The main solid wastes generated by the production process are: biologic sludge produced by effluent treatment, eucalyptus bark, lime sludge (CaCO3) and other alkali materials from the caustisizing plant (dregs and grits), besides wastes from brown stock and bleached pulp purification, civil work debris, institutional wastes and, most recently, fibers providing from the primary effluent treatment. All these wastes are deemed as Class II wastes (non-inert) according to ABNT (Brazilian Technical Standards Association) standards.
CENIBRA has implemented new solid waste management strategies founded on three essential aspects of environmental sustainability, namely: reduction, reutilization and recycling. A number of works were carried out by the production, utilities, administration, procurement, environment and forest areas in order to define and plan goals to make waste management a feasible, profitable business unit both from the environmental and commercial standpoints. Several control tools have been implemented over the year to provide actual data on generated wastes and their disposal and reutilization, with particular emphasis on recommendations for using wastes in the Company’s eucalyptus forests.
In addition to using lime sludge as soil correction agent, it’s being contemplated the use of dregs as a source of calcium and magnesium after enrichment with calcined dolomite, a magnesium-rich waste from the steel industry. Grits offer a great potential as soil stabilizing agent in forest roads (doctorate thesis). Ash from biomass boiler electrostatic precipitators is being used in eucalyptus planting as additional source of potassium and phosphorus. And bark not employed as fuel is being composted with biologic sludge from the ETS and subsequently used in eucalyptus planting as a source of nitrogen and other nutrients, besides providing extra organic matter and physical protection, and maintaining soil moisture. Reutilization and recycling of such materials will result in sizable cost reduction in terms of both input purchase and waste transportation and disposal, not to mention a significant landfill life extension.
A specific segregation approach has been adopted in the Waste Selection Station (WSS) for the disposal of hazardous wastes (Class I), such as oils, grease, agrochemicals packing, batteries and fluorescent lamps. Materials whose proper technical destination has not been implemented so far are sent to the hazardous waste cell, where appropriate safety facilities enable these materials to be suitably handled.
Selective Waste Collection
The institutional waste selective collection program has been consolidated since 2001, with significant generation reduction over the years. This program has also contributed to gradually bring down the amount of wastes disposed into the industrial landfill.
Concomitant with the reduction in volume, the increased institutional waste selectivity points out to the fact that contamination by hazardous wastes (oil, grease, etc.) is under control. Critical hazardous waste generation takes place during maintenance shutdown (GSD). A control approach using trained personnel has been adopted to provide guidance to and inspect the operations involving various types of wastes.