If there is one material that has become an inseparable part of human activity, it is paper. This thin sheet made from cellulose, a polysaccharide that plays an important role in the structure of plants, has been closely linked with humanity almost since the beginning.
However, the paper production industry consumes large amounts of energy and water, and also contributes significantly to global greenhouse gas emissions.
In fact, this industry has a significant impact on the environment, and the industrial process of producing paper from virgin fibers—mostly sourced from trees—is one of the largest sources of air and water pollution.
In recent decades, the use of recycled paper has increased significantly, helping to reduce the demand for raw materials and consume 70% less energy compared to paper made from virgin fibers. However, global paper demand continues to rise, and paper consumption is still considered a key indicator of development, accounting for about 4% of industrial GDP in the global economy.
Therefore, pollution control in the paper industry is essential, both in the production of pulp and final processing, as it is responsible for 2% of global industrial emissions.
The main gas emitted during the production of paper and cardboard is carbon dioxide (CO2), one of the main contributors to the greenhouse effect and the acceleration of climate change. For every kilogram of paper produced, approximately 3.3 kg of CO2 is released into the environment.
Reducing the amount of CO2 emitted into the air can be achieved through technological innovation and improving the efficiency of certain processes, such as paper drying. Similarly, by establishing networks of pollution sensors, polluting gases can be detected early and air quality deterioration can be prevented. This is the most effective solution to improve environmental conditions and ensure a more sustainable future for life on Earth.
Paper Production Process
Industrial paper production processes require virgin wood fibers, which must be sourced from sustainably managed forests.
First, the bark is removed so that the wood can be chipped into small pieces. These chips are then used to create a pulp mixture containing an organic polymer called lignin, which is a structural component of the tree’s cell walls and bark.
The pulp can be produced through a chemical process, in which the wood chips are cooked to extract the lignin. However, if a mechanical method is used, the wood fibers are separated to create basic paper products, such as newspaper and magazine paper.
Regardless of the method used, the pulp must be mixed with water at a water-to-pulp weight ratio of 100:1. After mixing, the mixture is spread out to evenly distribute the fibers that will form the sheet of paper. This sheet is then pressed to reduce its water content by 50%.
The next step is drying, where the paper sheet is passed through metal rollers at a temperature of 100ºC. A second roller system combines compression and heating to create the characteristic smooth and shiny surface of the paper.
Types of Pollution in the Paper Industry
Although the paper industry is one of the main drivers of economic development and progress, and our daily lives would be very different without paper, it also has a significant impact on the environment.
Firstly, paper production processes consume large amounts of energy and natural resources, especially water. Secondly, these processes are also responsible for generating solid waste and emitting greenhouse gases.
While recycled paper requires less energy to produce and is more sustainable, it still generates solid waste and consumes a significant amount of water.
The environmental impacts caused by the demand for paper can be categorized into different types of pollution:
Water Pollution
The paper industry is one of the largest consumers of water, using it in almost every process, from turning wood into pulp to bleaching paper. Producing one sheet of paper requires 10 liters of water, placing great pressure on this vital resource, which is essential for life on Earth.
Furthermore, the chemicals used in the production of pulp and in the final bleaching process, primarily chlorine dioxide, are also harmful to both the environment and human health.
Water is also used to remove paper fibers and inorganic compounds during manufacturing, as well as chemicals that result from reactions in various industrial processes.
The wastewater from these production processes eventually flows into natural water sources, contaminating ecosystems and harming aquatic life. This also directly affects the quality of water used by humans in their daily lives.
Waste Pollution
During the production of pulp and paper, many types of organic solid waste are generated, including wood waste, sludge, hemicellulose, lignin, tree resins, bark, caustic soda, removable organic halides, phenols, and volatile organic compounds. In addition, inorganic wastes such as ash, slag, and inorganic salts are also produced.
Besides the chemical waste from paper production, the industry generates many other pollutants, including paper itself. If paper is not recycled or properly processed after use, it can result in large amounts of waste.
White paper can take up to five years to decompose in the natural environment. As this waste accumulates, it can cause soil degradation and destruction of natural habitats.
Used paper and cardboard make up one of the largest categories of household waste. In 2021 alone, the European Union (EU) generated 84 million tonnes of packaging waste, of which 40.3% was paper and cardboard.
Deforestation
Since wood is the primary source of fiber for paper production, producing paper requires the logging of large areas of forest. It is estimated that about 17 trees are needed to produce one tonne of white paper.
Indiscriminate logging without a sustainable management plan leads to deforestation. This has significant impacts on climate change, as trees play a crucial role in absorbing CO2 – one of the main greenhouse gases.
The disappearance of forests also has severe consequences for biodiversity, as forest ecosystems are home to many species of flora and fauna.
Inks
Another way paper waste harms the environment is through the inks and other chemicals used in its production. These toxic substances are released into the environment and eventually, through soil, water, and air, affect human health.
Traditional inks contain volatile organic compounds (VOCs) that are harmful to both health and the environment.
The production of these inks requires large amounts of energy and natural resources. Furthermore, once the paper printed with such inks, like newspapers or official documents, is used, it becomes difficult to recycle because the process of separating the ink from the paper is both costly and complex.
Air Pollution in the Paper Industry
The use of fossil fuels in industrial paper production processes leads to the emission of heavy metals, fine particles, and dioxins from organochlorine compounds.
Most notably, it results in the release of greenhouse gases such as carbon dioxide (CO2), methane (CH4), nitrogen oxide (NO2), and sulfur dioxide (SO2), which directly contribute to the greenhouse effect, accelerating global warming—one of the greatest environmental threats of our time.
These air pollutants harm ecosystems and are directly linked to health problems, including various types of cancer and respiratory and cardiovascular diseases.
Another significant environmental challenge is the unpleasant odor generated by the paper industry. This is caused by volatile chemicals released into the air, which can also affect human health, leading to dizziness, headaches, and insomnia.
Occupational Hazards
Harmful components released during the paper-making process can contaminate the workplace if not handled properly. Workers in the paper industry are in constant contact with these harmful wastes, significantly increasing the risks of certain diseases through inhalation or accidental ingestion.
Furthermore, these workers are the first to be exposed to the unpleasant smells of the paper-making process. Although Spain currently has no laws regarding industrial odors, ensuring the best possible working conditions for employees in the paper industry would improve process efficiency and create a healthier, safer working environment.
Alternatives to Paper
The biggest challenge the paper industry faces today is how to become more sustainable and environmentally friendly. Given the amount of paper used in both professional and social life, this industry is essential. However, it is crucial to implement more ecological measures throughout the production process.
In addition to making production processes more efficient, one way to make the paper industry more sustainable is to stop using chlorine-based products in bleaching, particularly since these chemicals, when mixed with organic waste, generate harmful organochlorine compounds. This can be achieved through the use of cleaner technologies, reducing the use of harmful chemicals, such as pre-bleaching enzymes like xylanase, and promoting the production and use of recycled paper.
As mentioned, recycled paper is a promising alternative to traditional white paper because it requires fewer natural resources and less energy to produce. In fact, 52% of the paper and cardboard produced worldwide is made from recycled fibers. However, it still faces the drawbacks associated with polluting inks and the challenge of collecting and sorting it as recyclable material.
Another alternative to traditional paper that is gaining more attention is the use of fibers from other plants, such as bamboo, straw, and agricultural waste. This is more sustainable than tree cutting and helps preserve an important resource for absorbing CO2 from the atmosphere.
Similarly, paper produced from renewable sources other than wood has been proven to be of equal or even higher quality than traditional white paper. However, there are obstacles to using these plant fibers as they require significant investment in new machinery.
USE RECYCLED PAPER!
To minimize the environmental impact of the paper and pulp industry, several strategies can be implemented. These include sourcing materials from sustainably managed forests and using alternative fibers like bamboo and agricultural waste. Increasing the use of recycled paper, adopting energy-saving technologies, and using clean chemicals can reduce energy consumption, water use, and harmful emissions. Treating wastewater and recycling solid waste like wood chips and sludge can minimize pollution. Additionally, implementing carbon capture technologies, transitioning to renewable energy, and promoting environmentally friendly paper products can reduce the industry’s carbon footprint. Collaboration within the industry, strict regulations, and public incentives can promote sustainability, helping the paper industry contribute to a greener future. Use recycled paper to protect the environment and reduce the need for raw materials.
