domingo, 14 de marzo de 2010

campaign awareness ambientar

campaign
awareness ambientar


Currently the future of forests and the paper is very promising, because if the pace and mode of consumption continue as at present, useful tree species for wood production will decrease by 40%.
Experts indicate that deforestation will continue until the year 2020, and by then will be only 1,800 million hectares. Most of the losses will occur in the poorest regions of the Earth and affect the tropics. The disappearance of forests will result in corresponding increases in greenhouse gases, the advance of deserts, increased hunger and increased cancers of various types.

If we are to meet the next century with optimism and create a sustainable future for our children, we must recover, recycle and reuse more waste paper to meet the needs and prevent the disappearance of our forests and wildlife.

Why recycle paper?

The paper recycling processes are caused by environmental problems generated by the manufacture of new paper:

* The chemicals used emit unpleasant odors and heavily pollute the environment.
* Deforestation is necessary to obtain raw materials could reduce the forest, causing climatic imbalances.

Phases of paper recycling:

* The manufacture of recycled paper begins with the collection of waste paper in special containers
* The next step in a purification by filtration and centrifugation, to remove any foreign particles to the fiber elements, such as sand, varnish, wire, rope, etc..
* Once purified, the pasta is submerged in soapy water and air is injected to cause the emergence of bubbles. Thus, the ink is removed by flotation. The ink is transferred to landfills and incinerated with the use of its own heat energy.
* From this point, the dough obtained is the same process as the primary source of cellulose for paper production.

Comparing the manufacturing process of recycled paper to manufacture paper from virgin chemical pulp, we noted the following improvements in its environmental impact:

* Reduction of wood consumption, which favors the development of forest stands, with all the benefits it brings, and reduces the cost of felling, transport and handling.
* Reduction of primary energy consumption, whose savings can reach 62.5%.
* 86% reduction in water consumption.
* 92% reduction in the levels of water pollution, atmosphere and soil, as in the manufacture of recycled paper, chemicals used to regulate the alkalinity are biodegradable, thus reducing chemical pollution.
* Reduction of mass of MSW in landfills. In countries with high economic level, this reduction reaches up to 30%.

(Figure 1. Comparative data between the amount of energy and resources used to produce one ton of virgin paper and a ton of recycled paper)

Recycled Paper (production and use)

Today, the production and use of recycled paper are well established and widely accepted. The necessary technologies are available and can produce any kind and any quality of paper using waste paper as raw material. The recycling of waste paper presents several environmental benefits:

* Saves natural resources such as wood, energy and water
* Minimize water pollution and saves space in landfills and incinerators capacity.

Recycled paper can be used for the same purpose as the role of primary sources. There is evidence that recycled paper is harmful to humans due to contamination by:

* Germs and pathogens;
* Chemicals, eg formaldehyde;
* Dioxins and furans;
* Heavy metals, eg lead.
* Sewage sludge is distilled-grade waste that can be filled or incinerated together with municipal solid waste.

Paper Manufacturing

The basic raw material for the production of any type of paper is cellulose fiber plant. These fibers are found in the cell walls of all plants. Cellulose comprises approximately 40-50% dry weight of wood plants and plants that are not wood. Cellulose fibers are joined together by lignin. There are a variety of materials available for production of paper, eg, leaves, rice husks, bark, bamboo, grass, wood, flax, straw, banana leaves, etc.. Besides these main raw materials can also be used waste paper and old rags. Industrial paper manufacturers use wood as their main source of cellulosic fibers. The first step in the manufacture of paper pulp is the development of cellulosic fibers in which the adhesive material are separated from the lignin.

Technologies of waste paper recycling

The cellulose fiber has the special property of bonding fiber to fiber through an ion exchange of hydrogen when water is removed. The result is achieved stability and strength of paper. This process is reversible. Adding water reduces the strength of the adhesion of the fiber.

Because the fibers in the waste paper have been previously discussed, the muddy or shredding, with minimal cutting is all that is needed in the preparation of waste paper pulp. Choose equipment is substantial and procedures that minimize fiber shrinkage and cause as little damage to the fiber as possible. However, some quality loss should be considered when the fibrous material is reprocessed.

In addition to the fibrous material, waste paper is different impurities in the paste, of which the most important is the ink. If the ink is not removed, the final recycled paper presents a brownish or grayish. Therefore, recycling processes include modern paper deinking steps that remove up to 70% of the ink. It uses two types of de-inking processes: the washing and flotation. The latter minimizes the amount of polluted wastewater and the fibrous material losses. During the washing or flotation, also removed most of the fillers.

Environmental impacts of paper manufacturing from primary and secondary sources

To assess the environmental impacts of production and consumption of paper, several aspects are important:

Wood consumption

The amount of wood is needed as raw material for paper manufacturing depends on the type of wood, applied technology and quality requirements for fiber and paper. The production of pulp wood in general consumes less (1.02 to 1.12 t of wood per tonne of paper) Kraft pulp production (1.65 to 2.25 t of wood per ton of paper).

The environmental impacts of widespread use of wood due to growing consumption of paper depends on many factors (eg exploitation of natural forests, the expansion of monocultures, the availability of wood waste from the production of timber and furniture , the sustainability of forestry.). Because of sustainable forestry are not common everywhere, the growing consumption of paper generated by deforestation and adverse effects related to the environment.

Energy Use

When considering the energy consumption for manufacture of paper, it is important to make a 'life cycle analysis', which includes all the steps in the production and use of paper (eg, timber production, manufacturing paper, wood and paper transport, paper use, etc.).. To manufacture one tonne of virgin paper requires 7600 kWatts / h.

ENERGY AND RAW MATERIAL REQUIRED FOR THE MANUFACTURE OF PAPER

Considering that energy use has great influence on the consumption of natural resources (coal, oil and gas), the generation of air pollutants (particulates, SO2, NOx, greenhouse gases) and water consumption are recommends a reduction of overall energy balance for the manufacture of paper.

(Figure 2. Energy and materials required to produce one tonne of paper and re-use)

Potable water demand

Depending on the technology used for the production of kraft pulp or wood, water consumption varies greatly. While previous technologies consume up to 400 m3 of water per ton of paper, modern processes with water circuits require more or less closed only 20 to 50 m3 of water per ton of paper. In comparison, approximately 5 m3 of water per ton of paper, recycled paper production requires the smallest amount of drinking water.

Quantity and wastewater pollution

The use of large quantities of potable water for paper production generates large amounts of wastewater with a variety of contaminants. The steps in the process of removing the bark of wood, the separation of the adhesive substances such as lignin, removing ink and other impurities from waste paper pulp and the bleaching of pulp from both primary and secondary sources are relevant to the generation of wastewater.
It was ten o'clock recognize different pollutants of wastewater from paper mills that are considered hazardous. The most important are the organic chlorine compounds that come from chlorine bleaching processes (eg, chloroform, tetrachloroethane, chlorobenzene, chlorophenol, chloroacetic acid, dioxins and furans, biphenylene post-chlorinated). Often they are highly toxic, stable for long periods and accumulate in the biomass.

(Figure 3. Lots of energy, water and trees needed for paper production and recycling of different qualities)

Influence on the generation of municipal solid waste

Waste paper is a major component of municipal solid waste. If not recycled, must be unloaded in landfills or incinerated along with other waste fractions. This will take up space in landfills and capacity of municipal solid waste incinerators. Although the role is not considered hazardous waste, create air pollution when incinerated or contribute to the production of methane gas filtered during the process of anaerobic digestion in landfills. In many countries, recycling of waste paper has a long tradition and is supported by a well-established structure for the collection and processing.

Although incineration of paper generates energy, the energy saved by using waste paper as raw material for pulp production is higher. During the preparation of pulp, solid waste is generated. This applies to the paste produced from primary and secondary raw materials. The typical waste pulp preparing primary raw material like wood is bark, sludge washing operation and ash from power generation and chemicals. During the preparation of waste paper pulp, waste originating from the main classification of paper, removing impurities from the pulp and deinking process. On average, 0.19 m3 of solid waste generated per ton of recycled paper, while paper production from primary sources produces 0.08 to 0.16 m3 of solid waste per tonne. This waste must be unloaded in landfills. Some parts may also be used as incinerator fuel for energy production.

Using recycled paper

From the beginning, there have been doubts and objections to the use of recycled paper. Some critics had doubts about the acceptance by the consumer recycled paper because of its poor quality gray. Others feared the damaged recycled modern copiers and printers, or believed that the use of recycled paper were harmful to health. After many years of experience with the use of recycled paper, none of these objections have been found.

Health risks due to use of recycled paper

Sometimes, the waste paper is contaminated during use and may contain germs and pathogens that can cause disease. Therefore, there have been fears that recycled paper could be hygienically undesirable. However, during the production process of recycled paper, paper undergoes processing steps in which is heated to high temperatures (eg drying step) and, therefore, virtually sterilized. Some research has found that recycled paper is hygienically acceptable, even for food packaging.

The enormous advantages of PAPER RECYCLING

* Avoid deforestation of the forests. One ton of recycled paper avoids the cutting of 17 mature trees (of approx. 15 years of age).
* The production of recycled paper from 100% waste paper requires no wood.
* Recycling one ton of paper saves 20.000 liters of water and 4,000 kwh
* Energy savings. The manufacturing process of paper and cardboard from cellulose fiber recovered is an energy savings of 70%: that means 390,000 tonnes of oil per year.
* They could use the 2 ½ million tons of paper and cardboard that are discarded annually in Mexico.
* If half of the recycled waste paper on the planet could be saved 8 million hectares of forest per year, would prevent 73% of the pollution and would provide energy savings of 60%.
* Recycle all paper produced in Mexico for a year is equivalent to saving 33% of the energy needed to renew it.
* Depending on the quality and cleaning of waste paper, around 75 to 95% of it can be converted into new paper products.

Sources of information:

Reciclon, Bio Group.

• www.wrf.org.uk (World Resource Foundation)
• www.epa.gov (U.S. Environmental Protection Bureau)
• www.recyclersinfo.com (Information Recyclers Germany)
• www.waste.nl (waste consultants, Netherlands)
• www.bundesumweltamt.de (Federal Environmental Office, Germany)
• www.ilo.org (International Labor Office)

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