New recycling invention

Newly patented technology invented by ANSTO scientist, Dr Tony Taylor, can cheaply make sewage and waste water clean enough to drink and could cut water use by 60%, according to ANSTO's online magazine, Velocity.

Taylor, a microbiologist, has invented a revolutionary membrane bioreactor that he describes as a simple arrangement of gills that uses bacteria to operate as a lung and a stomach.

"The system literally eats waste matter and breathes air, so is self perpetuating," explained Taylor."The great thing about the technology is that, firstly, it's cheap and, secondly, it can be used in a variety of sizes for houses, unit complexes or municipal treatment plants.

"At this stage we have made a working model the size of a fridge freezer that can be used in a house to recycle waste and we are now looking for business partners to help develop and manufacture this size and bigger sizes in the future," he said.

Called the nano-particulate membrane bioreactor (NMB), the secret of this technology is in the membrane, which is inexpensive and is patented by ANSTO.

"In most similar technologies the biomass (fungi and bacteria) this is grown in liquid which means oxygen levels are low and aeration is expensive," explained Dr Taylor. "My membrane deals with these issues cheaply and effectively so the biomass can effectively do its job of eating all the rubbish and leaving the clean water behind.

"On one side of the membrane cells are grown in direct contact with air and, on the other side, the sewage and waste water flows, but at the same time feeds the cells through the extremely porous material," said Dr Taylor. "This process enables 50 times more biomass growth compared to other membrane surface culture technologies.

"At about $1 per square metre, this technology is cheaper than current membranes which can cost up to $500 per square metre," he said. Overall the whole new invention is a lot cheaper. Many sewage plants spend around $250,000 a year on electricity to aerate their systems and the NMB would cost around 20% of this figure.

There are many other uses to this invention, including: antibiotic and production; mining; bioremediation; and aquaculture.

In the case of aquaculture, the sludge from the sewage treatment process, which collects at the bottom of the bio-reactor can be used to feed prawns and yabbies and the NMB delivers so much oxygen to the water that higher organisms such as worms and insects appear in the sludge in 24 hours. This makes for ideal fish food.