Search results for "batch reactor"
showing 10 items of 50 documents
Multivariate SPC of a sequencing batch reactor for wastewater treatment
2007
Data from a sequencing batch reactor (SBR) operated for enhanced biological phosphorus removal from wastewater have been analysed in order to propose an efficient MSPC scheme of the process. Different multivariate bilinear approaches have been applied and compared in terms of their capabilities for on-line and off-line fault detection and diagnosis. The typical three-way data structure from a batch process was unfolded batch-wise and variable-wise. In the latter case, two models were built: with (AT) and without (WKFH) removing the main non-linear behaviour of the process data. Since the process consists of several stages, the monitoring strategies tested include: one model for all stages a…
Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems
2011
The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Rea…
Electrocatalytic carboxylation of chloroacetonitrile at a silver cathode for the synthesis of cyanoacetic acid
2008
Abstract The electrocatalytic carboxylation of chloroacetonitrile to cyanoacetic acid performed at silver cathodes was investigated both theoretically and experimentally. Silver exhibits powerful electrocatalytic activities towards the reduction of chloroacetonitrile. In CO 2 -saturated CH 3 CN, reduction of NCCH 2 Cl occurs at potentials that are about 0.7 V more positive than those observed at glassy carbon and gives cyanoacetic acid in good yields. Theoretical considerations on the effect of operative parameters on the performances of the process were confirmed by electrocarboxylation experiments performed in undivided cells equipped with sacrificial anodes both in a bench-scale electroc…
Performance of the auxotrophic Saccharomyces cerevisiae BY4741 as host for the production of IL-1β in aerated fed-batch reactor: role of ACA suppleme…
2009
Abstract Background Saccharomyces cerevisiae BY4741 is an auxotrophic commonly used strain. In this work it has been used as host for the expression and secretion of human interleukin-1β (IL1β), using the cell wall protein Pir4 as fusion partner. To achieve high cell density and, consequently, high product yield, BY4741 [PIR4-IL1β] was cultured in an aerated fed-batch reactor, using a defined mineral medium supplemented with casamino acids as ACA (auxotrophy-complementing amino acid) source. Also the S. cerevisiae mutant BY4741 Δyca1 [PIR4-IL1β], carrying the deletion of the YCA1 gene coding for a caspase-like protein involved in the apoptotic response, was cultured in aerated fed-batch rea…
Aerobic granular sludge: State of the art, applications, and new perspectives.
2018
The aerobic granular sludge (AGS) process has attracted significant interest over the last decade and is one of the most promising wastewater treatment technologies. AGS offers several advantages over conventional activated sludge (CAS) including excellent settling, and higher volumetric loading capacity. Because of porosity, concentration gradients develop and stratified aerobic, anoxic, and anaerobic layers develop throughout granule depth. This is the reason for simultaneous nutrient removal in a single tank. Aerobic granulation is influenced by many parameters including wastewater characteristics and operating conditions. Among these, the anaerobic upflow feeding strategy and a properly…
Effect of pH on biological phosphorus uptake.
2006
An anaerobic aerobic laboratory scale sequencing batch reactor (SBR) was operated to study the effect of pH on enhanced biological phosphorus removal. Seven steady states were achieved under different operating conditions. In all of them, a slight variation in the pH value was observed during anaerobic phase. However, pH rose significantly during aerobic phase. The increase observed was due to phosphorus uptake and carbon dioxide stripping. When pH was higher than 8.2-8.25 the phosphorus uptake rate clearly decreased. The capability of Activated Sludge Model No. 2d (ASM2d) and Biological Nutrient Removal Model No. 1 (BNRM1) to simulate experimental results was evaluated. Both models success…
Process understanding of a wastewater batch reactor with block-wise PLS
2007
In this work a systematic methodology ‘block-wise PLS’ has been applied to thoroughly analyse data from a sequencing batch reactor (SBR) operated for biological phosphorus removal from wastewater. The aim of this study was to diagnose process variables (collected by the inexpensive and low-maintenance sensors installed in the SBR) likely related to the main key indicator of process performance: the phosphorus removal efficiency (PRE), determined off-line in the quality control laboratory. In this way, it is intended to aid the process operators in the detection of abnormal values of these critical variables which would indicate undesirable process performance, so that, they could act on the…
Using Unfold-PCA for batch-to-batch start-up process understanding and steady-state identification in a sequencing batch reactor
2007
In chemical and biochemical processes, steady-state models are widely used for process assessment, control and optimisation. In these models, parameter adjustment requires data collected under nearly steady-state conditions. Several approaches have been developed for steady-state identification (SSID) in continuous processes, but no attempt has been made to adapt them to the singularities of batch processes. The main aim of this paper is to propose an automated method based on batch-wise unfolding of the three-way batch process data followed by a principal component analysis (Unfold-PCA) in combination with the methodology of Brown and Rhinehart 2 for SSID. A second goal of this paper is to…
Effect of the applied organic load rate on biodegradable polymer production by mixed microbial cultures in a Sequencing Batch Reactor
2006
This article studies the operation of a new process for the production of biopolymers (polyhydroxyalkanoates, PHAs) at different applied organic load rates (OLRs). The process is based on the aerobic enrichment of activated sludge to obtain mixed cultures able to store PHAs at high rates and yields. A mixture of acetic, lactic, and propionic acids at different concentrations (in the range 8.5-31.25 gCOD/L) was fed every 2 h in a sequencing batch reactor (SBR). The resulting applied OLR was in the range 8.5-31.25 gCOD/L/day. Even though, as expected, the increase in the OLR caused an increase in biomass concentration (up to about 8.7 g COD/L), it also caused a relevant decrease of maximal po…
Upgrade of citrus waste as a biofuel via slow pyrolysis
2015
Abstract Slow pyrolysis (200–650 °C) experiments on citrus residues (orange peel waste “OP” and lemon peel waste “LP”) were carried out in lab scale fixed bed batch reactor. Bio-oil and bio-char obtained by thermal degradation are more stable, more homogeneous and higher energy content fuels when compared to the parent feedstock. Thermogravimetric analysis (TGA) showed higher stability of LP waste, which appears related to the higher lignin content . Mass and energy yields of solid and liquid products (i.e., char and oil) were measured to determine the effects of peak temperature on feedstock. A linear correlation between Gross Calorific Value (GCV), peak temperatures and mass loss (ML) all…