Environmental impact of paper

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A pulp and paper mill in New Brunswick, Canada. Although pulp and paper manufacturing requires large amounts of energy, a portion of it comes from burning wood residue.

The environmental impact of paper is significant, which has led to changes in industry and behaviour at both business and personal levels. With the use of modern technology such as the printing press and the highly mechanised harvesting of wood, disposable paper has become a cheap commodity. This has led to a high level of consumption and waste. With the rise in environmental awareness due to the lobbying by environmental organizations and with increased government regulation there is now a trend towards sustainability in the pulp and paper industry.

Issues[edit]

The production and use of paper has a number of adverse effects on the environment which are known collectively as paper pollution. Pulp mills contribute to air, water and land pollution. Discarded paper is a major component of many landfill sites, accounting for about 35 percent by weight of municipal solid waste (before recycling).[1] Even paper recycling can be a source of pollution due to the sludge produced during de-inking.[2]

According to a Canadian citizens organization, "People need paper products and we need sustainable, environmentally safe production."[3] The amount of paper and paper products is enormous, so the environmental impact is also very significant. It has been estimated that by 2020 paper mills will produce almost 500,000,000 tons of paper and paperboard per year,[4] so great efforts are needed to ensure that the environment is protected during the production, use and recycling/disposal of this enormous volume of material.

Pulp and paper is the third largest industrial polluter to air, water, and land in both Canada and the United States, and releases well over 100 million kg of toxic pollution each year.[5]

Worldwide, the pulp and paper industry is the fifth largest consumer of energy, accounting for four percent of all the world's energy use. The pulp and paper industry uses more water to produce a ton of product than any other industry.[6]

Deforestation[edit]

Main article: Deforestation

Worldwide consumption of paper has risen by 400% in the past 40 years, with 35% of harvested trees being used for paper manufacture. Plantation forest, from where the majority of wood for pulping is obtained, is generally a monoculture and this raises concerns over the ecological effects of the practice.

Nitrogen dioxide and sulfur dioxide are major contributors of acid rain, whereas CO2 is a greenhouse gas responsible for climate change.

Water pollution[edit]

Waste water discharges for a pulp and paper mill contains solids, nutrients and dissolved organic matter such as lignin. It also contains alcohols, and chelating agents and inorganic materials like chlorates and transition metal compounds. Nutrients such as nitrogen and phosphorus can cause or exacerbate eutrophication of fresh water bodies such as lakes and rivers. Organic matter dissolved in fresh water, measured by Biological Oxygen Demand (BOD), changes ecological characteristics, and in worst-case scenarios leads to death of all higher living organisms. Waste water may also be polluted with organochlorine compounds. Some of these are naturally occurring in the wood, but chlorine bleaching of the pulp produces far larger amounts.[7]

Recycling the effluent (see black liquor) and burning it, using bioremediation ponds and employing less damaging agents in the pulping and bleaching processes can help reduce water pollution.

Discharges can also discolour the water leading to reduced aesthetics. This has happened with the Tarawera River in New Zealand which subsequently became known as the "black drain".[8][9]

Waste[edit]

Paper waste accounts for up to 40% of total waste in the United States, which adds up to 71.6 million tons of waste per year in the United States alone.[10] Paper waste like other wastes faces the additional hazard of toxic inks, dyes and polymers that could be potentially carcinogenic when incinerated, or comingled with groundwater via traditional burial methods such as modern landfills. Paper recycling mitigates this impact, but not the environmental and economic impact of the energy consumed by manufacturing, transporting and burying and or reprocessing paper products.

Wood pulping process[edit]

Chlorine and chlorine-based materials[edit]

Chlorine and compounds of chlorine are used in the bleaching of wood pulp, especially chemical pulps produced by the kraft process or sulfite process. Plants using elemental chlorine produced significant quantities of dioxins.[11] Dioxins are persistent organic pollutants that are generally recognized among the most toxic human-released pollutants in existence. Elemental chlorine has largely been replaced by chlorine dioxide and dioxin production very significantly reduced.[12][13]

As a result, from the 1990 onwards the use of elemental chlorine in the delignification process was substantially reduced and replaced with ECF (Elemental Chlorine Free) and TCF (Totally Chlorine Free) bleaching processes. In 2005, elemental chlorine was used in 19–20% of kraft pulp production globally, down from over 90% in 1990. 75% of kraft pulp used ECF, with the remaining 5–6% using TCF.[14] A study based on U.S. Environmental Protection Agency (EPA) data concluded that "Studies of effluents from mills that use oxygen delignification and extended delignification to produce ECF (elemental chlorine free) and TCF pulps suggest that the environmental effects of these processes are low and similar."[15] Most TCF pulp is produced in Sweden and Finland for sale in Germany,[12] all markets with a high level of environmental awareness. In 1999, TCF pulp represented 25% of the European market.[16]

TCF bleaching, by removing chlorine from the process, reduces chlorinated organic compounds to background levels in pulp mill effluent.[17] ECF bleaching can substantially reduce but not fully eliminate chlorinated organic compounds, including dioxins, from effluent. While modern ECF plants can achieve chlorinated organic compounds (AOX) emissions of less than 0.05 kg per tonne of pulp produced, most do not achieve this level of emissions. Within the EU, the average chlorinated organic compound emissions for ECF plants is 0.15 kg per tonne.[18]

However, there has been disagreement about the comparative environmental effects of ECF and TCF bleaching. On the one hand, paper and chemical industry-funded studies have generally found that there is no environmental difference between ECF and TCF effluents.[19] On the other hand, independent peer-reviewed study has found that, comparing conventional, ECF and TCF effluents before and after secondary treatment, “TCF effluents are the least toxic”.[20]

Sulfur, hydrogen sulfide, and sulfur dioxide[edit]

Main articles: Kraft process and Sulfite process

Sulfur-based compounds are used in both the kraft process and the sulfite process for making wood pulp. Sulfur is generally recovered, with the exception of ammonia-based sulfite processes, but some is released as sulfur dioxide during combustion of black liquor, a byproduct of the kraft process, or "red liquor" from the sulfite process. Sulfur dioxide is of particular concern because it is water soluble and is a major cause of acid rain. In 2006 the pulp and paper industry in Canada released about 60,000 tonnes of sulfur oxides (SOx) into the atmosphere, accounting for just over 4% of the total SOx emission from all Canadian industries.[21]

A modern kraft pulp mill is more than self-sufficient in its electrical generation and normally will provide a net flow of energy to the local electrical grid.[22] Additionally, bark and wood residues are often burned in a separate power boiler to generate steam.

Air emissions of hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, and other volatile sulfur compounds are the cause of the odor characteristic of pulp mills utilizing the kraft process. Other chemicals that are released into the air and water from most paper mills include the following:[23]

Bleaching mechanical pulp is not a major cause for environmental concern since most of the organic material is retained in the pulp, and the chemicals used (hydrogen peroxide and sodium dithionite) produce benign byproducts (water and, eventually, sodium sulfate, respectively).

However, the bleaching of chemical pulps has the potential to cause significant environmental damage, primarily through the release of organic materials into waterways. Pulp mills are almost always located near large bodies of water because they require substantial quantities of water for their processes. An increased public awareness of environmental issues from the 1970s and 1980s, as evidenced by the formation of organizations like Greenpeace, influenced the pulping industry and governments to address the release of these materials into the environment.[24] Environmental NGO pressure was especially intense on Swedish and Finnish pulp and paper companies.[25]

Conventional bleaching using elemental chlorine produces and releases into the environment large amounts of chlorinated organic compounds, including chlorinated dioxins.[7] Dioxins are recognized as a persistent environmental pollutant, regulated internationally by the Stockholm Convention on Persistent Organic Pollutants.

Dioxins are highly toxic, and health effects on humans include reproductive, developmental, immune and hormonal problems. They are known to be carcinogenic. Over 90% of human exposure is through food, primarily meat, dairy, fish and shellfish, as dioxins accumulate in the food chain in the fatty tissue of animals.[26]

Non-renewable resources[edit]

Clay or calcium carbonate are used as fillers for some papers. Kaolin is the most commonly used clay for coated papers.

Mitigation[edit]

Waste paper awaiting recycling in the Netherlands.

Some of the effect of the pulp and paper industry can be addressed and there is some change towards sustainable practices. The use of wood solely from plantation forests address concerns about loss of old growth forests.

Bleaching[edit]

The move to non-elemental chlorine for the bleaching process reduced the emission of the carcinogenic organochlorines. Peracetic acid, ozone[27] and hydrogen peroxide and oxygen are used in bleaching sequences in the pulp industry to produce totally chlorine free (TCF) paper.

Recycling[edit]

Main article: Paper recycling

There are three categories of paper that can be used as feedstocks for making recycled paper: mill broke, pre-consumer waste, and post-consumer waste.[28] Mill broke is paper trimmings and other paper scrap from the manufacture of paper, and is recycled internally in a paper mill. Pre-consumer waste is material that was discarded before it was ready for consumer use. Post-consumer waste is material discarded after consumer use such as old magazines, old telephone directories, and residential mixed paper.[29]

One concern about recycling wood pulp paper is that the fibers are degraded with each and after being recycled four or five times the fibers become too short and weak to be useful in making paper.[30]

The United States Environmental Protection Agency has found that recycling causes 35% less water pollution and 74% less air pollution than making virgin paper.[31] Pulp mills can be sources of both air and water pollution, especially if they are producing bleached pulp. Recycling paper decreases the demand for virgin pulp and thus reduces the overall amount of air and water pollution associated with paper manufacture. Recycled pulp can be bleached with the same chemicals used to bleach virgin pulp, but hydrogen peroxide and sodium hydrosulfite are the most common bleaching agents. Recycled pulp, or paper made from it, is known as PCF (process chlorine free) if no chlorine-containing compounds were used in the recycling process.[32]

Mechanical pulp mills[edit]

Wood pulp produced primarily by grinding wood is known as "mechanical pulp" and is used mainly for newsprint. These mechanical processes use fewer chemicals than either kraft or sulfite mills. The primary source of pollution from these mills is organic material such as resin acids released from the wood when it is processed. Mechanical wood pulp is "brightened," as opposed to bleached, using less toxic chemicals than are needed for chemical pulps.

Inks[edit]

Three main issues with the environmental impact of printing inks is the use of volatile organic compounds, heavy metals and non-renewable oils. Standards for the amount of heavy metals in ink have been set by some regulatory bodies.[33] There is a trend toward using vegetable oils rather than petroleum oils in recent years due to a demand for better sustainability.

Deinking recycled paper pulp results in a waste slurry which may go to landfill. De-inking at Cross Pointe's Miami, Ohio mill in the United States results in sludge weighing 22% of the weight of wastepaper recycled.[34]

In the 1970s federal regulations for inks in the United States governed the use of toxic metals such as lead, arsenic, selenium, mercury, cadmium and hexavalent chromium.[35]

See also[edit]

References[edit]

  1. ^ "Executive Summary: Municipal Solid Waste in the United States: 2005 Facts and Figures". US Environmental Protection Agency, Washington, DC. 2005. Retrieved 2008-05-06. [dead link]
  2. ^ "Paper Sludge - Waste Disposal Problem or Energy Opportunity, 1999 Engineering Conference Proceedings". Technical Association of the Pulp and Paper Industry (TAPPI), Norcross, GA. Retrieved 2008-05-07. 
  3. ^ "Clean Air - Clean Water - Pulp Info Centre". Reach for Unbleached Foundation, Comox, BC. Retrieved 2008-05-07. 
  4. ^ "Pulp (and Papermaking) Non-Fiction". Kadant Inc. Retrieved 2008-05-06. 
  5. ^ Environment Canada (1996). "National Pollutant Release Inventory, 1996."
  6. ^ "Paper, Printing & The Environment."[dead link] Earth Greetings Co., Glandore, South Australia. Accessed 2010-07-26.
  7. ^ a b "Effluents from Pulp Mills using Bleaching - PSL1". ISBN 0-662-18734-2 DSS. Health Canada. 1991. Retrieved 2007-09-21. 
  8. ^ "Iwi not giving up fight against Tasman mill discharges". Radio New Zealand. 18 December 2010. Retrieved 18 December 2010. 
  9. ^ Park, Stephen (February 2008). "Colour and Clarity of the Tarawera River 1991–2008". OCLC 230731509. [dead link]
  10. ^ EPA (28 June 2006). "General Overview of What's In America's Trash". United States Environmental Protection Agency. Retrieved 4 April 2012. 
  11. ^ Effluents from Pulp Mills using Bleaching - PSL1. Ottawa, ON: Health Canada and Environment Canada. 1991. ISBN 0-662-18734-2. Retrieved 2010-07-26.  Catalog no. En40-215/2E
  12. ^ a b "Frequently Asked Questions on Kraft Pulp Mills". Ensis (Joint research of Commonwealth Scientific and Industrial Research Organisation, Australia and Scion, New Zealand). 2005-03-04. [dead link]
  13. ^ "ECF: The Sustainable Technology". Alliance for Environmental Technology, Erin, ON and Washington, DC. Retrieved 2008-05-06. 
  14. ^ "Frequently Asked Questions on Kraft Pulp Mills" (PDF). Ensis/CSIRO (Australia) joint research [1]. 2005-03-04. Retrieved 2007-09-21. [dead link]
  15. ^ Paper Task Force (1995). "Environmental Comparison of Bleached Kraft Pulp Manufacturing Technologies."[dead link] White paper no. 5. Joint publication of Duke University, Environmental Defense Fund, Johnson & Johnson, McDonald's, Prudential Insurance Company of America and Time Inc.
  16. ^ Chlorine Free Products Association (Spring 1999). CFPA Today. 
  17. ^ Duke University, Environmental Defense Fund, Johnson&Johnson (December 1995). "Environmental comparison of bleached kraft pulp manufacturing" (PDF). Environmental Defense Fund [2]. Retrieved 2007-11-18. [dead link]
  18. ^ Ad Hoc Working Group of European Commission (May 2006). Revision of the Ecolabelling Criteria for Tissue Paper: Comments and background to the second draft proposal. [dead link]
  19. ^ "ECF and TCF: Toxicity An Analysis of Recent Published Data". The Alliance for Environmental Technology (International Association) joint research [3]. October 1994. Retrieved 2007-10-26. 
  20. ^ Tarkpea, Maria; et al. (1999). "TOXICITY OF CONVENTIONAL, ELEMENTAL CHLORINE–FREE, AND TOTALLY CHLORINE–FREE KRAFT-PULP BLEACHING EFFLUENTS ASSESSED BY SHORTTERM LETHAL AND SUBLETHAL BIOASSAYS". Environmental Toxicology and Chemistry 18 (11): 2487–2496. doi:10.1002/etc.5620181115. 
  21. ^ "2006 Air Pollutant Emissions for Canada (Tonnes)". Environment Canada. Retrieved 2008-05-07. 
  22. ^ Jeffries, Tom (1997-03-27). "Kraft pulping: Energy consumption and production". University of Wisconsin Biotech Center. [dead link]
  23. ^ Tilman, Anna (2008). "Pulp and Paper Pollution: The Toxic Legacy of Federal Neglect." Reach for Unbleached Foundation, Comox, BC.
  24. ^ Sonnenfeld, David A. (1999). "Social Movements and Ecological Modernization: The Transformation of Pulp and Paper Manufacturing, Paper: WP00-6-Sonnenfeld". Berkeley Workshop on Environmental Politics. Berkeley,CA: Institute of International Studies (University of California, Berkeley). Retrieved 2007-09-20. 
  25. ^ Auer, Matthew R. (1996). "Negotiating toxic risks: A case from the Nordic countries," Environmental Politics 5: 687-699.
  26. ^ "Dioxins and their effects on human health". World Health Organization. 2010 work. Retrieved 2010-06-11. 
  27. ^ "Ozone and Color Removal". Ozone Information. Retrieved 2009-01-09. 
  28. ^ "Debunking the Myths of Recycled Paper". Recycling Point Dot Com. Archived from the original on 2006-10-06. Retrieved 2007-02-04. 
  29. ^ "Recycling glossary". American Forest and Paper Association. Archived from the original on 2007-06-30. Retrieved 2007-10-20. 
  30. ^ "Paper Recycling Information Sheet". Waste Online. Retrieved October 20, 2007. [dead link]
  31. ^ "Recycle on the Go: Basic Information". US Environmental Protection Agency. October 18, 2007. Retrieved 2007-10-30. 
  32. ^ MacFadden, Todd; Michael P. Vogel (June 1996). "Facts About Paper". Printers' National Environmental Assistance Center, Montana State University. Retrieved 2007-10-30. 
  33. ^ http://www.cpima.org/HeavyMetals.pdf
  34. ^ "Recycling Paper and Glass". US Department of Energy. September 2006. Retrieved 2007-10-30. 
  35. ^ National Association of Printing Ink Manufacturers[dead link]

Further reading[edit]

Case Studies

Industry Profile

Life Cycle Assessment

New Technologies

External links[edit]