Module 10: Human Waste as a Resource in Agriculture

Question 1

primary treatment

Answer 1

physical screening and settling basin

Question 2

secondary treatment

Answer 2

reduce nitrogen content, anaerobic and aerobic tanks
- clarification tanks

Question 3

biosolids

Answer 3

a product of the wastewater treatment process that is semisolid and nutrient rich

Question 4

what are the benefits of biosolids of agricultural land application?

Answer 4

• source of nutrients
• improved soil quality

Question 5

what are the 503 regulations?

Answer 5

• appropriate application rates
• vector attraction reduction
• pathogen reduction
• toxic metal limits

Question 6

challenges to applying biosolids

Answer 6

• odor
• avoiding runoff and leaching nutrients
• meeting regulation standards
• transportation costs
• emerging contaminants

Question 7

reclaimed water

Answer 7

water that began as wastewater and has been processed and treated to meet standards for resuse

Question 8

what is and is not reclaimed water?

Answer 8

• is recycled water
• is not potable water or greywater

Question 9

reclaimed water challenges

Answer 9

• use in agricultural areas is limited due to distance
• use in agriculture limited due to cost and maintenance of infrastructure
• reclaimed water contains salts and nutrients and must be managed properly for irrigation to avoid salt damage and over fertilization

Question 10

reclaimed water benefits

Answer 10

• reduced groundwater withdrawals
• applies water to the soil rather than to a surface water body

Question 11

gray water

Answer 11

water that comes directly from showers, baths, washing machines, and bathroom sinks, does not include water from the toilet or dishwasher

Question 12

biosolid land application

Answer 12

• agriculture
• reclamation sites
• forestry
• lawns and home gardens

Question 13

primary treatment level

Answer 13

remove a portion of the suspended solids and organic matter from wastewater

Question 14

secondary treatment level

Answer 14

removal of biodegradable organic matter that is suspended or dissolved in the wastewater

Question 15

tertiary treatment level

Answer 15

• removal of any suspended solids, typically done through microscreens or other types of filtration systems once the water has passed through the settling tank
• final process
• include membrane filtration systems, chlorination, ultraviolet irradiation, constructed wetlands, or soil aquifer treatment

Question 16

which system level removes suspended solids?

Answer 16

primary, secondary, and tertiary

Question 17

which system level removes BOD?

Answer 17

secondary

Question 18

which system level removes disinfection/pathogens

Answer 18

secondary and tertiary

Question 19

what does the secondary treatment stage transform organic nitrogen into?

Answer 19

ammonium via mineralization
ammonium to nitrate via nitrification