Bioremediation was selected to clean up 1000 m³ soil contaminated with 1000 mg/kg n-nonane (C₉H₂₀), 1000 mg/kg toluene (C₇H₈), and 2000 mg/kg benzene 1,2-diol (C₆H₆O₂). The soil bulk density is 1,800 kg/m³.

(A) Estimate the average chemical structure/molecular formula of the contaminants (20%)

(B) Determine the most appropriate electron acceptor and metabolism mode for the destruction of the above hydrocarbon mixture (20%)

(C) Estimate the amount (kg) of electron acceptor (20%) and nutrient (nitrogen (20%) and phosphorous (20%)) needs Assumptions:

• Ammonia is used as the nitrogen source;

• Phosphorus need for microbial growth is approximately one-sixth of that for nitrogen source;

• The composition of the cellular structure is C₅H₇O₂N.

• The energy factors for the conversion of contaminants to biomass are listed in the following table:

Electron acceptor	fs value
O2	0.5
NO3	0.3
SO4	0.1
CO2