Environmental Engineering

LABORATORY #7 Disinfection: Chlorination of Wastewater Effluent Note: the original version of this laboratory experiment was written by the Association of Environmental Engineering Professors (Unit Operations and Unit Processes Laboratory Manual, 4th edition, 1998). In Spring 2005, Shamin Begum (graduate assistant) and Dr. Jacimaria Batista modified the laboratory to fit the coliform bacteria equipment available at UNLV. Learning objectives: 1. Students should be able to know what coliform bacteria are and why they were chosen as a measure of microbiological quality of waters. 2. Students should be able to explain the meaning of "concentration vs. time" as applied to disinfection of waters. 3. Students should be able to use an MPN table to interpret experimental data. 4. Students should be able to experimentally determine the inactivation rate constant and the coefficient of dilution.

Problem 7. The standard enthalpy for selected organic compounds is given in this problem. For each a-c below, calculate the net heats of combustion. Tell me the heat of combustion both in terms of per mol of fuel, and per mol of CO2 produced. (for combustion, you need 02 as a reactant and products will be H2O and CO2, do a simple balance. For the net heat released, the water is in the gas phase. Enthalpies for water, CO2 and 02 are provided in the tables in the notes uploaded to Canvas) А. Propane (C3н8): -103.8 k/mol B. n-Butane (C4H10): -124.7 kJ/mol C. Ethanol, (C2H5OH): -277.6 kJ/mol D. What of the above three fulels gets you the MOST energy per mol of CO2?

Which one of the following best illustrates a nonpoint source of pollution? oil leaking into the ocean from an oil rig ) wastewater from a coal-fired power plant storm-water drainage from the parking lot around a football stadium raw sewage released into a river when storm-water overflows a city's sewage treatment facility

10. Please identify the lake stratification layers then please describe what happens during spring and fall turnover.

2.8 How many kg/day of NaOH would need to be added to neutralize a waste stream generated by an industry producing 90,800 kg/day of sulfuric acid if 0.1% of the sulfuric acid is lost to the wastewater?The wastewater flow rate is 750,000 L/day.

Consider two strata of the same soil material that lie between two channels. The first stratum is confined and the second one is unconfined, and the water surface elevations in the channels are 24 m and 16 m above the bottom of the unconfined aquifer. What should be the thickness of the confined aquifer for which (1) the discharge through both strata are equal? (2) the discharge through the confined aquifer is half of that through the unconfined aquifer?

Problem 5. A sewer pipe 2 m in diameter is half full of water flowing at an average speed of 1.5m/sec with a BOD of 150 mg/L. The pipe flows into a basin (10,000 m³ volume), which is also fed by a stormwater pipe 1 m in diameter, half-full with water, flowing at 1.0 m/sec and no BOD.The basin has a constant volume, and a single outlet. What is the steady state concentration of BOD in this outlet stream? BOD degrades as a first order kinetics in the basin of 0.9 day'.

Blackwater has an industrial origin and contains metallic ions in excess that in an an aerobic atmosphere produce metallic sulphurs of a black colour.

2. A rapid sand filter has a sand bed depth of 762mm. Sand specific gravity = 2.65 Porosity (ɛ) = 0.41 Filtration rate = 1.53 Ips/m^2 Shape factor (4) = 0.80 Temperature = 15°C%3D H = 1.139 x 10³kg/m-s p = 999.1kg/m3 Determine the head loss for a clean filter using the Carman-Kozeny equation for a stratified bed.

18.12 For the following, calculate the hydroxide, carbonate, and bicarbonate alkalinity by the procedures (1} using alkalinity measurements alone and (2) using alkalinity plus pH measurements. The sample size is 100 mL, 0.020 N H2SO4 is used as the titrant,and the water temperature is 25°C (BG bromcresol green).