Environmental Engineering Reference
In-Depth Information
construction and hazardous ones, such as drums with spent oil, sludge, paint and adhesive
leftovers, and alkaline batteries (Elshorbagy and Alkamali, 2005).
During drilling, several solid waste materials are produced such as drill mud, drill cuttings,
franc sand, bottom wastes, and camp waste. Drill mud, which is a colloidal suspension of clay
and chemical additives, is used to lubricate the cutting action and to create hydrostatic pres-
sure to avoid uncontrollable blowouts. This mud is reused several times, but after recurrent use
needs to be disposed of. Drill cutting are pieces of rock and soil removed during drilling; and
franc sand is aluminum silicate beads injected into the wells to keep fractures open. Bottom
waste refers to dense sludge composed by crude oil, paraffin, asphaltics, reservoir material,
drilling mud, slightly radioactive material, and franc sand (“Pollution prevention opportunities
in oil and gas production, drilling, and exploration,” 1993).
Mining for metals leaves behind waste rock and tailing piles. In addition, during production
of alumina from ore, a solid waste called “red mud” is produced at a ratio of 2 tonnes per tonne
of alumina. Red mud is a slurry with a pH between 10 and 12 and is rich in aluminum oxides,
silicon, iron, titanium, sodium, and calcium (World Bank, 1999). The aluminum smelting
process produces 40 to 60 kg of solid residues per tonne of product, which includes spent
cathodes, spent pots, and cell linings among the most important (World Bank, 1999).
The main solid waste of the cellulose pulp industry is waste bark and from lumber mills
sawdust, bark, and shavings. All this solid waste is disposed of in several ways including
burned for energy, incinerated, landfilled, applied as soil amendment, and converted into land-
scaping materials.
Generation of postconsumer solid waste
Postconsumer solid waste is one of the most visible impacts of the use of packaging
(Fig. 12.3). In the United States, one-third of the municipal solid waste is attributed to food
and nonfood packaging (Ackerman, 1997). In countries with efficient solid waste collection
Other
3%
Wood
6%
Glass
5%
Paper
34%
Ruber, leather, and
textiles 7%
Metals
8%
Plastics
12%
Yard trimmings
13%
Food scraps
12%
Figure 12.3
Municipal solid waste generated in the United States by material in 2006.
From Environmental Protection Agency (EPA), 2007.
