contaminated land and groundwater

Question 1

sources of pollution x3

Answer 1

extraction of coals and metal ores= acidic water
oil+ gas extraction=organic pollutants
disposal of agricultural, domestic and commercial waste

Question 2

pollution problems x2

Answer 2

harm people, livestock+ wildlife
heavy metals locked up in insoluble sulphide under water table, change in conditions to oxidising= release of metals
bioaccumulation

Question 3

groundwater treatment x4

Answer 3

pumped up to surface to be treated
natural clays remove toxic metals from groundwater
ion exchange
changing pH to level so metals precipitate out metal hydroxides

Question 4

remediation of contaminated land x2

Answer 4

superficial deposits treated in situ or dug up and treated elsewhere- chemical neutralisation
phytoremediation - plants absorb heavy metals from soils

Question 5

stabilisation and solidification

Answer 5

aims to immobilise pollutants so they don’t leach away from disposal site. Binding agents used to reduce solubility of waste

Question 6

ion exchange

Answer 6

exchange toxic ions in groundwater for non-toxic ions