Search results for "waste disposal"
showing 10 items of 246 documents
Machine learning for energy cost modelling in wastewater treatment plants.
2018
Understanding the energy cost structure of wastewater treatment plants is a relevant topic for plant managers due to the high energy costs and significant saving potentials. Currently, energy cost models are generally generated using logarithmic, exponential or linear functions that could produce not accurate results when the relationship between variables is highly complex and non-linear. In order to overcome this issue, this paper proposes a new methodology based on machine-learning algorithms that perform better with complex datasets. In this paper, machine learning was used to generate high-performing energy cost models for wastewater treatment plants, using a database of 317 wastewater…
Neutron cross section measurements at n_TOF for ADS related estudies
2005
A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main res…
Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale
2011
The aim of this study was to assess the effect of several operational variables on both biological and separation process performance in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater. The pilot plant is equipped with two industrial hollow-fibre ultrafiltration membrane modules (PURON¿ Koch Membrane Systems, 30m 2 of filtration surface each). It was operated under mesophilic conditions (at 33°C), 70days of SRT, and variable HRT ranging from 20 to 6h. The effects of the influent COD/SO 4-S ratio (ranging from 2 to 12) and the MLTS concentration (ranging from 6 to 22gL -1) were also analysed. The main performance results were about 87% of COD removal, efflu…
Improvement of the thermophilic anaerobic digestion and hygienisation of waste activated sludge by synergistic pretreatment
2019
Hybrid disintegration of waste activated sludge (WAS) before the thermophilic anaerobic stabilization of WAS contributes to the intensification of organic compounds decomposition and increases the effectiveness of the anaerobic stabilization process compared to the fermentation of raw WAS. This article investigates the influence of a chemical-thermal pretreatment procedure with the use of NaOH and freezing by the dry ice on WAS. We found that the hybrid pretreatment of WAS causes higher concentration of released organics in the liquid phase (represented here as a change in soluble chemical oxygen demand - SCOD value) in comparison to these disintegration techniques used separately. The use …
Screening for potential fermentative hydrogen production from black water and kitchen waste in on-site UASB reactor at 20 degrees C.
2008
The potential of black water and a mixture of black water and kitchen waste as substrates for on-site dark fermentative hydrogen production was screened in upflow anaerobic sludge blanket reactors at 20 degrees C. Three different inocula were used with and without heat treatment. With glucose, the highest specific hydrogenogenic activity was 69 ml H2 g volatile solids(-1) d(-1) in batch assays and the highest hydrogen yield 0.44 mol H2 mol glucose(-1) in upflow anaerobic sludge bed reactor. The mixture of black water and kitchen waste degraded readily into volatile fatty acids in the reactors, thus showing potential for hydrogen production. In the conditions applied, however, the highest en…
Comparison of Activated Sludge Processes at Different Temperatures: 35°C, 27–55°C, and 55°C
2002
The performance of mesophilic (35°C; referred to as R1) and thermophilic (55°C; R3) laboratory activated sludge processes (ASPs) as well as ASP with a fluctuating temperature (27-56°C; R2) was compared. During the 124-day runs, in R1 and R3 hydraulic retention time was gradually reduced from 18 h to 3 h, corresponding to an increase in volumetric loading rate from 2 to 10 kg soluble COD m−3d−1; in R2 hydraulic retention time was gradually reduced from 18 to 4.5 h, corresponding to an increase in volumetric loading rate from 2 to 7.5 kg soluble COD m−3d−1. R1 removed on average 85% of soluble COD (GF50-filtered) that was approximately 10% more than R3. In R2 SCOD removal was dependent on the…
Monitoring pH and ORP in a SHARON reactor
2011
This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH…
A plant-wide energy model for wastewater treatment plants: application to anaerobic membrane bioreactor technology
2016
[EN] The aim of this study is to propose a detailed and comprehensive plant-wide model for assessing the energy demand of different wastewater treatment systems (beyond the traditional activated sludge) in both steady- and unsteady-state conditions. The proposed model makes it possible to calculate power and heat requirements (W and Q, respectively), and to recover both power and heat from methane and hydrogen capture. In order to account for the effect of biological processes on heat requirements, the model has been coupled to the extended version of the BNRM2 plant-wide mathematical model, which is implemented in DESSAS simulation software. Two case studies have been evaluated to assess t…
Environmental impact of submerged anaerobic MBR (SAnMBR) technology used to treat urban wastewater at different temperatures
2013
[EN] The objective of this study was to assess the environmental impact of a submerged anaerobic MBR (SAnMBR) system in the treatment of urban wastewater at different temperatures: ambient temperature (20 and 33 degrees C), and a controlled temperature (33 degrees C). To this end, an overall energy balance (OEB) and life cycle assessment (LCA), both based on real process data, were carried out. Four factors were considered in this study; (1) energy consumption during wastewater treatment; (2) energy recovered from biogas capture; (3) potential recovery of nutrients from the final effluent; and (4) sludge disposal. The OEB and LCA showed SAnMBR to be a promising technology for treating urban…
Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF)
2018
[EN] This research work proposes an innovative water resource recovery facility (WRRF) for the recovery of energy, nutrients and reclaimed water from sewage, which represents a promising approach towards enhanced circular economy scenarios. To this aim, anaerobic technology, microalgae cultivation, and membrane technology were combined in a dedicated platform. The proposed platform produces a high-quality solid- and coliform-free effluent that can be directly discharged to receiving water bodies identified as sensitive areas. Specifically, the content of organic matter, nitrogen and phosphorus in the effluent was 45 mg COD.L-1 , 14.9 mg N.L-1 and 0.5 mg P.L-1 , respectively. Harvested solar…