$22-6.$ If the influent ammonium concentration is $21\mathrm{.}8m\frac{g}{L},$ estimate the amount of alkalinity $($in

$m\frac{g}{L})$ that must be added to buffer the oxidation reaction assuming that a residual alkalinity of $80$

$m\frac{g}{L}$ as $CaC{O}_3$ is required to keep the $pH$ at approximately $7.$ Assume the influent alkalinity is $250$

$m\frac{g}{L}$ as $CaC{O}_3.$