Browsing by Author "Campitelli, Antonio"
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Item Open Access Cloth filters as alternative to the conventional membranes for solids removal from UASB effluents.(Cranfield University, 2018-12) Campitelli, Antonio; Jefferson, Bruce; Soares, Ana; Alibardi, LucaAnaerobic Membrane Bioreactors (anMBR) represent one of the most promising technology to achieve energy neutral or positive wastewater treatment with a high effluent quality. Despite this potential, its implementation is still restricted by the high costs of the ultrafiltration membrane. This thesis investigated the feasibility of using a cloth filter as an alternative to the conventional membranes for solids removal from an Upflow Anaerobic Sludge Blanket (UASB) effluent. The advantages of the cloth filter are the low cost of the material, simpler operation and maintenance procedures. However, solids removal efficiencies are lower than those of the ultrafiltration membrane. The removal efficiency depends on the pore size of the cloth and on the influent particle and solid profile load characterisation. The aim of this study is to assess the efficacy of cloth filters to treat UASB effluent. Effective solids separation was possible with the cloths tested with optimal performance achieved for the 1 and 10 µm non-woven cloths operated under low cross flow or dead end conditions. In these cases, solids removal efficiencies up to 67% were possible whilst maintaining a flux of 1000 LMH. In relation to the UASB operation, the sludge blanket height in the UASB was seen to correlate to the suspended solids removal and resulted in a progressively higher median particle size exiting the reactor. Further, incorporation of the separation in the recycle line deteriorated performance a little indicating that the cloth filters would be best configured post the recycle line.Item Open Access Hydrolysis and methanogenesis in UASB-AnMBR treating municipal wastewater under psychrophilic conditions: Importance of reactor configuration and inoculum(Frontiers Media, 2020-11-02) Ribera-Pi, Judit; Campitelli, Antonio; Badia-Fabregat, Marina; Jubany, Irene; Martínez-Lladó, Xavier; McAdam, Ewan; Jefferson, Bruce; Soares, AnaThree upflow anaerobic sludge blanket (UASB) pilot scale reactors with different configurations and inocula: flocculent biomass (F-UASB), flocculent biomass and membrane solids separation (F-AnMBR) and granular biomass and membrane solids separation (G-AnMBR) were operated to compare start-up, solids hydrolysis and effluent quality. The parallel operation of UASBs with these different configurations at low temperatures (9.7 ± 2.4°C) and the low COD content (sCOD 54.1 ± 10.3 mg/L and pCOD 84.1 ± 48.5 mg/L), was novel and not previously reported. A quick start-up was observed for the three reactors and could be attributed to the previous acclimation of the seed sludge to the settled wastewater and to low temperatures. The results obtained for the first 45 days of operation showed that solids management was critical to reach a high effluent quality. Overall, the F-AnMBR showed higher rates of hydrolysis per solid removed (38%) among the three different UASB configurations tested. Flocculent biomass promoted slightly higher hydrolysis than granular biomass. The effluent quality obtained in the F-AnMBR was 38.0 ± 5.9 mg pCOD/L, 0.4 ± 0.9 mg sCOD/L, 9.9 ± 1.3 mg BOD5/L and <1 mg TSS/L. The microbial diversity of the biomass was also assessed. Bacteroidales and Clostridiales were the major bacterial fermenter orders detected and a relative high abundance of syntrophic bacteria was also detected. Additionally, an elevated abundance of sulfate reducing bacteria (SRB) was also identified and was attributed to the low COD/SO42– ratio of the wastewater (0.5). Also, the coexistence of acetoclastic and hydrogenotrophic methanogenesis was suggested. Overall this study demonstrates the suitability of UASB reactors coupled with membrane can achieve a high effluent quality when treating municipal wastewater under psychrophilic temperatures with F-AnMBR promoting slightly higher hydrolysis rates