scholarly journals UASB Performance and Perspectives in Urban Wastewater Treatment at Sub-Mesophilic Operating Temperature

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 115
Author(s):  
Daniele Cecconet ◽  
Arianna Callegari ◽  
Andrea G. Capodaglio
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Operating Temperature ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Urban Wastewater ◽  
Cod Removal Efficiency

UASBs present several advantages compared to conventional wastewater treatment processes, including relatively low construction cost facilities, low excess sludge production, plain operation and maintenance, energy generation in the form of biogas, robustness in terms of COD removal efficiency, pH stability, and recovery time. Although anaerobic treatment is possible at every temperature, colder climates lead to lower process performance and biogas production. These factors can be critical in determining the applicability and sustainability of this technology for the treatment of urban wastewater at low operating temperature. The purpose of this study is the performance evaluation of a pilot-scale (2.75 m3) UASB reactor for treatment of urban wastewater at sub-mesophilic temperature (25 °C), below the optimal range for the process, as related to biogas production and organic matter removal. The results show that, despite lower methane production and COD removal efficiency compared to operation under ideal conditions, a UASB can still achieve satisfactory performance, and although not sufficient to grant effluent discharge requirements, it may be used as a pretreatment step for carbon removal with some degree of energy recovery. Options for UASB pretreatment applications in municipal WWTPs are discussed.

Effect of trace metals on the anaerobic degradation of volatile fatty acids in molasses stillage

1995 ◽  
Vol 32 (12) ◽  
pp. 121-129 ◽  
Author(s):  
A. Espinosa ◽  
L. Rosas ◽  
K. Ilangovan ◽  
A. Noyola
Keyword(s):  
Trace Metals ◽  
Propionic Acid ◽  
Removal Efficiency ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Organic Load ◽  
Methanogenic Activity ◽  
Cod Removal Efficiency

A laboratory UASB reactor was fed with cane molasses stillage at organic loadings from 5 to 21.5 kg COD/m3 d. With an organic load of 17.4 kg COD/m3 d, an accumulation of VFA, principally propionic acid, was observed due to little bioavailability or lack of trace metals (Fe, Ni, Co and Mo). Associated to this, the performance of the UASB reactor was low (44% COD removal efficiency), with an alkalinity ratio above 0.4. The addition of Fe (100 mg/l), Ni (15 mg/l), Co (10 mg/l) and Mo (0.2 mg/l) to the influent reduced significantly the level of propionic acid (5291mg/l to 251 mg/l) and acetic acid (1100 mg/l to 158 mg/l). The COD removal efficiency increased from 44% to 58%, the biogas production from 10.7 to 14.8 l/d (NTP) and 0.085 to 0.32 g CH4-COD/g SSV d for specific sludge methanogenic activity with propionic acid as substrate. These improved results were obtained with high COD (68.9 g/l) and organic load (21.5 kg COD/m3 d).

Thermophilic Anaerobic Treatment of Sulfate-Rich Pulp and Paper Integrate Process Water

1991 ◽  
Vol 24 (3-4) ◽  
pp. 149-160 ◽  
Author(s):  
J. Rintala ◽  
J. L. Sanz Martin ◽  
G. Lettinga
Keyword(s):  
Sulfate Reduction ◽  
Removal Efficiency ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Process Water ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Uasb Reactors

Anaerobic treatment of sulfate - rich (COD/SO4 ratio 1.4-2.1) clarified Whitewater from a thermomechanical pulping (TMP) process was studied in three laboratory-scale upflow anaerobic sludge blanket (UASB) reactors at 55°C and in batch digesters at 55° and 65°C. Different seed materials were used in the UASB reactors. The highest COD removal efficiency (effluent sulfide stripped) achieved was approximately 65 % in the UASB reactors. About 55 % COD removal efficiency was obtained at a loading rate of about 41 kgCODm−3d−1 in the UASB reactor seeded with thermophilic sludge cultivated with volatile fatty acids (VFAs). The total sulfide present in the liquid phase after anaerobic treatment accounted for approximately 65-78 % and 15-61 % of the removed COD in the batch digesters and the UASB reactors, respectively. Sulfate reduction was almost complete in the batch digesters, whereas about 24-64 % of sulfate was reduced in the UASB reactors. Acetate utilization for sulfate reduction was apparent in the batch digesters, whereas that could not be demonstrated in the UASB reactors. Sulfate reduction in the UASB reactors was obviously substrate limited. In conclusion, thermophilic anaerobic treatment is an alternative for the treatment of warm sulfate rich TMP process water.

Sludge deterioration in a full scale UASB reactor after a pH drop working under low loading conditions

2008 ◽  
Vol 57 (5) ◽  
pp. 797-802 ◽  
Author(s):  
L. Borzacconi ◽  
I. López ◽  
M. Passeggi ◽  
C. Etchebehere ◽  
R. Barcia
Keyword(s):  
Removal Efficiency ◽  
Biogas Production ◽  
Industrial Process ◽  
Full Scale ◽  
Cod Removal ◽  
Normal Operation ◽  
Uasb Reactor ◽  
Organic Load ◽  
Reactor Performance ◽  
Cod Removal Efficiency

A full scale UASB reactor treating the effluent of a malting plant was operated during nearly two years. During 37 weeks of operation the reactor worked with a COD removal efficiency of 80% and a biogas production of nearly 300 m3/d with a methane content of 77%. After the start up and during these months of operation the volumetric organic load was 4 kgCOD/m3.d and the specific organic load was between 0.2–0.4 kgCOD/kgVSS.d. The sludge SMA in this period was around 0.25 kgCOD/kg VSS.d. On week 37 as a result of a problem at the industrial process the pH in the reactor dropped to a value of 4.8. After pH recovering, the reactor worked with fluctuating COD values in the exit and showed a downward trend in the COD removal efficiency. On week 81 the presence of filaments in the granules was detected. High proportion of Chloroflexi filaments were detected by FISH in the sludge. Changes in the microbial population caused by the low pH probably destabilize the reactor performance. The presence of filamentous granules in the sludge and its further growing could be encouraged by the pH drop and the low specific organic load applied to the reactor. The low specific organic load was a consequence of the high VSS content in the UASB reactor, due to the lack of purges. The length of the filaments attached to the granules grew throughout time. In order to eliminate the sludge with poor settlement properties a recycle was applied to the reactor. As a consequence, low amount of granular sludge stayed in the reactor. At the end, COD concentration in the influent reached higher values than in normal operation; at the same time a complete sludge wash out occurred. On the other hand, using the same sludge (after the recycle implementation) in a bench scale reactor the good properties of the sludge were completely recovered.

scholarly journals Optimization of Biogas Production from Dairy Wastewater using Upflow Anaerobic Filter (UAF) Reactor

2020 ◽  
Vol 9 (4) ◽  
pp. 1469-1472
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Cod Removal ◽  
Dairy Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Filter ◽  
Cod Removal Efficiency

The present study explores the feasibility of biogas production from dairy wastewater in the UAF reactor with simultaneous wastewater treatment. The study was carried out at different hydraulic retention times (8h, 12h, 16h, 24h). Two different media such as pebble stone media and aggregate media were used as the packed media. The maximum COD removal efficiency of 91.55 % is achieved at the hydraulic retention time of 24 Hours with an organic loading rate of 1.35 kg/m3 /d for aggregate media, whereas for pebble stone media a maximum COD removal efficiency of 76.32 % is achieved. Before the start of the experiments, the COD/BOD ratio is fixed to 1.4 with initial COD and BOD of 1350 mg/L and 960 mg/L. So, from the results it is concluded that the Upflow Anaerobic Filter (UAF) Reactor can be used as a one of the best treatment methods for the diary wastewater treatment.

scholarly journals Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Cod Removal ◽  
Septic Tank ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Cod Removal Efficiency

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

Textile Wastewater Treatment Using Combined Process of Biological Wriggle Bed and Ozone Biological Aerated Filter

2012 ◽  
Vol 441 ◽  
pp. 589-592
Author(s):  
Zhi Min Fu ◽  
Yu Gao Zhang ◽  
Xiao Jun Wang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Textile Wastewater ◽  
Cod Removal ◽  
Biological Aerated Filter ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Aerated Filter ◽  
Textile Wastewater Treatment

A combined process of biological wriggle bed and ozone biological aerated filter was utilized to treat textile wastewater. Results showed that COD removal efficiency was almost 90.4%. The average effluent COD was 85.87 mg/L. The effluent colority was 64-32 times. This study indicated that the combined process is potentially useful for treating textile wastewater.

Biological wastewater treatment for removal of polymeric resins in UASB reactor: influence of oxygen

2008 ◽  
Vol 57 (7) ◽  
pp. 1047-1052 ◽  
Author(s):  
U. Durán ◽  
O. Monroy ◽  
J. Gómez ◽  
F. Ramírez
Keyword(s):  
Acrylic Acid ◽  
Vinyl Acetate ◽  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Cod Removal Efficiency ◽  
Consumption Rates ◽  
Polymeric Resins

The biological elimination of polymeric resins compounds (PRC) such as acrylic acid and their esters, vinyl acetate and styrene under methanogenic and oxygen-limited methanogenesis conditions was evaluated. Two UASB reactors (A and B) were used and the removal of the organic matter was studied in four stages. Reactor A was used as methanogenic control during the study. Initially both reactors were operated under methanogenic conditions. From the second stage reactor B was fed with 0.6 and 1 mg/L·d of oxygen (O2). Reactor A had diminution in chemical oxygen demand (COD) removal efficiency from 75±4% to 37±5%, by the increase of PRC loading rate from 750 to 1125 mg COD/L·d. In this reactor there was no styrene elimination. In reactor B the COD removal efficiency was between 73±5% and 80±2%, even with the addition of O2 and increase of the PRC loading rate, owing to oxygen being used in the partial oxidation of these compounds. In this reactor the yields were modified from 0.56 to 0.40 for CH4 and from 0.31 to 0.60 for CO2. The O2 in low concentrations increased 40.7% the consumption rates of acrylic acid, methyl acrylate and vinyl acetate, allowing styrene consumption with a rate of 0.103 g/L·d. Batch cultures demonstrated that under methanogenic and oxygen-limited methanogenesis conditions, the glucose was not used as an electron acceptor in the elimination of PRC.

scholarly journals Treatment of Reactive Dye Containing Textile Wastewater using Microwave Assisted Synthesized Poly(Diallyldimethylammonium Chloride)

2018 ◽  
Vol 41 (2) ◽  
pp. 165-174
Author(s):  
Mahmudur Rahman ◽  
Masud Rana ◽  
Zinia Nasreen ◽  
Md Mainul Hossain ◽  
Ayesha Sharmin
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Textile Wastewater ◽  
Reactive Dye ◽  
Cod Removal ◽  
Microwave Assisted ◽  
Diallyldimethylammonium Chloride ◽  
Cod Removal Efficiency ◽  
Textile Wastewater Treatment ◽  
Academy Of Sciences

Results on the applicability of microwave assisted synthesized poly(diallyldimethyl ammonium chloride) (polyDADMAC) in reactive dye containing textile wastewater treatment are reported. Diallyldimethylammonium chloride and poly(diallyldimethylammonium chloride) have been characterized by spectral means. The microwave assisted synthesized polyDADMAC has shown some effectiveness in textile wastewater treatment. COD removal efficiency of actual textile wastewater is below 30% whereas the standard dye sample shows about 50-60% COD removal efficiency. TDS and TSS also decreased after treatment of the wastewater with polyDADMAC.Journal of Bangladesh Academy of Sciences, Vol. 41, No. 2, 165-174, 2017

Two examples of anaerobic pre-treatment of wastewater in the beverage industry

1997 ◽  
Vol 36 (2-3) ◽  
pp. 311-319 ◽  
Author(s):  
Ute Austermann-Haun ◽  
Karl-Heinz Rosenwinkel
Keyword(s):  
Removal Efficiency ◽  
Fruit Juice ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Cod Removal ◽  
Load Variations ◽  
Cod Removal Efficiency ◽  
Beverage Industry ◽  
Pre Treatment ◽  
Uasb Reactors

Two examples of full scale UASB-reactors in a fruit juice factory and a brewery are given. In both cases, the design was based on semi-technical tests. Although the wastewater concentrations are rather similar and move within a low range, the parts of the anaerobic treatment plants and their design are different. In both cases, the COD removal efficiency in the UASB-reactors is consistently above 80%. It becomes apparent that UASB-reactors are very suitable for industries with seasonal load variations. The co-fermentation of a kieselguhre-sludge-mixture was tested in lab-scale experiments. It became obvious that the pellet structure of the biomass gets lost. Furthermore, it is shown that the running expenses of anaerobic pre-treatment are very low, even when combined with an aerobic stage.

scholarly journals Toward Optimization of Wood Industry Wastewater Treatment in Microbial Fuel Cells—Mixed Wastewaters Approach

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 263 ◽  
Author(s):  
Monika Kloch ◽  
Renata Toczyłowska-Mamińska
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Power Production ◽  
Cod Removal ◽  
Treatment Efficiency ◽  
External Resistance ◽  
Wood Industry ◽  
Cod Removal Efficiency ◽  
Industry Wastewater

Microbial fuel cell (MFC) has the potential to become a promising sustainable technology of wastewater treatment. Usually, the investigations on MFCs are aimed at maximized power production in the system. In this article, we focused on the optimization of wood industry wastewater treatment in MFC, in combination with municipal wastewater as a source of microorganisms. We investigated the influence of different external resistance (2000 Ω, 1000 Ω, 500 Ω, and 100 Ω) on power density and wastewater treatment efficiency (chemical oxygen demand (COD) removal) in 1-month MFC operation time. We found that the highest COD removal was for MFCs under R = 1000 Ω after 22 days of MFC operation, while the highest current density was obtained for the lowest applied resistance. The results imply that wastewater treatment parameters such as resistance and time of MFC operation should be a subject of optimization for each specific type of wastewater used, in order to maximize either wastewater treatment efficiency or power production in MFC. Thus, optimization of power production and COD removal efficiency in MFCs need to be run separately as different resistances are required for maximizing these two parameters. When COD removal efficiency is a subject of optimization, there is no universal value of external resistance, but it should be set to the specific wastewater characteristics.

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