A dye mill has a highly coloured wastewater with a flow of 32 million L/day. One suggestion has been to use biological measn to treat the watewater and remove the colour, so a pilot study is performed. Using a mixed batch reactor, the following data result:
Time; 0, 10, 20, 40, 80 Dye Concentration (mg/L); 900, 720, 570, 360, 230.
A completely mixed aerated lagoon (batch reactor) is to be used. How large must hte lagoon be to achieve a concentration of effluent that is 50 mg/L