EFLUENTES REAIS E APLICAÇÃO FRACIONADA DO SUBSTRATO TRUB OU GLYCEROL BRUTO: RÁPIDA ADAPTAÇÃO E ALTA EFICIÊNCIA PARA O TRATAMENTO DE DRENAGEM DE MINA

Código

ENES20200042

Autores

Eduardo Coutinho de Paula, Bárbara Franco Vieira, Renata Piacentini Rodriguez, Gustavo Ferreira Simões

Tema

07 - QUALIDADE DA ÁGUA E GEOQUÍMICA DE SEDIMENTOS

Resumo

Mine drainage (MD) is an effluent rich in sulfate, metals, and metalloids that can be treated by sulfate biological reduction using organic industrial by-products as the electron donor. Inoculum from methanogenic reactors can be used, but an adaptation period is needed to promote the dominance of sulfidogenic pathways. Trub (brewery residue) and crude glycerol (GB) are anaerobically degradable as electron donors but can lead to the accumulation of organic acids, acidifying the reactors. However, a previous contact between inoculum and real MD before electron donor addition proved to be efficient in increasing the flow of electrons to sulfidogenic pathways, making the adaptation faster than shown in the literature. The maintenance of a pH close to neutrality with satisfactory rates of sulfate removal, greater than 88% starting from 3756.4 mg.L-1 of sulfate, was achieved when the amount of substrate referring to the COD/sulfate ratio of 3 was added fractionally, in equal parts every 24h over 6 and 7 days, with GB and trub, respectively. The effluent generated has very low concentrations of sulfate, metals, and metalloids, and a high concentration of COD. With a pH greater than 6.86 and alkalinity above 3370 mg.L-1 of CaCO3, this effluent can be used to generate methane without the need for dilution water or alkaline additives. This proposal, therefore, consists of a highly sustainable destination for the three effluents used.