A pond of volume 10⁶ L receives influent stream water containing 75 mg/L soluble organic carbon and 6 mg/L inorganic carbon at a rate of 0.01 m3/s. Advection is much more important that diffusion or dispersion as a mechanism for transporting material at the inlet and outlet to the pond. In the pond 75% of the incoming organic matter is consumed by micro-organisms which convert 30% of the ingested organic carbon into new cellular material and release 70% as CO2 after respiration. The CO2 combines immediately with water to form H2CO3 and then rapidly becomes distributed among the three inorganic carbon species. Assume 50% of the cellular mass is carbon. The entire system is at steady state.

a. Write mass balances on total organic carbon (TOC), dissolved organic carbon (DOC), and total inorganic carbon (TIC), and compute the steady state concentrations of these species.

b. How much biomass is created per liter of influent?