Formation and characteristics of filamentous granular sludge

Abstract Aerobic granular sludge process as a promising biotechnology has been one of the research hotspots in the area of wastewater treatment during the last two decades. In our study, after around 60 days' operation, filamentous granular sludge (FGS) was formed under low aeration (SAV = 0.085 cm/s) and multi-feeding conditions. The characteristics of FGS and the performance of the FGS system for organic matter and nutrients removal were investigated. The results showed that COD and TOC removal efficiencies were relatively stable, while COD removal efficiency increased from 82% to 94% in the presence of sulfamethoxazole (SMZ) at low concentration (1 mg/L). At the same time, the TP removal efficiency could be improved and maintained at around 75%, while TN removal efficiency was flocculated at around 50%. The analysis of microbial diversity showed that Thiothrix and Trichococcus as typical filamentous species were detected and dominant in the FGS system. The abundance of Thiothrix increased from 15% to 34%, while Trichococcus decreased from 23% to 3% in the presence of SMZ.

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Isolation of microalgal strain from algal-bacterial aerobic granular sludge and examination on its contribution to granulation process during wastewater treatment in respect of nutrients removal, auto-aggregation capability and EPS excretion

Bioresource Technology Reports ◽

10.1016/j.biteb.2019.100330 ◽

2019 ◽

Vol 8 ◽

pp. 100330 ◽

Cited By ~ 3

Author(s):

Marjangul Nuramkhaan ◽

Yihao Zhang ◽

Xiaochuan Dong ◽

Wenli Huang ◽

Zhongfang Lei ◽

...

Keyword(s):

Wastewater Treatment ◽

Granular Sludge ◽

Aerobic Granular Sludge ◽

Nutrients Removal ◽

Granulation Process

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Treatment of high loaded swine slurry in an aerobic granular reactor

Water Science & Technology ◽

10.2166/wst.2011.381 ◽

2011 ◽

Vol 63 (9) ◽

pp. 1808-1814 ◽

Cited By ~ 21

Author(s):

M. Figueroa ◽

A. Val del Río ◽

J. L. Campos ◽

A. Mosquera-Corral ◽

R. Méndez

Keyword(s):

Organic Matter ◽

Nitrogen Removal ◽

Batch Reactor ◽

Granular Sludge ◽

Average Diameter ◽

Nitrogen Loading ◽

Aerobic Granular Sludge ◽

Swine Slurry ◽

Start Up ◽

Removal Efficiencies

Aerobic granular sludge grown in a sequential batch reactor was proposed as an alternative to anaerobic processes for organic matter and nitrogen removal from swine slurry. Aerobic granulation was achieved with this wastewater after few days from start-up. On day 140 of operation, the granular properties were: 5 mm of average diameter, SVI of 32 mL (g VSS)−1 and density around 55 g VSS (Lgranule)−1. Organic matter removal efficiencies up to 87% and nitrogen removal efficiencies up to 70% were achieved during the treatment of organic and nitrogen loading rates (OLR and NLR) of 4.4 kg COD m−3 d−1 and of 0.83 kg N m−3 d−1, respectively. However, nitrogen removal processes were negatively affected when applied OLR was 7.0 kg COD m−3 d−1 and NLR was 1.26 kg N m−3 d−1. The operational cycle of the reactor was modified by reducing the volumetric exchange ratio from 50 to 6% in order to be able to treat the raw slurry without dilution.

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Performance Evaluation of Continuous Flow Aerobic Granular Sludge Configurations

Revista de Chimie ◽

10.37358/rc.19.1.6900 ◽

2019 ◽

Vol 70 (1) ◽

pp. 283-285

Author(s):

Elena Elisabeta Manea ◽

Costel Bumbac

Keyword(s):

Wastewater Treatment ◽

Continuous Flow ◽

High Efficiency ◽

Wastewater Treatment Plants ◽

Granular Sludge ◽

Synthetic Wastewater ◽

Aerobic Granular Sludge ◽

Batch Reactors ◽

Nutrients Removal ◽

Flow Configurations

Increasing the efficiency and capacity of existing wastewater treatment plants can be carried out by using intensive biological processes. One of the currently studied biological solutions consists in using aerobic granular sludge in order to achieve both organics and nutrients removal simultaneously in one tank and with high efficiency. Aerobic granular sludge is currently used at full scale in sequential batch reactors, research for identifying the optimal solutions for continuous flow systems being carried out worldwide. The paper summarizes the results obtained for two continuous flow configurations with aerobic granular sludge, in terms of organics and nutrients removal for synthetic wastewater in laboratory conditions. Both experimental setups led to wastewater treatment efficiencies, with values ranging between 80 and 99% for COD, 85 and 99% for BOD5, 52 and 98% for NH4+ and 5 to 87% for TP.

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Reactivation of Frozen Stored Microalgal-Bacterial Granular Sludge under Aeration and Non-Aeration Conditions

Water ◽

10.3390/w13141974 ◽

2021 ◽

Vol 13 (14) ◽

pp. 1974

Author(s):

Yao Shen ◽

Lin Zhu ◽

Bin Ji ◽

Siqi Fan ◽

Yabin Xiao ◽

...

Keyword(s):

Wastewater Treatment ◽

Microbial Community ◽

Energy Saving ◽

Removal Efficiency ◽

Protein Secretion ◽

Dominant Species ◽

Granular Sludge ◽

Aeration Conditions ◽

Removal Efficiencies ◽

Microalgae Growth

In this paper, reactivation of microalgal-bacterial granular sludge (MBGS) stored at −20 °C for 6 months was investigated under respective aeration (R1) and non-aeration (R2) conditions. Results showed that the granular activity could be fully recovered within 21 days. The average removal efficiency of ammonia was higher in R1 (92.78%), while R2 showed higher average removal efficiencies of organics (84.97%) and phosphorus (85.28%). It was also found that eukaryotic microalgae growth was stimulated under aeration conditions, whereas prokaryotic microalgae growth and extracellular protein secretion were favored under non-aeration conditions. Sequencing results showed that the microbial community underwent subversive evolution, with Chlorophyta and Proteobacteria being dominant species under both conditions. Consequently, it was reasonable to conclude that the activity and structure of frozen stored MBGS could be recovered under both aeration and non-aeration conditions, of which aeration-free activation was more feasible on account of its energy-saving property. This study provides important information for the storage and transportation of MBGS in wastewater treatment.

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Effects of carbon to nitrogen ratio on the performance and stability of aerobic granular sludge

Environmental Engineering Research ◽

10.4491/eer.2019.284 ◽

2020 ◽

Vol 26 (1) ◽

Cited By ~ 1

Author(s):

HyunGu Kim ◽

JiTae Kim ◽

DaeHee Ahn

Keyword(s):

Organic Matter ◽

Removal Efficiency ◽

Extracellular Polymeric Substances ◽

Influencing Factor ◽

Granular Sludge ◽

Optical Microscope ◽

Volume Index ◽

Aerobic Granular Sludge ◽

Carbon To Nitrogen Ratio ◽

Nitrogen Ratio

The purpose of this study was to assess the nutrient salts removal efficiency and stability of the aerobic granular sludge (AGS) by change in C/N (carbon to nitrogen) ratio. The laboratory-scale experiments were performed to analyze the removal efficiencies for organic matter and contents of nitrogen, MLSS, sludge volume index, and extracellular polymeric substances (EPS) under C/N ratio conditions of 5.0, 10.0, 15.0, and 20.0. The microorganisms were observed using optical microscope and the microbial communities were analyzed using pyrosequencing. The increase in C/N ratio from 5.0 to 20.0 increased the organic matter and nitrogen removal efficiency to 95.9 and 79.1%, respectively. For the EPS contents, an influencing factor of granule stability, the polysaccharides to protein (PS/PN) ratio increased from 0.55 to 0.79. For the microbial community, the <i>Thauera</i> was the most common genus in ending phase occupying 63.7%. This microorganism is regarded as one contributing to organic matter degradation and improved production of EPS including AGS of microorganism, thus, may be an explanation of the results of this study such as increase in organic material in AGS and improvement of denitrification efficiency and contents of EPS with increase in C/N ratio.

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Aerobic granulation in a mechanical stirred SBR: treatment of low organic loads

Water Science & Technology ◽

10.2166/wst.2011.483 ◽

2011 ◽

Vol 64 (1) ◽

pp. 155-161 ◽

Cited By ~ 8

Author(s):

A. Mosquera-Corral ◽

B. Arrojo ◽

M. Figueroa ◽

J. L. Campos ◽

R. Méndez

Keyword(s):

Organic Matter ◽

Batch Reactor ◽

Granular Sludge ◽

Average Diameter ◽

Aerobic Granular Sludge ◽

Organic Loading Rate ◽

Mechanical Stirring ◽

Toc Removal ◽

N Removal ◽

Organic Matter Oxidation

Aerobic granular sludge was produced in a sequencing batch reactor (SBR) characterized by a height to diameter ratio of 2.5 and the use of mechanical stirring. Compact and regular aerobic granules of up to 1.75 mm of average diameter were formed in the reactor with an organic loading rate of 1.75 kg COD/(m3 d). Settling properties of the obtained aggregates were: sludge volumetric index of 30–40 mL/g VSS and settling velocity higher than 8 m/h. The effects of different carbon to nitrogen ratios (TOC/N) in the feeding on the organic matter oxidation and nitrification process were studied. The concentration of organic matter in the feeding was stepwise reduced (from 190.0 to 37.5 mg TOC/L) and ammonium increased (from 25 to 50 mg NH4+-N/L). TOC/N ratios of 7.50, 3.00, 1.50 and 0.75 g/g in the feeding were tested. The TOC removal percentage was around 80–95% during the whole operational period and the N removal percentages obtained in the reactor were up to 40%, however, physical properties of the granules were not maintained.

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Modelling the performance of anaerobic wastewater stabilization ponds

Water Science & Technology ◽

10.2166/wst.1995.0483 ◽

1995 ◽

Vol 31 (12) ◽

pp. 171-183 ◽

Cited By ~ 4

Author(s):

M. M. Saqqar ◽

M. B. Pescod

Keyword(s):

Wastewater Treatment ◽

Water Temperature ◽

Removal Efficiency ◽

Wastewater Treatment Plant ◽

Suspended Solids ◽

Treatment Plant ◽

Pond Water ◽

Removal Efficiencies ◽

Wastewater Stabilization Ponds ◽

Raw Wastewater

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.

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