Assignment 1
Question 1
(a) What are the 4 different pollutants in domestic wastewater (sewage). Name the methods by which each of these pollutants can be treated before disposal into waterways.
(b) Describe briefly the two ways phosphorus is removed from sewage in a wastewater treatment plant
(c) What are the pollutant removal mechanisms in an intermittently decanted aerated lagoons (IDAL) used in wastewater treatment plant.
Question 2
a) Compare the ultrafiltration with nanofiltration in terms of pressure, pore size and energy requirements (with typical values).
b) Explain the membrane bioreactor using a schematic diagram. What are the three main advantages of membrane bioreactor compared to the conventional biological treatment.
Question 3
a) Why is it important to have dewatering of digested sludge?
b) What are the beneficial uses of biosolids?
Question 4
a) What is the advantage of dual media filter over sand filter?
b) How can N removed from wastewater treatment?
Question 5
a.Compare the solids and bacterial concentrations allowed in the (i) treated sewage effluent and (ii) drinking water
b.How is microorganisms measured in sewage?
Question 6: A metal plating industry produces wastewater from Chromium (0.5 m3/d) and Nickel plating (0.5 m3/d) and waste acid cleaning (4 m3/d) activities. If the Chromium and Nickel concentrations are 0.01 kg/m3 and 0.005 kg/m3, find the amounts of Chromium and Nickel wasted on a daily basis. Suggest a simple waste minimization program in this industry.
Question 7: (30% of the marks for this assignment is for this question)
This question can be done in group of two
List two existing examples on water reuse practices (place, what purpose, standards, methodology used, benefits and cost). One example should be from references other than the lecture notes. You may find details from EPA documents, national and international conference proceedings, recently published textbooks and web sites.
Assignment 2
Question 1
The waste contributing steps to tomato processing industry is listed below with quantities and biochemical oxygen demand (BOD) and suspended solids (SS) values
|
Stream
|
Process Unit
|
Flow (L/min)
|
BOD (mg/L)
|
SS (mg/L)
|
|
#1
|
Prewashing units
|
1890
|
75
|
180
|
|
#2
|
Washer
|
1000
|
90
|
340
|
|
#3
|
Boiler feed water
|
1136
|
30
|
20
|
|
#4
|
Cooker
|
38
|
3520
|
7575
|
|
#5
|
Processing unit #1
|
76
|
4410
|
8890
|
|
#6
|
Processing unit #2
|
570
|
230
|
170
|
|
#7
|
Processing unit #3
|
380
|
450
|
540
|
a) Provide a suitable waste segregation (separation) and treatment scheme
b) What will be the flow and BOD concentration of the combined stream of #4 and #5
Question 2
List three methods to achieve waste minimization in paper and pulp manufacturing processes and indicate how and in which steps these methods can be employed?
Schematic diagram of the paper and pulp manufacturing processes and waste contributing steps are shown below:
Question 3
List 3 main human barriers of Waste minimization.
Question 4
Suggest a treatment method for reuse or by-product recovery for the following wastes.
a. Dairy (milk) waste containing whey (protein) material
b. Cutting oil waste coming from metal cutting machines
c. Dye waste from cloth dyeing (textile) industry.
Question 5
Using the flow diagram given below explain the role of
i) Filter
ii) Activated carbon
iii) Filter press
iv) Equalization (equalizing) tank.
Question 6
(a) What are the 2 different environmental problems of using incinerators? How can they be overcome?
(b) Based on the data provided below, calculate the charges for disposal of the waste with and without recycling at the transfer station, and comment on these costs.
Waste generated 10 tonnes
Recyclable waste 70 %
Transport costs $ 1 per tonne per km
Distance to landfill 120 km
Location of transfer station mid way
Cost of recovery at transfer station $10 per tonne
Sale value of recyclable goods $15 per tonne
Tipping cost $40 per tonne
Question 7
Estimate the moisture content and density 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 8
Describe the seawater desalination processes and their functions in a desalination plant in Australia. Compare the processes with Sydney's drinking water treatment plant process.
Assignment 3
1. Design a constructed wetland to treat domestic wastewater from a small town of 6000 population. Wastewater generation is at 160 litres per capita per day. The initial BOD of the primary treated wastewater is 180 mg/l and the treated wastewater needs to conform to a BOD standard of 30 mg/l. Fine and medium sized gravel are as substrate material for wetland bed of depth 0.6 m. Assume the water depth is 0.4 m and the hydraulic gradient is 0.003. Further assumptions are porosity of 40% and hydraulic conductivity of 10.2 x 10-2 m/sec. Annual average temperature of water is 27oC.
2. Calculate the volume of rain tank required for Rain Water Harvesting. The area of the roof is 100 m2. Assume the average ddemand is =50 L/person per day. The house is occupied by four people. The monthly rainfall is summarised in the table below.
|
Jan
|
Feb
|
Mac
|
Apl
|
May
|
Jun
|
July
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
|
103
|
117
|
131
|
127
|
123
|
128
|
98
|
81
|
68
|
76
|
83
|
78
|
3. Undertake a literature review of a BMP device of your choice. Focus on the planning, modelling, design and implementation aspects of the BMP. (not more than 5 pages). Literature on UTS online is generally sufficient for this purposes, however students must not be limited by this.