Paper recycling
Process

Paper recycling is reprocessing waste paper fibers back into a usable paper product

While there are differences depending on the specific type of paper being recycled ( corrugated fiberboard , newspaper, mixed office waste), recycling processes include the following steps:

1. Pulping: Adding water and applying mechanical action to separate fibers from each other.
2. Screening: Using screens, with either slots or holes, to remove contaminants that are larger than pulp fibers.
3. Centrifugal cleaning: Spinning the pulp slurry in a cleaner causes materials that are more dense than pulp fibers to move outward and be rejected.
4. Flotation: Passing air bubbles through the pulp slurry, with a surfactant present, causes ink particles to collect with the foam on the surface. By removing contaminated foam, pulp is made brighter. This step is sometimes called deinking.
5. Kneading or dispersion: Mechanical action is applied to fragment contaminant particles.
6. Washing: Small particles are removed by passing water through the pulp.
7. Bleaching: If white paper is desired, bleaching uses peroxides or hydrosulfites to remove colour from the pulp.
8. Papermaking: The clean (and/or bleached) fiber is made into a "new" paper product in the same way that virgin paper is made.
9. Dissolved air flotation: Process water is cleaned for reuse.
10. Waste disposal: The unusable material left over, mainly ink, plastics, filler and short fibers, is called sludge. The sludge is buried in a landfill, burned to create energy at the paper mill or used as a fertilizer by local farmers.

Standards

Every time paper is recycled, the fibres become shorter and weaker, so virgin pulp must be mixed with the used paper to provide strength. Because of the weakening, paper can only be recycled 4-6 times.

There is no universal standard for the maximum percentage of virgin pulp in recycled paper. [2] [3] Paper is available that includes anywhere from 10 to 100 percent "post-consumer" paper. [4] The EPA mandated the use of 50% post-consumer recycled paper by the federal government, state governments that receive federal funding, and many companies that receive money from the federal government. [5] The EPA does not regulate recycled paper used outside of the government; it only sets a minimum guideline. [2] The UK also does not have any legal standards, only non-mandatory guidelines instituted by a variety of different organizations. [2]

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 . [2] Mill broke includes paper trimmings from a virgin paper mill. Pre-consumer waste is material that was discarded before it was ready for consumer use. Post-consumer waste is material that was discarded after actually being used by a consumer.

Environmental effects

The EIA states on its website that "a paper mill uses 40 percent less energy to make paper from recycled paper than it does to make paper from fresh lumber." [6] Making paper from virgin fiber requires the use of highly polluting chemicals like chlorine [7] that are only required in either small amounts, or often not at all, when bleaching recycled paper. [ citation needed ] However, cholorine is rarely used at all in the virgin fiber manufacturing process due to its environmentally detrimental effects, instead substances such as hydrogen peroxide are utilized which results in the eventual production of oxygen and water when used to bleach either virgin or recycled paper fibers.

Continually harvesting forests contributes to soil erosion and degradation as the nutrients are continually removed with the trees. However, as the majority of nutrients are located in the banches and needles/leaves of trees and only the bole or trunk of the tree is generally used for paper production, sustainable forest management techniques minimize the nutrient loss to the soil. This means that farmed forests often require the use of large quantities of artificial fertilizer , the production, transportation and regular application of these is extremely energy intensive and enviromentally damaging.

The European Union , as part of the waste hierarchy in the Waste Framework Directive , stipulates that reuse or recycling of used paper and board is preferable to disposal. When choosing between landfill and incineration of waste materials the latter option is preferred, as value is recovered from the waste. Organic materials like paper decompose within landfills into biogas , containing methane, a greenhouse gases linked to global warming . [8]

Criticism

Many of the claimed benefits of paper recycling have fallen under criticism; criticized areas include the claim that recycling saves trees, reduces energy consumption, reduces pollution, creates desirable jobs, and saves money.

Recycling facts and figures

United States of America

In the U.S. paper products are the largest component of municipal solid waste , making up 31-38% of the composition of landfills . [9] In 2005 51.5 percent of the paper consumed in the U.S. was recovered for recycling. [10] . This means that today, over 51 million tons of paper and paper products are being recovered for recycling annually, representing a 76% increase over 1990 levels. The U.S. paper industry has set a goal to recover 55 percent of all the paper consumed in the U.S. by 2012. Paper packaging recovery, specific to paper products used by the packaging industry, was responsible for about 76.6% of packaging materials recycled with more than 24 million pounds recovered in 2005 [11]

Twenty years ago, only one curbside recycling program existed in the United States , which collected several materials at the curb. By 1998, 9,000 curbside programs and 12,000 recyclable drop-off centers had sprouted up across the nation. As of 1999, 480 materials recovery facilities had been established to process the collected materials. [12]

European Union

Paper recovery in Europe has a long history and has grown into a mature organization. The European papermakers and converters work together to meet the requirements of the European Commission and national governments. Their aim is the reduction of the environmental impact of waste during manufacturing, converting/printing, collecting, sorting and recycling processes to ensure the optimal and environmentally sound recycling of used paper and board products. In 2004, the paper recycling rate in Europe was 54.6% or 45.5 million tons.