A laboratory test was carried on a wastewater sample yielded the following results

BOD $=250$ mg$/$L$,$ Filtered BOD$=15$ mg$/$L after $30$ min of contact with biomass of MLSS concentration $3000$ mg$/$L$.$ Assume SVI of the contact tank effluent to be $125.$ Design a contact stabilization process with the following data. Assume all synthesis to take place in stabilization tank and $100\%$ efficiency of settler. The MLVSS$/$MLSS $=0\mathrm{.}8$

Q $=2$MLD

Se $=15$ mg$/$l

Yt$=0\mathrm{.}5$

Kd$=0\mathrm{.}1/$day

$$c $=8$ days

If recycling ratio is reduced by $10\%.$ For the same SVI. Calculate the new steady state biomass concentration in the stabilization tank.