Comparison and evaluation of empirical zone settling velocity parameters based on sludge volume index using a unified settling characteristics database

2003 ◽  
Vol 37 (16) ◽  
pp. 3821-3836 ◽  
Author(s):  
Dimosthenis.L Giokas ◽  
Glen.T Daigger ◽  
Marcos.von Sperling ◽  
Youngchul Kim ◽  
Panayotis.A Paraskevas
Keyword(s):  
Settling Velocity ◽  
Volume Index ◽  
Sludge Volume Index ◽  
Settling Characteristics

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.

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.

scholarly journals PENGARUH CO-PRECIPITATION BESI KLORIDA TERHADAP KINERJA LUMPUR AKTIF PADA PROSES PENGOLAHAN AIR LIMBAH DOMESTIK SINTETIK

REAKTOR ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 182
Author(s):  
Dian Fatikha Aristiami ◽  
I Nyoman Widiasa
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Suspended Solid ◽  
Volume Index ◽  
Sludge Volume Index ◽  
Mixed Liquor Suspended Solid ◽  
Effluent Quality ◽  
Co Precipitation ◽  
Settling Characteristics

The increase of population leads to an increase of the quantity of domestic wastewater. Activated sludge system is the most cost-efective to treat the domestic wastewater treatment. This study is aimed to evaluate the co-precipitation coagulant effect of FeCl3 on the growth of activated sludge, settling characteristics of the activated sludge, and effluent quality. sludge sedimentation characteristics (settling) as well as on the effluent quality. The activated sludge systems were operated in batch mode and synthetic domestic wastewaters with C:N:P ratio of 100:5:1 were used as feed wastewater. The growth of activated sludge was based on concentration of Mixed Liquor Suspended Solid (MLSS), settling characteristics of activated sludge was based on value of Sludge Volume Index (SVI), and effluent quality was based on turbidity, colour, N-ammonia concentration, and Chemical Oxygen Demand content. Results indicate that inhibition effect of FeCl3 to activated sludge activity was not significant at dosage ≤ 30 mg/L. Good settling characterisic (SVI 70-150 mg/L) was achieved at dosage of 20-30 mg/L. Finally, the best effluent quality, i.e. turbidity (9.4), colour (96), amonia removal (83.6%), and COD removal (72.97%), at dosage of 30 mg/L. Keywords: activated sludge; co-precipitation; domestic wastewater; wastewater treatment Abstrak Peningkatan jumlah penduduk mengakibatkan kenaikan jumlah air limbah domestik. Sistem lumpur aktif merupakan proses yang paling efektif untuk mengolah air limbah domestik. Penelitian ini bertujuan untuk mengevaluasi pengaruh co-precipitation koagulan FeCl3 terhadap pertumbuhan lumpur aktif, karakteristik pengendapan lumpur aktif, dan kualitas efluen. Sistem lumpur aktif dioperasikan secara curah dan umpan air limbah yang digunakan adalah air limbah domestik sintesis dengan rasio C:N:P = 100:5:1. Pertumbuhan lumpur aktif  berdasarkan konsentrasi Mixed Liquor Suspended Solid (MLSS), karakteristik pengendapan lumpur berdasarkan  nilai Sludge Volume Index (SVI), dan kualitas efluen berdasarkan tingkat kekeruhan, warna, kadar N-amonia dan kadar Chemical Oxygen Demand (COD). Hasil penelitian menunjukkan bahwa inhibisi FeCl3 terhadap aktivitas lumpur aktif tidak signifikan pada dosis ≤ 30 mg/L. Karakteristik pengendapan yang baik (SVI 70-150 mg/L) tercapai pada dosis 20-30 mg/L. Kualitas efluen terbaik, yaitu  kekeruhan (9,4),  warna (96), penyisihan amonia (83,6%) dan penyisihan COD (72,97%), pada dosis 30 mg/L. Kata kunci: lumpur aktif; co-precipitation; air limbah domestik; pengolahan air limbah  

Study of filamentous bacteria by image analysis and relation with settleability

2002 ◽  
Vol 46 (1-2) ◽  
pp. 363-369 ◽  
Author(s):  
M. da Motta ◽  
M.N. Pons ◽  
N. Roche
Keyword(s):  
Image Analysis ◽  
Wastewater Treatment ◽  
Settling Velocity ◽  
Treatment Plant ◽  
Volume Index ◽  
Morphological Parameters ◽  
Filamentous Bacteria ◽  
Sludge Volume Index ◽  
Floc Size ◽  
Different Temperatures

An automated procedure for the characterisation by image analysis of the morphology of activated sludge has been used to monitor the biomass in a pilot wastewater treatment plant during two runs inoculated with a different sludge and operated at two different temperatures. The bulking events were easily detected by image analysis. Correlations were found between settleability properties (Sludge Volume Index and settling velocity) and the morphological parameters (filament total length, filament number and floc size).

Characterisation of microbial flocs formed from raw textile wastewater in aerobic biofilm reactor (ABR)

2009 ◽  
Vol 60 (3) ◽  
pp. 683-688 ◽  
Author(s):  
Zaharah Ibrahim ◽  
Mohamad Faiz Mohd Amin ◽  
Adibah Yahya ◽  
Azmi Aris ◽  
Noor Azrimi Umor ◽  
...  
Keyword(s):  
Settling Velocity ◽  
Textile Wastewater ◽  
Biofilm Reactor ◽  
Volume Index ◽  
Sludge Volume Index ◽  
16S Rdna Sequence ◽  
Microbial Flocs ◽  
Irregular Structures ◽  
Paenibacillus Sp ◽  
Potential Use

Microbial flocs formed from raw textile wastewater in a prototype Aerobic Biofilm Reactor (ABR) system were characterised and studied for their potential use in the treatment of textile wastewater. After 90–100 days of operation, microbial flocs of loose irregular structures were obtained from the reactor with good settling velocity of 33 m/h and sludge volume index (SVI) of 48.2 mL/g. Molecular analysis of the flocs using PCR-amplified 16S rDNA sequence showed 98% homology to those of Bacillus sp, Paenibacillus sp and Acromobacter sp. Detection of Ca2 + (131 mg/g) and Fe2 + (131 mg/g) using atomic absorption spectrometer might be implicated with the flocs formation. In addition, presence of Co2 +  and Ni2 +  were indicative of the flocs ability to accumulate at least a fraction of the metals' present in the wastewater. When the flocs were used for the treatment of raw textile wastewater, they showed good removal of COD and colour about 55% and 70% respectively, indicating their potential application.

scholarly journals INFLUENCE OF STATIC MIXER ON THE FORMATION OF BIOGRANULES

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Suryati Sulaiman ◽  
Azmi Aris ◽  
Abdul Syukor Abd Razak ◽  
Khalida Muda ◽  
Aznah Nor Anuar
Keyword(s):  
Settling Velocity ◽  
Textile Wastewater ◽  
Suspended Solid ◽  
Volume Index ◽  
Batch Reactors ◽  
Static Mixer ◽  
Sequencing Batch Reactors ◽  
Air Velocity ◽  
Sludge Volume Index

Present study aimed at evaluating the formation of biogranules using sequencing batch reactors (SBRs) in treating textile wastewater under the influence of static mixer. Three sets of experiment were run with different superficial air velocity (SAV) of 0.5, 1.4 and 2.1 cms-1, each set consisting of two SBR one with and one without static mixer. The developed biogranules in reactors with static mixer (R1M, R2M and R3M) showed good results after approximately 70 days. The biomass in the reactor reached mix liquor suspended solid (MLSS) of 5.75 gL-1 with sludge volume index (SVI) of 107.4 mLg-1 and settling velocity (SV) of 70.3 mh-1 in R1M; MLSS of 7.18 gL-1 with SVI of 29.5 mLg-1 and SV of 80.4 mh-1 for R2M and MLSS of 7.38 gL-1 with SVI of 36.3 mLg-1 and SV of 74.2 mh-1 for R3M. The use of static mixer has contributed to biogranules development with good settling properties.

Automated monitoring of activated sludge in a pilot plant using image analysis

2001 ◽  
Vol 43 (7) ◽  
pp. 91-96 ◽  
Author(s):  
M. da Motta ◽  
M. N. Pons ◽  
N. Roche
Keyword(s):  
Image Analysis ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Size Distribution ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Settling Velocity ◽  
Treatment Plant ◽  
Volume Index ◽  
Sludge Volume Index

An automated procedure for the characterisation by image analysis of the morphology of activated sludge has been used to monitor the biomass in a pilot wastewater treatment plant, in complement to the usual settleability (sludge volume index, settling velocity) and size distribution (by laser granulometry) measurements.

Effect of carbohydrate and protein in the EPS on sludge settling characteristics

2001 ◽  
Vol 43 (6) ◽  
pp. 193-196 ◽  
Author(s):  
H.-S. Shin ◽  
S.-T. Kang ◽  
S.-Y. Nam
Keyword(s):  
Volume Index ◽  
Batch Reactors ◽  
Airflow Rate ◽  
Sequencing Batch Reactors ◽  
Constant Ratio ◽  
Sludge Volume Index ◽  
Protein Ratio ◽  
Sludge Settling ◽  
Precise Role ◽  
Settling Characteristics

EPSs have been believed to play a bonding role in microbial floc formation. However, the precise role is not well known. In this study, sludge settling characteristics and the carbohydrate to protein ratio in the EPS were tested at various airflow rates. Sludge was collected from three modified sequencing batch reactors (MSBRs), which were operated with airflow rates of 0.8 L/min, 2 L/min and 4 L/min, respectively. During the operation periods, the reactor operated at an airflow rate of 0.8 L/min showed a sludge volume index (SVI) of 80 to 90 mL/g and a constant ratio of carbohydrate to protein in the EPS, while a significant increase of this ratio and the SVI occurred in the other reactors. High airflow rate increased the amount of carbohydrate in the EPS, but the protein level was almost constant for reactors with airflow rates of 2 L/min and 4 L/min. The higher ratio of carbohydrate to protein caused the bulking of the sludge; hence it was not favourable for sludge settling. The ratio of carbohydrate and protein in the EPS is inferred to be essential for solid floc formation.

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