Mercury and other metals

Hg

Of the heavy metals, mercury is a major concern due to its toxicity and high volatility. It is subject to the European Waste Incineration Directive, which puts limits on emissions to air, so the flue gas is treated post-combustion. The resulting toxic fly ash must be handled as hazardous waste.

Acute exposure to mercury vapour can lead to irritation of the lungs, coughing, chest pain and shortness of breath, and central nervous system (CNS) effects such as tremors and mood changes. Chronic exposure also leads to CNS effects such as increased excitability, excessive shyness and irritability.

Cadmium emissions from an incinerator the size of the Exeter plant are approximately equivalent to one-eightieth of the emissions from a medium sized UK coal-fired power station.

Acute inhalation exposure to cadmium can lead to irritation of the lungs. Chronic exposure can cause a build-up of cadmium in the kidneys that can lead to kidney disease.

Although zinc poses no documented health risks, if its physical state is altered during use then health risks can be created. Inhalation of metallic oxide fumes can lead to metal fume fever.

Non-ferrous and/or ferrous metals are recovered (separated from Municipal Solid Waste or Incinerator Bottom Ash) and recycled from most incinerators in the UK.

Hydrogen halides

HHal

Hydrogen fluoride and hydrogen chloride, but not hydrogen bromide, are subject to the European Waste Incineration Directive, which puts strict limits on emissions to air.

They are acidic gases primarily released to air from combustion of fuels which contain trace amounts of fluoride, chloride or bromide. They are highly corrosive, and inhalation of air containing low levels of hydrogen chloride can cause throat irritation or asthma. Exposure to higher levels may result in effects including rapid breathing, blue colouring of the skin, fluid accumulation in the lungs and in extreme cases severe swelling of the throat, suffocation and death. Inhalation of air containing hydrogen fluoride can cause irritation of the eyes, nose and throat. Exposure to high levels may cause muscle spasms and can damage the lungs and heart and in extreme cases can result in death. 

Pattern – Bonds

Bonds

Download this pattern as a pdf

See also the patterns for the atoms and the number and colours of atoms and bonds needed for each particle.

Wool
Needles
Double knit
3.75mm DPNS

Pattern – joining two atoms of the same colour

Cast on 4 sts, leaving a 20 cm tail
Knit i-cord for 16 rows
Cast off i-cord, leaving a 20 cm tail

Pattern – joining two different colour atoms

Cast on 4 sts, leaving a 20 cm tail
Knit i-cord for 8 rows
Knit 1 stitch i-cord, join the second colour and knit the rest of the row
Knit i-cord for 7 rows
Cast off i-cord, leaving a 20 cm tail

Knot the tails of the two colours at the join.
Thread each tail in turn onto a needle, pass through the cord of the same colour, cut so ends stay inside.
Work the knot inside the cord, and the stitches so they even out.

 

Thread each 20cm tail onto a needle and sew the bond onto the atom.
Pass remaining tail through atom, cut so ends stay inside.

Pattern – Atom

Atoms

Download this pattern as a pdf

See also the patterns for the bonds between atoms and the number and colours of atoms and bonds needed for each particle.

Our prototypes were made with bog-standard acrylic wool, and the atoms stuffed with a slightly shredded half of a plastic charity collection bag. These are the sorts of materials that will be burnt in the Incinerator. But really, anything that is weatherproof will be suitable.

If you are new to knitting, some of the codes below may be a mystery. But the internet is full of
marvels such as tutorials and knitting videos. It’s how we learnt i-cord.

kfb
*..*
k2tog
skpo
knit into the front an back of the stitch
repeat stitches in between
knit two together
slip stitch, knit next stitch, pass slip stitch over the knitted stitch
Wool
Needles
Tension
Double knit
3.75mm
26 stitches to 10cm

The atom will be approx 20 cm in circumference.

Pattern

Cast on 12 sts

r1
r2
r3
r4
r5
r6
r7-r18
r19
r20
r21
r22
knit
purl
kfb into each st (24 sts)
purl all
*k1, kfb* across row (36 sts)
cast on 1 st, purl across row, cast on 1 st at end (38 sts)
continue in stocking stitch for 12 rows starting with a knit row
k2tog, *k1, skpo* (25 sts)
purl
k2tog, *skpo* to last 3 sts, k1, k2tog (13 sts)
p1, *p3tog*

Cut yarn leaving a 20 cm tail.
Thread onto needle, thread through remaining stitches and pull tight.
Sew edges together, stuff atom, thread through casting on stitches and pull tight.
Knot tails together, thread onto needle and pass through atom, and cut so ends stay inside.