Neco Model Questions Vol1 2020 Chemistry Question 4

A factory discharges 5 000 L day\(^{-1}\) of effluent containing pollutant Y at a concentration of \(0.8\ \text{mg\,L}^{-1}\). The effluent passes through three treatment stages in series: * Stage 1 (adsorption) removes 40 % of the pollutant present. * Stage 2 (biological degradation) removes 30 % of the pollutant remaining after Stage 1, and during this stage the flow rate is reduced by 10 % (the water is recycled), after which the reduced flow proceeds to Stage 3. * Stage 3 (advanced oxidation) restores the original flow rate and removes 50 % of the pollutant remaining after Stage 2. Calculate (a) the final concentration of pollutant Y (in mg L\(^{-1}\)) after all stages, (b) the total mass of pollutant Y removed per day (in g), and (c) the overall percentage removal efficiency. Present your answer as the three values in the order asked, separated by semicolons.