scholarly journals Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge – a review

2021 ◽  
Author(s):  
N. A. Hamiruddin ◽  
N. A. Awang ◽  
S. F. Mohd Shahpudin ◽  
N. S. Zaidi ◽  
M. A. M. Said ◽  
...  
Keyword(s):  
Control Strategy ◽  
Extracellular Polymeric Substances ◽  
Structural Model ◽  
Granular Sludge ◽  
Operating Conditions ◽  
Aerobic Granular Sludge ◽  
Microbial Distribution ◽  
Thickness Variability ◽  
Standard Operating Condition ◽  
The Stability

Abstract Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategy for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.

scholarly journals Effects of Phosphorus on Loosely Bound and Tightly Bound Extracellular Polymer Substances in Aerobic Granular Sludge

2019 ◽  
Vol 33 (1) ◽  
pp. 59-68 ◽  
Author(s):  
L. L. Yan ◽  
X. L. Zhang ◽  
Z. L. Chen ◽  
Y. Ren ◽  
S. Liu ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Extracellular Polymeric Substances ◽  
Three Dimensional ◽  
Granular Sludge ◽  
Physicochemical Characteristics ◽  
Aerobic Granular Sludge ◽  
Phosphorus Concentration ◽  
Quenching Effect ◽  
The Stability ◽  
Extracellular Polymer

The stability of aerobic granular sludge (AGS) is closely related to its extracellular polymeric substances (EPS). In this study, the composition and physicochemical characteristics of EPS in AGS were determined to evaluate their roles in AGS stability. The study evaluated the influence of influent phosphorus concentration on EPS protein (PN), polysaccharide (PS) and orthophosphate content, zeta potential (ζ) and fluorescence spectrum (EEM) in loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). With higher influent phosphorus concentration, the PN, PS and orthophosphate content were higher, as was the zeta potential in TB-EPS, but it had less influence on LB-EPS. Three-dimensional, synchronous fluorescence spectroscopy and fluorescence region integral (FRI) showed that protein-like substances were the primary components of LB-EPS and TB-EPS. Phosphorus had a dynamic quenching effect on EPS at a concentration between 0 mg L–1 and 17.5 mg L–1, which is the indirect production of phosphorus by cations. An increased concentration of influent phosphorus was beneficial to AGS stability

scholarly journals A Unified Control Strategy of Distributed Generation for Grid-Connected and Islanded Operation Conditions Using an Artificial Neural Network

2021 ◽  
Vol 13 (11) ◽  
pp. 6388
Author(s):  
Karim M. El-Sharawy ◽  
Hatem Y. Diab ◽  
Mahmoud O. Abdelsalam ◽  
Mostafa I. Marei
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Control System ◽  
Distributed Generation ◽  
Control Strategy ◽  
Current Control ◽  
Operating Conditions ◽  
Pi Controllers ◽  
Artificial Neural ◽  
The Stability

This article presents a control strategy that enables both islanded and grid-tied operations of a three-phase inverter in distributed generation. This distributed generation (DG) is based on a dramatically evolved direct current (DC) source. A unified control strategy is introduced to operate the interface in either the isolated or grid-connected modes. The proposed control system is based on the instantaneous tracking of the active power flow in order to achieve current control in the grid-connected mode and retain the stability of the frequency using phase-locked loop (PLL) circuits at the point of common coupling (PCC), in addition to managing the reactive power supplied to the grid. On the other side, the proposed control system is also based on the instantaneous tracking of the voltage to achieve the voltage control in the standalone mode and retain the stability of the frequency by using another circuit including a special equation (wt = 2πft, f = 50 Hz). This utilization provides the ability to obtain voltage stability across the critical load. One benefit of the proposed control strategy is that the design of the controller remains unconverted for other operating conditions. The simulation results are added to evaluate the performance of the proposed control technology using a different method; the first method used basic proportional integration (PI) controllers, and the second method used adaptive proportional integration (PI) controllers, i.e., an Artificial Neural Network (ANN).

Stability of aerobic granular sludge under low energy consumption: Optimization of granular size distribution by a novel internal component

2021 ◽  
Author(s):  
Runjuan Cao ◽  
Yatong Ji ◽  
Taixing Han ◽  
Jingsong Deng ◽  
Liang Zhu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Granular Sludge ◽  
Pollutant Removal ◽  
Low Energy ◽  
Aerobic Granular Sludge ◽  
Mesh Screen ◽  
Energy Consumption Optimization ◽  
Low Energy Consumption ◽  
Internal Component ◽  
The Stability

To enhance the stability and pollutant removal performance of an aerobic granular sludge (AGS), four groups of AGS reactors with different pore sizes of mesh screen (R1 is control reactor,...

The stability of aerobic granular sludge under 4-chloroaniline shock in a sequential air-lift bioreactor (SABR)

2013 ◽  
Vol 140 ◽  
pp. 126-130 ◽  
Author(s):  
Liang Zhu ◽  
Mei-le Lv ◽  
Xin Dai ◽  
Jia-heng Zhou ◽  
Xiang-yang Xu
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
The Stability ◽  
Air Lift

scholarly journals A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 20 ◽  
Author(s):  
Petter H. Gøytil ◽  
Damiano Padovani ◽  
Michael R. Hansen
Keyword(s):  
Control Strategy ◽  
Operating Conditions ◽  
Mode Switching ◽  
Loss Of Control ◽  
Unstable Behavior ◽  
Wide Range ◽  
Stability Issue ◽  
Underlying Mechanisms ◽  
The Stability ◽  
Proper Operation

This paper concerns the stability issue of pump-controlled single-rod cylinders, known as mode switching. First, a review of the topic is provided. Thereafter, the most recently proposed solution for the elimination of mode switching is investigated and shown to result in unstable behavior under certain operating conditions. A theoretical analysis is provided demonstrating the underlying mechanisms of this behavior. Based on the analysis, a novel control strategy is proposed and investigated numerically. Proper operation and stability are demonstrated for a wide range of operating conditions, including situations under which the most recently proposed solution results in unstable behavior and loss of control over the actuator.

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