A Comparative Research on Sludge Properties under Different Wastewater Quality Conditions

2013 ◽  
Vol 706-708 ◽  
pp. 467-471
Author(s):  
Xue Song Li ◽  
Meng Zhao ◽  
Mei Zhang
Keyword(s):  
Comparative Research ◽  
Ph Value ◽  
Low Ph ◽  
Volume Index ◽  
Late Period ◽  
Sludge Volume Index ◽  
Sludge Bulking ◽  
Wastewater Quality ◽  
Sludge Properties ◽  
Do Concentration

Objective: to explore the wastewater quality conditions which made sludge bulk easily, and the sludge properties when sludge bulking happened. Methods: wastewater was treated by SBR process, and sludge volume index (SVI) in different wastewater quality conditions was determined by controlling water temperature, dissolved oxygen (DO) and pH value. Conclusion: under low temperature conditions, effect of DO concentration on SVI was great; and the lower DO concentration, the more serious sludge bulking. But pH value had less effect on SVI, and only mild filamentous sludge bulking happened on activated sludge at low pH value (pH=6.0-6.5). Moreover, SVI tended to be steady at late period of operation, and the average was 203 mL/g.

Monitoring activated sludge settling properties using image analysis

2004 ◽  
Vol 50 (7) ◽  
pp. 281-285 ◽  
Author(s):  
R. Jenné ◽  
E.N. Banadda ◽  
I.Y. Smets ◽  
J.F. Van Impe
Keyword(s):  
Image Analysis ◽  
Activated Sludge ◽  
Volume Index ◽  
Filament Length ◽  
Sludge Volume Index ◽  
Filamentous Bulking ◽  
Sludge Properties ◽  
Fully Automatic ◽  
The One ◽  
Sludge Settling

The goal of this study is to develop a monitoring system for activated sludge properties, as this is an essential tool in the battle against filamentous bulking. A fully automatic image analysis procedure for recognising and characterising flocs and filaments in activated sludge images has been optimised and subsequently used to monitor activated sludge properties in a lab-scale installation. The results of two experiments indicate that the image information correlates well with the Sludge Volume Index. It is shown that, at the onset of filamentous bulking, there is an increase in total filament length on the one hand, and a change in floc shape on the other hand.

Study on the Influence of SRT on Nitrogen Removal and Sludge Properties of A/O-MBR Bioreactor

2011 ◽  
Vol 374-377 ◽  
pp. 946-950
Author(s):  
Zhi Hua Zhang ◽  
Zhi Qiang Liu ◽  
Gai Jing Yu ◽  
Xiu Bo Chen ◽  
Bai Ge Su
Keyword(s):  
Exponential Decay ◽  
Nitrogen Removal ◽  
Sedimentation Rate ◽  
Retention Time ◽  
Membrane Bioreactor ◽  
Domestic Sewage ◽  
Volume Index ◽  
Sludge Volume Index ◽  
N Removal ◽  
Sludge Properties

Anoxic/Oxic Membrane Bioreactor (A/O-MBR) was used to treat domestic sewage, the effect of different sludge retention time (SRT) on nitrogen removal and the sludge properties were investigated. The results indicated that the change of NH3-N removal increased gradually with the SRT extension, then basically tends to be stable. The systematic elimination effect of TN rises with the SRT extension and then slightly tends to decrease. MLVSS/MLSS presents a gradually declining trend with the SRT extension. Sludge volume index (SVI) reduces along with the SRT extension according to the exponential decay tendency, but sludge sedimentation rate (SV30) increases progressively by two step multinomial tendency.

On-line measurements of settling characteristics in activated sludge

1997 ◽  
Vol 36 (4) ◽  
pp. 307-312
Author(s):  
Michael R. Rasmussen ◽  
Torben Larsen
Keyword(s):  
Activated Sludge ◽  
Settling Velocity ◽  
Continuous Measurement ◽  
Batch Reactor ◽  
Volume Index ◽  
Sludge Volume Index ◽  
Dynamic Variations ◽  
On Line ◽  
Settling Column ◽  
Settling Characteristics

An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The results were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity, which was not apparent in the DSVI (Diluted Sludge Volume Index).

Effects of sludge settling characteristics in the BNR system

2000 ◽  
Vol 42 (3-4) ◽  
pp. 283-288 ◽  
Author(s):  
Z. Yun ◽  
W. Yo ◽  
Y. Yi ◽  
S. Choi ◽  
E. Choi ◽  
...  
Keyword(s):  
Settling Tank ◽  
Volume Index ◽  
Anoxic Zone ◽  
Sludge Volume Index ◽  
Analytical Accuracy ◽  
Fast Settling ◽  
Sludge Settling ◽  
Extracellular Polymer ◽  
Sludge Settleability ◽  
Settling Characteristics

Although the BNR system design assumes no sludge settling problems in the final settling tank, the fluctuation of daily loading and up to 40% of anaerobiosis in the BNR system would be considerable factors in determining the sludge settleability. The sludge volume index (SVI) is a classical parameter to examine the sludge settleability but it has a limited value to evaluate the overall settling characteristics. The extracellular polymer (ECP) content in sludge has long been considered as an indicator of biological flocculation in activated sludge process, but the skepticism on analytical accuracy limits the usage in settling study. This study focused on evaluating the BNR system performance related to the sludge settling characteristics under the controlled laboratory environment. A 5-stage BNR system (anaerobic-anoxic-3 stage oxic) was operated with the HRTs from 3.9 to 7.6 hours. In order to determine the sludge settling properties, both SVI and ECP content were monitored. The ECP contents in the sludge sample were measured by the slime-washing step followed by high-G centrifugation and sonication. The gel-electrophoresis was used to detect the DNA in the sonicated samples to determine the intracellular polymer contamination. It has been found that the anaerobiosis in the anaerobic and anoxic zone that consisted of 37% of reactor volume could not deteriorate the sludge settling properties even at the HRT of 3.9 hours. The SVI values of sludge taken from the reactor with the HRT of 7.2 hours averaged to less than 50 mL/gr. It was postulated that a fast settling sludge in the BNR system could not always ensure production of clear effluent. The sludge with very low SVI might not achieve a complete biological flocculation potential. In addition, the degree of denitrification in the BNR system could be related to the sludge settleability.

scholarly journals Degradation of methylene blue by natural manganese oxides: kinetics and transformation products

2019 ◽  
Vol 6 (7) ◽  
pp. 190351 ◽  
Author(s):  
Shuangxi Zhou ◽  
Zhiling Du ◽  
Xiuwen Li ◽  
Yunhai Zhang ◽  
Yide He ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Manganese Oxides ◽  
Ph Value ◽  
Low Cost ◽  
Reaction System ◽  
Transformation Products ◽  
Low Ph ◽  
Initial Concentration ◽  
Environmental Material ◽  
High Redox Potential

In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m 2 g −1 , it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4–8) and initial concentration of MB (10–50 mg l −1 ), but positively with the dosage of MnO x (1–5 g l −1 ). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.

scholarly journals Characteristics of the Coagulate Obtained During the Process of Model Wastewater Treatment

2015 ◽  
Vol 1 ◽  
pp. 9
Author(s):  
Julija Brovkina ◽  
Galija Shulga ◽  
Jurijs Ozolins ◽  
Zilgma Irbe ◽  
Maris Turks ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Volume Index ◽  
Optimal Time ◽  
Sludge Volume Index ◽  
Organic Part ◽  
Main Drawback ◽  
Average Size ◽  
By Products ◽  
Polyaluminium Chloride

In the process of wastewater treatment by coagulation a large amount of sediment is being produced, which is the main drawback of this method. Therefore, the development of utilization or recirculation technology of the waste obtained, the research of the obtained by-products should be conducted. Within the scope of this work, the sediment, that is being formed during the coagulation of the model wastewater containing the wood originated pollutants, was studied. Using the aluminium-containing composition coagulant on a base of polyaluminium chloride, coagulates characterized by the low sludge volume index within 30 minutes (89 ml g-1), and the optimal time of sedimentation is 20-30 minutes. The coagulate particles have an average size of 45.8 μm. The derived coagulate is composed primarily of carbon (27.9%), oxygen (49.4%) and aluminum (10.9%). Carbon, oxygen and hydrogen belong to an organic part of coagulate-the wood pollutants, which, in turn, has a high content of hemicellulose. It is concluded that the existing hemicellulose in the obtained coagulate is characterized by O-acetyl-4-O-methyl-D-glucuron-β-D-xylan with β-(1-4)-glucomannose.

Settling Characteristics of Activated Sludge in Danish Treatment Plants with Biological Nutrient Removal

1994 ◽  
Vol 29 (7) ◽  
pp. 157-165 ◽  
Author(s):  
Gert Holm Kristensen ◽  
Per Elberg Jørgensen ◽  
Per Halkjær Nielsen
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Volume Index ◽  
Biological Nutrient Removal ◽  
Sludge Volume Index ◽  
Filamentous Microorganisms ◽  
Best Parameter ◽  
One Year ◽  
Sludge Settling ◽  
Settling Characteristics

In 1989-91, a study was performed to investigate the settling characteristics of activated sludge in Danish treatment plants with biological nutrient removal. The study included three screening series on 38 treatment plants. Furthermore, the study included investigations during one year on seasonal variations in sludge settling characteristics at three treatment plants. The screening investigations were performed in November 1989 and May and September, 1990. Results showed that in the May-screening, 35-45% of the plants had a filament index of 2-2.5 or above, corresponding to a sludge volume index above 150 ml/g. When comparing data for diluted and non-diluted sludge volume indices, a SVI value of 150 ml/g seemed parallel to a DSVI of 110 ml/g. In the November- and September-screenings, some 30% of the plants had activated sludge showing a filament index in or above the critical area. Dominating filamentous microorganisms were found to be (in decreasing order): Microthrix parvicella, Type 0041, Type 021N, Type 0092, Type 0914, and Type 1851. A distinct variation over the year in sludge settling characteristics was found for the three plants. Sludge settling characteristics improved during summer, and deteriorated during winter. For activated sludge with a high content of filamentous microorganisms, the best parameter to follow the variations in sludge settling properties was the filament number. If the activated sludge concentration, the MLSS, varied significantly, the specific filament number was to be applied.

Prediction of thickening capacity using diluted sludge volume index

1983 ◽  
Vol 17 (10) ◽  
pp. 1427-1431 ◽  
Author(s):  
Ben Koopman ◽  
Keith Cadee
Keyword(s):  
Volume Index ◽  
Sludge Volume Index

Improvement of the intersection method for the quantification of filamentous organisms: basis and practice for bulking and foaming bioindication purposes

2016 ◽  
Vol 74 (6) ◽  
pp. 1274-1282 ◽  
Author(s):  
Humbert Salvadó
Keyword(s):  
Wastewater Treatment Plants ◽  
Two Dimensions ◽  
Volume Index ◽  
Filament Length ◽  
Improved Method ◽  
Sludge Volume Index ◽  
Filamentous Microorganisms ◽  
Different Types ◽  
Intersection Method ◽  
The Impact

Bulking and foaming phenomena in activated sludge wastewater treatment plants are in most cases related to the abundance of filamentous microorganisms. Quantifying these microorganisms should be a preliminary stage in their control. In this paper, the simplicity of quantifying them based on the intersection method is demonstrated, by redescribing the theory and applying a new improved protocol; new data of interest are also provided. The improved method allows us to use it with stained smears, including epifluorescence techniques. The error that could be made, when considering the distribution of filamentous bacteria in fresh microscope preparations in two dimensions rather than three is negligible. The effect of the different types of filamentous microorganisms on the settleability was also studied. The effect of the total extended filament length on the sludge settleability was shown to depend on the type of filamentous organism and how it aggregates. When these groups of filamentous organisms are found in small aggregations and there is an increase in the number of filamentous organisms, the sludge volume index (SVI) increases proportionally to the filament length. However, when aggregation increases, the impact on the SVI is significantly lower.

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