Portal de Periódicos da CAPES

Control of effluent from the manufacturing of bleached pulp and paper from bagasse

1992; Elsevier BV; Volume: 24; Issue: 4 Linguagem: Inglês

10.1016/0045-6535(92)90411-j

1879-1298

Jens Folke, Mayelin Guerra,

Enzyme-mediated dye degradation

Waste water and its treatment have been studied for pulp and paper manufacturing from sugar cane bagasse and compared to wood pulping and straw pulping. The study included the ability of an activated sludge/aerated lagoon plant to remove chlorophenolics from the effluent. on the basis of a chemical wastewater. This paper is a compilation of the results. The Panchito Gómez Toro Plant is a greenfield integrated pulp and paper mill from 1984 using a modified kraft process based on wet depithed bagasse. The daily pulping capacity is 200 tonnes of air dry pulp (t90). The bleach plant has four stages (C/D E H D). The wastewater treatment is based on aerated, activated sludge and subsequent treatment in a stabilization lagoon with 11 days' retention time. The operation of the activated sludge plant is troublesome due to shock loads of TSS (total suspended solids) and COD (chemical oxygen demand) from the mill, and an inadequate supply of chemicals for coagulation in primary treatment. Consequently, the influent to and the effluent from the activated sludge plant are often high in TSS and COD. The effluent from the lagoon is colored and high in TSS. The quantities of chlorophenolics formed during the bleaching of brown pulp are unexpectedly high. By analogy to a previous study of straw pulp bleaching this is presumably due to high temperatures in the chlorination tower and inappropriate control of chlorine dosing. Generally, chlorophenolics are removed biologically, especially during lagoon treatment. Still, some highly chlorinated and highly substituted phenolics resist the biological wastewater treatment. Conclusions are that aerated stabilization basins are more energy-effective for effluent treatment in tropical zones than activated sludge treatment, and in developing countries they may perform better owing to a better resistance towards shock loads of TSS from improper fiber control in the mill.