From Toilet To Brickyard: Recycling Biosolids To Make Sustainable Bricks
January 22, 2019: RMIT University
Associate Professor Abbas Mohajerani with a biosolids brick. Credit: RMIT University
How can you recycle the world's stockpiles of treated sewage sludge and boost sustainability in the construction industry, all at the same time? Turn those biosolids into bricks.
Biosolids are a by-product of the wastewater treatment process that can be used as fertiliser, in land rehabilitation or as a construction material.
Around 30% of the world's biosolids are stockpiled or sent to landfill, using up valuable land and potentially emitting greenhouse gases, creating an environmental challenge.
Now a team at RMIT University in Melbourne, Australia, has demonstrated that fired-clay bricks incorporating biosolids could be a sustainable solution for both the wastewater treatment and brickmaking industries.
Published this month in the journal Buildings, the research showed how making biosolids bricks only required around half the energy of conventional bricks.
As well as being cheaper to produce, the biosolids bricks also had a lower thermal conductivity, transferring less heat to potentially give buildings higher environmental performance.
The United States produces about 7.1 million tonnes of biosolids a year, while the EU produces over 9 million tonnes. In Australia, 327,000 tonnes of biosolids are produced annually.
The study found there was a significant opportunity to create a new beneficial reuse market -- bricks.
About 5 million tonnes of the biosolids produced in Australia, New Zealand, the EU, US and Canada currently go to landfill or stockpiles each year. Using a minimum 15% biosolids content in 15% of bricks produced could use up this 5 million tonnes.
Lead investigator Associate Professor Abbas Mohajerani said the research sought to tackle two environmental issues -- the stockpiles of biosolids and the excavation of soil required for brick production.
"More than 3 billion cubic metres of clay soil is dug up each year for the global brickmaking industry, to produce about 1.5 trillion bricks," Mohajerani, a civil engineer in RMIT's School of Engineering, said.
"Using biosolids in bricks could be the solution to these big environmental challenges.
"It's a practical and sustainable proposal for recycling the biosolids currently stockpiled or going to landfill around the globe."
The research examined the physical, chemical and mechanical properties of fired-clay bricks incorporating different proportions of biosolids, from 10 to 25%.
The biosolid-enhanced bricks passed compressive strength tests and analysis demonstrated heavy metals are largely trapped within the brick. Biosolids can have significantly different chemical characteristics, so the researchers recommend further testing before large-scale production.
The biosolids bricks are more porous than standard bricks, giving them lower thermal conductivity.
The research also showed brick firing energy demand was cut by up to 48.6% for bricks incorporating 25% biosolids. This is due to the organic content of the biosolids and could considerably reduce the carbon footprint of brick manufacturing companies.
The results of a comparative Life Cycle Assessment and an emissions study conducted as part of the research confirmed biosolids bricks offered a sustainable alternative approach to addressing the environmental impacts of biosolids management and brick manufacturing.
Abbas Mohajerani, Aruna Ukwatta, Tristan Jeffrey-Bailey, Michael Swaney, Mohtashim Ahmed, Glen Rodwell, Simon Bartolo, Nicky Eshtiaghi, Sujeeva Setunge. A Proposal for Recycling the World’s Unused Stockpiles of Treated Wastewater Sludge (Biosolids) in Fired-Clay Bricks. Buildings, 2019; 9 (1): 14 DOI: 10.3390/buildings9010014
Bird Of The Month
Silvereye, Zosterops lateralis. Warriewood Wetlands
We have so many wonderful photographers and so many bird-lovers in Pittwater that one of our regular very best photographers has suggested we share a 'Bird of the Month' throughout 2019.
We start we a tiny gregarious songbird. This one was photographed in Warriewood Wetlands - bird paradise!
The Silvereye is a very small bird with a conspicuous ring of white feathers around the eye, and belongs to a group of birds known as white-eyes.
Silvereyes feed on insect prey, fruit and nectar.
Silvereye pairs actively defend a small territory. The nest is a small, neatly woven cup of grasses, hair, and other fine vegetation, bound with spider web. It is placed in a horizontal tree fork up to 5m above the ground. The nest is constructed by both sexes, who both also incubate the bluish-green eggs. If conditions are suitable two to three clutches will be raised in a season.
Minimum Size: 10cm
Maximum Size: 12cm
Average size: 11cm
Average weight: 11g
Breeding season: August to February; later in the north
Clutch Size: 2 to 3, rarely 4
Habitat: Coastal heath, shrublands, forests, farms, and urban areas.
Bird description from the book "Birds of Warriewood Wetland Irrawong Reserve - An Introductory Field Guide", published by PNHA
Photo by Michael Mannington, Community Photography
Avalon Boomerang Bags 2019 Start Date +
WEEKLY WORKSHOPS CONTINUE IN 2019
TUESDAY 5TH February will be our first day back.
WORKSHOPS are held Tuesdays during the school term
at the Avalon Recreation Centre 11.30 - 3.30pm
Everyone is welcome; come for an hour or come for all 4, we'll even provide a cuppa and guaranteed laughs. Non-sewers also very useful.
Pop in with your excess fabric donations or spare enviro bag donations. We also sell our very handy Boomerang Bag coffee cups, stainless steel drink bottles and other enviro products and of course, our "Bought to Support" bags.
Our Christmas Celebration was truly that - a celebration of all that we have achieved together. We've made lots of bags, reduce much fabric from landfill, helped Avalon move towards using less plastics, made friendships and been a small cog in the wheel doing our bit for a better environment tomorrow.
Thanks to all those who helped organise - the food, the drinks, the 'real' glasses and "real" plates, the fabric serviettes, the fruit mince pies and the Christmas "star" decoration activity....a lovely day.
Recognition
Round of applause and congratulations to our local 2018 Eco Heroes - our very own Avalon Boomerang Bag volunteer Row Handley, and Manly Boomerang Bag coordinator Jude Furniss. Both of these incredible women are part of many environmental groups making a huge impact in the local community and for the conservation of the environment particularly our oceans and waters ways. Thank you both and our best wishes for your projects in 2019 and beyond.
Got time to sew over the holidays - need fabric ????
Reply to this email or call Robyn 0412 314 754
Sonic Sea Screening At Avalon Cinema: Feb 13
Living Ocean have initiated this campaign to raise awareness that 3D seismic testing is mooted for this year off our coastline and the public needs to be made aware of what that involves to realise what is at stake.
They will have a balanced panel of experts to discuss the movie and also the issues for all life in the area from any effects of the testing. Also the reality of offshore gas fields and how it could impact fishing, tourism, whale watching plus the hazards that failure of any equipment resulting from the industrialisation of rigs just offshore could produce.
Living Ocean successfully campaigned with NOPSEMA against 2D testing offshore scheduled for peak northern migration of Humpback whales last year. However small scale 2D testing went ahead anyway in 2018.
Get your ticket HERE ($11.64)
Council Issues Warning To Beware Of Suspect Tree Operators
January 2019: NBC
Northern Beaches Council is warning the community to be wary of unscrupulous tree lopping operators who flout the law, making residents liable for thousands of dollars of fines for their illegal works.
Ray Brownlee said Council is aware of rogue tree tradesman currently door knocking in Avalon and offering to cheaply remove or trim large trees without Council permission. This follows a spate of similar incidents at around the same time last year.
“Our community is passionate about trees and at Council we are committed to protecting as much of our tree canopy as possible,” Mr Brownlee said.
“Most trees over 5m high are protected and residents need Council approval to prune more than ten percent of the tree or remove it. This ensures we maintain the green environment that is so valued by our community.
“Without consent to prune or remove the trees, residents can attract thousands of dollars in fines.
“If in doubt, residents should contact Council to ensure they, or those they contract, are working within the law.”
Mr Brownlee said that a good tree operator will be knowledgeable about what is permitted, be appropriately insured and qualified to undertake the work.
“If an operator can’t demonstrate they meet these requirements, residents should think twice about employing them to do the job in case they ended up being liable for their illegal activities.
“If the work is illegal, then that leaves the property owner at risk of being fined because the contractors have usually left with no traceable contact information,” Mr Brownlee said.
Property owners who are approached by contractors should contact Council first, to check that the work complies with Council’s tree controls or visit our website. Residents can also contact NSW Fair Trading on 13 32 20.
Visit:
How Hot Are Atoms In The Shock Wave Of An Exploding Star?
January 22, 2019
An international team of researchers combined observations of nearby supernova SN1987A, made with NASA's Chandra X-Ray Observatory, with simulations to measure the temperature atoms in the shock wave that occurs from the explosive death of a star. This image superimposes synthetic X-ray emission data onto a density map with from the simulation of SN1987A. Credit: Marco Miceli, Dipartimento di Fisica e Chimica, Università di Palermo, and INAF-Osservatorio Astronomico di Palermo, Palermo, Italy
A new method to measure the temperature of atoms during the explosive death of a star will help scientists understand the shock wave that occurs as a result of this supernova explosion. An international team of researchers, including a Penn State scientist, combined observations of a nearby supernova remnant -- the structure remaining after a star's explosion -- with simulations in order to measure the temperature of slow-moving gas atoms surrounding the star as they are heated by the material propelled outward by the blast.
The research team analyzed long-term observations of the nearby supernova remnant SN1987A using NASA's Chandra X-ray Observatory and created a model describing the supernova. The team confirmed that the temperature of even the heaviest atoms -- which had not yet been investigated -- is related to their atomic weight, answering a long-standing question about shock waves and providing important information about their physical processes. A paper describing the results appears January 21, 2019, in the journal Nature Astronomy.
"Supernova explosions and their remnants provide cosmic laboratories that enable us to explore physics in extreme conditions that cannot be duplicated on Earth," said David Burrows, professor of astronomy and astrophysics at Penn State and an author of the paper. "Modern astronomical telescopes and instrumentation, both ground-based and space-based, have allowed us to perform detailed studies of supernova remnants in our galaxy and nearby galaxies. We have performed regular observations of supernova remnant SN1987A using NASA's Chandra X-ray Observatory, the best X-ray telescope in the world, since shortly after Chandra was launched in 1999, and used simulations to answer longstanding questions about shock waves."
The explosive death of a massive star like SN1987A propels material outwards at speeds of up to one tenth the speed of light, pushing shock waves into the surrounding interstellar gas. Researchers are particularly interested in the shock front, the abrupt transition between the supersonic explosion and the relatively slow-moving gas surrounding the star. The shock front heats this cool slow-moving gas to millions of degrees -- temperatures high enough for the gas to emit X-rays detectable from Earth.
"The transition is similar to one observed in a kitchen sink when a high-speed stream of water hits the sink basin, flowing smoothly outward until it abruptly jumps in height and becomes turbulent," said Burrows. "Shock fronts have been studied extensively in the Earth's atmosphere, where they occur over an extremely narrow region. But in space, shock transitions are gradual and may not affect atoms of all elements the same way."
The research team, led by Marco Miceli and Salvatore Orlando of the University of Palermo, Italy, measured the temperatures of different elements behind the shock front, which will improve understanding of the physics of the shock process. These temperatures are expected to be proportional to the elements' atomic weight, but the temperatures are difficult to measure accurately. Previous studies have led to conflicting results regarding this relationship, and have failed to include heavy elements with high atomic weights. The research team turned to supernova SN1987A to help address this dilemma.
Supernova SN1987A, which is located in the nearby constellation called the Large Magellanic Cloud, was the first supernova visible to the naked eye since Kepler's Supernova in 1604. It is also the first to be studied in detail with modern astronomical instruments. The light from its explosion first reached earth on February 23, 1987, and since then it has been observed at all wavelengths of light, from radio waves to X-rays and gamma waves. The research team used these observations to build a model describing the supernova.
Models of SN1987A have typically focused on single observations, but in this study, the researchers used three-dimensional numerical simulations to incorporate the evolution of the supernova, from its onset to the current age. A comparison of the X-ray observations and the model allowed the researchers to accurately measure atomic temperatures of different elements with a wide range of atomic weights, and to confirm the relationship that predicts the temperature reached by each type of atom in the interstellar gas.
"We can now accurately measure the temperatures of elements as heavy as silicon and iron, and have shown that they indeed do follow the relationship that the temperature of each element is proportional to the atomic weight of that element," said Burrows. "This result settles an important issue in the understanding of astrophysical shock waves and improves our understanding of the shock process."
Marco Miceli, Salvatore Orlando, David N. Burrows, Kari A. Frank, Costanza Argiroffi, Fabio Reale, Giovanni Peres, Oleh Petruk, Fabrizio Bocchino. Collisionless shock heating of heavy ions in SN 1987A. Nature Astronomy, 2019; DOI: 10.1038/s41550-018-0677-8