Back to Search
Start Over
Physico-chemical pre-treatments of anaerobic digestion liquor for aerobic treatment
- Source :
- Scopus, RUO. Repositorio Institucional de la Universidad de Oviedo, instname
- Publication Year :
- 2020
-
Abstract
- Centrifugation of anaerobically digested sewage sludge gives rise to a solid phase, which could be employed as a fertilizer, and a liquid fraction (ADL), which should be treated before being spilled out. This is not an easy task because this liquor is characterized for presenting high COD (~16000 mg O2/L), high ammonium content (~4000 mg/L) and low biodegradability (BOD5/COD ~0.2). With the objective to pre-treat this aqueous waste before its treatment by means of more traditional aerobic processes, different physico-chemical methods (ultrasound, ozonation, hydrolysis and wet air oxidation) were assessed in this work. Ultrasound and thermal hydrolysis gave solubilizations around 47% and 68% respectively. The best results in terms of total COD removal were obtained when wet air oxidation (8 h, 160 C-200 °C and 6.0 MPa) and ozonation (8 h, 25 °C, 12 g/h O3) techniques were employed achieving COD degradations of 71% and 38%, respectively. The pre-treatment of ADL with the four assayed techniques improved considerably the biodegradability (BOD5/COD) of the effluent, with values around 0.3–0.4, depending on the treatment. The experimental data were successfully fitted by kinetic models and the kinetic constants for the solubilization and degradation steps were obtained. Application of the proposed models can be of interest for the optimization and selection of the most suitable techniques and operational conditions, in each particular case.
- Subjects :
- Environmental Engineering
0208 environmental biotechnology
02 engineering and technology
010501 environmental sciences
Management, Monitoring, Policy and Law
Waste Disposal, Fluid
01 natural sciences
Hydrolysis
Bioreactors
Anaerobiosis
Wet oxidation
Waste Management and Disposal
Effluent
0105 earth and related environmental sciences
Aqueous solution
Sewage
Chemistry
General Medicine
Biodegradation
Thermal hydrolysis
Pulp and paper industry
020801 environmental engineering
Anaerobic digestion
Oxidation-Reduction
Sludge
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Scopus, RUO. Repositorio Institucional de la Universidad de Oviedo, instname
- Accession number :
- edsair.doi.dedup.....44e3b048e662c43c14272f26a6017ffc