Overall estimation of mesophilic high-rate anaerobic sludge digestion in internal circulation anaerobic digester integrated with sewage source heat pump

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Y. Jiang ◽  
J. Wu ◽  
L. Tian ◽  
L. Shi ◽  
Z. P. Cao

Sewage source heat pump was integrated with internal circulation anaerobic digester (ICAD) to decrease the treatment cost of waste activated sludge. In the experiment, mesophilic digestion in ICAD was combined with thermal treatment at 60 °C with hydraulic retention time (HRT) of 1 day as pretreatment. The heat pump supplied heat recovering from the effluent of the wastewater treatment plant. The energy consumed by the heat pump was 39.2 and 48.6% less than the gas boiler and coal boiler respectively at a given amount of supplied heat. When the HRT of digestion was 10 days, the average total VSS removal and biogas yield rates of the system were 58.8% and 1.33 m3 · kgVSS−1 respectively. The integration of ICAD and sewage source heat pump offers a low-cost sludge treatment process with satisfactory organic removal.

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Tao Wang ◽  
Zhenxing Huang ◽  
Hongyan Ren ◽  
Hengfeng Miao ◽  
Minxing Zhao ◽  
...  

This study aimed to investigate the effectiveness of the full-scale internal circulation (IC) reactor in biodegrading of municipal solid waste (MSW) fresh leachate under mesophilic conditions, where the anaerobic process stability, biogas yield, and sludge granulation were intensively investigated. The effects of operational parameters on the influent organic loading rate (OLR), chemical oxygen demand (COD) removal efficiency, alkalinity (ALK), pH, volatile fatty acids (VFAs) accumulation, and effluent recirculation were also studied. The results showed that the reactor operated stably and effectively. The COD removal efficiency and biogas yield could be maintained at (92.8 ± 2.0)% and (0.47 ± 0.05) m3/kg CODremoval, respectively, with the influent OLR (24.5 ± 0.9) kg COD/(m3 d) and hydraulic retention time (HRT) 2.7d during the stable operation phase. Meanwhile, this study demonstrated that 1.5–3.0 m/h would be the optimal Vup for the reactor, corresponding to the effluent recirculation of 32.5–78.0 m3/h. Moreover, it was found that the content of extracellular polymeric substances (EPS) in the anaerobic sludge increased from 50.3 to 140.7 mg/g volatile suspended solids (VSS), and the sludge had good granular performance during the reactor operation.


1986 ◽  
Vol 18 (12) ◽  
pp. 99-108 ◽  
Author(s):  
Gatze Lettinga ◽  
Look Hulshoff Pol

Of the high rate anaerobic wastewater treatment systems the UASB (Upflow Anaerobic Sludge Blanket) reactor has found the widest application. Therefore the attention with respect to design, operation and economy will be focussed on this reactor type. In designing a UASB reactor specific attention is needed for the GSS (Gas-Solids Separator) device and the feed inlet system. For soluble wastewater generally no phase separation is required. Only for wastewaters high in suspended solids pre-acidification in a separate acidification reactor can be beneficial. Increasing attention is given to the development of modified UASB systems, such as a combination of a sludge bed reactor and an anaerobic filter. Other possible modified UASB systems may be found in a FS (Floating Settling) UASB reactor, the EGSB (Expanded Granular Sludge Bed) reactor and the UASB IC (Internal Circulation) reactor. As many factors are involved in the costs of a UASB reactor, only some rough data on reactor costs are presented.


Due to the rate increase for potable water need, the general market trend is the vertical expansions for water treatment plants instead of the horizontal ones. By upgrading the existing plants using new technology to reach the maximum capacity and conserve the water quality parameters as the Egyptian Code states. The most benefits of plant upgrading are no new land is needed also, low cost solution, as we could upgrade the WTP as mentioned before without adding major civil works comparing with the construction of new water treatment. This study aims to upgrade the existing water treatment plants using dissolved air floatation system, in order to reach the maximum possible capacity using several possible scenarios without adding major civil works. The study shows that, the scenario which involves DAF technology then sedimentation and filtration has the best removal efficiency because it has three treatment phases. The use of one treatment phase from floatation or sedimentation followed by filtration achieved lower efficiency. At last direct filtration, considering low removal efficiencies due to the high rate of filtration which allowed the suspended solids to escape.For the application upon Al Ameriyah water treatment plant, the first proposal which involves five combined tanks, two tube settler and one filter tank is the most convenient proposal to be achieved. Since it has quiet high value 72 points in the technical evaluation with the least estimated cost 85,769,200 LE. The use of DAF technology combined with sedimentation gives the chance to increase the existing plant capacity from 520000 m3 /day to 864815 m3 /day with rate of increase equals 66.31% which is a cheap and happy solution.


2008 ◽  
Vol 58 (2) ◽  
pp. 373-377
Author(s):  
Soosan J. Panicker ◽  
M. C. Philipose ◽  
Ajit Haridas

The Buoyant Filter Bio-Reactor (BFBR) is a novel and very efficient method for the treatment of complex wastewater. Sewage is a complex wastewater containing insoluble COD contributed by fat and proteins. The fat and proteins present in the domestic sewage cause operational problems and underperformance in the Upflow Anaerobic Sludge Blanket Reactor, used now for treating sewage anaerobically. The biogas yield from the BFBR is 0.36 m3/kg COD reduced and the methane content was about 70–80%. Production of methane by anaerobic digestion of organic waste had the benefit of lower energy costs for treatment and is thus environmentally beneficial to the society by providing a clean fuel from renewable feed stocks. The BFBR achieved a COD removal efficiency of 80–90% for an organic loading rate of 4.5 kg/m3/d at a hydraulic retention time of 3.25 hours. The effluent COD was less than 100 mg/l, thus saving on secondary treatment cost. No pretreatment like sedimentation was required for the influent to the BFBR. The BFBR can produce low turbidity effluent as in the activated sludge process (ASP). The land area required for the BFBR treatment plant is less when compared to ASP plant. Hence the problem of scarcity of land for the treatment plant is reduced. The total expenditure for erecting the unit was less than 50% as that of conventional ASP for the same COD removal efficiency including land cost.


2010 ◽  
Vol 150 ◽  
pp. 39-39
Author(s):  
Jing Wu ◽  
Pengjuan Zhao ◽  
Lei Tian ◽  
Lin Shi ◽  
Hanchang Shi

2019 ◽  
Vol 14 (4) ◽  
pp. 802-807 ◽  
Author(s):  
T. L. G. Hendrickx ◽  
B. Pessotto ◽  
R. Prins ◽  
L. Habets ◽  
J. Vogelaar

Abstract The ICX (Internal Circulation eXperience) is the next generation high rate anaerobic reactor. The unique design with a two-stage phase separation device enables excellent biomass retention. The novel biomass retention device allows for high volumetric loading rates to be applied compared to IC (internal circulation) and UASB (Upflow Anaerobic Sludge Bed) reactors. Since the first demonstration test in 2013, more than 70 full scale ICX reactors have been built, ranging in size from 85 to 5,000 m3. This paper presents the results of the first ICX demonstration reactor (85 m3) and from a full scale ICX reference (350 m3). These results confirm that very high volumetric loading rates can be achieved with the ICX, whilst maintaining a stable and high COD removal efficiency. Biomass growth is clearly demonstrated in both the demonstration reactor and in the full scale reference, proving that efficient biomass retention is achieved in the ICX.


2020 ◽  
Vol 7 (2) ◽  
pp. 43 ◽  
Author(s):  
Matia Mainardis ◽  
Marco Buttazzoni ◽  
Daniele Goi

Up-flow anaerobic sludge blanket (UASB) reactor belongs to high-rate systems, able to perform anaerobic reaction at reduced hydraulic retention time, if compared to traditional digesters. In this review, the most recent advances in UASB reactor applications are critically summarized and discussed, with outline on the most critical aspects for further possible future developments. Beside traditional anaerobic treatment of soluble and biodegradable substrates, research is actually focusing on the treatment of refractory and slowly degradable matrices, thanks to an improved understanding of microbial community composition and reactor hydrodynamics, together with utilization of powerful modeling tools. Innovative approaches include the use of UASB reactor for nitrogen removal, as well as for hydrogen and volatile fatty acid production. Co-digestion of complementary substrates available in the same territory is being extensively studied to increase biogas yield and provide smooth continuous operations in a circular economy perspective. Particular importance is being given to decentralized treatment, able to provide electricity and heat to local users with possible integration with other renewable energies. Proper pre-treatment application increases biogas yield, while a successive post-treatment is needed to meet required effluent standards, also from a toxicological perspective. An increased full-scale application of UASB technology is desirable to achieve circular economy and sustainability scopes, with efficient biogas exploitation, fulfilling renewable energy targets and green-house gases emission reduction, in particular in tropical countries, where limited reactor heating is required.


2019 ◽  
Vol 80 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Juliana Lemos Soares ◽  
Magali Christe Cammarota ◽  
Melissa Limoeiro Estrada Gutarra ◽  
Isaac Volschan

Abstract This work evaluates the reduction of scum accumulation on the top surface of upflow anaerobic sludge blanket (UASB) reactors by the addition of hydrolytic enzymes in their feed. For over 1 year, two UASB reactors of 1.4 L were maintained at 30 °C and continuously fed with synthetic domestic wastewater (containing 150 mg/L of soybean oil) under a hydraulic retention time of 10 h. The Control reactor was only fed with synthetic wastewater. Beginning at the 226th day of operation, low-cost hydrolytic enzymes (obtained by solid-state fermentation of Aspergillus terreus, a fungus isolated from a primary sewage sludge) were added into the feed of the other reactor (Test) for a lipase activity of 24 U/L, considerably reducing the formation of scum. In the Test reactor, the scum showed oil and grease (O&G) concentration between 0.8 and 1.3 g/L and an accumulation rate of 20 to 27 mg O&G/d. In the Control reactor, the scum had values twice as high (1.5–2.5 g/L and 34–51 mg O&G/d, respectively) and there were more operational problems. During the entire period of operation, both reactors presented high chemical oxygen demand removal (>80%), with no loss of effluent quality due to the addition of the enzymes.


Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2462
Author(s):  
Larryngeai Gutu ◽  
Moses Basitere ◽  
Theo Harding ◽  
David Ikumi ◽  
Mahomet Njoya ◽  
...  

Biological wastewater treatment processes such as activated sludge and anaerobic digestion remain the most favorable when compared to processes such as chemical precipitation and ion exchange due to their cost-effectiveness, eco-friendliness, ease of operation, and low maintenance. Since Abattoir Wastewater (AWW) is characterized as having high organic content, anaerobic digestion is slow and inadequate for complete removal of all nutrients and organic matter when required to produce a high-quality effluent that satisfies discharge standards. Multi-integrated systems can be designed in which additional stages are added before the anaerobic digester (pre-treatment), as well as after the digester (post-treatment) for nutrient recovery and pathogen removal. This can aid the water treatment plant effluent to meet the discharge regulations imposed by the legislator and allow the possibility for reuse on-site. This review aims to provide information on the principles of anaerobic digestion, aeration pre-treatment technology using enzymes and a hybrid membrane bioreactor, describing their various roles in AWW treatment. Simultaneous nitrification and denitrification are essential to add after anaerobic digestion for nutrient recovery utilizing a single step process. Nutrient recovery has become more favorable than nutrient removal in wastewater treatment because it consumes less energy, making the process cost-effective. In addition, recovered nutrients can be used to make nutrient-based fertilizers, reducing the effects of eutrophication and land degradation. The downflow expanded granular bed reactor is also compared to other high-rate anaerobic reactors, such as the up-flow anaerobic sludge blanket (UASB) and the expanded granular sludge bed reactor (EGSB).


Sign in / Sign up

Export Citation Format

Share Document