CFD for wastewater treatment: an overview

2016 ◽  
Vol 74 (3) ◽  
pp. 549-563 ◽  
Author(s):  
R. W. Samstag ◽  
J. J. Ducoste ◽  
A. Griborio ◽  
I. Nopens ◽  
D. J. Batstone ◽  
...  

Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), with application to almost all unit processes. This paper provides an overview of CFD applied to a wide range of unit processes in water and WWT from hydraulic elements like flow splitting to physical, chemical and biological processes like suspended growth nutrient removal and anaerobic digestion. The paper's focus is on articulating the state of practice and research and development needs. The level of CFD's capability varies between different process units, with a high frequency of application in the areas of final sedimentation, activated sludge basin modelling and disinfection, and greater needs in primary sedimentation and anaerobic digestion. While approaches are comprehensive, generally capable of incorporating non-Newtonian fluids, multiphase systems and biokinetics, they are not broad, and further work should be done to address the diversity of process designs. Many units have not been addressed to date. Further needs are identified throughout, but common requirements include improved particle aggregation and breakup (flocculation), and improved coupling of biology and hydraulics.

Author(s):  
Александр Семёнович Макаров ◽  
Игорь Павлович Лутков ◽  
Наталия Александровна Шмигельская ◽  
Виктория Алексеевна Максимовская ◽  
Галина Владимировна Сивочуб ◽  
...  

Представлены результаты исследований физико-химических и органолептических показателей крымских и донских аборигенных красных сортов в системе «виноград-виноматериал» из Ампелографической коллекции института «Магарач» (с. Вилино Бахчисарайского района). Установлено, что активность окислительных ферментов (пероксидазы и монофенол-монооксигеназы) практически во всех сортах была низкой или отсутствовала. Технологический запас фенольных веществ в изученных сортах винограда находился в достаточно широком диапазоне - от 2139 до 3865 мг/дм, в т.ч. технологический запас красящих веществ - от 149 (Кокур красный) до 1232 мг/дм (Безымянный). Определено, что из сорта винограда Кефесия получаются виноматериалы с хорошими пенистыми свойствами (Vболее 800 см). Установлено, что соотношение массовых концентраций винной и яблочной кислот было оптимальным (более 1) во всех исследуемых сортах. Высокими дегустационными оценками отмечены сорта Цимладар, Безымянный и Солнечная Долина 58. По совокупности проведенных исследований основных и дополнительных физико-химических и органолептических показателей в системе «виноград-виноматериал» и технологической оценки крымских и донских аборигенных красных сортов винограда, произрастающих в Ампелографической коллекции института «Магарач», можно заключить, что для производства игристых вин представляют интерес виноматериалы из аборигенных красных сортов винограда Кефесия, Солнечная Долина 58, Цимладар, Безымянный. The article presents the results of studies of the physical-chemical and organoleptic characteristics of native red grape varieties of Crimea and Don in the system “grapes-wine material” from the Ampelographic collection of Magarach Institute (village Vilino, Bakhchisaray district). It was established that the activity of oxidizing enzymes (peroxidase and monophenol-monooxygenase) was low or absent in almost all varieties. The technological stock of phenolic substances in the studied grape varieties was in a rather wide range - from 2139 to 3865 mg/dm, including the technological reserve of coloring substances - from 149 (‘Kokur Krasnyi’) to 1232 mg/dm (‘Bezymyannyi’). Good foaming capacity (V more than 800 cm) was achieved in wine materials made of ‘Kefesiya’ grape variety. The ratio of mass concentrations of tartaric and malic acids was optimal (more than 1) in all varieties under study. High tasting evaluation gained the varieties ‘Tsimladar’, ‘Bezymyannyi’ and ‘Solnechnaya Dolina 58’. Basing on the combination of studies of essential and additional physical-chemical and organoleptic parameters in the system “grapes-wine material” and on the technological assessment of native red grapes of Crimea and Don that grow in the Ampelographic collection of the Magarach Institute, we can draw the following conclusion: wine materials made of native red grape varieties ‘Kefesiya’, ‘Solnechnaya Dolina 58’, ‘Tsimladar’, ‘Bezymyannyi’ are of interest to the production of sparkling wines.


2013 ◽  
Vol 67 (5) ◽  
pp. 1159-1164 ◽  
Author(s):  
L. Yerushalmi ◽  
O. Ashrafi ◽  
F. Haghighat

Greenhouse gas (GHG) emission and energy consumption by on-site and off-site sources were estimated in two different wastewater treatment plants that used physical–chemical or biological processes for the removal of contaminants, and an anaerobic digester for sludge treatment. Physical–chemical treatment processes were used in the treatment plant of a locomotive repair factory that processed wastewater at 842 kg chemical oxygen demand per day. Approximately 80% of the total GHG emission was related to fossil fuel consumption for energy production. The emission of GHG was reduced by 14.5% with the recovery of biogas that was generated in the anaerobic digester and its further use as an energy source, replacing fossil fuels. The examined biological treatment system used three alternative process designs for the treatment of effluents from pulp and paper mills that processed wastewater at 2,000 kg biochemical oxygen demand per day. The three designs used aerobic, anaerobic, or hybrid aerobic/anaerobic biological processes for the removal of carbonaceous contaminants, and nitrification/denitrification processes for nitrogen removal. Without the recovery and use of biogas, the aerobic, anaerobic, and hybrid treatment systems generated 3,346, 6,554 and 7,056 kg CO2-equivalent/day, respectively, while the generated GHG was reduced to 3,152, 6,051, and 6,541 kg CO2-equivalent/day with biogas recovery. The recovery and use of biogas was shown to satisfy and exceed the energy needs of the three examined treatment plants. The reduction of operating temperature of the anaerobic digester and anaerobic reactor by 10°C reduced energy demands of the treatment plants by 35.1, 70.6 and 62.9% in the three examined treatment systems, respectively.


2020 ◽  
Vol 12 (7) ◽  
pp. 2697
Author(s):  
Sibel Uludag-Demirer ◽  
Nathan Olson ◽  
Rebecca Ives ◽  
Jean Pierre Nshimyimana ◽  
Cory A. Rusinek ◽  
...  

This study investigated the use of iron and aluminum and their combinations as electrodes to determine the technically sound and economically feasible electrochemical approach for the treatment of anaerobic digestion effluent. The results indicated that the use of iron as anode and cathode is the most suitable solution among different electrode combinations. The reduction of turbidity, total chemical oxygen demand, total phosphorus, total coliforms, Escherichia coli, Enterococci, and phages in the reclaimed water were 99%, 91%, 100%, 1.5 log, 1.7 log, 1.0 log, and 2.0 log, respectively. The economic assessment further concluded that the average treatment cost is $3 per 1000 L for a small-scale operation handling 3000 L wastewater/day. This study demonstrated that the electrocoagulation (EC) is a promising technique for the recovery and reclamation of water from anaerobic digestion effluent. Even though its energy consumption is higher and the nitrogen removal is insufficient compared to some conventional wastewater treatment technologies, there are several advantages of the EC treatment, such as short retention time, small footprint, no mixing, and gradual addition of coagulants. These features make EC technology applicable to be used alone or combined with other technologies for a wide range of wastewater treatment applications.


Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1557 ◽  
Author(s):  
Li ◽  
Wang ◽  
Peng ◽  
Huyan ◽  
Cacalano

One of many types of extracellular vesicles (EVs), exosomes are nanovesicle structures that are released by almost all living cells that can perform a wide range of critical biological functions. Exosomes play important roles in both normal and pathological conditions by regulating cell-cell communication in cancer, angiogenesis, cellular differentiation, osteogenesis, and inflammation. Exosomes are stable in vivo and they can regulate biological processes by transferring lipids, proteins, nucleic acids, and even entire signaling pathways through the circulation to cells at distal sites. Recent advances in the identification, production, and purification of exosomes have created opportunities to exploit these structures as novel drug delivery systems, modulators of cell signaling, mediators of antigen presentation, as well as biological targeting agents and diagnostic tools in cancer therapy. This review will examine the functions of immunocyte-derived exosomes and their roles in the immune response under physiological and pathological conditions. The use of immunocyte exosomes in immunotherapy and vaccine development is discussed.


2011 ◽  
Vol 63 (9) ◽  
pp. 2004-2009 ◽  
Author(s):  
P. M. Sutton ◽  
B. E. Rittmann ◽  
O. J. Schraa ◽  
J. E. Banaszak ◽  
A. P. Togna

A wastewater-treatment flowsheet was developed to integrate uniquely designed biological processes with physical-chemical unit processes, allowing conversion of the organic carbon in the wastewater to methane, the removal and recovery of phosphorus and nitrogen from the wastewater, and the production of water suitable for reuse. In the flowsheet, energy is derived from the wastewater by first shunting a large fraction of the organic carbon in the wastewater to a solids slurry which is treated via anaerobic digestion. The anaerobic digestion system consists of focused pulsed (FP) pretreatment coupled to anaerobic membrane bioreactors (MBRs). Computer modelling and simulation results are used to optimize design of the system. Energy generation from the system is maximized and costs are reduced by using modest levels of recycle flow from the anaerobic MBRs to the FP pretreatment step.


2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).


2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.


Author(s):  
Rami Obeid ◽  
Elias Wehbe ◽  
Mohamad Rima ◽  
Mohammad Kabara ◽  
Romeo Al Bersaoui ◽  
...  

Background: Tobacco mosaic virus (TMV) is the most known virus in the plant mosaic virus family and is able to infect a wide range of crops, in particularly tobacco, causing a production loss. Objectives: Herein, and for the first time in Lebanon, we investigated the presence of TMV infection in crops by analyzing 88 samples of tobacco, tomato, cucumber and pepper collected from different regions in North Lebanon. Methods: Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), revealed a potential TMV infection of four tobacco samples out of 88 crops samples collected. However, no tomato, cucumber and pepper samples were infected. The TMV+ tobacco samples were then extensively analyzed by RT-PCR to detect viral RNA using different primers covering all the viral genome. Results and Discussion: PCR results confirmed those of DAS-ELISA showing TMV infection of four tobacco samples collected from three crop fields of North Lebanon. In only one of four TMV+ samples, we were able to amplify almost all the regions of viral genome, suggesting possible mutations in the virus genome or an infection with a new, not yet identified, TMV strain. Conclusion: Our study is the first in Lebanon revealing TMV infection in crop fields, and highlighting the danger that may affect the future of agriculture.


2017 ◽  
Vol 2017 (9) ◽  
pp. 3062-3082
Author(s):  
Gokce Kor-Bicakci ◽  
Timothy Abbott ◽  
Emine Ubay-Cokgor ◽  
Cigdem Eskicioglu

2020 ◽  
Vol 67 (1) ◽  
pp. 148-155
Author(s):  
Anatoliy V. Fedotov ◽  
Viktor S. Grigoriev ◽  
Dmitriy A. Kovalev ◽  
Andrey A. Kovalev

To speed up the wastewater treatment under aerobic conditions and to optimize the processes of anaerobic wastewater treatment in digesters, immobilization technologies of microorganisms and enzymes on solid carriers are used. Ceramic carriers based on aluminosilicates and alumina are one of the promising inorganic biomass carriers. (Research purpose) To study the structure of porous ceramic biomass carriers for anaerobic processing of organic waste and evaluate the prospects for their use. (Materials and methods) The substrate for anaerobic digestion was a mixture of sediments of the primary and secondary sewage sumps of the Lyubertsy treatment facilities. K-65 cattle feed was used to ensure the constancy of the composition of organic substances in substrates as a cosubstrate. The authors used the method of low-temperature nitrogen adsorption of Bruner-Emmett-Teller to study the pore structure and specific surface of solid carriers on a specific surface analyzer Quntachrome Autosorb-1. (Results and discussion) The main characteristics (specific surface, volume of micro- and mesopores, predominant pore radius, water absorption and others) of chamotte foam lightweight and highly porous corundum ceramics were determined. It was revealed that ceramic materials with a developed surface and electrically conductive material provided an increase in biogas yield by 3.8-3.9 percent with an increase in methane content by an average of 5 percent. (Conclusions) The results of anaerobic digestion showed a positive effect of both a conductive carrier and highly porous ceramic materials on the process of anaerobic bioconversion of organic waste into biogas. It is advisable to expand experimental studies on the use of a conductive carrier with a developed surface based on highly porous ceramics.


Sign in / Sign up

Export Citation Format

Share Document