An Attempt to Develop Aerobic Granular Sludge in Continuous Airlift Reactors

2021 ◽  
Vol 1025 ◽  
pp. 265-272
Author(s):  
Muhammad Syafiq Mohd Shafei ◽  
Zulkifly Jemaat
Keyword(s):  
Wastewater Treatment ◽  
Operation Mode ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Cod Removal ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Aerobic Granules ◽  
Reactor Performance ◽  
Airlift Reactors

Recent advancement on biological wastewater treatment is via granular sludge technology. It is widely known that, aerobic granular sludge has been developed in a batch operation since its discovery. Yet, most of the wastewater treatment plant (WWTP) is operated in continuous mode. Now, the real challenge is how to adopt the granular technology while maintaining present operation mode of WWTP. Thus, this study attempts to evaluate the feasibility of developing aerobic granular sludge in continuous airlift reactors feed with two different substrates, namely glucose and acetate. Two identical airlift reactors (6 L) were employed and operated at room temperature (30°C). Prior to the substrate feeding, both reactors were inoculated with seed sludge obtained from a palm oil mill anaerobic pond. One of the reactors was fed with 2000 mg COD L-1 of glucose (ALR1) and the other reactor with 2000 mg COD L-1 of acetate (ALR2). The hydraulic retention time (HRT) and organic loading rate (OLR) for both reactors were maintained at 4 days and between 0.2 to 0.5 kg m-3day-1 respectively. Dissolved oxygen was maintained between 5.0 and 6.0 mg O2L-1 and supplied by air compressor. The reactor performance was monitored based on COD removal. Aerobic granules developed throughout the study period was evaluated based on granules size and morphology, sludge volumetric index (SVI30) and SVI5/SVI30 ratio analysis. Results showed that ALR1 demonstrated the formation of filamentous-type aerobic granules with most of the SVI30 average at 100 to 190 mL g-1. Ratio SVI5/SVI30 analysis was evaluated at 0.2 and 0.5. The largest granules size obtained during the experiment was about 600 μm on day-136 and average granules size obtained at 200 to 400 μm. ALR1 able to achieve 95% COD removal. For ALR2, round shaped aerobic granules were developed with average SVI30 from 100 to 1000 mLg-1. SVI5/SVI30 analysis indicated an average ratio between 0.7 and 0.9. The average granules size was between 30 to 50 μm and the largest was 78 μm on day-60. 90% of COD removal efficiency was obtained in ALR2. In conclusion, ALR fed with acetate had indicated better aerobic granules characteristics as compared to glucose fed reactor. Furthermore, the study demonstrated that to develop aerobic granules in continuous reactors is feasible.

scholarly journals Study on aerobic granular sludge formation in sequencing batch reactors for tapioca wastewater treatment

2013 ◽  
Vol 16 (1) ◽  
pp. 40-48
Author(s):  
Phuong Thi Thanh Nguyen ◽  
Phuoc Van Nguyen ◽  
Anh Cam Thieu
Keyword(s):  
Granular Sludge ◽  
Biomass Accumulation ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Batch Reactors ◽  
Aerobic Granules ◽  
Toxic Substances ◽  
Sequencing Batch Reactors

Aerobic granular sludge has attracted extensive interest of researchers since the 90s due to the advantages of aerobic granules such as good settling ability, high biomass accumulation, being resistant to high loads and being less affected by toxic substances. Studies, however, which have mainly been carried out on synthetic wastewater, cannot fully evaluate the actual ability of aerobic granules. Study on aerobic granular sludge was performed in sequencing batch reactors, using seeding sludge taken from anaerobic sludge and tapioca wastewater as a substrates. After 11 weeks of operation, the granules reached the stable diameter of 2- 3 mm at 3.7 kgCOD/m3.day organic loading rate. At high organic loads, in range of 1.6 - 5 kgCOD/m3.day, granules could treat effectively COD, N, P with performance of 93 – 97%; 65 – 79% and 80 – 95%, respectively.

scholarly journals WASTEWATER CHARACTERIZATION AND SEQUENCING BATCH REACTOR OPERATION FOR AEROBIC GRANULAR SLUDGE CULTIVATION

2019 ◽  
Vol 31 (1) ◽  
Author(s):  
Hazlami Fikri Basri ◽  
Aznah Nor Anuar ◽  
Mohd Hakim Ab Halim
Keyword(s):  
Wastewater Treatment ◽  
Cycle Time ◽  
Wastewater Treatment Plant ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Operation Cycle ◽  
Influent Wastewater

Studying the possibility of forming aerobic granules on real domestic sewage was a logical step in the scaling-up process and development of Aerobic Granular Sludge (AGS) technology. It was noted that influent wastewater composition and Sequencing Batch Reactor (SBR) operation cycle time are important factors that can influence the formation of AGS. Therefore, this study aims to determine the suitability of influent wastewater from Bunus Wastewater Treatment Plant (WWTP) for AGS cultivation and then propose a proper SBR operation cycle time. In this study, wastewater characterization was done for the influent of wastewater treatment plant located in Bunus, Kuala Lumpur. The result was then analysed and compared with previous research to determine the suitability of AGS cultivation. The information on SBR from previous studies were also gathered to propose SBR operation cycle time that suit the Bunus WWTP influent. The findings indicate that the wastewater can be characterized as low strength domestic wastewater with low organic and nutrients content. The values of related parameters in this study have shown that influent wastewater of Bunus WWTP is suitable for cultivating AGS. For the proposed SBR operation, the cycle time is 3h, which consist of 60 min (fill), 110 min (aerate), 5 min (settle), and 5 min (discharge), respectively.

Research on COD Removal and SOUR of Aerobic Granule with Intermittent Aeration in Continuous Flow System

2012 ◽  
Vol 518-523 ◽  
pp. 478-484 ◽  
Author(s):  
Feng Deng ◽  
Rui Zhang
Keyword(s):  
Removal Efficiency ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Operation Mode ◽  
Granular Sludge ◽  
Cod Removal ◽  
Aerobic Granular Sludge ◽  
Intermittent Aeration ◽  
Cod Removal Efficiency ◽  
The Impact

The impact of intermittent aeration on aerobic granular sludge in a continuous flow reactor was studied. Nine intermittent aeration modes were set up to investigate the change of DO, pH, COD removal efficiency and SOUR. The results showed DO and pH had different change tendencies. The 3-1 mode was the optimal mode under these experiment conditions. In aerating stage, the highest COD removal efficiency could achieve 96.32%. Stopping aeration for one hour, COD removal efficiency could still reach at 90.20%. This operation mode could save about 25% energy consumption theoretically. The comparison of SOUR between continuous aeration and 4-2 mode showed that the intermittent aeration had little effect on granular sludge activity. The theory of stress & damage and unbalanced growth could explain this appearance.

scholarly journals Performance of Aerobic Granular Sludge in Treating Soy Sauce Wastewater at Different Hydraulic Retention Time

2018 ◽  
Vol 7 (4.35) ◽  
pp. 564
Author(s):  
Hasnida Harun ◽  
Hazren A. Hamid ◽  
Norshuhaila Mohamed Sunar ◽  
Faridah Hanim Ahmad ◽  
Aznah Nor Anuar ◽  
...  
Keyword(s):  
Reaction Time ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Suspended Solid ◽  
Soy Sauce ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Reactor Performance ◽  
Dense Granules ◽  
Aerobic And Anaerobic

Aerobic granular sludge had shown its capability in treating soy sauce wastewater, but its reactor performance, granules properties and biokinetics in different hydraulic retention times (HRT) is still unknown. To ensure the reactor is performed in optimum condition, a judicially selection of HRT is important. The study was conducted in a high and slender column operated according to a sequential batch reactor (SBR) with a sequence of aerobic and anaerobic/anoxic reaction phases. Three different HRTs (8, 16, 24 h) and different anaerobic and aerobic reaction time were evaluated. In the study demonstrated the increase in HRT could reduce the organic loading rate (OLR) as well as biomass yield (Yobs, Y), endogenous decay rate (kd) and overall specific biomass growth rate (µoverall). It was observed a slight increase in the mixed liquor suspended solid (MLSS) and the granules mean size as the OLR decreased. Meanwhile, in the lowest HRT reactor, a narrow diameter range of aerobic granule from 3 to 100 µm was observed due to the development of small and dense granules. The HRT of 24h with aerobic and anaerobic/anoxic reaction time of 3.88 and 7.77h respectively is the SBR’s best performances due to the improvement of the aerobic granular physical properties.

THE IMPACT OF REACTOR HEIGHT/DIAMETER (H/D) RATIO ON AEROBIC GRANULAR SLUDGE (AGS) FORMATION IN SEWAGE

2015 ◽  
Vol 77 (32) ◽  
Author(s):  
Nik Azimatolakma Awang ◽  
Md. Ghazaly Shaaban
Keyword(s):  
Batch Reactor ◽  
Granular Sludge ◽  
Aeration Rate ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Aerobic Granules ◽  
Working Volume ◽  
Stable Conditions ◽  
The Impact ◽  
Reactor Height

Until now, the development of aerobic granules sludge (AGS) has been extensively reported using sequencing batch reactor (SBR) with reactor height/diameter (H/D) ratio of over 10. This is because the formation process of aerobic granules itself is depending upon the flowing trajectory inside reactor indulge by reactor height and superficial air velocity (SUAV). Thus, this study aims to determine effect of reactor H/D ratio on performance of AGS develop in two SBRS with equal working volume and organic loading rate (OLR). The two SBRs namely as SBR1 and SBR2 had a difference in reactor H/D ratio of 11.3 and 4.4, respectively. At an aeration rate of 4 L/min,  SUAV for SBR1 was two time higher than in SBR2, which were 1.33 cm/s and 0.7 cm/s, respectively. Thus, the SBR2 configuration condition seems unfavorable for development of compact aerobic granules. However, it was found that aerobic granules can be developed in both SBRs at an OLR as low as 0.12 kg CODs/m3 d and up to 0.49 kg CODs/m3 d. Mature aerobic granules were successfully developed after 49 and 89 days of formation, for Batch1 AGS and Batch2 AGS, respectively. At stable conditions, the highest CODs removal and SS effluent for Batch1 AGS and Batch2 AGS were more than 80% and below 26 mg/L, respectively. While effluent performance in both reactors was high, analysis on SVI30 indicated that SBR1 produced more sludge than SBR2. Compare to SBR1, at similar settling time of 15 min, SBR2 provide a short settling distance for biomass which was preferable in case of system breakdown due to shock OLR.

scholarly journals Powdered keramsite as unconventional method of AGS technology support in GSBR reactor with minimum-optimum OLR

2018 ◽  
Vol 44 ◽  
pp. 00024 ◽  
Author(s):  
Joanna Czarnota ◽  
Adam Masłoń ◽  
Monika Zdeb
Keyword(s):  
Batch Reactor ◽  
Granular Sludge ◽  
High Energy ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Aerobic Granules ◽  
Technology Support ◽  
Technological Parameters ◽  
The Stability ◽  
The Impact

Aerobic Granular Sludge (AGS) technology becomes a very competitive method to activated sludge system. Its main advantages include: high energy efficiency and low investment costs. Despite this fact, intensive research on biogranulation optimization are still carried out, both at laboratory and technical scale. In order to intensify the AGS technology, new methods of biogranulation and ways of improving the stability of aerobic granules are sought. So far, several studies have been conducted in this area, with using among others: chemical coagulants, dosage fragments of granules and powdered materials. The aim of this study was to evaluate the impact of powdered keramsite on the feasibility of rapid aerobic granulation in a GSBR reactor with a minimum-optimum organic loading rate (OLR). The research presents an effective way of cultivating stable aerobic granules in a Granular Sequencing Batch Reactor (GSBR) under specific technological parameters.

High rate thermophilic anaerobic wastewater treatment in compartmentalized upflow reactors

1994 ◽  
Vol 30 (12) ◽  
pp. 251-261 ◽  
Author(s):  
J. B. van Lier ◽  
F. Boersma ◽  
M. M. W. H. Debets ◽  
G. Lettinga
Keyword(s):  
Wastewater Treatment ◽  
Volatile Fatty Acids ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Organic Loading Rate ◽  
Reactor Performance ◽  
Operation Performance ◽  
Granulation Process ◽  
Typical Sequence

Thermophilic anaerobic treatment of acidified and partially acidified wastewater was studied using Upflow Staged Sludge Bed (USSB) reactors. Reactors were composed of various compartments of which each was equipped with a gas-solid separator. This novel approach for thermophilic wastewater treatment led to a reduction or even elimination of major biological and physical limitations of conventional high rate thermophilic conversion processes. The main achievements of the plugflow reactor were i) very low concentrations of volatile fatty acids (VFA) in the effluent, ii) a high degree of sludge retention, and iii) stable reactor performance. The start-up of the reactors was done with either ‘crushed’ mesophilic granular sludge (MGS) or the digested organic fraction of municipal solid waste (OFMSW) as inoculum. A mixture of VFA and a mixture of sucrose-VFA were used as feed. A good operation performance was achieved within 1 month, and the granulation process of the thermophilic biomass was clearly visible after 1-1.5 months of operation. Within 2-3 months, the organic loading rate could be increased up to 100 kg sucrose-VFA-COD m−3 day−1 with a COD removal efficiency exceeding 90% at a HRT of 2-2.5 h. No significant wash-out of the thermophilic biomass was observed despite the extreme biogas load of 40-50 m3 m−3 reactor day. A certain percentage of sucrose was essential for the thermophilic granulation process; in the reactors treating solely the VFA mixture almost no granules were formed. Nevertheless, also in the latter reactors a satisfactory biomass hold up was observed despite the disperse nature of the sludge. The advantage of using compartmentalized reactors was clearly demonstrated under extreme loading conditions. A typical sequence in the degradation of the partially acidified substrate was found. In the first compartment sucrose was converted, followed by the conversion of butyrate and acetate in the next compartments. Propionate was the most difficult intermediate to degrade, but in the last compartments even this fatty acid was degraded almost completely.

scholarly journals Molecular mechanisms governing aerobic granular sludge processes

2015 ◽  
Vol 10 (2) ◽  
pp. 277-281 ◽  
Author(s):  
Yan Zhou ◽  
HuiJuan Xu ◽  
Yu Liu
Keyword(s):  
Wastewater Treatment ◽  
Quorum Sensing ◽  
Structural Stability ◽  
Significant Role ◽  
Molecular Mechanisms ◽  
Granular Sludge ◽  
Cellular Communication ◽  
Aerobic Granular Sludge ◽  
Aerobic Granules ◽  
Aerobic Granulation

The aerobic granular sludge process is a promising technology for wastewater treatment. The formation and structure of aerobic granules are traditionally thought to depend highly on selection pressures, while the underlying molecular mechanisms are unclear. It is well known that bacteria coordinate their behavior using small signaling molecules, known as quorum sensing (QS). This paper is an attempt to provide updated information on QS mechanisms governing granular sludge processes. It is shown that QS-mediated cellular communication has a significant role throughout aerobic granulation, including granule development, structural stability and integrity maintenance. Such understanding is helpful for developing novel aerobic granular sludge processes.

Parameter Optimisation of Aerobic Granular Sludge at High Temperature Using Response Surface Methodology

2017 ◽  
Vol 7 (3) ◽  
pp. 1522 ◽  
Author(s):  
Syahira Ibrahim ◽  
Norhaliza Abdul Wahab ◽  
Aznah Nor Anuar ◽  
Mustafa Bob
Keyword(s):  
Response Surface Methodology ◽  
Wastewater Treatment ◽  
High Temperature ◽  
Response Surface ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Sequencing Batch Reactors

This paper proposes an improved optimisation of sequencing batch reactors (SBR) for aerobic granular sludge (AGS) at high temperature-low humidity for domestic wastewater treatment using response surface methodology (RSM). The main advantages of RSM are less number of experiment required and suitable for complex process. The sludge from a conventional activated sludge wastewater treatment plant and three sequencing batch reactors (SBRs) were fed with synthetic wastewater. The experiment were carried out at different high temperatures (30, 40 and 50°C) and the formation of AGS for simultaneous organics and nutrients removal were examined in 60 days. RSM is used to model and to optimize the biological parameters for chemical oxygen demand (COD) and total phosphorus removal in SBR system. The simulation results showed that at temperature of 45.33°C give the optimum condition for the total removal of COD and phosphorus, which correspond to performance index R<sup>2</sup> of 0.955 and 0.91, respectively.

scholarly journals Characterizing the structure of aerobic granular sludge using ultra-high field magnetic resonance

2020 ◽  
Vol 82 (4) ◽  
pp. 627-639
Author(s):  
Catherine M. Kirkland ◽  
Julia R. Krug ◽  
Frank J. Vergeldt ◽  
Lenno van den Berg ◽  
Aldrik H. Velders ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Magnetic Resonance ◽  
Wastewater Treatment Plants ◽  
Granular Sludge ◽  
Structural Features ◽  
Aerobic Granular Sludge ◽  
Aerobic Granules ◽  
Bulk Fluid ◽  
Characterization Methods ◽  
Non Invasive

Abstract Despite aerobic granular sludge wastewater treatment plants operating around the world, our understanding of internal granule structure and its relation to treatment efficiency remains limited. This can be attributed in part to the drawbacks of time-consuming, labor-intensive, and invasive microscopy protocols which effectively restrict samples sizes and may introduce artefacts. Time-domain nuclear magnetic resonance (NMR) allows non-invasive measurements which describe internal structural features of opaque, complex materials like biofilms. NMR was used to image aerobic granules collected from five full-scale wastewater treatment plants in the Netherlands and United States, as well as laboratory granules and control beads. T1 and T2 relaxation-weighted images reveal heterogeneous structures that include high- and low-density biofilm regions, water-like voids, and solid-like inclusions. Channels larger than approximately 50 μm and connected to the bulk fluid were not visible. Both cluster and ring-like structures were observed with each granule source having a characteristic structural type. These structures, and their NMR relaxation behavior, were stable over several months of storage. These observations reveal the complex structures within aerobic granules from a range of sources and highlight the need for non-invasive characterization methods like NMR to be applied in the ongoing effort to correlate structure and function.

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