Experimental comparison between MBBR and activated sludge system for the treatment of municipal wastewater

2000 ◽  
Vol 41 (4-5) ◽  
pp. 375-382 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi ◽  
F. Tatàno
Keyword(s):  
Activated Sludge ◽  
Organic Substance ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Internal Surface ◽  
Experimental Comparison ◽  
Ammonium Removal ◽  
Winter Range ◽  
Activated Sludge System ◽  
Removal Efficiencies

The aim of the described experimentation was the comparison of a low cost MBBR and an activated sludge system (AS). The MBBR applied system consists of the FLOCOR-RMP® plastic media with a specific surface area of about 160 m2/m3 (internal surface only). The comparison with activated sludge (AS) was performed by two parallel treatment lines. Organic substance removal and nitrification were investigated over a 1-year period. Comparing the results obtained with the two lines, it can be observed AS totCOD removal efficiencies were higher than MBBR ones; the average efficiencies for totCOD removal were 76% for MBBR and 84% for AS. On the contrary, the solCOD removals resulted alike (71% for both systems). In spite of the remarkable variations of wastewater temperature, mainly in winter (range of 5–21°C), the average ammonium removal efficiency resulted 92% for MBBR and 98% for AS. With an ammonium loads up to 1.0 g m2 d−1 (up to 0.12 kg m−3 d−1), nitrification efficiencies in MBBR were more than 98%. At higher loads decrease in the MBBR efficiency was registered; that is related to the increase in the applied COD load.

scholarly journals Laboratory-scale investigation on the role of microalgae towards a sustainable treatment of real municipal wastewater

2018 ◽  
Vol 78 (8) ◽  
pp. 1726-1732 ◽  
Author(s):  
S. Petrini ◽  
P. Foladori ◽  
G. Andreottola
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Batch Reactor ◽  
Low Cost ◽  
Oxygen Demand ◽  
Cost Effective ◽  
P Uptake ◽  
Ammonium Removal ◽  
N Assimilation

Abstract Engineered microalgal-bacteria consortia are an attractive solution towards a low-cost and sustainable wastewater treatment that does not rely on artificial mechanical aeration. In the research conducted for this study, a bench-scale photo-sequencing-batch reactor (PSBR) was operated without external aeration. A spontaneous consortium of microalgae and bacteria was developed in the PSBR at a concentration of 0.8–1.7 g TSS/L. The PSBR ensured removal efficiency of 85 ± 8% for chemical oxygen demand (COD) and 98 ± 2% for total Kjeldahl nitrogen (TKN). Nitrogen balance revealed that the main mechanisms for TKN removal was autotrophic nitrification, while N assimilation and denitrification accounted for 4% and 56%, respectively. The development of dense microalgae–bacteria bioflocs resulted in good settleability with average effluent concentration of 16 mgTSS/L. The ammonium removal rate was 2.9 mgN L−1 h−1, which corresponded to 2.4 mgN gTSS−1 h−1. Although this specific ammonium removal rate is similar to activated sludge, the volumetric rate is lower due to the limited total suspended solids (TSS) concentration (three times less than activated sludge). Therefore, the PSBR footprint appears less competitive than activated sludge. However, ammonium was completely removed without artificial aeration, resulting in a very cost-effective process. Only 50% of phosphorus was removed, suggesting that further research on P uptake is needed.

Treatment of municipal wastewater in a CIRCOX® airlift reactor with integrated denitrification

1997 ◽  
Vol 36 (1) ◽  
pp. 173-181 ◽  
Author(s):  
C. T. M. J. Frijters ◽  
D. H. Eikelboom ◽  
A. Mulder ◽  
R. Mulder
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Loading Rate ◽  
Airlift Reactor ◽  
Loading Rates ◽  
Activated Sludge System ◽  
Conversion Rates ◽  
Substrate Conversion ◽  
Airlift Pump ◽  
Interesting Alternative

In this study it was investigated whether the CIRCOX® airlift technology with integrated denitrification was suitable to treat municipal wastewater. The standard CIRCOX® reactor was extended with an anoxic compartment. The sludge on carrier is circulated alternately over the anoxic and oxic compartments by means of an airlift pump. The study was performed in two pilot reactors, a standard CIRCOX® reactor and a CIRCOX® reactor with integrated denitrification. Concerning BOD conversion and nitrification, no differences between the two systems were observed. It was shown that both BOD and nitrogen were removed efficiently. In the effluent, mean soluble BOD concentrations of 7 mg/l were attained at varying COD loading rates. Nitrification was complete in both reactors at temperatures above 15°C and at COD conversion rates of more than 2.5 kg COD/m3/d. Nitrification rates below 15°C were higher as compared to a low loaded activated sludge system. Substrate conversion rates were found to be constant throughout the denitrifying reactor. Denitrification matched the rates theoretically feasible. This could be achieved by controlling the recirculation and the aeration in relation to the loading rate. It can be concluded that the denitrifying CIRCOX® airlift technology seems to be an interesting alternative to treat municipal wastewater.

scholarly journals Coke oven wastewater treatment by two activated sludge systems

2013 ◽  
Vol 8 (1) ◽  
pp. 16-22
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Coke Oven ◽  
Synthetic Wastewater ◽  
Removal Efficiencies ◽  
Activated Sludge Systems

In this study two bench scale activated sludge systems were used, a CSTR and an SBR for the treatment of coke – oven wastewater. Both reactors were inoculated with activated sludge from a municipal wastewater treatment plant. At the first stages of operation, reactors were feed by a mixture of municipal wastewater and synthetic wastewater. Full acclimatization of the microorganisms to synthetic wastewater was achieved in 60 days. The operation of the reactors was divided into three distinct periods. The first period was characterized by the treatment of high organic but non-toxic synthetic wastewater. During this period COD and BOD5 removal efficiencies reached 95 and 98% respectively, in both reactors. Nutrient removal was better in the SBR reactor rather than in the CSTR. In the second period phenol was added in concentrations up to 300 mg l-1. Degradation of phenol started about the 20th day after its introduction to the reactors. In this period no effects of phenol to nutrient removal were observed, whereas the removal efficiency of organic matter in both reactors was slightly decreased. During the third period phenol concentrations of the influent were gradually increased to 1000 mg l-1, while cyanide and thiocyanite were added to the influent composition to concentrations reaching concentrations of 20 and 250 mg l-1 respectively. The composition of the influent of this period was a full assimilation of coke oven wastewater. Introduction of increased phenol concentrations along with cyanide compounds initiated irreversible effects on the activated sludge microfauna of the CSTR causing inherent problems to the treatment process, while SBR showed greater capacity to withstand and degrade toxic compounds. The beginning of this period was characterized by decreased settleability of the suspended solids as well as decrease of organic matter and nutrient removal efficiencies. Monitoring of the effluent characteristics during this period reported over 90% for organic load, 85% of nutrient removal and over 90% of phenol and cyanide removal in SBR, while the removal efficiencies for the CSTR were 75, 65 and 80% respectively.

scholarly journals Performance of Novel Contact Stabilization Activated Sludge System on Domestic Wastewater Treatment

2015 ◽  
Vol 19 (2) ◽  
pp. 7
Author(s):  
Andrés Felipe Torres Franco ◽  
Nancy Vásquez Sarria ◽  
Jenny Rodriguez Victoria
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Growth Zone ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Activated Sludge System ◽  
Suspended Growth ◽  
Removal Efficiencies ◽  
Final Effluent

A pilot-scale study was conducted to evaluate a traditional contact stabilization activated sludge system (CSASC) and a modified CSAS (CSASM) treating domestic wastewater. The CSASC system was comprised of a contact reactor (CR), a stabilization reactor (SR) and a secondary settler (SS); the CSASM included a second CR, a second SS (CR2 and SS2), and a modified SR (SRM) divided into four zones: an attached-suspended growth zone which allowed the system to reach an average sludge retention time close to 36 d and favored the occurrence of nitrification; an anoxic zone for denitrification occurrence; an aerated suspended growth zone with a high presence of organic carbon; and an additional aerated suspended growth zone with a high ammonia concentrations environment. The CSASC’s removal efficiencies of chemical oxygen demand (COD) and total ammonia nitrogen (TAN) were respectively 94±4 % and 53±12%; whereas CSASM’s efficiencies were 88±7% for COD and 92±7% for TAN. Concentrations of TAN and NO3 --N in the CSASC’s final effluent were 14.3±5.2 and 5.0±2.9 mg×L-1; and 4.8±4.4 and 9.1±5.8 mg×L-1 in the CSASM’s final effluent. Results demonstrated that the proposed configuration obtained higher nitrogen removal efficiencies than traditional CSAS.</p>

scholarly journals Distribution of human fecal marker GB-124 bacteriophages in urban sewage and reclaimed water of São Paulo city, Brazil

2017 ◽  
Vol 16 (2) ◽  
pp. 289-299 ◽  
Author(s):  
Tatiana Prado ◽  
Antônio de Castro Bruni ◽  
Mikaela Renata Funada Barbosa ◽  
Vilma Marques Santos Bonanno ◽  
Suzi Cristina Garcia ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Reclaimed Water ◽  
Sao Paulo ◽  
São Paulo ◽  
Virus Removal ◽  
Urban Sewage ◽  
Viral Marker ◽  
Activated Sludge Processes

Abstract Bacteriophages infecting Bacteroides fragilis GB-124 have been described as potential markers of human fecal contamination in water sources. The aim of this study was to evaluate the occurrence of GB-124 phages in raw sewage, secondary effluents and reclaimed water of the São Paulo city using a low-cost microbial source tracking method. Samples were collected monthly from April 2015 to March 2016 in four municipal wastewater treatment plants that operate with activated sludge processes followed by different tertiary treatments (sand-anthracite filtration, membrane bioreactor/reverse osmosis) and final chlorination. GB-124 phages were detected in 100% of the raw sewage samples, with viral loads varying from 7.5 × 103 to 1.32 × 106 PFU/L. Virus removal efficiency in activated sludge processes ranged from 1.89 to 2.31 log10. Frequencies of phage detection were lower in reclaimed water samples (0–22.2%). The results indicated that GB-124 phage could be a complementary low-cost viral marker for the detection of human fecal pollution in waters impacted with urban sewage in this region. However, the datasets of tertiary effluents resulted in several samples with concentrations below the detection limit (DL ≤1 PFU/mL) suggesting the need to obtain analytical methods with lower DL for greater accuracy of negative results.

Performance evaluation of a UASB - activated sludge system treating municipal wastewater

2001 ◽  
Vol 43 (11) ◽  
pp. 323-328 ◽  
Author(s):  
M. von Sperling ◽  
V. H. Freire ◽  
C. A. de Lemos Chernicharo
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Large City ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Warm Climate ◽  
Conventional Activated Sludge ◽  
Activated Sludge System ◽  
Solids Concentration ◽  
Sufficient Detail

Recent research has indicated the advantages of combining anaerobic and aerobic processes for the treatment of municipal wastewater, especially for warm-climate countries. Although this configuration is seen as an economical alternative, is has not been investigated in sufficient detail on a worldwide basis. This work presents the results of the monitoring of a pilot-scale plant comprising of an UASB reactor followed by an activated sludge system, treating actual municipal wastewater from a large city in Brazil. The plant was intensively monitored and operated for 261 days, divided into five different phases, working with constant and variable inflows. The plant showed good COD removal, with efficiencies ranging from 69% to 84% for the UASB reactor, from 43% to 56% for the activated sludge system only and from 85% to 93% for the overall system. The final effluent suspended solids concentration was very low, with averages ranging from 13 to 18 mg/l in the typical phases of the research. Based on the very good overall performance of the system, it is believed that it is a better alternative for warm-climate countries than the conventional activated sludge system, especially considering the total low hydraulic detention time (4.0 h UASB; 2.8 h aerobic reactor; 1.1 h final clarifier), the savings in energy consumption, the absence of primary sludge and the possibility of thickening and digesting the aerobic excess sludge in the UASB reactor itself.

Ammonium removal by native microbes and activated sludge within the Jialu River basin and the associated microbial community structures

2017 ◽  
Vol 76 (12) ◽  
pp. 3358-3367 ◽  
Author(s):  
Guangyi Zhang ◽  
Luji Yu ◽  
Panlong Liu ◽  
Zheng Fan ◽  
Tingmei Li ◽  
...  
Keyword(s):  
Activated Sludge ◽  
River Basin ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Cost Effective ◽  
Native Community ◽  
Ammonium Removal ◽  
Microbial Community Structures ◽  
Removal Efficiencies ◽  
Microbial Sources

Abstract To explore the availability of native microbes and activated sludge for ammonium removal, the native microbes and activated sludge in Jialu River basin were investigated in terms of ammonium-removing activities and their microbial communities using spectrophotometry and high-throughput sequencing. NH4+-N and total nitrogen (TN) in the targeted river ranged from 2.45 ± 1.76 to 8.56 ± 2.54 mg/L and from 3.42 ± 2.79 to 13.49 ± 5.06 mg/L, respectively. Both the native microbes and activated sludge had strong ammonium-removing activities with the removal efficiencies of more than 94%. High-throughput sequencing results indicated that, after five batches of operation, the class Gammaproteobacteria (28.55%), Alphaproteobacteria (14.55%), Betaproteobacteria (13.89%), Acidobacteria (8.82%) and Bacilli (7.04%) were dominated in native community, and there was a predominance of Gammaproteobacteria (21.57%), Betaproteobacteria (16.33%), Acidobacteria (12.41%), Alphaproteobacteria (10.01%), Sphingobacteriia (6.92%) and Bacilli (6.66%) in activated sludge. These two microbial sources were able to remove ammonium, while activated sludge was more cost-effective.

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