Viabilidade do processo de tratamento anaeróbio do resíduo da industrialização da mandioca em sistema de duas fases

• Ano de defesa: 1996
• Autor(a) principal: Sampaio, Brasília Maria Lofiego
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Engenharia Química; UEM; Maringá, PR; Departamento de Engenharia Química
• Palavras-chave em Português: Mandioca; Resíduos; Tratamento; Beneficiamento; Tratamento de resíduo; Industrialização da mandioca; Processo anaeróbico; Resíduo líquido (Manipueira); Problemas ambientais; Tratamento de efluentes; Brasil.; Engenharias; Engenharia Química
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/3852

The propose of this work was to analyse the feasibility of the anaerobic process performance to treat the manioc industry wastewater, "manipueira", under ambient temperature. This anaerobic process consisted of the separation of the acidogenic stage from the methanogenic stage, operating in series continuously. The wastewater used (manipueira) was obtained from the maniocflour industrial process of the INDEMIL, industry which is located in Formosa, district of Paranavaí, Northwest of Paraná. The system was essentially constituted by two reactors connected in series. In the first reactor the acid stage took place and in the second the methane phase occurred. The acid reactor start occurred after its inoculation with anaerobic sludge from Maringá's Sewer Treatment Station. The acid reactor with perfect mixture characteristics was made from acrylic material and had a volume of 5 litres. This reactor was operated under ambient temperature and pH between 5.0 and 5.5. Its hydraulic retention time was 1 day. Three affluent streams, "manipueira" having COD concentration of 3,000, 4,000 and 6,000 mg/L, were tested in this reactor. The reactor homogenised by a magnetic agitation. In the methane reactor the inoculation occurred with the same sludge used in the acid reactor. This methanogenic reactor had a hybrid characteristic between a CSTR and fixed bed reactor. The total reactor volume was 20 litres and its fixed bed portion consisted of 50 % of this volume, which was filled with rigid dried bamboo packing (2 cm x 2 cm size) This hybrid reactor was continuously fed with the acid reactor effluent and was operated under ambient temperature and pH varying from 7.0 to 7.5. During the experiment, at the inlets and outlets of both reactors, the following parameters were accompanied and controlled: pH, COD, alkalinity, volatile acid, free cyanide, volume and composition of produced gases. The acid reactor operated during a period of 255 days, the methane reactor for 110 days and the complete system of anaerobic treatment for 110-day period. The acid reactor allowed an average percentage of COD reduction of 31.7%. with a medium increase of the volatile acidity of 42,4%. The free cyanide concentration suffered a reduction at about 90.3%. The alkalinity in the acid reactor was enough to enable the tamponment near to that required in the methanogenesis. A good level of stability was observed in the methane reactor. This was evidenced by the regularity of the reduction percentage of COD, free cyanide, volatile acid and methane percentage produced in the gases mixture. In this reactor the COD, volatile acid and free cyanide average of removal were 89%, 92,6% and 61,2%, respectively. The gas volume produced by the reactor was 0.5L per gram of removal COD, with a methane average percentage at about 64%. The results obtained for the process as a whole, under ambient temperature, are similar to those obtained in systems with controlled temperature. The COD, volatile acid and free cyanide average percentages of reduction were 94%, 87% and 96.7%, respectively. This results allow to consider as feasible the process of anaerobic treatment in two stages , which may have a great potential of application in the treatment of other organic effluents.