Ozone is sometimes used as a disinfectant for drinking water (e. g. the dallas east side water treatment plant). ozone is highly reactive and will inactivate most pathogens while imparting a "good" taste, odor, and color to the water. it was found that ozone reactions in water nearly follow first‐order kinetics in ozone concentration such that its concentration decreases by 50% in 12 minutes. a water supplier wants to inject ozone into a pipe bringing water to the treatment plant to pre‐ disinfect the influent. the 3‐ft diameter pipe is 3,400 feet long with a steady flow rate of 10,000 gpm. what concentration of ozone (in mg/l) would be injected at the head of the pipe so that there will be an ozone concentration of 1 mg/l at the pipe’s exit into the plant? the pipe may be realistically assumed to act as an ideal pfr.