Nitrite reductase will convert nitrite to ammonium. There are two types of nitrite reductase characteristics given below;

a) Both nitrite reductase consist of a single 63kD polypeptide

b) In leaf chloroplasts and root plastids contain different forms of the nitrite reductase enzyme

c) In shoot nitrite reductase directly dependent on the light reaction by the ferredoxin, it activates nitrite reductase in choloroplast

d) NADPH in the roots is provided by pentose phosphate pathway, it also activate nitrite reductase in the plastids

Which of the correct statement about nitrite reductase characteristics?

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#Question id: 14262

#SCPH05 I Biotechnology

The BOD5 value of a waste-water feed stream to an activated-sludge unit is S0 = 300 mg/l, and the effluent is desired to be S = 30 mg/l. The feed flow rate is F = 2× 10^7 l/day. For the recycle ratio of α = 0.5 and a steady-state biomass concentration of X = 5 g/l, Use the following kinetic parameters:

 

calculate Required reactor volume (V). 

_______________10^6

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#Question id: 14263

#SCPH05 I Biotechnology

The BOD5 value of a waste-water feed stream to an activated-sludge unit is S0 = 300 mg/l, and the effluent is desired to be S = 30 mg/l. The feed flow rate is F = 2× 10^7 l/day. For the recycle ratio of α = 0.5 and a steady-state biomass concentration of X = 5 g/l, Use the following kinetic parameters:

 

calculate Biomass concentration in recycle (Xr).

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#Question id: 14264

#SCPH05 I Biotechnology

The BOD5 value of a waste-water feed stream to an activated-sludge unit is S0 = 300 mg/l, and the effluent is desired to be S = 30 mg/l. The feed flow rate is F = 2× 10^7 l/day. For the recycle ratio of α = 0.5 and a steady-state biomass concentration of X = 5 g/l, Use the following kinetic parameters:

 

calculate Hydraulic residence time

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#Question id: 14265

#SCPH05 I Biotechnology

For the activated-sludge, the specific growth rate of cells is given by 

 

The following parameter values are known: F = 500 l/h, α = 0.4, ɣ = 0.1, Xe = 0, V = 1500 l, Ks = 10 mg/l, µm = 1 h-1 , kd = 0.05 h-1 , S0 = 1000 mg/l, Y M X/S = 0.5 g dw/g substrate. Calculate the substrate concentration (S) in the reactor at steady state. -------------------------

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#Question id: 14266

#SCPH05 I Biotechnology

For the activated-sludge, the specific growth rate of cells is given by 

 

The following parameter values are known: F = 500 l/h, α = 0.4, ɣ = 0.1, Xe = 0, V = 1500 l, Ks = 10 mg/l, µm = 1 h-1 , kd = 0.05 h^-1 , S0 = 1000 mg/l, Y M X/S = 0.5 g dw/g substrate.. Calculate the cell concentration in the reactor. 

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#Question id: 14267

#SCPH05 I Biotechnology

In a trickling biological filter, the BOD value of the feed stream is S_0i = 500 mg/l with a feed flow of F = 10³ l/h. The effluent BOD value is desired to be S₀ = 10 mg/l. The following kinetic parameters for the biocatalysts are known: r_m = 20 mg/S/l .h and K_s = 200 mg S/l. The biofilm thickness is L = 0.1 mm. The cross-sectional area of the filter is A = 2 m² , and the biofilm surface area per unit volume of the bed is a = 500 cm² /cm³ . Assume that dissolved oxygen is the rate-limiting substrate and the diffusion coefficient of oxygen is D_O2 = 2 × 10^-5 cm² /s. Determine the required height of the bed. You can assume first-order bioreaction kinetics?

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