Hybrid activated sludge/biofilm process for the treatment of municipal wastewater in a cold climate region: a case study

2011 ◽  
Vol 63 (6) ◽  
pp. 1121-1129 ◽  
Author(s):  
Daniele Di Trapani ◽  
Magnus Christensso ◽  
Hallvard Ødegaard
Keyword(s):  
Activated Sludge ◽  
Low Temperatures ◽  
Biofilm Reactor ◽  
Cold Climate ◽  
Hybrid Process ◽  
Climate Region ◽  
Conventional Activated Sludge ◽  
Experimental Campaign ◽  
Suspended Biomass ◽  
Biofilm Process

A hybrid activated sludge/biofilm process was investigated for wastewater treatment in a cold climate region. This process, which contains both suspended biomass and biofilm, usually referred as IFAS process, is created by introducing plastic elements as biofilm carrier media into a conventional activated sludge reactor. In the present study, a hybrid process, composed of an activated sludge and a moving bed biofilm reactor was used. The aim of this paper has been to investigate the performances of a hybrid process, and in particular to gain insight the nitrification process, when operated at relatively low MLSS SRT and low temperatures. The results of a pilot-scale study carried out at the Department of Hydraulic and Environmental Engineering at the Norwegian University of Science and Technology in Trondheim are presented. The experimental campaign was divided into two periods. The pilot plant was first operated with a constant HRT of 4.5 hours, while in the second period the influent flow was increased so that HRT was 3.5 hours. The average temperature was near 11.5°C in the overall experimental campaign. The average mixed liquor SRT was 5.7 days. Batch tests on both carriers and suspended biomass were performed in order to evaluate the nitrification rate of the two different biomasses. The results demonstrated that this kind of reactor can efficiently be used for the upgrading of conventional activated sludge plant for achieving year-round nitrification, also in presence of low temperatures, and without the need of additional volumes.

Performance of a hybrid activated sludge/biofilm process for wastewater treatment in a cold climate region: Influence of operating conditions

2013 ◽  
Vol 77 ◽  
pp. 214-219 ◽  
Author(s):  
Daniele Di Trapani ◽  
Magnus Christensson ◽  
Michele Torregrossa ◽  
Gaspare Viviani ◽  
Hallvard Ødegaard
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Cold Climate ◽  
Operating Conditions ◽  
Climate Region ◽  
Biofilm Process

Evaluation of hybrid processes for nitrification by comparing MBBR/AS and IFAS configurations

2007 ◽  
Vol 55 (8-9) ◽  
pp. 43-49 ◽  
Author(s):  
E. Germain ◽  
L. Bancroft ◽  
A. Dawson ◽  
C. Hinrichs ◽  
L. Fricker ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Biofilm Reactor ◽  
Nitrite Accumulation ◽  
Removal Rates ◽  
Solids Retention ◽  
Different Temperatures ◽  
Suspended Biomass ◽  
The Media ◽  
Population Counts ◽  
Ammonia Oxidising Bacteria

An integrated fixed-film activated sludge (IFAS) pilot plant and a moving bed biofilm reactor coupled with an activated sludge process (MBBR/AS) were operated under different temperatures, carbon loadings and solids retention times (SRTs). These two types of hybrid systems were compared, focusing on the nitrification capacity and the nitrifiers population of the media and suspended biomass alongside other process performances such as carbonaceous and total nitrogen (TN) removal rates. At high temperatures and loadings rates, both processes were fully nitrifying and achieved similarly high carbonaceous removal rates. However, under these conditions, the IFAS configuration performed better in terms of TN removal. Lower temperatures and carbon loadings led to lower carbonaceous removal rates for the MBBR/AS configuration, whereas the IFAS configuration was not affected. However, the nitrification capacity of the IFAS process decreased significantly under these conditions and the MBBR/AS process was more robust in terms of nitrification. Ammonia oxidising bacteria (AOB) and nitrite oxidising bacteria (NOB) population counts accurately reflected the changes in nitrification capacity. However, significantly less NOBs than AOBs were observed, without noticeable nitrite accumulation, suggesting that the characterisation method used was not as sensitive for NOBs and/or that the NOBs had a higher activity than the AOBs.

scholarly journals Enhancing treated wastewater effluent characteristics using hybrid biofilm/activated sludge process – a case study

2020 ◽  
Vol 81 (2) ◽  
pp. 217-227
Author(s):  
Khalid Hassan ◽  
Olfat Hamdy ◽  
Mohamed Helmy ◽  
Hossam Mostafa
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Hybrid Reactor ◽  
Conventional Activated Sludge ◽  
Fill Fraction ◽  
Hydraulic Load

Abstract This paper documents the results of 12 months of monitoring of an upgraded hybrid moving bed biofilm reactor-conventional activated sludge wastewater treatment plant (MBBR-CAS WWTP). It also targets the assessment of the increment of the hydraulic load on existing treatment units with a zero construction and land cost. The influent flow to the plant was increased from 21,000 m3 d−1 to 30,000 m3 d−1, 40% of the existing CAS reactor volume was used for the MBBR zone with a carrier fill fraction of 47.62% and with Headworks Bio ActiveCell™ 515 used as media; no modifications were made for the primary and secondary tanks. The hybrid reactor showed high removal efficiencies for biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and total suspended solids (TSS), with average effluent values recording 33.00 ± 8.87 mg L−1, 52.90 ± 9.65 mg L−1 and 29.50 ± 6.64 mg L−1 respectively. Nutrient removals in the hybrid modified biological reactor were moderate compared with carbon removal despite the high C/N ratio of 12.33. Findings in this study favor the application of MBBR in the upgrading of existing CAS plants with the plant BOD5 removal efficiency recording an increase of about 5% compared with the plant before upgrade and effluent values well within the legal requirements.

Application of a Hybrid Process with Biofilm and Suspended Biomass for Treating Petrochemical Wastewater

2010 ◽  
Vol 113-116 ◽  
pp. 469-473 ◽  
Author(s):  
Jing Bo Guo ◽  
Fang Ma ◽  
Chein Chi Chang ◽  
Li Wei
Keyword(s):  
Wastewater Treatment ◽  
Hybrid System ◽  
Biomass Concentration ◽  
Hybrid Process ◽  
Petrochemical Wastewater ◽  
Feasible Alternative ◽  
Suspended Biomass ◽  
Pollutants Removal ◽  
Biofilm Process ◽  
Refractory Organics

To improve the efficiency of petrochemical wastewater treatment, a hybrid system with both attached and suspended biomass was proposed to replace the existing biofilm process. According to the performances of the hybrid system, the optimal suspended biomass concentration in the tank was determined around 1000 mg/L. When the average influent COD and NH4+-N concentration were 395.7 mg/L and 13.5 mg/L, the according removal efficiencies of the hybrid system were up to 84% and 69%, compared to 74% and 20% when operated with the biofilm system. The GC-MS analysis showed that both the amounts and types of refractory organics in the effluent of hybrid system were greatly reduced when compared with those of the previous biofilm process. The foaming problem was also resolved along with the enhanced pollutants removal efficiency. The hybrid process was an economic and feasible alternative for petrochemical wastewater treatment, which ensured carbonaceous oxidation, nitrification and decomposition of refractory substances.

The combined effects of carbon/nitrogen ratio, suspended biomass, hydraulic retention time and dissolved oxygen on nutrient removal in a laboratory-scale anaerobic–anoxic–oxic activated sludge biofilm reactor

2017 ◽  
Vol 77 (1) ◽  
pp. 248-259 ◽  
Author(s):  
D. S. Manu ◽  
Arun Kumar Thalla
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Retention Time ◽  
Nutrient Removal ◽  
Hydraulic Retention Time ◽  
Appropriate Technology ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Biological Nutrient Removal ◽  
Suspended Biomass

Abstract The current trend in sustainable development deals mainly with environmental management. There is a need for economically affordable, advanced treatment methods for the proper treatment and management of domestic wastewater containing excess nutrients (such as nitrogen and phosphorus) which can cause eutrophication. The reduction of the excess nutrient content of wastewater by appropriate technology is of much concern to the environmentalist. In the current study, a novel integrated anaerobic–anoxic–oxic activated sludge biofilm (A2O-AS-biofilm) reactor was designed and operated to improve the biological nutrient removal by varying reactor operating conditions such as carbon to nitrogen (C/N) ratio, suspended biomass, hydraulic retention time (HRT) and dissolved oxygen (DO). Based on various trials, it was seen that the A2O-AS-biofilm reactor achieved good removal efficiencies with regard to chemical oxygen demand (95.5%), total phosphorus (93.1%), ammonia nitrogen concentration (NH4+-N) (98%) and total nitrogen (80%) when the reactor was maintained at C/N ratio of 4, suspended biomass of 3 to 3.5 g/L, HRT of 10 h, and DO of 1.5 to 2.5 mg/L. Scanning electron microscopy (SEM) of suspended and attached biofilm showed a dense structure of coccus and bacillus bacteria with the diameter ranging from 0.3 to 1.2 μm. The Fourier transform infrared (FTIR) spectroscopy results indicated phosphorylated macromolecules and carbohydrates mix or bind with extracellular proteins in exopolysaccharides.

Experimental Comparison between Moving Bed Biofilm Reactor (MBBR) and Conventional Activated Sludge (CAS) for River Purification Treatment Plant

2015 ◽  
Vol 1113 ◽  
pp. 806-811 ◽  
Author(s):  
Lariyah Mohd Sidek ◽  
Hairun Aishah Mohiyaden ◽  
Hidayah Basri ◽  
Gasim Hayder Ahmed Salih ◽  
Ahmad Hussein Birima ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Physical Performance ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Biofilm Reactor ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Conventional Activated Sludge

Moving Bed Biofilm Reactor (MBBR) systems have been proven as an effective technology for water treatment and have been used for Biochemical Oxygen Demand/Chemical Oxygen Demand (BOD/COD-removal), as well as for nitrification and denitrification in municipal and industrial wastewater treatment. Conventional Activated Sludge (CAS), in particular, has been extensively used in wastewater treatment since decades ago. In this study, physical performance results for both MBBR and CAS were compared and evaluated on laboratory scale basis. The study aims to identify the best system performance in terms of constituent removal efficiency for effective management of the river purification plant. A novel parallel MBBR and CAS pilot plant were fabricated and operated to compare the physical performance of MBBR and CAS. Analysis of the performances for MBBR and CAS show, MBBR has higher COD (85%), AN (75%) and TSS (80%) removal rate compared to CAS COD (53%), AN (53%) and TSS (69%). For BOD removal rate, CAS shows 68% removal rate whereas MBBR shows only 65%. Thus CAS has shown slightly higher removal rate than MBBR. In terms of sludge production, MBBR sludge is less than CAS. Overall performance proves that MBBR has better rate of constituent removal efficiency compared to CAS in the laboratory basis study.

Role of Psychrotrophic Bacteria in the Degradation of Waste Activated Sludge

1981 ◽  
Vol 16 (1) ◽  
pp. 15-22
Author(s):  
J.G. Henry ◽  
D. Prasad
Keyword(s):  
Activated Sludge ◽  
Low Temperatures ◽  
Suspended Solids ◽  
Waste Activated Sludge ◽  
Aeration Tank ◽  
Experimental Conditions ◽  
Psychrotrophic Bacteria ◽  
Conventional Activated Sludge ◽  
Viable Bacteria ◽  
Plate Counts

Abstract A series of batch and semi-continuous laboratory scale aerobic reactors was evaluated, with emphasis on the microbiological aspects. Batch treatment of waste activated sludge (COD 10,000 mg/l) was carried out over a period of eight weeks in three separate reactors at 5, 10 and 20°C. A semi-continuous unit operating at 5°C was investigated at a loading rate of 0.64 kg VSS/m3/day. Analyses performed included pH, O2 uptake rate, total solids, suspended solids, volatile suspended solids and COD determinations. The microbiological tests included total plate counts (20°C) and psychrotrophic counts (l°C). Results indicated that long (impractical) detention times were required to aerobically treat waste activated sludge at low temperatures. At temperatures supposedly favourable to psychrotrophic growth, it was found that the proportion of psychrotrophic bacteria could not develop to a significant level and remained at less that 1% of the total viable bacterial population, regardless of the mode of operation or the detention time. This is in contrast to the finding that approximately 54% of the viable bacteria in the aeration tank of a large conventional activated sludge plant, operating at a mixed liquor temperature of 13°C, were psychrotrophic. It is apparent that psychrotrophic bacteria played an insignificant role in the degradation of waste activated sludge at low temperatures, (5 and 10°C) and that biological oxidation was performed primarily be mesophilic bacteria. The study indicated that under the experimental conditions employed, the amount of available substrate present was one of the major regulating factors in the development or selection of psychrotrophic bacteria.

Microbial characteristics of a CANON reactor during the start-up period seeding conventional activated sludge

2013 ◽  
Vol 67 (3) ◽  
pp. 635-643 ◽  
Author(s):  
Tao Liu ◽  
Dong Li ◽  
Hui-ping Zeng ◽  
Xiao-yan Chang ◽  
Jie Zhang
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Biofilm Reactor ◽  
Conventional Activated Sludge ◽  
Community Shift ◽  
Start Up ◽  
Bacterial Morphology ◽  
Nitrite Oxidizing Bacteria ◽  
Canon Process

An up-flow oxygen-controlled biofilm reactor filled with volcanic filter was used for a completely autotrophic nitrogen-removal over nitrite (CANON) process. The reactor was successfully established by seeding conventional activated sludge at ambient temperature without additional biomass inoculation. An average total nitrogen (TN) removal rate of 1.1 kg·(m3 d)−1 was achieved after 180 days' operation. The bacterial morphology, community structure and spatial distribution of nitrogen removal microorganisms were analyzed by using some molecular biotechniques. Denaturant gel gradient electrophoresis (DGGE) profiles showed a distinct community shift of nitrite oxidizing bacteria (NOB) during the start-up period, which was not the same as that of aerobic ammonium-oxidizing bacteria (AerAOB) or anaerobic ammonium-oxidizing bacteria (AnAOB). Phylogenetic results indicated the predominance of Nitrosomonas, ‘Candidatus Brocadia fulgida’ and Nitrobacter for nitrogen removal in the system, all of which coexisted without a distinguishable niche on the biofilm.

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