To remove heavy metals such as lead, chromium, arsenic and others from mine waste water using agricultural waste such as rice husk, coconut husk, sawdust and maize cob by converting each agricultural waste into activated carbon through thermochemical process using an electric furnace, sodium chloride, distilled water, beaker, sieve, magnetic stirrer and mass balance. An atomic absorption spectrometer analysis will be performed after mixing mine waste water with each activated carbon. In order to remove the heavy metals from mine waste water give a thorough explanation to the following questions and reason for each answer.

a) What temperature should the each agricultural waste be heated in the electric furnace to prevent the agricultural waste from burning?

b) To thoroughly mix the mine waste water and the activated carbon with a magnetic stirrer in a solution of distilled water and sodium chloride, what should be the time taken?

c) To chemically activate the carbon with distilled water and sodium chloride, what should be the ratio of distilled water and sodium chloride?

d) To dry the chemically activated carbon in an oven, what should be the suitable temperature to make it dry?

e) What should be the ratio of mine waste water and activated carbo when mixed thoroughly to perform the atomic absorption spectrometer analysis test?