Week 10: Waste recovery and integrated balances
Where every organic stream goes, and whether the balance closes when you add it up.
Every stream goes somewhere. Household food waste, spent mushroom substrate, fish sludge, and the meat and dairy that weeks 4 and 5 sent away unprocessed each need a named destination and a mass in dry matter — and the balance has to close, with any loss stated as an assumption rather than left as a residual. A compost design states the pasteurisation target it is designed against and whose standard that is. Biogas is recorded and not credited; only the digestate's nutrients count toward anything. Alice Springs leads, because it is the site where the heat does most of the work for you. This is the first week where the subsystems stop being separate: an arrow drawn wrongly in week 3 shows up here as a balance that will not close.
This week
- Lecture, 10 May 2027
- Every stream goes somewhereWeek 10 — routing food waste, spent substrate, meat and dairy and fish sludge through compost and digestion, and closing the mass balance that is not banded
- Tutorial, 13 May 2027
- Closing the mass balanceWeek 10 tutorial — route every organic stream to a destination and prove, in dry matter, that nothing has quietly disappeared
- Assessed, due 13 May 2027
- Quiz 4: Storage, saturation and closing the balance4 % of the course mark. Week 10 — why annual water balances mislead, where storage stops buying performance, and what is deliberately not banded
- Worked example
- Alice SpringsThe Nguyens' home leads this week, because its climate makes this subsystem easy. All five homes are compared on the lecture page.
What you leave with
A closed dry-matter balance in which every organic stream has a destination and every loss term is stated.
You have finished the tutorial when all of this is true, and you can tell without asking anyone:
- every organic stream has a named destination and a mass in dry matter
- your balance closes, with any loss term stated as an assumption rather than as a residual
- your compost design states the pasteurisation target it is designed against and whose standard it is
- biogas, if produced, is recorded and not credited
- your food-waste figures come from your home's audit rather than the course convention
Assignment milestone
Quiz 4 (4 %), on weeks 9–10.
Where this sits
With the measured year in hand you size, cost and compare the options, then argue for the one you recommend — the cheapest arrangement that meets the household's own targets, plus an honest case for any dollar spent beyond it.
Expected effort
About 8 hours this week: 2 h lecture and notes, 2 h tutorial, 1 h preparation and quiz, 3 h assignment 2. The assignment hours go into: Waste balance closed; recovery options costed.
A planning guide from the semester planner, not a requirement and not a measurement of anyone. Tutorial submission sits inside the tutorial hours and the quiz inside preparation; neither is counted twice.