VCE Environmental Science

This week we had an interesting visit form our CSIRO “Scientists in Schools” partner, Melissa Toilf. Melissa is an environmental scientist who works for the Department of Land and Water, specializing in research about wastewater treatment. One of her current projects is looking at producing biodiesel from algae grown in wastewater. The algae uses the nutrients (nitrogen and phosphoros) in the water for growth, it is then harvested and separated to extract the fatty acids, which can be used as a form of biodiesel fuel. Although this process is not currently commercially viable, the scientists at CSIRO are working on improving the techniques  to enable more sustainable water treatment and energy use.

You all should be working hard, revising for exams at present, so use your time effectively. Past exams are available on the VCAA website, and you would benefit from completing at least five of these prior to your final examination.

Unit 4 of VCE Environmental Science is about Ecologically Sustainable Development, including the Environmental Management Systems of government and businesses. Every reputable organisation in Australia should be considering the impacts of climate change on their business – even if they are skeptical of the anthropogenic causes of global warming, changing climate will affect resource managment, agriculture, manufacturing, transport and consumer spending. An Emissions Trading Scheme (or Carbon Pollution Reduction Scheme) will result in rising energy costs and hopefully provide opportunities for increased recycling, improved renewable energy technologies and greater uptake of low-emission vehicles. Companies that plan for climate change, using Environmental Risk Assessment principles, will be most prepared to act to reduce the threats to their economic, social and environmental sustainability.

At Hawkesdale P12 College we aim to reduce our energy use from from the grid and reduce solid waste going to landfill by recycling. In September our 5.5 KWh photovoltaic solar system was installed. This was made possible through a federal government grant from the National Solar in Schools program ($50,000) and a state government grant of $15,000. You can see our current energy production and total since installation at the Sunny WebBox site. By using renewable energy we hope to reduce our carbon footprint and educate students and the community about the benefits of solar power.

The 350 network, supported by World Vision Australia, is a group of over 200 organisations around the world who support a target of 350ppm of carbon dioxide so that our atmosphere is “similar to the one on which civilization developed and to which life on earth is adapted”. The 24th of October is International Day of Climate Action – you can join a local action or register your own here.  Calculate how much carbon dioxide you produce each year using this Energy Requirements Survey.

This post is part of a global project “Blog Action Day 2009” about climate change. From the previous post: More information about Co-generation Plants from the Energy Globe Portal. More on heat-pump technologies, cogeneration and refrigeration research from the Swiss Federal Office of Energy.

Image Source

We were pleased to welcome Matt Boyce, Environment and Sustainability Manager at Midfield Meats, into our class today. Matt spoke generally about the company and his role and more specifically about the EMS at Midfield and the new co-generation plant. As a food processing industry, large amounts of water and energy are used and consequently, high greenhouse gas emissions are released. The EMS, produced in 2005,  also addresses noise, dust, odour, solid waste and waste water. As power and water are two of the most costly inputs into the company, Midfield planned to implement projects that would address cost savings in these areas.

An Adelaide company, SBA Engineering, have installed the Combined Heat and Power generator, which is leased by Midfield. By installing the plant, Midfield aim to reduce their energy costs and greenhouse gas emissions by at least 40%.  For example, since the plant was installed in April, electricity use from the grid has been reduced from around 1,150MWh to 600 MWh per month, a decrease of 48%.  Use of natural gas, a ‘cleaner’ fuel that produces fewer greenhouse gas emissions, has increased by about 33%. The cogeneration plant runs in conjunction with a geothermal bore, which also reduces energy costs by supplying water at a higher temperature than the town supply (40C compared to 15-18C). The geothermal water is treated, using reverse osmosis, heated by the cogeneration plant and the water used for cleaning within the plant.

The company are also in the planning stages of a biodiesel plant, turning animal fat (tallow) into fuel. The plant will have the potential to produce 12 million litres of biodiesel each year, reducing vehicle emissions by almost 30,000 tonnes of carbon dioxide gas equivalent  each year. This biodeisel, a renewable fuel without the issues of ethanol (turning food into fuel) will be used by the freight division of the company and excess fuel sold on the wholeslae market.

Heron Island is a 20-hectare coral cay, 65km east of Gladstone, at the southern end of the Great Barrier Reef. Half of the island is a national park, one quarter is the University of Queensland Research Station and one quarter is the Resort. The island can be occupied by up to 400 people at any one time, with up to 200 resort guests, 100 staff and 100 scientists and students at the HIRS. The resort is advertised as an ecotourist destination, with opportunities to swim with sting-rays, reef sharks, sea turtles and other marine life. It is certainly nature-based, with ample bird life, coral reefs teeming with fish and invertebrates and walks through rare Pisonia forest. The island also has extensive opportunities for environmental education with ‘The Heron Gazette’ in every room, daily news leaflets – the ‘Heron Times’- with information about local species and island activities, as well as the well-designed and equipped Information Centre, staffed by friendly and helpful resort employees. The resort holds regular information nights, about the biology of sea turtles or star-watching, as well as daily reef or forest walks or excursions to the Research Station. It also has a popular Junior Ranger program for 7 to 12 year olds. However, is the resort an ecologically sustainable development? I went behind the scenes, to areas that many tourists don’t even think about – the desalination plant, sewerage treatement plant and recycling and waste collection areas to find out.

All the fresh water used on the island is produced from this desalination plant, which pumps water from the sea, filters out particles, including living organisms, and then forces the water through fine membranes. The filters consist of layers of gravel, coarse and fine sand, which remove algae and floating debris. The salty brine is returned to the sea, and the fresh water is pumped up to high storage tanks. The whole process is energy intensive, powered by four huge diesel generators.

Sewerage treatment isn’t something a lot of people like to think about – but imagine what life would be like without it! All the wastewater from the toilets (so-called ‘black’ water) is pumped to concrete sinks, where it is mixed and aerated and then passed into settling ponds. Bacteria consume some of the nutrients, but the remaining sludge is emptied into concrete evaporating ponds, lined with sand. As the water evaporates, the sludge dries and cracks and is eventually shovelled into skips and removed from the island.

This waste, together with food scraps from the kitchen (frozen to prevent putrification) and recyclables (cardboard, glass, aluminium and plastics) must all be shipped off the island and disposed of appropriately. Any waste escaping would provide excessive nutrients to the delicate coral reef ecosystem, causing increased algal growth and disrupting the existing food webs. Transport of people (staff and patrons), products (food, drinks and other consumables, furniture and equipment etc) and waste materials to and from the island requires enormous quantities of fossil fuels.

At present, the island’s energy needs are provided by fossil fuels (diesel and gas), with solar panels for hot water requirements. What further renewable energy sources could be used to  make this development more environmentally sustainable? Geothermal or hydropower are not available and solar PV panels would only be able to supply a small proportion of the island’s energy requirements.

Aquaflow Bionomic Corporation - turning algae grown on sewerage ponds into fuel.

Ecogeneration News - general information about processing biomass for renewable energy.

EM Matters – Solar Energy on Queensland’s Lady Elliot Island and Solar PV Sparkles on Magnetic Island

Earth2Tech – Clean Energy Island – Maldives Goes Carbon Neutral

Energy Island - a world of clean energy and water