Assessment of the environmental performance of sugarcane companies based on waste disposed of on the soil

Purpose

This study aimed to present an index (IEP) to evaluate the environmental performance of the sugar-energy industrial process based on the waste generated in manufacturing operations. The residues considered in this study were: vinasse, filter cake, ash and soot, residual waters, and sewage sludge.

Methods

The index created was developed to take into account, and to be directly proportional to the environmental impact of each residue generated by the sugar-energy production, to the relative spatial dispersion that each waste can reach, and to the environmental fragility of the hydrographic basin where the plant under evaluation is inserted and works. The lower IEP, the better the company valuation.

Results

The index was tested in a real company and exhibited an IEP Total = 1,4.10¹³ km².p/yr, which shows weak waste management by the enterprise. Vinasse was responsible for 50% of the IEP Total, while filter cake contributed 45% to it. Ash and soot, residual waters, and sewage sludge were together responsible for 5% of the IEP Total.

Conclusion

The theoretical conception used in this study is inspiring for the development of new studies on environmental assessment measurement. The study showed that vinasse is the most problematic waste in environmental terms, a conclusion that is in line with academic studies. Nevertheless, the waste with the greatest potential impact on the environment is filter cake. Despite this, filter cake presented a lower IEP(i) than vinasse, given that its negative impact on the basin is smaller. Both wastes contributed 95% of the IEP Total, which places them among the residues to be managed with greater attention.