Treatment of the sludge paper recycling industries by composting

Abstract

The sludge generated in the paper recycling industries presents characteristics of a fibrous mass of brown color, being classified as residue II A – no inert. Previously, most of the industries have had the landfill as the final form of disposal of this kind of waste. However, nowadays, the companies are looking for better usable alternatives for those residues, as the treatment for using the residues as inputs in other processes and products, with the intention to avoid or to reduce environmental liabilities. In this context, the aim of the present work was the study of a biological treatment for the paper recycling sludge, through the construction, operation and monitoring of windrow composting. Due to the intrinsic characteristics of the sludge, as low C/N ratio and high content of nitrogen, it had been necessary to add residue of pruning and weeding and sugarcane bagasse in the experiments to reach appropriate values for the composting. At the end of the experiment, the residue of pruning and weeding with sludge composting, generated an organic compost, potentially usable as a fertilizer, which complies to the established values for the Ministry of Agriculture, instituted by the Instruction Normative n° 25 of 23/07/2009.

Key words: sludge, paper, composting.