Environmental Engineering question: A drinking water treatment facility is planning to reduce operation cost and residence time for one of the reactors in the treatment plant. What type of rectors will you recommend and why? a. Batch reactor b. Plug flow reactor c. Continuously stirred tank reactor

Environmental Engineering: Water Treatment Please consider each of the following points: a. Determine the required residence time for each reactor of 3 equal volume CSTRs in series given a zero-order reaction with a reaction rate constant, k = -5 mg/L hr. The influent concentration is 125 mg/L and 95% conversion is required across the three-reactor system. What is the total reactor system residence time? b. Determine the required residence time for a single CSTR given the same conditions.  c. Determine the required residence time for a PFR given the same conditions. d. Why are all three residence time the same?

Please upload your full solution to the following problem. A series of experiments was conducted in a batch reactor to assess the disinfection by chlorine of the protozoan Giardia lamblia. In each experimental run, the concentration of free available chlorine was varied and the time required to kill 99 percent of the organisms was determined. The results showed that a Ct value of 100 mg-min/L was sufficient to achieve 2-log removal. Assume that the Chick- Watson model holds with n = 1. A. What value is the psuedo-first order disinfection rate coefficient k (min ¹) when the chlorine concentration is 1 mg/L? B. At a chlorine concentration of 1 mg/L and a contact time of 10 minutes, what fraction of the G. lamblia organisms would be killed? C. At a chlorine concentration of 10 mg/L and a contact time of 5 minutes, estimate the fraction of the G. lamblia organisms that would be killed. 4

Mr.X performs the laboratory test and determines that 12 mg/l of alum dose is required to treat the water. What is the quantity of alum required to treat 14 million liters of water per day at a treatment plant. Also determine the amount of carbon dioxide gas produced per liter of water during treatment. B I U GGG 25 85 ET M 69