question: Why does water permanently damage paper?
comment: It's not so much that water damages paper, it just makes it malleable again. A lot of our more basic things (ceramics and paper are the first things that come to mind) rely on making a bunch of wet stuff and then drying it when it's shaped a certain way. Paper, you get a bunch of wood pulp and process it through water and other chemicals, and then dry it in very thin flat sheets. Adding water back in just makes it malleable again, and easier to tear for that matter, and if you have too much water moving around it, it will just dissolve into the water, but if you wet a piece of paper, and set it under something heavy and flat on top of a flat surface and heat it up, it will become usable paper again (though it will likely not feel the same as the paper you had to begin with, as there are additional processes that give paper a better feel). If there's ink or pencil lead on the paper, it will just wash away in the water. Water is often called the universal solvent, so it's pretty apt that it can just disintegrate paper when used correctly.
passages: In Canada, federal and provincial environmental law is the primary source of regulations for pulp and paper mills. The following three listed Federal regulations are related to emissions to water:
  
  BULLET::::1. Pulp and Paper Effluent Regulations: sets standards for the level of acute lethality to fish, biochemical oxygen demand and total suspended solids. Mills are also required to conduct environmental effects monitoring to determine the impact of their effluents on receiving waters and investigate the causes of, and solutions for, environmental effects associated with mill effluent.
   Section::::Mitigation.:Regulations.
  
  Pulp and paper is a heavily regulated industry in North America. U.S. and Canadian regulations are summarized below.
  
  Section::::Mitigation.:Regulations.:United States.
  
  Section::::Mitigation.:Regulations.:United States.:Air and water pollution.
  
  EPA first issued national wastewater standards, known as effluent guidelines, for pulp and paper mills in 1974, pursuant to the Clean Water Act. The agency established numeric limitations for several conventional pollutants. In 1982, EPA amended the regulations with numeric limitations for pentachlorophenol, trichlorophenol and zinc. Effluent limitations are implemented in National Pollutant Discharge Elimination System (NPDES) permits, which are renewed every five years. ("See" United States regulation of point source water pollution.)
   Various techniques, such as refining of the pulp and wet pressing on the paper machine can be used to reduce the strength loss of the paper upon wetting. To improve the wet strength it is common to use chemicals. The use of chemicals can retain as much as 10% to 30% of the original dry strength of the paper. The wet strength chemicals may improve the dry strength of the paper as well.
  
  Section::::Wet strength chemicals.
   BULLET::::- nitrates
  
  BULLET::::- methanol
  
  BULLET::::- benzene
  
  BULLET::::- volatile organic compounds, chloroform.
  
  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).
   Wastewater 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. Wastewater 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.
   In Canada, the pulp and paper industry released 5% of the total industrial waste disposed of to water in 2015. In 2014, 97.5%, 99.9% and 99.8% of effluent samples from pulp and paper mills met regulatory requirements for toxicity tests on fish, biochemical oxygen demand, and total suspended solids, respectively.
   BULLET::::- Carolyn Harris worked as head of Columbia University Libraries' Preservation Division from 1981 until 1987, where she worked closely with Paul Banks. She published extensive research throughout her career, especially dealing with mass deacidification of wood-pulp paper.
  
  BULLET::::- Peter Waters, former Conservation Officer at the Library of Congress in Washington, DC, worked in the areas of disaster recovery and preparedness, and the salvaging of water-damaged paper goods.
  
  BULLET::::- Nicholson Baker is a contemporary American novelist and author of "Double Fold", a criticism of libraries' destruction of paper-based media.
   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".
  
  One ton of paper pollutes 20,000 gallons of water. 
  
  Section::::Issues.:Paper waste.
   BULLET::::2. Pulp and Paper Mill Effluent Chlorinated Dioxins and Furans Regulations: issued under the Canadian Environmental Protection Act and applies to polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans in mill effluents.
  
  BULLET::::3. Pulp and Paper Mill Defoamer and Wood Chip Regulation: regulates use of defoamers containing dibenzofuran or dibenzo-para-dioxin at pulp and paper mills using a chlorine bleaching process.
   Standard office paper has traditionally been designed for use with typewriters and copy machines, where the paper usually does not get wet. With these papers, moisture tends to wick through the fibers and away from the point of contact. For inkjet printing, this dulls edges of lines and graphic boundaries, and lessens pigment intensity.
   Canadian Standards Association (CSA).
  
  The Forest Stewardship Council (FSC).
  
  Section::::Mitigation.:Pulp bleaching.
  
  The move to non-elemental chlorine for the bleaching process reduced the emission of the carcinogenic organochlorines. Peracetic acid, ozone and hydrogen peroxide and oxygen are used in bleaching sequences in the pulp industry to produce totally chlorine free (TCF) paper.
  
  Section::::Mitigation.:Recycling.
   Section::::Issues.:Chlorine and chlorine-based materials.
  
  Chlorine and compounds of chlorine are used in the bleaching of wood pulp, especially chemical pulps produced by the kraft process or sulfite process. In the past, plants using elemental chlorine produced significant quantities of dioxins, persistent and very toxic organic pollutants. From the 1990s onward, 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. As a result, dioxin production was also significantly reduced.
   A life cycle inventory of a comparison of paper vs plastic cups shows environmental effects of both with no clear winner.
  
  Polyethylene (PE) is a petroleum-based coating on paper cups that can slow down the process of biodegrading of the paper it coats.
   In the mid-19th century, machine-made paper was introduced, and wood became the most common, least expensive ingredient, especially in newspapers. The presence of lignin in wood pulp paper causes acid to degrade the cellulose, which causes the paper to become unstable and discolored over time. In addition, paper has the natural ability to absorb and retain moisture from the atmosphere, making it prone to the growth of mold, fungi, and bacteria.
   BULLET::::- Laplante, Benoît and Rilstone, Paul, Environmental Inspections and Emissions of the Pulp and Paper Industry: The Case of Quebec, April 1995, World Bank Policy Research Working Paper No. 1447.
  
  Industry Profile
  
  BULLET::::- World Bank Group, Pulp and Paper Mill, Pollution Prevention and Abatement Handbook, July 1998.
  
  BULLET::::- United States Environmental Protection Agency, Profile of the Pulp and Paper Industry 2nd Edition, November 2002.
  
  Life Cycle Assessment
  
  BULLET::::- Forest Products Association of Canada, Life Cycle Assessment and Forest Products:A White Paper, September 2010
  
  New Technologies
   Paper made from wood-based pulp that has not had its lignin removed turns yellow, becomes brittle, and deteriorates over time. When exposed to light and/or heat, the molecules in the acidic paper will break down even faster. Acidic wood-pulp paper became commonplace in the late 19th century, and in the 1930s William Barrow (a chemist and librarian) published a report about the deterioration of acidic paper in the libraries. For fear of the gradual disintegration of written materials, measures have since been taken to improve the quality of paper.
   Some thermal papers are coated with BPA, a chemical considered to be an endocrine disruptor. This material can contaminate recycled paper. BPA can transfer readily to the skin in small amounts:
   BULLET::::- Damaging light, particularly UV light, which fades and destroys media over time by breaking down the molecules.
  
  BULLET::::- Atmosphere contains small traces of sulfur dioxide and nitric acid which turn media yellow and break the fibers down.
  
  BULLET::::- Humidity and moisture also aid in the breakdown of media. If there is too much, the document can be attacked by bacteria, and if too little, cellulose material breaks down.
  
  BULLET::::- Temperature, particularly elevated ones, can destroy some media. Low temperatures can cause the water to form crystals which expands destroying the structure of paper-based documents.
  
  Section::::Online photo albums.
   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.
  
  The United States Environmental Protection Agency has found that recycling causes 35% less water pollution and 74% less air pollution than making virgin paper.
   Sometimes wet strength can be obtained by curtain coating a polymer onto a paper or paperboard. Laminating a plastic film is also a method of providing wet strength.
  
  Section::::Applications.
  
  A wide range of paper materials are wet strengthened:
  
  BULLET::::- Tissue paper
  
  BULLET::::- Filter paper
  
  BULLET::::- Liquid packaging board
  
  BULLET::::- Paper bag
  
  BULLET::::- Paper chemicals
  
  Section::::Environmental considerations.
  
  Recycling of wet strengthened paper requires higher intensity reworking conditions in the re-pulping process to break the fibre web. Some wet strength papers are not considered recyclable.
   Section::::Bleaching chemical pulps.:Ozone.
   Co-styrene-maleic anhydride and co-styrene acrylate are common binders associated with a cationic starch pigment in Inkjet printing paper. Table 1 shows their surface tension under given conditions.
  
  There have been several studies that have focused on how the paper printing quality is dependent on the concentration of these binders and ink pigment. Data from the experiments are congruent and stated in Table 2 as the corrected contact angle of water, the corrected contact angle of black ink, and the total surface energy.
   Surface chemistry of paper
  
  The surface chemistry of paper is responsible for many important paper properties, such as gloss, waterproofing, and printability. Many components are used in the paper-making process that affect the surface.
  
  Section::::Pigment and dispersion medium.
   Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.
  
  Section::::Environmental impact.
  
  The production and use of paper has a number of adverse effects on the environment.
   Nitrogen oxides (NO) sulfur oxides (SO) and carbon dioxide (CO) are all emitted during pulp and paper manufacturing. NOx and SOx are major contributors of acid rain and CO is a greenhouse gas responsible for climate change. In 2014, the pulp and paper industry in North America was responsible for about 0.5% of the total SO and NO releases from industrial and non-industrial sources.
  
  Section::::Issues.:Water pollution.
  
presuppositions: Water damages paper. Water damages paper.
corrections: Water makes paper malleable. Water makes paper malleable but doesn't damage it.
raw_presuppositions: Water damages paper. Water damages paper.
raw_corrections: Water makes paper malleable. Water makes paper malleable but doesn't damage it.