A widely explored myth is that waste paper recycling saves forests and preserves natural resources. On the contrary, cellulose is always obtained from cultivated trees, a renewable resource. And the energy consumed in recycling paper is in some cases many times greater than the energy used in its fabrication from cellulose. Besides, paper recycling is an activity that consumes large amounts of water and, if the proper precautions such as treatment of waste water are not taken, it can be highly polluting. One of the most serious problems with the recycling of paper is the paint that has to be separated in order to result in a high quality product. There are two chemical processes which are most commonly used: the first is the addition of large amounts of chemical products during the making of the pulp to “wash” the mixture, or the injection of air through the pulp mass with the posterior removal of paint and others impurities that float with the foam. The second method, in which the results are not of such good quality but that, on the other hand, requires less water, is done with the dispersion of the paint throughout the whole mass of the pulp. In both methods, the environment should always be remembered and the proper adjustments in this sense might need larger investments
Fonte: | Warmer Bulletin - World Resource Foundation |
Autor: | J. H. Penido |
Email do Autor: | jpenido@resol.com.br |