Get Advice on Live Video Call
Earn $ Cash $ with
consultations on Bissoy App

A continuous process is set up for treatment of wastewater. Each day, 103 kg cellulose and 105 kg bacteria enter in the feed stream, while 102 kg cellulose and 1.5 x 102 kg bacteria leave in the effluent. The rate of cellulose digestion by the bacteria is 8 x 102 kg d-1. The rate of bacterial growth is 4x 102 kg d-l; the rate of cell death by lysis is 6 x 102 kg d-1. Write balances for cellulose and bacteria in the system.

Correct Answer: 1× 102 kg, 9.965 × 104 kg
Cellulose is not generated by the process, only consumed. Using a basis of 1 day, the cellulose balance in kg is : (103 – 102 + 0 – 8 x 102) = accumulation Therefore, 1× 102 kg cellulose accumulates in the system each day. Performing the same balance for bacteria: (105 – 1.5 x 102 + 4 x 102 – 6 x 102) = accumulation Therefore, 9.965 × 104 kg bacterial cells accumulate in the system each day.

The fresh feed to an ammonia synthesis reactor contains nitrogen, hydrogen and 2.0 mole per cent inerts. The molar ratio of H2:N2 is 3:1. The product stream consists of pure ammonia. Since conversion in the reactor is only 15%, a recycle stream is used and in order to avoid build-up of inerts, a purge stream is withdrawn. The rate of purge stream is adjusted to keep inert concentration in the recycle stream at 8 mole per cent. For a fresh feed rate of 100 moles/hr. Note that recycle stream contains only nitrogen, hydrogen and inerts. The N2:H2 ratio of 1:3 is maintained in every process stream, and calculate the moles of nitrogen entering the reactor and in the recycle stream?

The fresh feed to an ammonia synthesis reactor contains nitrogen, hydrogen and 2.0 mole per cent inerts. The molar ratio of H2:N2 is 3:1. The product stream consists of pure ammonia. Since conversion in the reactor is only 15%, a recycle stream is used and in order to avoid build-up of inerts, a purge stream is withdrawn. The rate of purge stream is adjusted to keep inert concentration in the recycle stream at 8 mole per cent. For a fresh feed rate of 100 moles/hr. Note that recycle stream contains only nitrogen, hydrogen and inerts. The N2:H2 ratio of 1:3 is maintained in every process stream, and calculate the number of moles, moles of inerts and moles of hydrogen in the recycle stream?

The fresh feed to an ammonia synthesis reactor contains nitrogen, hydrogen and 2.0 mole per cent inerts. The molar ratio of H2:N2 is 3:1. The product stream consists of pure ammonia. Since conversion in the reactor is only 15%, a recycle stream is used and in order to avoid build-up of inerts, a purge stream is withdrawn. The rate of purge stream is adjusted to keep inert concentration in the recycle stream at 8 mole per cent. For a fresh feed rate of 100 moles/hr. Note that recycle stream contains only nitrogen, hydrogen and inerts. The N2:H2 ratio of 1:3 is maintained in every process stream. Calculate the moles of ammonia produced.

Which of the following events occur during the stationary phase of bacterial growth?
P. Rise in cell number stops.
Q. Spore formation in some Gram-positive bacteria such as Bacillus subtilis.
R. Cell size increases in some Gram-negative bacteria such as Escherichia coli.
S. Growth rate of bacterial cells nearly equals their death rate.
T. Decrease in peptidoglycan cross-linking.

S1: Different countries show different pattern of growth.
P: Many others have a high birth rate with a low death rate.
Q: Some have a high birth rate and still have a high death rate.
R: The developing countries show the most rapid growth rate.
S: Some others like the European nations, have a low birth rate and a low death rate.
S6: Compared to this in Europe the growth rate is low.

The Proper sequence should be:

In balanced growth phase of a cell,
P. All components of a cell grow at the same rate.
Q. Specific growth determined by cell number or cell mass would be the same.
R. The growth rate is independent of substrate concentration.
S. The growth rate decreases with decreasing substrate concentration.

A bacteria gives birth to two new bacteria in each second and the life span of each bacteria is 5 seconds. The process of the reproduction is continuous until the death of the bacteria. initially there is one newly born bacteria at time t = 0, the find the total number of live bacteria just after 10 seconds :

The BOD5 of an effluent from a coke oven plant is 25 mg/L, and the effluent discharge is 4 ML/d. The receiving stream has a BOD5 of 2 mg/L and the stream flow is 40 ML/d. What will be the BOD5 in the stream just below the mixing zone?

Which of the following statements are true/false?
1. Every worker who has worked fora period of 240 days or more in a factory during a calendar year shall be allowed during the subsequent calendar year, leave with wages.
2. A worker who has been allowed leave for not less than four days, in the case of an adult, and five days, in the case of a child shall, before his leave begins, be paid the wages due for the period of the leave allowed.
3. If a worker works in a factory works for more than nine hours in any day or for more than 40 hours in any week, he shall, in respect of overtime work, be entitled to wagesat the rate oftwicehis ordinary rate of wages.4. The periods of work of an adult worker in a factory shall be so arranged that inclusive of his intervals for rest, they shall not spread over more than eleven and a half hours in any day.

Check for deflection due to prestressing force if given data is Prestressing force is 182×103 eccentricity of cable is 105, Length of the cable is 1000, elastic modulus of concrete is 34×103, Moment of inertia is 3200×105?