scholarly journals Insights into the Anaerobic Hydrolysis Process for Extracting Embedded EPS and Metals from Activated Sludge

2021 ◽  
Vol 9 (12) ◽  
pp. 2523
Author(s):  
Barbara Tonanzi ◽  
Agata Gallipoli ◽  
Andrea Gianico ◽  
Maria Cristina Annesini ◽  
Camilla Maria Braguglia
Keyword(s):  
Activated Sludge ◽  
Metal Removal ◽  
Wastewater Treatment Plants ◽  
Anaerobic Fermentation ◽  
Oxygen Demand ◽  
Organic Loading Rate ◽  
Waste Streams ◽  
Hydrolysis Process ◽  
Acidic Conditions ◽  
Anaerobic Environment

The amount of sewage sludge generated from wastewater treatment plants globally is unavoidably increasing. In recent years, significant attention has been paid to the biorefinery concept based on the conversion of waste streams to high-value products, material, and energy by microorganisms. However, one of the most significant challenges in the field is the possibility of controlling the microorganisms’ pathways in the anaerobic environment. This study investigated two different anaerobic fermentation tests carried out with real waste activated sludge at high organic loading rate (10 g COD L−1d−1) and short hydraulic retention time (HRT) to comprehensively understand whether this configuration enhances extracellular polymeric substance (EPS) and metal solubilisation. The quantity of EPS recovered increased over time, while the chemical oxygen demand to EPS ratio remained in the range 1.31–1.45. Slightly acidic conditions and sludge floc disintegration promoted EPS matrix disruption and release, combined with the solubilisation of organically bound toxic metals, such as As, Be, Cu, Ni, V, and Zn, thereby increasing the overall metal removal efficiency due to the action of hydrolytic microorganisms. Bacteroidetes, Firmicutes, and Chloroflexi were the most abundant phyla observed, indicating that the short HRT imposed on the systems favoured the hydrolytic and acidogenic activity of these taxa.

scholarly journals Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge

2021 ◽  
Vol 11 (4) ◽  
pp. 1889 ◽  
Author(s):  
Agnieszka Micek ◽  
Krzysztof Jóźwiakowski ◽  
Michał Marzec ◽  
Agnieszka Listosz ◽  
Tadeusz Grabowski
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Treated Wastewater ◽  
Contaminant Removal ◽  
Nitrogen And Phosphorus ◽  
Wastewater Samples ◽  
Polish Law

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

scholarly journals Improving and upgrading an existing activated sludge with a compact MBBR – disc filters parallel line for municipal wastewater treatment in touristic alpine areas

2020 ◽  
Vol 15 (2) ◽  
pp. 515-527
Author(s):  
L. Desa ◽  
P. Kängsepp ◽  
L. Quadri ◽  
G. Bellotti ◽  
K. Sørensen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Parallel Line ◽  
Ammonium Nitrogen ◽  
Biofilm Reactor ◽  
Municipal Wastewater Treatment ◽  
Yearly Average

Abstract Many wastewater treatment plants (WWTP) in touristic areas struggle to achieve the effluent requirements due to seasonal variations in population. In alpine areas, the climate also determines a low wastewater temperature, which implies long sludge retention time (SRT) needed for the growth of nitrifying biomass in conventional activated sludge (CAS). Moreover, combined sewers generate high flow and dilution. The present study shows how the treatment efficiency of an existing CAS plant with tertiary treatment can be upgraded by adding a compact line in parallel, consisting of a Moving Bed Biofilm Reactor (MBBR)-coagulation-flocculation-disc filtration. This allows the treatment of influent variations in the MBBR and a constant flow supply to the activated sludge. The performance of the new 2-step process was comparable to that of the improved existing one. Regardless significant variations in flow (10,000–25,000 m3/d) and total suspended solids (TSS) (50–300 mg/L after primary treatment) the effluent quality fulfilled the discharge requirements. Based on yearly average effluent data, TSS were 11 mg/L, chemical oxygen demand (COD) 27 mg/L and total phosphorus (TP) 0.8 mg/L. After the upgrade, ammonium nitrogen (NH4-N) dropped from 4.9 mg/L to 1.3 mg/L and the chemical consumption for phosphorus removal was reduced.

scholarly journals Evaluation of the accuracy of two simple methods for microscopic activated sludge analysis

2018 ◽  
Vol 78 (10) ◽  
pp. 2104-2112
Author(s):  
Mateusz Sobczyk ◽  
Agnieszka Pajdak-Stós ◽  
Edyta Fiałkowska ◽  
Wioleta Kocerba-Soroka ◽  
Joanna Starzycka-Giża ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Microscopic Analysis ◽  
Volume Index ◽  
Sign Test ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Effluent Quality ◽  
Significant Difference

Abstract Biological microscopic analysis is a popular method employed in wastewater treatment plants worldwide for evaluating activated sludge condition. However, many operators still have reservations regarding its reliability. In this study, we evaluated and compared two methods of microscopic sludge investigation: the sludge index (SI) and the Eikelboom–van Buijsen method (EB). We investigated 79 activated sludge samples from nine treatment plants located in southern Poland over a 1-year period. For each sample, sludge volume index values were calculated and compared with the results of evaluation made on the basis of microscopic analysis. Additionally, the effluent quality was analysed in 45 of 79 cases, including investigation of suspended solids, biochemical oxygen demand, chemical oxygen demand, total nitrogen and total phosphorous. The sign test and Wilcoxon matched pairs test showed that a significant difference existed between the two investigated methods. General conclusions from both methods do not provide reliable information concerning nitrogen and phosphorus removal. The EB method had a tendency to be more conservative in its general conclusions than the SI method. Both are highly reliable for estimating activated sludge quality and solid separation properties.

scholarly journals Multivariate analysis of activated sludge community in full-scale wastewater treatment plants

2020 ◽  
Vol 28 (3) ◽  
pp. 3579-3589
Author(s):  
Mateusz Sobczyk ◽  
Agnieszka Pajdak-Stós ◽  
Edyta Fiałkowska ◽  
Łukasz Sobczyk ◽  
Janusz Fyda
Keyword(s):  
Multivariate Analysis ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Community Composition ◽  
Process Parameters ◽  
Wastewater Treatment Plants ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Principal Component ◽  
Composition Process

AbstractWe investigated changes in protozoa and metazoa community in relation to process parameters in activated sludge from four wastewater treatment plants (WWTPs) throughout the period of 1 year. Principal component analysis (PCA) showed that activated sludge from investigated treatment plants had different dominating species representatives and community composition mainly depends on individual features of the treatment plants. Redundancy analysis (RDA) showed that the temperature in bioreactors was the most relevant factor explaining changes in the microorganism community, whereas reduction rate of chemical oxygen demand (COD), biological oxygen demand (BOD5), suspended solids (SS), and total nitrogen (TN) did not sufficiently explain the variation in protozoa and metazoan community composition. The results indicate that in stable working WWTP it is difficult to find a pronounced link between activated sludge species composition, process parameters, and plant configuration. Applied multivariate analysis can be a valuable tool for the exploration of the relations between community composition and WWTP process parameters.

scholarly journals Initiating Biodegradation of Polyvinylpyrrolidone in an Aqueous Aerobic Environment: Technical Note / Zainicjowanie Biodegradacji Poliwinylopirolidonu W Środowisku Wodno-Tlenowym: Notatki Techniczne

2013 ◽  
Vol 20 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Marketa Julinova ◽  
Jan Kupec ◽  
Roman Slavik ◽  
Maria Vaskova
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Waste Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Technical Note ◽  
Aerobic Biodegradation ◽  
Municipal Wastewater Treatment

Abstract A synthetic polymer, polyvinylpyrrolidone (PVP - E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process - co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm-3, with the ratio between PVP and the cosubstrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm-3. Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation.

Practical experience with full-scale structured sheet media (SSM) integrated fixed-film activated sludge (IFAS) systems for nitrification

2014 ◽  
Vol 71 (4) ◽  
pp. 545-552 ◽  
Author(s):  
Hua Li ◽  
Jia Zhu ◽  
James J Flamming ◽  
Jack O'Connell ◽  
Michael Shrader
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Contact Process ◽  
Plug Flow ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Practical Experience ◽  
Full Scale ◽  
Fixed Film ◽  
The Usa

Many wastewater treatment plants in the USA, which were originally designed as secondary treatment systems with no or partial nitrification requirements, are facing increased flows, loads, and more stringent ammonia discharge limits. Plant expansion is often not cost-effective due to either high construction costs or lack of land. Under these circumstances, integrated fixed-film activated sludge (IFAS) systems using both suspended growth and biofilms that grow attached to a fixed plastic structured sheet media are found to be a viable solution for solving the challenges. Multiple plants have been retrofitted with such IFAS systems in the past few years. The system has proven to be efficient and reliable in achieving not only consistent nitrification, but also enhanced bio-chemical oxygen demand removal and sludge settling characteristics. This paper presents long-term practical experiences with the IFAS system design, operation and maintenance, and performance for three full-scale plants with distinct processes; that is, a trickling filter/solids contact process, a conventional plug flow activated sludge process and an extended aeration process.

Fate of tetracycline resistant bacteria as a function of activated sludge process organic loading and growth rate

2007 ◽  
Vol 55 (1-2) ◽  
pp. 291-297 ◽  
Author(s):  
S. Kim ◽  
J.N. Jensen ◽  
D.S. Aga ◽  
A.S. Weber
Keyword(s):  
Growth Rate ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Tetracycline Resistance ◽  
Organic Loading Rate ◽  
Resistant Bacteria ◽  
Activated Sludge Process ◽  
Organic Loading ◽  
Specific Growth Rates ◽  
Evaluation Parameters

The objective of this research was to elucidate the fate of tetracycline resistant bacteria as a function of activated sludge organic loading rate and growth rate. Techniques employed to evaluate the effect of these factors on the fate of tetracycline resistant bacteria were: (1) resistant bacteria concentrations in the SBR biomass; (2) production of tetracycline resistant bacteria as measured by a combination of effluent efflux and intentional solids wasting; (3) net specific growth rates as determined by an SBR population balance; and (4) percentage of resistance as determined by normalising resistant concentrations to total concentrations. Based on these evaluation parameters, increases in organic loading and growth rate both resulted in amplification of tetracycline resistance. These trends were observed for activated sludge reactors loaded with typical municipal background tetracycline concentrations (∼1 μg/L) and those receiving influent augmented with 250 μg/L tetracycline. Accordingly, biological wastewater treatment plants, such as the activated sludge process, may be significant sources of antibiotic resistance to the environment.

Application of cigarette filter rods as biofilm carrier in an integrated fixed-film activated sludge reactor

2013 ◽  
Vol 67 (8) ◽  
pp. 1793-1801 ◽  
Author(s):  
Ahmad Sabzali ◽  
Mahnaz Nikaeen ◽  
Bijan Bina
Keyword(s):  
Activated Sludge ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Cigarette Filter ◽  
Biofilm Reactors ◽  
Biofilm Carrier ◽  
Fixed Film ◽  
Activated Sludge Reactor

Bio-carriers are an important component of integrated fixed-film activated sludge (IFAS) processes. In this study, the capability of cigarette filter rods (CFRs) as a bio-carrier in IFAS processes was evaluated. Two similar laboratory-scale IFAS systems were operated over a 4-month period using Kaldnes-K3 and CFRs as IFAS media. The process performance was studied by using chemical oxygen demand (COD). The organic loading rate was in the range 0.5–2.8 kgCOD/(m3·d). The COD average removal efficiencies were 89.3 and 93.9% for Kaldnes-K3 (reactor A) and cigarette filters (reactor B), respectively. The results demonstrate that the performance of the IFAS reactor containing CFRs was comparable to the reactor using Kaldnes. The CFRs, which have a high porous surface area and entrapment ability for microbial cells, could be successfully used in biofilm reactors as a bio-carrier.

scholarly journals PERFORMANCE OF H2O2 - AERATED BIOFILTER IN TREATMENT OF WASTEWATER CONTAINING HUMIC ACID

2018 ◽  
Vol 54 (2A) ◽  
pp. 149
Author(s):  
Le Van Tuan
Keyword(s):  
Humic Acid ◽  
Activated Sludge ◽  
Potassium Dihydrogen Phosphate ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Treatment Conditions ◽  
Long Time

This work presents the results of adding H2O2 into a modified aerated biofilter (ABF) for treatment of refractory organic constituents in wastewater. The activated sludge, taken from wastewater treatment system of Hue Beer Company, was long-time cultured in laboratory with beef extract-peptone solution. The synthetic wastewater was prepared from solutions of glucose, ammonium acetate, sodium bicarbonate, potassium dihydrogen phosphate, sodium chloride, potassium chloride, calcium chloride and magnesium sulphate. As a refractory organic compound, humic acid (HA) was added into the wastewater; and parameters of chemical oxygen demand (COD) and color were measured to estimate the treatment performance. The experiments were conducted in continuous mode to observe the effects of H2O2 concentration (25–100 mg/L) and hydraulic retention time (HRT: 24–18 hours; according to organic loading rate, OLR: 0.51–0.67 kg-COD/m3/d) on the aerated biofilter system, under identical treatment conditions (COD: 505 ± 10 mg/L, HA concentration: 25 mg/L, pH: 7.0 ± 0.2, temperature: 25 ± 3.0 oC, and air flow rate: 1.0 ± 0.1 L/min). At the concentration of H2O2 50 mg/L and HRT of 24 hours, the ABF reactor yielded highyielded highyielded high yielded high yielded highyielded highyielded highyielded highyielded highest treatment est treatmentest treatmentest treatmentest treatmentest treatment est treatmentest treatmentest treatment efficienc efficiencefficiencefficiencefficiencefficienc efficiency (95(95 % COD and COD and COD and COD and COD and COD and COD and 74 % color colorcolorcolor). Consequently, H2O2 could be used to improve the effectiveness of activated sludge process in treatment of wastewater containing refractory organic compounds.

Effect of Aeration Rate on the Hydrolysis and Acidification of Waste Activated Sludge in Thermophilic Aerobic Conditions

2013 ◽  
Vol 664 ◽  
pp. 111-116
Author(s):  
Ya Nan Hou ◽  
Chun Xue Yang ◽  
Ai Juan Zhou ◽  
Ai Jie Wang
Keyword(s):  
Fatty Acids ◽  
Activated Sludge ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Ventilation Rate ◽  
Aeration Rate ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Hydrolysis Process ◽  
Soluble Chemical Oxygen Demand

This study investigated the effect of aeration rates on the hydrolysis process of Waste Activated Sludge (WAS) with thermophilic aerobic microbes and explained by the change of solubilization of lipids, carbohydrates and proteins in sludge under different aeration rates (0.03 vvm, 0.05 vvm, 0.07 vvm, 0.09 vvm, 0.11 vvm). The results revealed that with the increase of aeration rate, the accumulation of volatile fatty acids (VFAs) in the treated sludge was decreased. Only 2 142 mg COD/L was accumulated at the ventilation rate of 0.11 vvm, while the highest accumulation which was 4 088 mg/L at the ventilation rate of 0.05 vvm. Further investigation showed that under optimal aeration rate which was 0.05 vvm, theromophilic aerobic microbes facilitated the organism hydrolysis and increased the biodegradability of WAS significantly. The concentration of carbohydrates was improved remarkably from 70 mg COD/L to 560 mg COD/L compared with the control (the process without aeration) at 65°C. Meanwhile, the concentration of protein was increased stably due to the high activity of protease, and reached the peak of 1 320 mg COD/L after 72h, then decline at the later period. The maximal soluble chemical oxygen demand (SCOD) was 5 600 mg/L and VFAs was 4 088 mg COD/L, which would be beneficial to the followed digestion process. Therefore, appropriate aeration is efficient to improve the accumulation of soluble organic matters and VFAs in WAS.

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