decompostable food waste

Question 11

Gutter inlet

Answer 11

Grate on street, can obstruct traffic and collect debris.

Question 12

Inlet

Answer 12

Intercepts sheet flow and directs it to pipes. Curb, gutter, or combination.

Question 13

Leachate

Answer 13

Highly contaminated liquid from direct contact with waste. Can mix with groundwater or seep out of landfill - from using soil to naturally filter.

Question 14

Leaching field

Answer 14

Part of septic system, distributes liquid uniformly over an area. Effluents percolate down water table, microorganisms and pollutants removed. Uses filtration, adsorption, and bio decomposition.

Question 15

Mixed liquor

Answer 15

Combination of activated sludge and waste water in aeration tank.

Question 16

Municipal solid waste

Answer 16

Any material thrown away or discarded - has no economic value.

Question 17

Percolation test

Answer 17

Estimated hydraulic conductivity of soil - an indirect measure of soil permeability.
Process: dig hole, soak with clean water, fill to 8 inches with water, record time for water to drop 6 inches.

Question 18

Primary treatment

Answer 18

Grit removal: filters out non biodegradable gritty material (eggshells, coffee grounds, sand).
Primary sedimentation: similar to drinking water process, primary clarifier, sludge removal at bottom, skimmers for FOG on top.

Question 19

Recharge basin

Answer 19

Designed to recharge ground water/ aquifers. Must be in permeable soils.

Question 20

Refuse

Answer 20

Type of MSW, includes garbage and rubbish.

Question 21

Retention basin

Answer 21

Holds water all the time. May have aesthetic or recreational uses, may form permanent pond or lake.

Question 22

Rubbish

Answer 22

Dry, non putrescible material. Part of refuse.

Question 23

Secondary treatment

Answer 23

Removes solids and BODs not settled out in primary tanks. Minimum 85% removal efficiency of BODs and TSS. Usually biological - microorganisms consume organics, convert to H2O and CO2 - provide a good environment for microorg.
Trickling filter or activated sludge.
Disinfection - chlorine or UV light.

Question 24

Sedimentation basin

Answer 24

Excavated areas, collect and retain storm water. Trap suspended particles and dissipate energy from storm surge.

Question 25

Septic tank

Answer 25

Remove settle-able and floating solids. Solids separated to decompose, liquid sent to leaching field.

Question 26

Sludge

Answer 26

Solids at bottom of primary sedimentation tank, mechanic arm removes sludge.

Question 27

Swale

Answer 27

Shallow depression/ditch designed to collect and transport water. Reduces velocity of flow, runoff may infiltrate. Provides sheet flow (wider) vs. channel flow.

Question 28

Trash

Answer 28

Bulky waste material, requires special handling. Second type of MSW.

Question 29

Trickling filter

Answer 29

Filter medium (rocks) with microbes, waste water trickled over contact microbes. Microbes eat organic matter, water drains to underdrain.

Question 30

Wet ponds

Answer 30

For higher particulate removal, similar to retention basins. Higher removal rate than retention basins, better at removing TSS and particulates.

Question 31

Problems associated with storm water runoff

Question 32

Storm water as a source of non-point source pollution

Question 33

Impact of Land Development / Urbanization on storm water runoff

Question 34

Difference between sanitary and storm sewer

Question 35

Location and spacing of inlets

Question 36

Benefits and problems of storm water storage basis

Question 37

Types of storm water storage basins

Question 38

Flooding as an environmental problem

Question 39

Processes of a waste water treatment plant (i.e. how does it all work and work together?)

Question 40

Process of a septic system (i.e. how does it work and why?)

Question 41

Relationship between concentration of solids and liquids in sludge

Question 42

Importance of sludge treatment prior to dispose (i.e. why do we treat it?)

Question 43

Methods of sludge disposal

Question 44

Identify the primary purpose of solid waste processing

Question 45

Explain the benefit of waste composting

Question 46

Choose a recyclable stream of MSW and discuss three factors associated with its recycling