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

Water ◽  
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.

scholarly journals Formation and characteristics of filamentous granular sludge

2020 ◽  
Author(s):  
Wenjing Cheng ◽  
Liguo Zhang ◽  
Wenjie Xu ◽  
Yichen Sun ◽  
Junfeng Wan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Microbial Diversity ◽  
Removal Efficiency ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Nutrients Removal ◽  
Toc Removal ◽  
Removal Efficiencies ◽  
Research Hotspots

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.

Modelling the performance of anaerobic wastewater stabilization ponds

1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
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.

scholarly journals Occurrence and Removal of Veterinary Antibiotics in Livestock Wastewater Treatment Plants, South Korea

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 720 ◽  
Author(s):  
Jin-Pil Kim ◽  
Dal Rae Jin ◽  
Wonseok Lee ◽  
Minhee Chae ◽  
Junwon Park
Keyword(s):  
Wastewater Treatment ◽  
South Korea ◽  
Removal Efficiency ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Veterinary Antibiotics ◽  
Livestock Wastewater ◽  
Treatment Processes ◽  
Removal Efficiencies ◽  
A2o Process

In this study, livestock wastewater treatment plants in South Korea were monitored to determine the characteristics of influent and effluent wastewater, containing four types of veterinary antibiotics (sulfamethazine, sulfathiazole, chlortetracycline, oxytetracycline), and the removal efficiencies of different treatment processes. Chlortetracycline had the highest average influent concentration (483.7 μg/L), followed by sulfamethazine (251.2 μg/L), sulfathiazole (230.8 μg/L) and oxytetracycline (25.7 μg/L), at five livestock wastewater treatment plants. Sulfathiazole had the highest average effluent concentration (28.2 μg/L), followed by sulfamethazine (20.8 μg/L) and chlortetracycline (11.5 μg/L), while no oxytetracycline was detected. For veterinary antibiotics in the wastewater, a removal efficiency of at least 90% was observed with five types of treatment processes, including a bio-ceramic sequencing batch reactor, liquid-phase flotation, membrane bioreactor, bioreactor plus ultrafiltration (BIOSUF) and bio best bacillus systems. Moreover, this study evaluated the removal efficiency via laboratory-scale experiments on the conventional contaminants, such as organic matter, nitrogen, phosphorus and veterinary antibiotics. This was done using the hydraulic retention time (HRT), under three temporal conditions (14 h, 18 h, 27 h), using the anaerobic–anoxic–oxic (A2O) process, in an attempt to assess the combined livestock wastewater treatment process where the livestock wastewater is treated until certain levels of water quality are achieved, and then the effluent is discharged to nearby sewage treatment plants for further treatment. The removal efficiencies of veterinary antibiotics, especially oxytetracycline and chlortetracycline, were 86.5–88.8% and 87.9–90.8%, respectively, exhibiting no significant differences under various HRT conditions. The removal efficiency of sulfamethazine was at least 20% higher at HRT = 27 h than at HRT = 14 h, indicating that sulfamethazine was efficiently removed in the A2O process with increased HRT. This study is expected to promote a comprehensive understanding of the behavior and removal of veterinary antibiotics in the livestock wastewater treatment plants of South Korea.

scholarly journals Microalgal-Bacterial Granular Sludge Process in Non-Aerated Municipal Wastewater Treatment under Natural Day-Night Conditions: Performance and Microbial Community

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1479
Author(s):  
Shulian Wang ◽  
Lin Zhu ◽  
Bin Ji ◽  
Huan Hou ◽  
Yingqun Ma
Keyword(s):  
Wastewater Treatment ◽  
Relative Abundance ◽  
Municipal Wastewater ◽  
Engineering Application ◽  
Granular Sludge ◽  
System Stability ◽  
Municipal Wastewater Treatment ◽  
Treatment Technology ◽  
Filamentous Microorganisms ◽  
Removal Efficiencies

The microalgal-bacterial granular sludge (MBGS) process is expected to meet the future requirements of municipal wastewater treatment technology for decontamination, energy consumption, carbon emission and resource recovery. However, little research on the performance of the MBGS process in outdoor treatment was reported. This study investigated the performance of the MBGS system in treating municipal wastewater under natural alternate day and night conditions in late autumn. The results showed that the average removal efficiencies of Chemical oxygen demand (COD), NH4+-N and PO43−-P on daytime before cooling (stage I, day 1−4) could reach 59.9% ± 6.8%, 78.1% ± 7.9% and 61.5% ± 4.5%, respectively, while the corresponding average removal efficiencies at night were 47.6% ± 8.0%, 56.5% ± 17.9% and 74.2% ± 7.6%, respectively. Due to the dramatic changes in environmental temperature and light intensity, the microbial biomass and system stability was affected with fluctuation in COD and PO43−-P removal. In addition, the relative abundance of filamentous microorganisms (i.e., Clostridia and Anaerolineae) decreased, while Chlorella maintained a dominant position in the eukaryotic community (i.e., relative abundance > 99%). This study can provide a theoretical basis and technical support for the further engineering application of the MBGS process.

Analysis and Improvement of Low Removal Efficiency of COD in Coking Wastewater Treatment

2012 ◽  
Vol 518-523 ◽  
pp. 3120-3123 ◽  
Author(s):  
Ya Er Ba ◽  
Zi Fu Li ◽  
Ying Tian ◽  
Yang Zhang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Biological Treatment ◽  
Conventional Treatment ◽  
Coke Plant ◽  
Coking Wastewater ◽  
Inhibitory Compounds ◽  
Removal Efficiencies ◽  
Pre Treatment ◽  
Coke Plant Wastewater

Conventional treatment of coke plant wastewater includes pre-treatment, biological treatment and coagulation sedimentation. Due to the presence of refractory and inhibitory compounds, the conventional biological treatment is not efficient in removing COD to meet the effluent standard. The improving methods of the removal efficiencies were discussed.

scholarly journals Comparative Studies on the Chemo and Biosynthesized Nanomaterials for the Remediation of Pharmaceutical Residues in Wastewater

2020 ◽  
Vol 45 (6) ◽  
Author(s):  
C. M. Ngwu ◽  
J. C. Nnaji ◽  
S. O. Odoemelam ◽  
F. J. Amaku
Keyword(s):  
Ascorbic Acid ◽  
Zinc Oxide ◽  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Wastewater Remediation ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
X Ray ◽  
Removal Efficiencies

In the present study, comparison was made on the wastewater remediation efficiencies of chemically and biologically synthesized magnetite and zinc oxide nanoparticles. Starchytarpheta indica (snake weed) leaf extract was used as a reducing and capping agent in the green synthesis of magnetite and zinc oxide. The synthesized nanoparticles (NPs) were characterized by X-ray diffraction studies (XRD), Field emission scanning electron microscopy (FESEM) and Fourier transform infra-red spectroscopy (FTIR). These synthesized nanoparticles were further applied in the treatment of industrial pharmaceutical effluent basically comprising amoxicillin, acetaminophen and ascorbic acid. The NPs all performed differently in the removal of these pharmaceutical active compounds. Results showed that the NPs had significant removal efficiencies for acetaminophen, ranging from 67.07 % - 93.59 %, with bio-ZnO having the highest removal efficiency and magnetite giving the least. The range of removal efficiency for ascorbic acid was 54.35 % - 100 %, Magnetite and bio-magnetite showed the highest removal efficiencies whereas bio-ZnO had the least removal rate. Wastewater treatment for the removal of amoxicillin residues with the synthesized nanoparticles was not quite significant, negative removal patterns were observed for wastewater treatment with bio-ZnO and magnetite, a removal rate of 16.82 % was obtained for treatment with bio-magnetite, ZnO NPs had the highest removal efficiency of 49.73 %. Generally, ZnO and bio-magnetite NPs displayed better removal capacities than the other NPs, with overall removal rates of 64.71 % and 48.92 % for ZnO and bio-magnetite NPs respectively.

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