organic nutrient pollution

Question 1

2 effects

Answer 1

-Deoxygenation
-pathogen , disease spread such as cholera and typhoid

Question 2

Treatment

Answer 2

-pre treatment uses screens to trap suspended items such as plastic
-primary treatment is sedimentation causing faecal solids/sludge to sink to bottom so can be removed separately
-sludge can be sent to landfill , this wastes nutrients or in agriculture as a fertiliser
-secondary treatment , aeration so bacteria can break down remaining organic matter
-tertiary treatment , used if discharge site for effluent is ecologically sensitive or poi for humans , when phosphates removed by adding iron sulfate which produces iron phosphate which can be used as fertiliser