Question 1 Indicate the important water quality constituents in the following wastewater streams:

(i) storm water
(ii) wastewater from a sanitary landfill

Question 2 A particular wastewater stream has dissolved oxygen (DO) concentration of 2.0 mg / L and a discharge rate of 0.5 m3 / s. The river into which it is being discharged has DO equal to 8.3 mg / L, a flow rate of 4.35 m3 / s and a temperature of 20 °C. The saturated value of DO at 20 °C is 9.1 mg / L,

(a) Assuming complete and instantaneous mixing, estimate the initial dissolved oxygen deficit of the mixture of wastewater and river water just downstream from the discharge point.
(b) Assuming the critical DO condition occurs at 4 km downstream, draw a graph to show the trend of the variation of the DO at 2 km and 10 km downstream of the discharge point (calculation not necessary).
(c) What are the main factors that affect the DO concentration given by Streeter-Phelphs equation?

Question 3 Suggest a technology that can be used to treat the following wastes

(a) particulates from a Cement factory (about 0.1 microns particles)
(b) particulates from a Flour factory (about 5 microns particles)
(c) organic pollutants from air in the Painting industry
(d) Sulfur dioxide from the air in the Chemical industry

Question 4 A jet engine has a sound pressure level of 90 dB, as heard from a distance of 30 m. A ground crew member is standing 30 m away from a four-engine jet. What sound pressure level (SPL) reaches his ear when the first engine is turned on? Then when the second is started, so that two engines are running? When the third begins and then when all four are running?. Assume there is no background noise.(Use the chart provided in the class notes).

Question 5 In a big city of 1 million population, the waste management authority (WMA) is asked to prepare a report on solid waste management practices. You are the project officer in the WMA. Assume the city has similar socio-economic condition as Sydney
(a) Estimate the amount of solid waste produced per year
(a) Explain a material recovery facility you will adopt in this city

(b) The conventionally used sanitary landfill is not suitable for the city due to the non-availability of land. Suggest alternative technological solutions to economically handle the solid waste generated in the city.

Question 6 Estimate the moisture content, density and energy content of a solid waste sample with the composition given in Table below.

Component
Percentage by Mass
Moisture (%)
Density (kg/m3)
Energy (KJ/kg)
Food waste
Paper
Garden trimmings
Wood
Metal cans
20
50
15
5
10
70
8
60
20
2
290
85
110
250
90
4650
16700
6550
18700
500

Question 7 Explain why it is important to maintain environmental flows in river. Outline why it is especially important to maintain low to very low flows

Question 8 Explain the difference between regulated rivers and unregulated rivers

Question 9 Describe how past practices has led to some of the problems associated with the provision of environmental flow problems in rivers in New South Wales.

Question 10 Outline some new Government initiatives being undertaken to provide environmental flow in rivers.

Question 11 Describe what information can be obtained from models such as HEC RAS that is useful for environmental flow analysis.

Question 12 The World Commission on Environment and Development defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their needs.

This assignment requires both reflection on the meaning and implication of the objectives of ecological sustainable development.

To achieve this aim the student is required to undertake an original field study. The information must be gained from observations of the student. The information must not be obtained from previous work undertaken from another source or from the internet.
Select a site ( the size is not important but a large site is very difficult to assess in the timeframe of the assignment)

Describe the a) location
b) ecological features using the following subheadings as a guide only:

¨ habitat
¨ vegetation-biodiversity
¨ soil and water quality (visual assessment only)

From the above information, identify whether the site is under pressure (e.g. from housing development). In addition write a brief report (no more than 3 pages) to assess the environmental impacts of possible changes of land use on and around your site making any recommendations that would lead to a more sustainable approach