VCE Environmental Science

Water discharge from Portland Aluminium

By now you should have all your information, including relevant data, about fluoride as a pollutant at Portland Aluminium. Your report should include the characteristics of fluoride, including strategies that reduce the risk of pollutants affecting human health and the environment as well as the direct and indirect effects on the health of humans and the environment.

“On completion of this unit the student should be able to describe the characteristics of pollutants and evaluate the management options for reducing the risk of a pollutant affecting the health of the environment and humans.”

It is important that you make an attempt to evaluate the management options that Portland Aluminium have implemented to reduce fluoride emissions at the smelter. Have they been successful? Could they  be improved? Compare emissions from Portland to other aluminium smelters – how do they measure up?

The Portland Aluminium smelter is situated on 600 hectares of land, 500 of which form “Smelter in the Park”, a once-barren area that has been revegetated with a large variety of indigenous plants. This area forms a buffer zone, that protects surrounding residents from the full impact of gaseous emissions from the smelter. There are five monitoring stations at different locations around the smelter that provide data on fluoride and sulfur emissions on a regular basis. Portland Aluminium also routinely test their workers, using urine and blood tests, as well as exposure badges, which monitor the levels of fluoride that staff have been subjected to.

Environmental scientists also do water testing and take tail-bone samples of the local kangaroos and teeth, bone and horn samples of the beef cattle , to test for long-term fluoride exposure. An international botanist expert visits annually to check for signs that toxic emissions may be affecting local vegetation. Signs of fluoride exposure include yellowing and curling of leaves and tissue death.

Portland Aluminium use several methods to prevent excessive fluoride emissions, including the A398 fluoride recovery system, in which fluoride emissions are captured from the hooded aluminium pots and forced through a conveyor of alumina, to form reacted or fluoride-enriched alumina. This is then added to the pots, which reduces the temperature (and therefor the energy required) to obtain the pure aluminium. The particulate and gaseous emissions are filtered through huge canvas bags, also coated with alumina, which traps 98% of fluoride.

In the potrooms, the major point source of fluoride emissions, Portland Aluminium have laser air monitoring of gaseous fluoride, with a traffic light system – green, amber and red. Between 045ppb and 600ppb, the lights are green; between 600ppb and 800ppb the lights are amber and above 800ppb the lights are red, which indicates an error in the process – too many hoods open at the same time.

The Victorian governmetn has produced this site, “Fluoride in the air environment“, which describes the sources of fluoride in Victoria and how it is monitored, including EPA limits.

Hawkesdale P12 College has registered with the CO2nnect project to learn about carbon dioxide emissions produced on the way to and from school each day. We will collect data on how far each student travels to school, their method of transport and enter these details into a database. We will complete a questionnaire and compare our responses to those of other schools in Australia and internationally. Think about how our results will differ from an urban school in Australia (in Warrnambool or Melbourne for example) and schools in highly populated countries such as India, Africa or China.

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This is a reverse osmosis water treatment plant in Korea, similar to the desalination plant proposed for a site near Wonthaggi, Victoria. The state government has recently released an Environmental Effects Statement that included detailed studies of the effects on local flora and fauna, significant indigenous and fossil sites, land values, coastal views and the community. The EES concluded that there would be no serious, irreversible damage caused by the desalination plant, although over 1 million tonnes of greenhouse gas emissions will be produced each year of operation. Read the article here.

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The first outcome for this term is as follows:
“Describe the characteristics of pollutants, and evaluate management options for reducing the risk of a pollutant affecting the health of the environment and humans.”
You are required to write a report describing the properties and effects of fluoride. This task is worth 25% of your school-assessed course-work. We will be visiting Portland Aluminium on Wednesday 6th August (departing 9.00am and returning 3.30pm) to meet the environmental officer and obtain primary data regarding fluoride emissions from point, diffuse and fugitive sources.

You can access the unit-4-assessment-task-fluoride sheet here.

You can use the following resources:

Victorian Government – Fluoride in the air environment

National Pollutants Inventory – Fluoride compounds

Alcoa in Australia – Environmental Sustainability

Australian Aluminium Council – 2007 Sustainability report

Spent Pot Lining Treatment and Fluoride Recycling Project

Environmental Improvement Plan for Portland Aluminium (2003/4)

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Professor Ross Garnaut has warned that the Great Barrier Reef, Kakadu’s wetland system and the Murray-Darling Basin are all at risk from the warmer, drier temperatures and rising sea-levels caused by climate change. Professor Garnaut released his draft review of the social and economic effects of a carbon emissions scheme yesterday. “The risk can be substantially reduced by strong and early action by all major ecomonies”, he said in a speech to the National Press Club.

On the same day, Origin Energy has finally committed to building a $640 million gas-fired power plant at Mortlake. The 1,000 MW facility will be built in stages and, when completed, will produce enough electricity to power up to 1.5 million homes. Energy and Resources Minister, Peter Batchelor, claims that the gas-fired plant will emit 70% less greenhouse gases than a brown coal fired plant.

The Warrnambool Standard reported today that “about 1,000 native trees and shrubs will be planted at the Hawkesdale Racecourse Reserve as the Moyne Shire aims to improve it’s green credentials.” The project will help to offset the carbon emissions from the council’s 57 cars for one year. The Hawkesdale Racecourse Reserve is an area of Crown land that once contained the golf course. Keith Davis, the Moyne Shire’s Environment co-ordinator, said that the new native trees and shrubs will enhance and buffer existing vegetation and increase species diversity. The new plantings will avoid the areas of valuable native grasslands and threatened species, such as clover glycine.
Carbon Offsetting aims to reduce carbon emissions by balancing sources of carbon dioxide and other greenhouse gases (emissions from cars in this case) with sinks (trees, shrubs and carbon-storing vegetation).

The Moyne Shire also has at least one Toyota Prius as part of their fleet – a petrol-electric hybrid that achieves fuel efficiency in the order of 5.7 litres per 100 kilometres. Less petrol used means less greenhouse gas emissions!