Coagulation-flocculation of anaerobically treated sugarcane stillage

Autor(es)

Rodrigues, Isabella Junqueira ^[1] ; Fuess, Lucas Tadeu ^[2] ; Biondo, Lucas ^[1] ; Santesso, Caroline Antonelli ^[1] ; Garcia, Marcelo Loureiro ^[1]

Afiliação do(s) autor(es)

^[1] UNESP Univ Estadual Paulista, Dept Petr & Metallogeny, Inst Geosci & Exact Sci, BR-13506900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul & Sanitat, Lab Biol Proc, BR-13563120 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Desalination and Water Treatment; v. 52, n. 22-24, p. 4111-4121, 2014.
• Citações Web of Science: 5

Resumo

Anaerobic digestion applied to stillage usually results in treatment performances. However, effluents from anaerobic reactors still present a residual polluting load due to the presence of organic recalcitrant compounds. Additional treatment methods, such as coagulation-flocculation, may be utilized to improve the final effluent quality. In this study, we assessed the processes of coagulation and flocculation for sugarcane stillage samples previously submitted to anaerobic digestion, aiming to obtain optimal conditions for the physicochemical treatment. Natural corn starch and ferric chloride were tested as coagulants. While starch was considered as not suitable for the treatment for the tested conditions, ferric chloride assays presented satisfactory results. The investigated parameters included coagulant solution dose, rapid mixing gradient and time, flocculation gradient and time, and sedimentation time. Their adjusted values at which better performances obtained were, respectively, 1.6 g L-1, 325 rpm, 10 s, 65 rpm, 20 and 20 min. The best color, turbidity, and chemical oxygen demand removal efficiencies were 95, 97, and 65%, respectively. Stillage pH variation to alkaline conditions did not result in improved removal efficiencies. Although relatively high removal efficiencies of constituents were obtained, the final effluent characteristics did not fit regulations of water reuse in the agriculture through fertigation. However, stillage can definitely become more easily managed if better final effluent quality control parameters are achieved, enabling for example effluents discharge in water bodies. (AU)

• Processo FAPESP: 10/04101-8 - Avaliação da capacidade de recuperação de energia em reatores anaeróbios aplicados ao tratamento de resíduos com alta concentração orgânica
• Beneficiário: Lucas Tadeu Fuess
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 11/02183-0 - Avaliação dos processos de coagulação e mistura rápida em efluentes de reatores anaeróbios para fins de reuso
• Beneficiário: Isabella Junqueira Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 11/05956-0 - Aplicação das operações unitárias de floculação e sedimentação em efluente de reator anaeróbio tratando vinhaça para fins de reuso
• Beneficiário: Lucas Biondo
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica