Energetic valorization of the algae sludge generated in the treatment of sanitary sewage

Name: Oswaldo Paiva Almeida Filho
Type: PhD thesis
Publication date: 06/12/2016

Namesort descending Role
Sérvio Túlio Alves Cassini Advisor *

Examining board:

Namesort descending Role
Marcio Ferreira Martins Co advisor *
Marco Antônio Almeida de Souza External Examiner *
Renato Ribeiro Siman Internal Examiner *
Ricardo Franci Gonçalves Co advisor *
Sérvio Túlio Alves Cassini Advisor *

Summary: It is known that the wastewater effluent from the facultative pond containing organic and mineral materials that generate environmental problem. The nitrogen volatilization can cause air pollution and phosphorus permeates the solid harming groundwater. Applying flocculation and sedimentation were obtained maximum throughput of 0.363 ± 0.014 mg l-1 in bench and 277.4 mg L-1 in situ. It is possible to supernatant with lower values of CLA, NTK PT and 85%, 60% and 6% respectively in relation to wastewater pond. We studied and recommended drying conditions and storage algal slime. The algal sludge has a strong odor, reddish brown and dark green beans, with irregular edges and rounded shape. It has been classified as non-hazardous, non-inert and no acute toxicity The value of PCS is 21.29 ± 0.96 kJ.kg-1, higher than the renewable trees, between 150 and 425 ° C takes place the first oxidation at low temperature and the fixed carbon formed is possibly oxidized between 425-770 ° C. The generated gases have the presence of 30% O2, 28.4% CO2 and 36,62% of H2 and CO with 443 ppm. For aerating the algal sludge is recommended use it in the form of briquettes. Study was conducted based on the energy return on investment, EROI index to four models evaluating the influence of the addition of CO2 in the LAT, the algal sludge participating in power generation in UASB and gasification of discarded sludge. The addition of CO2 in the LAT an increase of 10% in the EROI. The algal sludge contributes to the 39.89% increase in energy generation and 50.12% in use for generating the UASB. The EROI values obtained for the gasification to the models 3 and 4 were 1.78 and 1.39, meaning that much of the energy produced is consumed by generation. This value results in low EROI values systems with gasification, but which are justified for environmental mitigation. It is recommended to evaluate joint and external gasification to sewage treatment systems.

Access to document

Acesso à informação
Transparência Pública

© 2013 Universidade Federal do Espírito Santo. Todos os direitos reservados.
Av. Fernando Ferrari, 514 - Goiabeiras, Vitória - ES | CEP 29075-910