Lessons learnt from 15 years of ICA in anaerobic digesters

2006 ◽  
Vol 53 (4-5) ◽  
pp. 25-33 ◽  
Author(s):  
J.P. Steyer ◽  
O. Bernard ◽  
D.J. Batstone ◽  
I. Angelidaki
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Energy Production ◽  
Control Strategies ◽  
Operating Conditions ◽  
High Rate ◽  
Anaerobic Digesters ◽  
Treatment Processes ◽  
On Line ◽  
Rate Processes

Anaerobic digestion plants are highly efficient wastewater treatment processes with inherent energy production. Despite these advantages, many industries are still reluctant to use them because of their instability confronted with changes in operating conditions. There is therefore great potential for application of instrumentation, control and automation (ICA) in the field of anaerobic digestion. This paper will discuss the requirements (in terms of on-line sensors needed, modelling efforts and mathematical complexity) but also the advantages and drawbacks of different control strategies that have been applied to AD high rate processes over the last 15 years.

Rapid determination of fractal structure of bacterial assemblages in wastewater treatment: implications to process optimisation

1998 ◽  
Vol 38 (2) ◽  
pp. 9-15 ◽  
Author(s):  
J. Guan ◽  
T. D. Waite ◽  
R. Amal ◽  
H. Bustamante ◽  
R. Wukasch
Keyword(s):  
Wastewater Treatment ◽  
Fractal Structure ◽  
Structural Information ◽  
Rapid Determination ◽  
Fractal Dimensions ◽  
Structure Information ◽  
Treatment Processes ◽  
On Line ◽  
Bacterial Aggregates

A rapid method of determining the structure of aggregated particles using small angle laser light scattering is applied here to assemblages of bacteria from wastewater treatment systems. The structure information so obtained is suggestive of fractal behaviour as found by other methods. Strong dependencies are shown to exist between the fractal structure of the bacterial aggregates and the behaviour of the biosolids in zone settling and dewatering by both pressure filtration and centrifugation methods. More rapid settling and significantly higher solids contents are achievable for “looser” flocs characterised by lower fractal dimensions. The rapidity of determination of structural information and the strong dependencies of the effectiveness of a number of wastewater treatment processes on aggregate structure suggests that this method may be particularly useful as an on-line control tool.

Evaluation of flocculation and dissolved air flotation as an advanced wastewater treatment

2001 ◽  
Vol 43 (8) ◽  
pp. 83-90 ◽  
Author(s):  
A. C. Pinto Filho ◽  
C. C. Brandão
Keyword(s):  
Wastewater Treatment ◽  
Domestic Wastewater ◽  
High Rate ◽  
Advanced Treatment ◽  
Dissolved Air Flotation ◽  
Anaerobic Reactor ◽  
Treatment Processes ◽  
Domestic Wastewater Treatment ◽  
Air Flotation ◽  
Dissolved Air

A bench scale study was carried out in order to evaluate the applicability of dissolved air flotation (DAF) as an advanced treatment for effluents from three different domestic wastewater treatment processes, namely: (i) a tertiary activated sludge plant ; (ii) an upflow sludge blanket anaerobic reactor (UASB); and (iii) a high-rate stabilization pond.

scholarly journals Integrated Approach for Wastewater Treatment and Biofuel Production in Microalgae Biorefineries

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2282
Author(s):  
Sanjeet Mehariya ◽  
Rahul Kumar Goswami ◽  
Pradeep Verma ◽  
Roberto Lavecchia ◽  
Antonio Zuorro
Keyword(s):  
Wastewater Treatment ◽  
Energy Demand ◽  
Energy Production ◽  
Effective Means ◽  
Integrated Approach ◽  
Biofuel Production ◽  
World Population ◽  
Treatment Processes ◽  
Current Scenario ◽  
Valuable Compounds

The increasing world population generates huge amounts of wastewater as well as large energy demand. Additionally, fossil fuel’s combustion for energy production causes the emission of greenhouse gases (GHG) and other pollutants. Therefore, there is a strong need to find alternative green approaches for wastewater treatment and energy production. Microalgae biorefineries could represent an effective strategy to mitigate the above problems. Microalgae biorefineries are a sustainable alternative to conventional wastewater treatment processes, as they potentially allow wastewater to be treated at lower costs and with lower energy consumption. Furthermore, they provide an effective means to recover valuable compounds for biofuel production or other applications. This review focuses on the current scenario and future prospects of microalgae biorefineries aimed at combining wastewater treatment with biofuel production. First, the different microalgal cultivation systems are examined, and their main characteristics and limitations are discussed. Then, the technologies available for converting the biomass produced during wastewater treatment into biofuel are critically analyzed. Finally, current challenges and research directions for biofuel production and wastewater treatment through this approach are outlined.

Modeling Mass Transfer in Biological Wastewater Treatment Processes

1986 ◽  
Vol 18 (6) ◽  
pp. 35-45 ◽  
Author(s):  
John C. Kissel
Keyword(s):  
Mass Transfer ◽  
Computer Simulation ◽  
Wastewater Treatment ◽  
Biological Treatment ◽  
Process Models ◽  
High Rate ◽  
Biological Wastewater Treatment ◽  
Trickling Filter ◽  
Treatment Processes ◽  
Individual Effects

Parameters characterizing intrasolid, liquid/solid, and gas/liquid mass transport phenomena in biological treatment systems are required if mass transfer is to be included in process models. Estimates of such parameters are presented and discussed. Collective and individual effects of mass transfer resistances are illustrated by computer simulation of a high-rate trickling filter.

Intelligent control system based on blackboard concept for wastewater treatment processes

1998 ◽  
Vol 37 (12) ◽  
pp. 77-85 ◽  
Author(s):  
T. Ohtsuki ◽  
T. Kawazoe ◽  
T. Masui
Keyword(s):  
Wastewater Treatment ◽  
Control System ◽  
Activated Sludge ◽  
Intelligent Control ◽  
Software Agents ◽  
High Rate ◽  
Target System ◽  
Activated Sludge Process ◽  
Intelligent Control System ◽  
Treatment Processes

An intelligent control system for wastewater treatment processes has been developed and applied to fullscale, high-rate, activated sludge process control. In this control system, multiple software agents that model the target system using their own modeling method collaborate by using data stored in an abstracted database named ‘blackboard’. The software agents, which are called ‘expert modules’, include a fuzzy expert system, a fuzzy controller, a theoretical activated sludge model, and evaluators of raw data acquired by various online sensors including a respirometer. In this paper, the difficulties of controlling an activated sludge system by using a single conventional strategy are briefly reviewed, then our approach to overcome these difficulties by using multiple modeling methods in the framework of an ‘intelligent control system’ is proposed. Case studies of applications to a high-rate activated sludge process that treats BOD and nitrogen of human excrement are also presented.

Application of the IWA Anaerobic Digestion Model (ADM1) for simulating full-scale anaerobic sewage sludge digestion

2005 ◽  
Vol 52 (1-2) ◽  
pp. 487-492 ◽  
Author(s):  
Y. Shang ◽  
B.R. Johnson ◽  
R. Sieger
Keyword(s):  
Wastewater Treatment ◽  
Steady State ◽  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Biochemical Parameter ◽  
Full Scale ◽  
Anaerobic Digesters ◽  
Biogas Yield ◽  
Volatile Solids

A steady-state implementation of the IWA Anaerobic Digestion Model No. 1 (ADM1) has been applied to the anaerobic digesters in two wastewater treatment plants. The two plants have a wastewater treatment capacity of 76,000 and 820,000 m3/day, respectively, with approximately 12 and 205 dry metric tons sludge fed to digesters per day. The main purpose of this study is to compare the ADM1 model results with full-scale anaerobic digestion performance. For both plants, the prediction of the steady-state ADM1 implementation using the suggested physico-chemical and biochemical parameter values was able to reflect the results from the actual digester operations to a reasonable degree of accuracy on all parameters. The predicted total solids (TS) and volatile solids (VS) concentration in the digested biosolids, as well as the digester volatile solids destruction (VSD), biogas production and biogas yield are within 10% of the actual digester data. This study demonstrated that the ADM1 is a powerful tool for predicting the steady-state behaviour of anaerobic digesters treating sewage sludges. In addition, it showed that the use of a whole wastewater treatment plant simulator for fractionating the digester influent into the ADM1 input parameters was successful.

Minimisation of excess sludge production in a WWTP by coupling thermal hydrolysis and rapid anaerobic digestion

2005 ◽  
Vol 52 (10-11) ◽  
pp. 255-263 ◽  
Author(s):  
J. Chauzy ◽  
S. Graja ◽  
F. Gerardin ◽  
D. Crétenot ◽  
L. Patria ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Pilot Plant ◽  
Hydraulic Retention Time ◽  
Wastewater Treatment Plants ◽  
Control Line ◽  
Thermal Hydrolysis ◽  
Excess Sludge ◽  
Anaerobic Digesters ◽  
Sludge Production

In many cases, reducing sludge production could be the solution for wastewater treatment plants (WWTP) that here difficulty evacuating the residuals of wastewater treatment. The aim of this study was to test the possibility of minimising the excess sludge production by coupling a thermal hydrolysis stage and an anaerobic digestion with a very short HRT. The tests were carried out on a 2,500 p.e. pilot plant installed on a recycling loop between the clarifier and the actived sludge basin. The line equipped with the full scale pilot plant produced 38% TSS less than the control line during a 10 week period. Moreover, the rapid anaerobic digestion removed, on average, more than 50% of the total COD load with a hydraulic retention time (HRT) of 3 days. Lastly, the dryness of the remaining excess sludge, sanitised by the thermal hydrolysis, was more than 35% with an industrial centrifuge. This combination of thermal hydrolysis and rapid anaerobic digestion equally permits a significant gain of compactness compared to traditional anaerobic digesters.

On-line estimation of unmeasured inputs for anaerobic wastewater treatment processes

2003 ◽  
Vol 11 (9) ◽  
pp. 1007-1019 ◽  
Author(s):  
Didier Theilliol ◽  
Jean-Christophe Ponsart ◽  
Jérôme Harmand ◽  
Cédric Join ◽  
Pascal Gras
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Wastewater Treatment ◽  
Treatment Processes ◽  
On Line

On-Line Thermal Balancing Technique for a Large Turbo-Generator

1992 ◽  
Vol 114 (1) ◽  
pp. 60-66 ◽  
Author(s):  
M. Zumbach ◽  
G. Schweitzer ◽  
K. Schoellhorn
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Operating Conditions ◽  
Loop Control ◽  
Turbo Generator ◽  
Closed Loop Control System ◽  
Input Signals ◽  
Loop Control System ◽  
On Line ◽  
A New Technique

In this paper a new technique is proposed to rebalance automatically a large turbo-generator during operation. The sensitivity of the rotor unbalances to thermal asymmetries in the rotor is exploited by mounting some heating elements and using them as actively controlled actuators. The shaft vibrations are measured and used as input signals of the feedback controller. Unbalances thus can be compensated during rotor operation. A theoretical model of the thermo-elastic rotor has been developed and an appropriate closed-loop control system has been designed. The simulation results are verified on a special test rig with digital control allowing for varioius control strategies and various operating conditions.

Removal efficiency of pharmaceuticals and personal care products with varying wastewater treatment processes and operating conditions – conception of a database and first results

2008 ◽  
Vol 57 (1) ◽  
pp. 49-56 ◽  
Author(s):  
C. Miège ◽  
J.M. Choubert ◽  
L. Ribeiro ◽  
M. Eusèbe ◽  
M. Coquery
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Personal Care Products ◽  
Operating Conditions ◽  
Personal Care ◽  
Scientific Publications ◽  
Treatment Processes ◽  
First Results ◽  
Mean Concentration

We created a database in order to quantitatively assess the occurrence and removal efficiency of PPCPs in WWTPs. From 113 scientific publications, we compiled 5887 data on the concentrations and loads of PPCPs in WWTP influents and effluents, and on their removal efficiency. The first outputs of our database include: (1) a list of the most frequently studied molecules, their frequency of detection, their mean concentration and removal in liquid influent and effluent; (2) a comparison of the removal efficiency for different WWTP processes; (3) a study of the influence of the operating conditions (sludge and hydraulic retention times).

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