a)An industry generates a waste stream containing 5.0 mmol/L of an organic contaminant and must meet an effluent limitation that allows a maximum of 1.0 mol/d of the contaminant to be discharged. Adsorption of the contaminant on PAC follows a Langmuir isotherm with Kads ¼ 12.0 L/mmol and qmax ¼ 1.8 mmol/g. How much carbon would be used per liter of wastewater and per day in an equilibrium adsorption process if the process flow was 400,000 L/d?

(b) The plant is considering an expansion that would double its wastewater flow rate to 800,000 L/d. However, the discharge limitation will not change. Compute the increases in the required concentration and daily requirement for PAC.

(c) Determine the total daily requirement for activated carbon after the expansion if the treatment process is carried out in two steps: first, some activated carbon is added to the water and, after the system reaches equilibrium, the activated carbon is filtered out and a second, equal dose of activated carbon is added to achieve the treatment goal.

Answer rating: 100% (QA)

a The maximum amount of contaminant that can be discharged per day is 10 mold The amount of contaminant present in the wastewater stream is 50 mmolL To determine the amount of PAC required for adsorpt... View the full answer