scholarly journals Real-Time Determination of Total Solids in UASB Reactors Using a Single Emitter Ultrasonic Sensor

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1437
Author(s):  
Priscilla N. P. Neves ◽  
Lariza S. Azevedo ◽  
Martijn Hoep ◽  
Thiago Bressani-Ribeiro ◽  
Matthijs Wiersma ◽  
...  
Keyword(s):  
Real Time ◽  
Low Cost ◽  
Anaerobic Sludge ◽  
Retention Capacity ◽  
Total Solids ◽  
Solids Concentration ◽  
Solids Content ◽  
Definition Of ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

The lack of proper sludge withdrawal routines has been one of the main causes of solids washout and consequent deterioration of effluent quality from up-flow anaerobic sludge blanket (UASB) reactors treating sewage in developing countries. The establishment of an adequate sludge withdrawal routine depends on the knowledge of the sludge mass inside the reactor, but for this, it is necessary to continuously monitor the solid’s profile along the height of the digestion compartment of such reactors. Knowing the sludge concentration at the highest point of this compartment, immediately before the passage of the liquid to the settling compartment, allows the definition of more robust strategies for sludge discharge, in order to not exceed the retention capacity (storage) of solids in the reactor. To couple with that, a low-cost ultrasound sensor was developed and tested with the aim of monitoring total solids concentration inside UASB reactors. Bench and demo-scale tests were performed to validate the developed technology. Results have shown that the sensor can provide real-time values of total solids inside the reactor with 0.1% accuracy up to 1% total solids content.

Improved nitrogen removal in upflow anaerobic sludge blanket (UASB) reactors by incorporation of Anammox bacteria into the granular sludge

2004 ◽  
Vol 49 (11-12) ◽  
pp. 69-76 ◽  
Author(s):  
J.E. Schmidt ◽  
D.J. Batstone ◽  
I. Angelidaki
Keyword(s):  
In Situ Hybridisation ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
Appropriate Technology ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
The Third ◽  
Anammox Activity ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Upflow anaerobic sludge blanket reactors may offer a number of advantages over conventional mixed-tank, SBR, and biofilm reactors, including high space-loading, low footprint, and resistance to shocks and toxins. In this study, we assessed the use of upflow anaerobic sludge blanket (UASB) reactor technology as applied to anaerobic ammonia removal, or Anammox. Four 200 ml UASB reactors were inoculated with 50% (by volume) anaerobic granular sludge and 50% flocular sludge from different sources (all with the potential for containing Anammox organisms). Tools used to assess the reactors included basic analyses, fluorescent in-situ hybridisation, and mathematical modelling, with statistical non-linear parameter estimation. Two of the reactors showed statistically identical Anammox activity (i.e., identical kinetic parameters), with good ammonia and nitrite removal (0.14 kgNHx m-3 reactor day-1, with 99% ammonia removal). The third reactor also demonstrated significant Anammox activity, but with poor identifiability of parameters. The fourth reactor had no statistical Anammox activity. Modelling indicated that poor identifiability and performance in the third and fourth reactors were related to an excess of reduced carbon, probably originating in the inoculum. Accumulation of Anammox organisms was confirmed both by a volume loading much lower than the growth rate, and response to a probe specific for organisms previously reported to mediate Anammox processes. Overall, the UASB reactors were effective as Anammox systems, and identifiability of the systems was good, and repeatable (even compared to a previous study in a rotating biological contactor). This indicates that operation, design, and analysis of Anammox UASB reactors specifically, and Anammox systems in general, are reliable and portable, and that UASB systems are an appropriate technology for this process.

scholarly journals A Portable Fuzzy Driver Drowsiness Estimation System

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4093
Author(s):  
Alimed Celecia ◽  
Karla Figueiredo ◽  
Marley Vellasco ◽  
René González
Keyword(s):  
Real Time ◽  
Traffic Accidents ◽  
Fuzzy Inference ◽  
Low Cost ◽  
Raspberry Pi ◽  
Inference System ◽  
Visual Occlusion ◽  
Computational Performance ◽  
Estimation System ◽  
Definition Of

The adequate automatic detection of driver fatigue is a very valuable approach for the prevention of traffic accidents. Devices that can determine drowsiness conditions accurately must inherently be portable, adaptable to different vehicles and drivers, and robust to conditions such as illumination changes or visual occlusion. With the advent of a new generation of computationally powerful embedded systems such as the Raspberry Pi, a new category of real-time and low-cost portable drowsiness detection systems could become standard tools. Usually, the proposed solutions using this platform are limited to the definition of thresholds for some defined drowsiness indicator or the application of computationally expensive classification models that limits their use in real-time. In this research, we propose the development of a new portable, low-cost, accurate, and robust drowsiness recognition device. The proposed device combines complementary drowsiness measures derived from a temporal window of eyes (PERCLOS, ECD) and mouth (AOT) states through a fuzzy inference system deployed in a Raspberry Pi with the capability of real-time response. The system provides three degrees of drowsiness (Low-Normal State, Medium-Drowsy State, and High-Severe Drowsiness State), and was assessed in terms of its computational performance and efficiency, resulting in a significant accuracy of 95.5% in state recognition that demonstrates the feasibility of the approach.

scholarly journals Constraints, performance and perspectives of anaerobic sewage treatment: lessons from full-scale sewage treatment plants in Brazil

2019 ◽  
Vol 80 (3) ◽  
pp. 418-425 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
L. A. Chamhum-Silva ◽  
C. A. L. Chernicharo
Keyword(s):  
Sewage Treatment ◽  
Full Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Operational Performance ◽  
Anaerobic Sludge ◽  
Anaerobic Reactors ◽  
Anaerobic Sludge Blanket ◽  
Operational Constraints ◽  
Uasb Reactors ◽  
Design Construction

Abstract There are hundreds of full-scale upflow anaerobic sludge blanket (UASB) reactors in operation in various parts of the tropical world, notably in India and Latin America, Brazil being the holder of the largest park of anaerobic reactors for sewage treatment in the world. Despite the recognized advantages of UASB reactors, there are problems that have prevented their maximum operational performance. Neglecting the existence and delaying the solution of these challenges can jeopardize the important advances made to date, impacting the future of anaerobic technology in Brazil and in other countries. This work aims to evaluate the operational performance of five full-scale UASB reactors in Brazil, taking into account a monitoring period ranging between two and six years. The main observed design, construction, and operational constraints are discussed. Some outlooks for important upcoming developments are also provided, considering that most of the observed drawbacks can be tackled without significant increases on reactor costs.

Denitrification on the top of UASB reactors of rice wastewaters

2001 ◽  
Vol 44 (4) ◽  
pp. 79-82 ◽  
Author(s):  
L. F. Lopes ◽  
P. R. Koetz ◽  
M. S. Santos
Keyword(s):  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Food Industries ◽  
Denitrification Reactor ◽  
Mixed Reactor ◽  
South Of Brazil ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors ◽  
Maximum Removal

Parboiled rice industry is one of main food industries in the south of Brazil. The main parts of the processing are the humidification and gelatinization of the grain. This procedure increases the productivity and nutritive and cooking values of the product. Some of these industries in the region utilize upflow anaerobic sludge blanket (UASB) reactors as a biological treatment for carbon removal. For nitrogen removal, the proposed system aims to eliminate an extra denitrification reactor, making this step in the top of the UASB, an anoxic zone of the reactor. Nitrification was performed in aerated mixed reactor of 3,6 L. A fraction of the NR was recycled in the top of UASB reactor above the sludge blanket. Recycled ratio varied from 0; 1:0.5; 1:1.0; to 1:1.5. The maximum removal efficiency of NTK was 80%. The results confirm the viability of the proposed system for denitrification.

scholarly journals 3D MODELLING AND DESIGNING OF DEXTO:EKA:

2012 ◽  
pp. 13-17
Author(s):  
SULABH KUMRA ◽  
SHILPA MEHTA ◽  
SHALIJA RAHEJA
Keyword(s):  
Control System ◽  
Real Time ◽  
Motion Capture ◽  
Low Cost ◽  
3D Modelling ◽  
General Design ◽  
Simple Motion ◽  
Technical Specifications ◽  
Definition Of ◽  
Intuitive Interface

The presented paper is concerned with designing of a low-cost, easy to use, intuitive interface for the control of a slave anthropomorphic teleo- operated robot. Tele-operator “masters”, that operate in real-time with the robot, have ranged from simple motion capture devices, to more complex force reflective exoskeletal masters. Our general design approach has been to begin with the definition of desired objective behaviours, rather than the use of available components with their predefined technical specifications. With the technical specifications of the components necessary to achieve the desired behaviours defined, the components are either acquired, or in most cases, developed and built. The control system, which includes the operation of feedback approaches, acting in collaboration with physical machinery, is then defined and implemented.

Degradation of chlorinated aromatic compounds in UASB reactors

1995 ◽  
Vol 31 (1) ◽  
pp. 249-259 ◽  
Author(s):  
Nina Christiansen ◽  
Hanne V. Hendriksen ◽  
Kimmo T. Järvinen ◽  
Birgitte K. Ahring
Keyword(s):  
Metabolic Pathways ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Ring Cleavage ◽  
Anaerobic Sludge ◽  
Chlorinated Phenols ◽  
Desulfomonile Tiedjei ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Data on anaerobic degradation of chloroaromatic compounds in Upflow Anaerobic Sludge Blanket Reactors (UASB-reactor) are presented and compared. Special attention is given to the metabolic pathways for degradation of chlorinated phenols by granular sludge. Results indicate that PCP can be degraded in UASB-reactors via stepwise dechlorination to phenol. Phenol will subsequently be converted to benzoate before ring cleavage. Dechlorination proceeds via different pathways dependent upon the inocula used. Results are further presented on the design of special metabolic pathways in granules which do not possess this activity using the dechlorinating organism, Desulfomonile tiedjei. Additionally, it is shown that it is possible to immobilize Dechlorosporium hafniense, a newly isolated dechlorinating anaerobe, into granular sludge, thereby introducing an ability not previously present in the granules.

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