Homework #1 due Sep 15


Homework #2 due Oct 1

1. Estimate the number of moles of electron carriers and ATP/GTP produced from the following reactions:
a) complete oxidation of glucose to CO2 with oxygen as electron acceptor
b) complete oxidation of butane to CO2 with oxygen as electron acceptor

2. As an environmental consultant you are asked to evaluate the option of remediating groundwater contaminated with nitrate. One of the technologies you are considering is the anaerobic biological removal of nitrate by denitrification. Explain the microbial degradation strategy you will adopt for the anaerobic system. In particular, explain the half reactions that would be involved in the degradation process, and clearly identify the electron donor and acceptor. Based on your chosen amendment, and a vale of fs = 0.3 (fraction of electrons used for cell synthesis) calculate the minimum concentration of amendment that will be required to achieve complete nitrate removal from an existing concentration of 100 mg/L in groundwater.
3. Determine the carbonaceous and nitrogenous oxygen demand in mg/L for a 1L solution containing 300 mg acetic acid (CH3COOH) and 300 mg glycine (CH2(NH2)COOH).
4. The 5-day BOD for a wastewater is 210 mg/L. If the BOD removal rate can be approximated by a first order process with a first order rate constant of 0.23 day-1, calculate the 10-day BOD and ultimate BOD for the wastewater. Plot the degradation of BOD with time for this wastewater.

Homework #3 due October 20

1. Problem 3.1 in text

2. Problem 3.5 in text

3. Problem 3.18 in text


Homework #4 due Nov 19

1. Using results from the BOD test carried out by the class, calculate the 5-day BOD of the water sample collected from Gwynns Run during the class field trip on Nov 7, 2003.

2. Using influent BOD and VSS measurements for the Gwynns Run water sample and design specification of the set of three treatment lagoons being built, estimate the performance of the proposed facility for an assumed base flowrate of 100 L/s. Use rate parameters and other information as provided in Example 7.1 for an aerated lagoon. Also calculate the performance if the lagoons are operated as stabilization lagoons (Example 7.6) instead of aerated lagoons.

3. Kitchen waste that is dumped into the sink exerts a significant oxygen demand in wastewater treatment plants. Calculate the cost of electricity to supply oxygen to treat 1kg of used vegetable oil that is dumped into a kitchen sink. Note: This is an open ended problem, and requires you to make several assumptions. Your job is to make the best possible assumptions to come up with the cost. You should be able to find the required data to solve this problem from your texts and handouts. See me if you have any questions.

Homework #5 due Dec 3

1. Use the steady-state water treatment plant modeling program developed by Garnica and Speitel (1999) to solve Example problem 9.1 in text. Compare the performance of the 1-sludge and 2-sludge designs in the removal of BOD and N.

Design a new configuration of reactors that can achieve better effluent quality for both BOD and N removal.