Tratamento do efluente de uma recicladora de plásticos utilizando coagulante não metálico e compostagem

Abstract

Plastic is the most consumed raw material in the modern world and recycling is vitally important, both in society and the environment, however this activity generates a liquid effluent with high organic values which must be properly treated. The traditional physical chemical treatment method using coagulation generally features aluminum or iron based coagulants, however the slurry generated in this process contains heavy metals, resulting in improper slurry that is not suitable for any other application and must be directed to an industrial landfill. This study details an environmentally friendly process for effluent treatment, with organic tannin using as a flocculant agent on waste water from the polypropylene plastic recycling industry. Results show a 78.4% COD reduction and more than 90% of some heavy metal contamination had been removed. With the resulting slurry composting was carried out, utilizing conic windrows with native grass and rice hull as organic substrates, obtaining a compound that can be used as organic fertilizer. The organic tannin application proved to be a perfectly suitable coagulant opposite traditional metallicbased coagulants, and had the advantage that the slurry can be used as a composting raw material to produce a natural fertilizer liable for agricultural applications.