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Published: 19 September 2011

Case for capping our high level of e-waste contamination

Australian environmental researchers warn that fourteen kinds of heavy metals and toxic flame retardants have been detected in contaminated water draining from landfill sites in Australia.

Old iMacs at a recycling transfer station: Most of our old computers and TVs end up in landfill, leaching toxic chemicals into the environment.
Credit: hroe/istockphoto

Steps should be taken to prevent further leaching, as traces of these metals were also found in groundwater adjacent to the landfills, says Ms Peeranart Kiddee and Professor Ravi Naidu from CRC CARE and The University of South Australia.

‘Most of these materials have probably leaked from electronic waste, which includes old computers, mobile phones, refrigerators, televisions, batteries, wires with flame-retardant casings and more,’ says Prof. Naidu.

‘As e-waste only came into the picture 10 years or so ago, we used to dispose of most of it in landfills. Approximately 84 per cent of e-waste was dumped, with only 10 per cent being recycled in those days.’

Toxic metals measured by the researchers included arsenic, cadmium, cobalt, chromium and zinc.

Water leaching from landfills also contained PBDEs (polybrominated diphenyl ethers), flame-retardant chemicals found in many electronic products. PBDEs are persistent organic pollutants (POPs) and can be highly toxic to both humans and the environment.

‘The content of PBDEs found in Australian landfill leachates is much higher than those from Japan,’ Prof. Naidu says.

‘When groundwater is contaminated it in turn contaminates soil. Both water and soil can be used for growing crops, with the result that the toxins may enter the food chain, which is highly undesirable.

‘It will be very expensive and impractical to excavate what’s already buried, due to the large size of these dumping grounds.

‘What we can do now is find out how extensive the problem is, and develop cost-effective ways to prevent the leaching. One way is to put a cap on the sites, which can minimise the impact of rainfall to them. Another is to erect underground barriers that will absorb and immobilise the pollutants.

Meanwhile, the Australian Government has released for public comment draft regulations for a national TV and computer recycling scheme.

The aim of the proposed regulations – made under the Product Stewardship Act 2011, which came into effect in August 2011 – is to boost the volume of televisions, computers and computer products recycled in Australia to 80 per cent by 2021-22.

Key elements of the draft regulations include:

  1. Recycling targets for televisions and computers to start at 30 per cent in 2012-13, rising progressively to 80 per cent by 2021-22

  2. Minimum reasonable access requirements to establish national coverage of collection services, which will need to be fully met by June 2013

  3. The annual threshold at which an importer or manufacturer is covered by the regulations set at 15 000 units for computer products and 5000 units for televisions and computers.

Submissions can be made up until 10 October 2011.

Source: CRC CARE/Australian Government website

Published: 26 September 2011

Renewable energy sector to benefit from wind-speed research

Craig Macaulay

While some recent international studies have shown a decrease in wind speeds in several parts of the globe, including Australia, more recent results from CSIRO show that Australia’s average wind speed is actually increasing.

The ability to accurately quantify long-term variations in wind speeds is essential to the viability of Australia’s wind power sector.
The ability to accurately quantify long-term variations in wind speeds is essential to the viability of Australia’s wind power sector.
Credit: Gregory Heath

CSIRO scientists have analysed wind speed observations to understand the causes of variations in near-ground-level wind and explore long-term wind speed trends.

Accurate estimates of long-term trends provide a useful indicator for circulation changes in the atmosphere and are invaluable for the planning and financing of sectors such as wind energy, which need to map risk management under a changing climate.

‘We have a good picture of wind energy availability across Australia from previous CSIRO wind mapping and, with the growth of wind farms, there is an emerging need to understand how climate change can affect the wind resource,’ says Dr Alberto Troccoli, lead author of a recent paper published in Journal of Climate. 1

‘Wind power production is expected to increase greatly over the coming years and the associated electricity system will be subject to variations of several hundred megawatts – depending on wind availability.

‘The ability to quantify with accuracy these long-term variations is essential to the sector from an economic point of view.’

Dr Troccoli said that, averaged across Australia over 1989–2006, wind speeds measured at a height of 10 metres had increased by 0.69 per cent per annum, compared to a decline of 0.36 per cent per annum for wind speeds measured at 2m height.

‘The potential for increasing the efficiency of energy operations by using quality weather and climate information is therefore apparent and one of the first steps is the standardisation of wind recording stations.

‘Wind observations, like other meteorological variables, are sensitive to the conditions in which they are observed – for example, where the instrumentation sits relative to topographical features, vegetation and urban developments.’

The team found that the wind speed trends over Australia are sensitive to the height of the station, with winds measured at 10m displaying an opposite and positive trend to those reported by a previous study, which analysed only winds measured at 2m.

Light winds measured at 10m, a height that represents better the free atmospheric flow, tend to increase more rapidly than the average, whereas strong winds increase less rapidly than the average winds. Light and strong wind measured at a height of 2m tend to vary in line with the average winds.

‘Our work shows a number of challenges with the consistency of the observations during their period of operation and between sites across Australia,’ adds Dr Troccoli.

‘The quality of future wind observational datasets will depend on having consistency between sites, particularly with respect to measurement procedure, maintenance of instrumentation, and detailed records of the site history.’

He said the work has implications for a variety of sectors beyond wind energy including building construction, coastal erosion, and evaporation rates.

The conjunction of energy and meteorology is the central theme of the International Conference Energy & Meteorology on the Gold Coast in November.

Read Dr Troccoli’s thoughts on What’s the energy forecast? Bringing meteorology and generation together in the online forum, The Conversation.

1 A. Troccoli, K. Muller, P. Coppin, R. Davy, C. Russell and A. Hirsch (2011) Long-term wind speed trends over Australia. Journal of Climate, doi: 10.1175/2011JCLI4198.1

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