scholarly journals A Study on the Possibility of Measuring Sludge Sedimentation Using Contrast Detection Characteristics of CdS Photoresistors

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7817
Author(s):  
Seong-Min Hong ◽  
Hyun-Ook Kim ◽  
Choong-Gon Kim
Keyword(s):  
Treatment Process ◽  
Settling Velocity ◽  
Light Emitting Diode ◽  
Volume Index ◽  
Wastewater Treatment Process ◽  
Light Emitting ◽  
Calculation Algorithms ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Detection Characteristics

Although operators periodically measure the sludge volume index (SVI) to stabilize the bioreactor and solid–liquid separation during the wastewater treatment process, there is a problem of inconsistency attributed to the subjective judgment of the operator. This study aims to investigate the possibility of securing objective data by employing CdS (cadmium–sulfur) photoresistors for SVI measurements. The sedimentation velocity of settling sludge was measured using LED (Light Emitting Diode) lights at the same level as the installed CdS photoresistors. As a result of the experiment, the settling velocity of sludge in the CdS photoresistors’ installation position H1 to H8 (non-flocculent settling), H9 to H12 (discrete flocculent settling) and H13 to H18 (zone settling and compressive settling), was 0.594 mm/s, 0.180 mm/s and 0.056 mm/s, respectively. Through this study, it was confirmed that measuring sludge sedimentation using the CdS photoresistors is possible. If the measurement of solid matter in sludge using several sludge sedimentation measurements is enabled in the future, it will be possible to develop calculation algorithms to measure the SVI.

Effect of C/N ratio on nitrous oxide emission from swine wastewater treatment process

2004 ◽  
Vol 49 (5-6) ◽  
pp. 359-371 ◽  
Author(s):  
N. Kishida ◽  
J.H. Kim ◽  
Y. Kimochi ◽  
O. Nishimura ◽  
H. Sasaki ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Treatment Process ◽  
N2o Emission ◽  
Swine Wastewater ◽  
N2o Emissions ◽  
Wastewater Treatment Process ◽  
Phase Study ◽  
Solid Liquid ◽  
Solid Liquid Separation

To evaluate control parameters for nitrous oxide (N2O) emissions in the swine wastewater treatment process, the N2O emission was compared in the activated sludge from SBRs acclimated in different carbon/nitrogen (C/N) ratios. N2O emission from a denitrification phase was very strongly dependent on C/N ratio of swine wastewater, and the total N2O emission in the operating condition of BOD5/TN ratio of 2.6 was approximately 270 times greater than that in BOD5/TN ratio of 4.5. However, the effect of C/N ratio on N2O emission amount from nitrification was not significant in an oxic phase study. It is considered that stabilization of the C/N ratio through optimal solid-liquid separation of slurry or use of an external carbon source is indispensable for effective N2O emission control from nitrogen removal process of swine wastewater.

Influence of Bio-Filter Bed on Treatment of Domestic Sewage in Purifying Tank

2011 ◽  
Vol 183-185 ◽  
pp. 1009-1013
Author(s):  
Chang Wang ◽  
Zhi Cheng Wang ◽  
Bin Fang ◽  
Qing Zhu Jia ◽  
Gui Ju Li
Keyword(s):  
Treatment Process ◽  
Sewage Treatment ◽  
Domestic Sewage ◽  
Mean Values ◽  
Key Technology ◽  
Effluent Quality ◽  
The Mean ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Filter Bed

The influence of bio-filter on domestic sewage treatment in purifying tank was studied in this paper. The result shows that when all the three zones were added bio-filter the mean values of effluent COD and NH3-N were 37.8mg/L and 9.64mg/L respectively, which shows that the bio-filter bed is a key technology and plays important roles for solid-liquid separation, bio-sorption and bio-degradation, to raise the effluent quality in the sewage treatment process.

Upgrading performance of an activated sludge process through addition of talqueous powder

1996 ◽  
Vol 34 (5-6) ◽  
pp. 75-83 ◽  
Author(s):  
J. Cantet ◽  
E. Paul ◽  
F. Clauss
Keyword(s):  
Activated Sludge ◽  
Control Unit ◽  
Physical Structure ◽  
Experimental Models ◽  
Volume Index ◽  
Liquid Separation ◽  
Floc Structure ◽  
Rapid Effect ◽  
Solid Liquid ◽  
Solid Liquid Separation

This study is intended to induce better performance of existing activated sludge wastewater plants without modifying the physical structure of the plant. The process consists in injecting a specific mineral powder into the aeration stage with two precise purposes: firstly to improve floc structure and thus facilitate solid/liquid separation in the clarifier, and secondly to reduce nitrogenous pollution. By means of two experimental models the indisputable and rapid effect of talc/chlorite blend on the solid/liquid separation was established (with a sludge volume index improvement by a factor of 2 to 3 within a few days) compared with a control unit. The increase in nitrification capacity of the system is also clearly shown with nitrification yields being increased by 30%. These results lead us to believe that it is possible to use this process of enhanced nitrification for running a plant reliably without dysfunctioning. Problems linked to hydraulic or biological excess loading can be solved this way. Moreover, the addition of talqueous powder improves sludge dewaterability.

Dosage Control for a Higher Efficiency of the Separation Process

1990 ◽  
Vol 22 (7-8) ◽  
pp. 233-243 ◽  
Author(s):  
Guenter Schrank
Keyword(s):  
Separation Efficiency ◽  
Separation Process ◽  
Separation Plant ◽  
Wastewater Treatment Process ◽  
Process Step ◽  
Liquid Dispersion ◽  
Flotation Cell ◽  
Biological Decomposition ◽  
Solid Liquid ◽  
Solid Liquid Separation

Apart from the biological decomposition of dissolved organic components, the wastewater treatment process is mainly a solid-liquid separation process. Solids: Inorganic and organic undissolved matter are separated from the liquid stream in several process steps. To ensure a good separation efficiency many different chemicals are added to the solid-liquid dispersion. Among other things, the variety of flocculants makes it very difficult to control the polymer dosage. However, weak flocculant dosage control can strongly affect the efficiency of the separation plant or equipment, and the predicted effectiveness of this process step cannot be achieved. To counter this difficulty, a control system working in most applications has been developed. This system works almost independently of the separation process or the type of flocculant used. The system and its function will be described using three different field installations in different applications as examples. These are a sedimentation basin, a flotation cell and a filtration plant. Depending on the function of operation in the past as well as on the size of the plant, the payback period will most certainly cover less than half a year.

Synchronization of Chaotic Quantum Dot Light Emitting Diodes under Optical Feedback Effect

2020 ◽  
pp. 144-148
Keyword(s):  
Quantum Dot ◽  
Delay Time ◽  
Chaos Synchronization ◽  
Optical Feedback ◽  
Light Emitting Diode ◽  
Feedback Effect ◽  
Complete Synchronization ◽  
Light Emitting ◽  
Coupling Methods ◽  
Coupling Parameters

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.

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