Skip to content

SciTech

Scientists find value in waste incineration ash

by Rachel England 11 Feb 2011
Scientists find value in waste incineration ash

A team of Italian researchers have developed a low-cost technique for extracting valuable elements from fly ash produced by Municipal Solid Waste Incineration (MSWI).

MSWI reduces the volume and weight of social refuse and generates power as it is burnt. The resulting fly ash contains a variety of sought-after elements, including silica, aluminium, iron, calcium and bromine.

However, it also contains elements of lead, zinc, mercury and cadmium (among other heavy metals), making it a hazardous waste material and as such it is predominantly sent to landfill. It's been thought that fly ash would help to improve the properties of cement, but the danger of metals leaching into the environment is too high.

Previous attempts at turning fly ash into a safe substance have included diluting it with blast furnace slag, thermal treatment and vitirification (turning it into glass), washing and solidification, but these processes only serve to create further waste.

The new research saw the introduction of colloidal silica to the mix, where samples of fly ash from sites in France and Italy were suspended in silica solutions for an hour before being dried into a powder called COSMOS.

Leaching tests subsequently revealed that a far lower amount of zinc leached from the COSMOS sample than the raw ash sample, and that no leached lead was detected at all.

Any soluble salts in the COSMOS material were washed out after the metal stabilising process, meaning both the salts and COSMOS would become available as secondary materials. Furthermore, as carbon dioxide is sequestered during the COSMOS production, this could have positive implications for carbon credit trading.

MSWI ash is pH 12 and contains a large amount of electrolytes, which creates preferable conditions for undertaking the COSMOS process in such a way as to safely and effectively reuse materials. If the technique is developed effectively, fly ash would become a safe and useful additive to cement after all. Furthermore, the material reuse would reduce the demand and exploitation of natural resources.


Trending Eco-Friendly Clothing

Love My Planet Women's Relaxed Fit Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Love My Planet Women's Relaxed Fit Hoodie
Love My Planet women's eco-friendly relaxed fit hoodieSize Guide Centimeters 8 10 12 14 16 18 Bust 84 88 92 97 103 108 Waist 66 70 75 80 85 91 Hips 91 95 99 104 109 116 Bust: Measure around the fullest part of...
£38.00
£38.00
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Penguins Hate Push-Ups men's eco-friendly pullover HoodieSize Guide Centimeters XS S M L XL XXL Height 171 175 179 183 189 195 Chest 86 93 99 104 116 129 Waist 71 76 81 89 99 112 Chest: Measure all round your chest just below...
£38.00
£38.00
Close
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Earth
Quick Add
Close
Notify me
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Lightning Bolt kids eco-friendly long sleeve t-shirtSize Guide Centimeters 3-4yrs 5-6yrs 7-8yrs 9-10yrs 11-12yrs Height 98 112 125 136 147 Chest 60 66 70 75 84 Chest: Measure all around your chest just below your armpits. Height: Your natural height If you fall between...
£18.00
£18.00
Close
Notify me
Notify me
Notify me
Union Jack Tote Bag
Earth
Quick Add
Close
Notify me
Notify me
Union Jack Tote Bag
Union Jack eco-friendly colour tote bagProduct Specification Organic Cotton Tote Bag. Twill Weave (170gsm). 37 x 42 cm (7cm gusset.) Made in India / Designed on the Isle of Wight. Wash Cool, Hang Dry.
£16.00
£16.00
Close
Notify me
Notify me
Prev Post
Next Post

Eco-Friendly Shop

Women's Clothing

Eco-Friendly Clothing for Women Our online shop offers a wide range of sustainable women’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Men's Clothing

Eco-Friendly Clothing for Men Our online shop offers a wide range of sustainable men’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Kids Clothing

Eco-Friendly Clothes for Kids Our online shop offers a wide range of sustainable kids clothing products, including t-shirts, hoodies and jumpers. Our garments...
Shop Now
Someone recently bought a
[time] ago, from [location]

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Earth Times
Sign up for exclusive updates, new arrivals & insider only discounts

Recently Viewed

Edit Option
Back In Stock Notification
this is just a warning
Login
Shopping Cart
0 items

Before you leave...

Take 20% off your first order

20% off

Enter the code below at checkout to get 20% off your first order

CODESALE20

Continue Shopping