Environmental impact of the paper industry

April 1, 2024
Environmental impact of the paper industry - Kunak

If there is one material that by its nature has become an inseparable part of human activity, it is paper. This thin sheet made from cellulose, a polysaccharide which is an important structural component in plants, has been inextricably linked with humanity almost since its beginnings.

However, the paper production industry consumes vast amounts of both energy and water. It also contributes significantly to global greenhouse gas emissions. (Dai, M. et al, 2024)

Indeed, the sector has a significant impact on the environment, and the industrial process to produce paper from virgin fibres, which are mostly sourced from trees, is one of the biggest producers of both air and water pollution.

Over recent decades, there has been a notable increase in the use of recycled paper, which requires less raw material to produce and 70% less energy. However, the demand for paper continues to rise globally and its consumption is still used to measure development as it represents around 4% of industrial GDP for the world’s economy.

As a result, 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), which is one of the main contributors to the greenhouse effect and the acceleration of climate change. For every kilogram of paper produced, 3.3 kg of CO2 is released into the atmosphere.

Reducing the amount of COemitted into the air can be achieved through technological innovation and by improving the efficiency of certain processes, such as paper drying. Similarly, by establishing networks of pollution sensors, such as those offered by Kunak, polluting gases can be detected early and the deterioration of air quality can be avoided. This is the most effective way to contribute towards improving environmental conditions and guaranteeing a more sustainable future for life on the planet.

Paper industry processes

Industrial paper processes require virgin wood fibres and these must come from sustainably managed forests.

First, the bark is removed so that the wood can be chipped. These chips are used to produce a paste made from an organic polymer (lignin), which forms part of the cell walls in the tree and its bark.

The paste can be made using a chemical process in which the wood chips are cooked to extract the lignin. However, if mechanical methods are used, the fibres are separated to make basic paper products, such as newspaper and magazine paper.

Regardless of which process is used, the paste needs to be mixed with water, with a water-to-paste weight ratio of 100:1. Once mixed, the paste is spread out to evenly distribute the fibres that will form the sheet of paper. This sheet is then pressed to reduce its water content by 50%.

Now, it is time to start the drying, and the sheet of paper is passed through metal rollers at 100ºC. A second roller system provides a combination of compression and heat to produce that typical shiny satin finish.

Environmental impact of the paper industry - Kunak

Infographic on the paper manufacturing process – Source Cepi (click on the image to see full size)

Types of paper industry pollution

While the paper industry is certainly one of the main drivers of economic development and progress, and our daily lives would certainly be unrecognisable without paper, the sector has a significant impact on the environment.

Firstly, the processes required to produce paper consume a lot of energy and natural resources, such as water. Secondly, these same processes are responsible for generating solid waste and producing greenhouse gases.

While recycled paper requires less energy to produce and is more sustainable, it still generates solid waste and consumes a remarkable amount of water.

The environmental consequences of the demand for paper can be divided into several different types of pollution:

Water pollution

The paper industry is one of the main consumers of water, using it in every process, from the transformation of wood into pulp to the bleaching of paper. It requires 10 litres of water to produce one sheet of paper, and this puts great pressure on a natural resource which is essential for life on Earth.

Furthermore, the chemicals used to produce wood pulp and those used in the final bleaching processes, mostly chlorine dioxide, are also harmful to both the environment and human health.

Water is also used to remove fibres and inorganic products used in manufacturing, as well as chemicals resulting from reactions that take place during various industrial processes.

Effluent water eventually reaches natural bodies of water, thereby contaminating their ecosystems and harming aquatic life. This also has a direct impact on the quality of the water we drink and use in our daily lives.

Environmental impact of the paper industry - Kunak

Detail of the paper production process

Waste pollution

During the pulp and paper manufacturing process, organic solid residues are produced such as wood waste, sludge, hemicellulose, lignin, resins, bark, caustic soda, removable organic halides, phenols and volatile organic compounds. Other inorganic residues are also produced, such as ash, slag and inorganic salts.

As well as the various chemical discharges resulting from paper production, the industry generates many other pollutants. These include the paper itself, as it can generate huge volumes of waste if it is not recycled or properly processed after use.

White paper can take up to five years to decompose in nature. In turn, as this waste accumulates, it can cause degradation of the soil and habitats.

Used paper and cardboard make up one of the biggest categories of household waste. While in 2021 the EU generated 84 million tonnes of packaging waste, of which 40.3% was paper and cardboard.

Deforestation

As wood is the main source of fibre to make paper pulp, producing paper requires the felling of large areas of forest. It is estimated that about 17 trees are needed to produce one tonne of white paper.

Indiscriminate logging of forests without a sustainable management plan leads to deforestation. In turn, this has significant implications for climate change as trees are an important sink of CO2, one of the main greenhouse gases.

The disappearance of forests also has serious consequences on biodiversity because their ecosystems are home to a wide range of species of flora and fauna.

Environmental impact of the paper industry - Kunak

Paper inks are harmful to health and the environment.

Inks

Another way that paper waste damages 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, have an impact on human health.

Traditional inks contain volatile organic compounds (VOCs) that are harmful to both health and the environment.

Manufacturing these inks requires large amounts of energy and natural resources. Furthermore, once used, paper printed with such inks, such as newspapers or official documents, is difficult to recycle because the process of separating the ink and the paper is both costly and complex.

Environmental impact of the paper industry - Kunak

External view of a paper mill

Paper industry air pollution

The use of fossil fuels during industrial paper production processes leads to the emission of heavy metals, fine particles and dioxins from organochlorine compounds.

But above all, it leads to the release of greenhouse gases such as carbon dioxide (CO2), methane (CH4), nitrogen oxide (NO2) and sulphur dioxide (SO2) that directly increase the greenhouse effect that contributes to global warming, one of the biggest environmental threats of our time.

These air pollutants are harmful to ecosystems and are directly linked to health problems, including many types of cancer and respiratory and cardiovascular diseases. (Dionne, J., & Walker, T.R., 2021)

Another major environmental challenge is the unpleasant smell generated by the paper industry. This is caused by volatile chemicals that are released into the air. This can also impact human health, causing 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 such harmful waste and this can significantly increase the risks of certain diseases through inhalation or accidental ingestion.

Furthermore, these workers are the first to be exposed to the bad smell of the paper-making process. Although Spain currently has no legislation regarding unpleasant industrial odours, ensuring the best possible working conditions for employees in the paper industry guarantees more efficient processes and a healthier and safer working environment.

Alternatives to paper

The main challenge that the paper industry faces today is how to become more sustainable and respectful of the environment. Due to the amount of paper we use both professionally and socially, this industry is an essential part of life. However, it is vital to implement more ecological measures in all its production processes.

As well as working to make processes more efficient, one way of making the industry more sustainable is to stop the use of chlorine products in bleaching, particularly since, after they are used, when mixed with organic residues, they generate organochlorine compounds which are harmful to both eco-systems and human health. This could be achieved through the use of cleaner technologies, a reduction of the use of hazardous chemicals, such as pre-bleaching enzymes like xylanase (Gupta, G.K., et al 2019), and the promotion of the production and use of recycled paper.

As already mentioned, recycled paper represents a promising alternative to traditional white paper because it requires less natural resources and energy to produce. In fact, 52% of the paper and cardboard produced worldwide is made using recycled fibres. However, it still has all the drawbacks linked to polluting inks, as well as the challenge of collecting and sorting it as a recyclable material.

Another alternative to traditional paper that is gaining greater prominence is the use of fibres from other plants, such as bamboo, straw and agricultural waste. This is more sustainable than felling trees, and by reducing deforestation, it preserves an important resource for capturing CO2 from the atmosphere.

Similarly, paper produced from renewable sources other than wood has been proven to be of a similar or even higher quality than traditional white paper. However, there are obstacles to the use of these plant fibres as they require significant investment in new machinery.

Kunak solutions for paper industry pollution

Controlling paper mill air pollution is essential if paper mills want to comply with air quality regulations and ensure that they have a minimal impact on nearby populations, as well as their workers.

Although polluting gases emitted by the industry are dispersed in the air and carried by the wind, overcoming mountain barriers, they contribute towards deteriorating air quality, which in turn is a contributing factor in the premature death of millions of people per year and aggravates cardiovascular and respiratory diseases. (Daza, O.A., & Vidal, A. 2018)

With Kunak AIR sensor networks, it is possible to monitor the air in and around paper mills, enabling the early detection of diluted pollutants in the air. Some of the gases generated by paper factors, such as sulphur dioxide (SO2), are responsible for the unpleasant odour associated with the industry.

Using specific cartridges in Kunak AIR sensor stations, it is possible to measure its intensity and establish short- and medium-term exposure values before they produce a physiological response.

A competitive and diversified industrial sector guarantees a strong and resilient economy. But putting growth ahead of the environment and people’s well-being will lead to dire consequences. The alternative is to ensure that these sectors, like the paper industry, can continue their activity in a more efficient and controlled way, and that begins with knowing the impact that they have on the environment.

Sources & References

Gupta, G. K., Liu, H., & Shukla, P. (2019) – Pulp and paper industry–based pollutants, their health hazards and environmental risks.

Dionne, J., & Walker, T. R. (2021) – Air pollution impacts from a pulp and paper mill facility located in adjacent communities, Edmundston, New Brunswick, Canada and Madawaska, Maine, United States.

Dai, M., Sun, M., Chen, B. et al (2024) – Country-specific net-zero strategies of the pulp and paper industry.