Banca de DEFESA: RODRIGO ALMERIA RAGIO
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : RODRIGO ALMERIA RAGIO
DATA : 23/02/2022
HORA: 09:30
LOCAL: UFABC - Online
TÍTULO:
Effect of adding organic and inorganic coagulants in UASB effluent for post-treatment by Ultrafiltration (UF) membranes
PÁGINAS: 146
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Ambiental
SUBÁREA: Saneamento Básico/Esgotos/Reator Anaeróbico
RESUMO:
The upflow anaerobic sludge blanket reactor (UASB) is an important milestone in wastewater treatment sustainability, but it usually requires post-treatment in order to meet discharge standards or allow reuse water production. Natural coagulants have great potential for anaerobic effluent treatment with lesser environmental impact, while the adoption of microfiltration (MF) and ultrafiltration (UF) external membrane modules has been increasingly frequent for the post-treatment of this effluent. However, technical and economical comparison of these technologies is not frequently realized. Another possibility is the pre-addition of coagulants to the membrane system, but researches evaluating this use for natural coagulants are rare. In this context, the objective of this work was to investigate and compare coagulation, flocculation and sedimentation with tannin-based and Al-based coagulants with membrane filtration systems with different pore size (MF and UF) for treatment of UASB effluent, in addition to evaluating the adding of coagulants in a UF system. Commercial modified tannin (TANm) and polyaluminum chloride (PACl), in active principle dosages of 10-500 mg/L were used in jar test assays, where TANm affected less the pH, consumed less alkalinity and produced less sludge compared to PACl, but this reached higher turbidity (89-97%), COD (70-72%) and phosphorus (65-98%) in dosage interval of 25 to 100 mg/L. Filtration assays were made in a test cell simulating crossflow filtration, with excellent turbidity (96%) and COD (69-72%) removal with both membranes. Higher operational flux and lesser fouling resistance were obtained with MF, despite higher flux decay. Economical evaluation showed that operational costs were higher for coagulation systems due to coagulants and sludge disposal costs. For membrane filtration systems with coagulant addition, active principle dosages of 10, 25 and 40 mg/L were employed, with addition to the test cell after rapid mixing. Critical flux, filterability and fouling reversibility assays were performed and indicated higher critical flux, less flux decay and specific cake layer resistance with use of coagulants, with higher permeate production, but with increase in irreversible fouling. Pollutant removal was similar for the evaluated systems, except for additional turbidity, color and UV-absorbing organic compounds (UV254) removal with coagulants, beyond additional phosphorus removal with PACl. Economic evaluation indicated that coagulants are capable of reducing required membrane area for treatment, reducing membrane exchange and chemical cleaning costs, but the coagulants cost is high too. The system with 10 mg/L of TANm pre-addition presented the lesser total cost and the estimated return time for investment (simple payback) was from 1.9 to 0.4 year. Future trials with upscaling are recommended and evaluation of additional relevant parameters for reuse water production.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1073159 - EDUARDO LUCAS SUBTIL
Membro Titular - Examinador(a) Externo à Instituição - ROSÂNGELA BERGAMASCO - UEM
Membro Titular - Examinador(a) Externo à Instituição - MIRIAM CRISTINA SANTOS AMARAL
Membro Suplente - Examinador(a) Interno ao Programa - 2342998 - RODRIGO DE FREITAS BUENO
Membro Suplente - Examinador(a) Externo à Instituição - JOSÉ CARLOS MIERZWA - USP