24th April 2011 Marvellous Mushrooms

A week ago, I mentioned how mushrooms were being used to take agricultural waste and turn it into an alternative to Styrofoam. Well, not only can mushroom be used to provide a biodegradable packaging material, it seems they could be used to break down disposable nappies which may take centuries to rot away.

The problem with nappies is they are high in cellulose, which does not decay quickly. However, oyster mushrooms will feed on this and can completely break down a nappy in 4 months. The nappies are steam treated to prevent the spread of disease, and then the mushrooms should, theoretically, be safe to eat. The  problem with this is that the cost of the steam treating may make it non-viable. On the other hand, the selling of the mushrooms is really just a bonus compared with destruction of potentially billions of dirty nappies.

Source: The Economist: Bottom feeders

18th April 2012 Bah Styrofoam! Yay Mushrooms!

Styrofoam gets everywhere and it will still be around in 10 000 years.

What alternative is there?

Mushrooms! The blocks are not made from these mycelium but are grown. The mycelium are mixed with local agricultural waste which is placed in a mould and kept in the dark for 5 days.  At the end of the five days, fibres have filled the mould making the block of packaging material.

This packaging material never has to end up as landfill as it can be used to improve soil.  It wont be around in 10000 years and it's also fire resistant.

It is already being used by some companies instead of Styrofoam.



USA Science Festival Blog: Revolutionizing product packaging  for another video
Ecovative Design the company growing the packaging
Steelcase goes diy with home grown packaging a company using the packaging

18th April 2011 Paper and Carbon-13

Why study carbon-13 uptake by trees?

The uptake of carbon-13 instead of carbon-12 by plants is dependent on environmental conditions, and as such is an indicator of environmental changes. Plants prefer carbon-12 over carbon-13. When photosynthesis is intense, they have to use carbon dioxide which contains carbon-13.  Due to the burning of fossil fuels, themselves low in carbon-13, the fraction of carbon-13 compared with carbon-12 in the air has decreased.

How can carbon-13 uptake be measured?

When testing trees for the amount of carbon-13 in atmospheric carbon dioxide, scientists have to take samples from many trees from different places. It can also be measured by using ice cores.

So what's new?

Instead of travelling the world in search of trees, Prof. Dan Yakir, Weizmann Institute of Science, went to the library. He took samples from magazines and newspapers dated 1880-2000. These magazines were from two European and two American publishers. He analysed the amount of carbon-13 in these paper samples to see if they reflected the changes in environment caused by fossil fuel burning.

Why does this matter?

The analysis of the carbon-13 content of the paper showed that its concentration in the atmosphere has decreased demonstrating the increased use of fossil fuels. The change in the carbon-13 levels in paper are consistent with the carbon-13 levels in the air and tree rings. This means that the technique could perhaps be used to provide data for climate scientists.  If independent sources for air levels of carbon-13 are available, then this technique could be used to date manuscripts.

Sources

Weizmann Institute of Science: Pollution history preserved in paper
Reading between the lines: Papers report on global change
Wikipedia: Suess effect