Перегляд за Автор "Ivanov, Volodymyr M."

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Application of iron-reducing bacteria for phosphate removal from returned liquor of municipal wastewater treatment plant
(2005) Ivanov, Volodymyr M.; Stabnikov, Victor; Tay, Stephen; Tay, Joo
The aim of this research was to examine efficiency of enrichment culture and isolated strains of iron-reducing bacteria for the removal of phosphate from return liquor of municipal wastewater treatment plant (MWWTP) with ferric hydroxide as a source of Fe (III). Bacterial reduction of ferric hydroxide enhanced phosphate removal from return liquor. The obtained data could be used for the design of a new biotechnology of anaerobic removal or recovery of phosphate from return liquor of MWWTP.
Biocement: green building-and energy-saving material
(2012) Chu, Jian; Ivanov, Volodymyr M.; Stabnikov, Victor; He, Jia; Li, Bing; Naemi, Maryam
Cement and chemical grouts have often been used for soil strengthening. However, high cost, energy consumption, and harm to environment restrict their applications. Biocement could be a new green building- material and energy-saving material. Biocement is a mixture of enzymes or microbial biomass with inorganic chemicals, which can be produced from cheap raw materials. Supply of biocementing solution to the porous soil or mixing of dry biocement with clayey soil initiate biocementation of soil due to specific enzymatic activity. Different microorganisms and enzymes can be used for production of biocement.
Development of microbial geotechnology in Singapore
(2011) Chu, Jian; Ivanov, Volodymyr M.; He, Jia; Li, Bing; Naemi, Maryam; Stabnikov, Victor
Both nature processes and laboratory studies have shown that microorganisms can be used to improve the engineering properties of soil. As such, it is possible to develop methods that utilize the microbial process to treat soil in a way similar to that of cement. When more knowledge is accumulated through research findings and technology development, a new branch of geotechnical engineering – the Microbial Geotechnology can be established. The Microbial Geotechnology can have the following three applications: (a) biocementation to increase the strength of soil, (b) bioclogging to reduce the permeability of soil, and (c) biogas to increase the liquefaction resistance of sandy soil. Some types of microorganisms or bioprocesses that may contribute to the biocementation, bioclogging or biogas effects are identified and discussed. Some experimental data are presented to show that the permeability of sand can be reduced by four orders of magnitude and the strength of sand can be increased to a substantial value after the soil has been treated using bacteria. However, the whole study still stays at the laboratory stage and much more efforts are required to turn this scientific idea into viable technologies
Effect of iron hydroxide on phosphate removal during anaerobic digestion of activated sludge
(2004) Stabnikov, Victor; Tay, Stephen; Tay, Joo; Ivanov, Volodymyr M.
Addition of ferric hydroxide to the reactor of methanogenic fermentation of activated sludge followed microbial reduction of Fe (III) and formation of ferrous ions, which precipitated phosphate. It was shown that 66.6 – 99.6 % of dissolved phosphate with initial concentration of 1000 – 3500 mg РО43-/l can be removed by the addition of ferric hydroxide in concentration of 6420 mg Fe (III)/l and anaerobic sludge with iron-reducing activity. Optimal ratio of added Fe(III): removed dissolved phosphate, ensured not less than 95 % removal of phosphate was 2. These data could be used in a new technology of anaerobic treatment of wastewater with simultaneous removal of phosphate.
Formation of water-impermeable crust on sand surface using biocement
(2011) Stabnikov, Victor; Naemi, Maryam; Ivanov, Volodymyr M.; Chu, Jian
This paper examines the feasibility of using calcium-based biocement to form an impermeable crust on top of a sand layer. The biocement used was a mixture of calcium salt, urea, and bacterial suspension, which hydrolyzed urea with production of carbonate and an increase of the pH level. Applying 0.6 g of Ca per cm2 of sand surface, the permeability of the biocemented sand can be reduced from 10−4 m/s to 1.6•10−7 m/s (or 14 mm/day) due to formation of the crust on sand surface. The rupture modulus (maximum bending stress) of the crust was 35.9 MPa, which is comparable with that of limestone. The formation of a water-impermeable and high strength crust layer on sand surface could be useful for the construction of aquaculture ponds in sand, stabilization of the sand dunes, dust fixation in the desert areas, and sealing of the channels and reservoirs in sandy soil.
Improvement of sludge quality by iron-reducing bacteria
(2004) Ivanov, Volodymyr M.; Wang, J.-Y.; Stabnikov, Victor; Xing, Zikun; Tay, Joo
Sewage sludge can be used in agriculture as organic fertilizer. However, one of the obstacles for this use is the high concentration of heavy metals and the presence of sulphides (acidifying soil or compost). The aim of this research was to develop the biotechnology for improving the quality of sewage sludge that would be used as organic fertilizer. Microbial reduction of inexpensive sources of Fe(III) in anaerobic digester is proposed as a means of preventing the accumulation of sulphide and of enhancing the accumulation of phosphate in sewage sludge. Industrial grade iron hydroxide can serve as a suitable source of Fe(III) The results show that almost all dissolved phosphate is recovered by the reaction with Fe2+. Additionally, the activity of iron-reducing bacteria inhibits the production of sulphide by sulphate-reducing bacteria and the growth of these bacteria in anaerobic digesters.
Iron-and calcium-based biogrouts for porous soils
(2012) Ivanov, Volodymyr M.; Chu, Jian; Stabnikov, Victor
Chemical grouts are often used to reduce the hydraulic conductivity of soil for seepage control purposes. However, chemical grouts can be expensive and environmentally unfriendly. Therefore, two new biogrouts or microbial-based grouting materials were developed.
Iron-mediated removal of ammonia from strong nitrogenous wastewater of food processing
(2004) Ivanov, Volodymyr M.; Wang, J.-Y.; Stabnikova, Elena; Krasinko, Victoria; Stabnikov, Victor; Tay, Stephen; Tay, Joo
The combination of microbial reduction and further microbial oxidation of iron was applied to the treatment of food-processing wastewater and recovery of ammonium. Fe2+ ions were formed by iron-reducing bacteria under anaerobic conditions. Ammonium was recovered by co-precipitation with negatively charged iron hydroxides produced during oxidation of Fe2+ by iron-oxidizing bacteria under microaerophilic conditions. The value-added by-product of this process can be used as a slowly released ammonium fertilizer.
Microbial method for construction of aquaculture pond in sand
(2013) Chu, Jian; Ivanov, Volodymyr M.; Stabnikov, Victor; Li, Bing
A method to construct an aquaculture pond in sand using microbial biocementation is presented in this paper. The microbially induced calcium carbonate precipitation process was used to form a low-permeability layer in sand for the construction of a water pond model in the laboratory. The test results indicated that the permeability of sand was reduced from the order of 10−4 m/s to 10−7 m/s when an average 2.1 kg of calcium (Ca) per m2 of sand surface was precipitated. The bending strengths of the walls and the base of the model pond were in the range of 90–256 kPa. The unconfined compressive strengths for the samples taken from the walls and the base of the pond were in the range of 215–932 kPa.
Microbially induced calcium carbonate precipitation on surface or in the bulk of soil
(2012) Chu, Jian; Stabnikov, Victor; Ivanov, Volodymyr M.
Microbial precipitation of calcium carbonate takes place in nature by different mechanisms. One of them is microbially induced carbonate precipitation (MICP), which is performed due to bacterial hydrolysis of urea in soil in the presence of calcium ions. The MICP process can be adopted to reduce the permeability and/or increase the shear strength of soil. In this paper, a study on the use of Bacillus sp., which was isolated from tropical beach sand, to perform MICP either on the surface or in the bulk of sand is presented. If the level of calcium salt solution was below the sand surface, MICP took place in the bulk of sand. On the other hand, if the level of calcium salt solution was above the sand surface, MICP was performed on the sand surface and formed a thin layer of crust of calcium carbonate. After six sequential batch treatments with suspension of urease-producing bacteria and solutions of urea and calcium salt, the permeability of sand was reduced to 14 mm/day (or 1.6×10−7 m/s) in both cases of bulk and surface MICP. Quantitiesof precipitated calcium after six treatments were 0.15 and 0.60 g of Ca per cm2 of treated sand surface for the cases of bulk or surface MICP, respectively. The stiffness of the MICP treated sand also increased considerably. The modulus of rupture of the thin layer of crust was 35.9 MPa which is comparable with limestone.
Phosphate removal from return liquor of municipal wastewater treatment plant using iron-reducing bacteria
(2005) Ivanov, Volodymyr M.; Stabnikov, Victor; Zhuang, W. Q.; Tay, Joo; Tay, Stephen
The application of iron-reducing bacteria (IRB) for phosphate removal from return liquor (liquid fraction after activated sludge digestion and anaerobic sludge dewatering) of municipal wastewater treatment plant was studied. Methods and Results: Enrichment culture and two pure cultures of IRB, Stenotrophomonas maltophilia BK and Brachymonas denitrificans MK identified by 16S rRNA gene sequencing, were produced using return liquor of WWTP as carbon and energy source and iron hydroxide as oxidant. The final concentration of phosphate increased from 70 to 90 mg l-1 in control and decreased from 70 to 1 mg l-1 in experiment. The mass ratio of removed P to produced Fe(II) was 0.17 g P g-1 Fe(II). S. maltophilia BK showed the ability to reduce Fe(III) using such xenobiotics as diphenylamine, m-cresol, 2,4-dichlorphenol and p-phenylphenol as sole source of carbon under anaerobic conditions. Bacterial reduction of ferric hydroxide enhanced phosphate removal from return liquor. Significance and Impact of Study: An ability of facultative anaerobes Stenotrophomonas maltophilia BK and Brachymonas denitrificans MK to reduce Fe(III) was shown. These bacteria can be used for anaerobic removal of phosphate and xenobiotics by bacterial reduction of ferric ions.
Screening and selection of microorganisms for the environmental biotechnology process
(2013) Ivanov, Volodymyr M.; Stabnikov, Victor; Hung, Yung-Tse
CONTENT Major physiological groups of microorganisms Periodic table of prokaryotes Use of periodic table for theoretical selection of prokaryotes in environmental engineering Connection between cell shape and physical properties of medium rRNA-based phylogenetic classification cannot be used for theoretical selection in environmental engineering Methods of selection and of isolation of microorganisms Selection of microbial aggregates Growth-related and survival-related selection of microorganisms ///ЗМІСТ Головні фізіологічні групи мікроорганізмів Періодична таблиця прокаріот Використання періодичної таблиці для теоретичної селекції прокаріотів в інженерії довкілля Взаємозв'язок між формою клітини і фізичними властивостями середовища Філогенетична класифікація, що базована на рРНК, не може бути використана для теоретичної селекції в інженерії довкілля Методи селекції та виділення мікроорганізмів Селекція мікробних агрегатів Селекція мікроорганізмів по відношенню до росту та виживання ///СОДЕРЖАНИЕ Главные физиологические группы микроорганизмов Периодическая таблица прокариот Использование периодической таблицы для теоретической селекции прокариотов в инженерии окружающей среды Взаимосвязь между формой клетки и физическими свойствами среды Филогенетическая классификация, основанная на рРНК, не может быть использована для теоретической селекции в инженерии окружающей среды Методы селекции и выделения микроорганизмов Селекция микробных агрегатов Селекция микроорганизмов по отношению к росту и выживаемости
The effect of various iron hydroxide concentrations on the anaerobic fermentation of sulfate-containing model wastewater
(2006) Stabnikov, Victor; Ivanov, Volodymyr M.
Addition of ferric hydroxide and iron-reducing bacteria in anaerobic treatment of sulphate-containing wastewater reduced sulphate reduction and production of sulphide, increased removal of total organic carbon (TOC) and methane production. Influence of ferric addition on sulphate-containing wastewater treatment depended on Fe(III) dosage, which can be determined as a molar ratio of Fe(ІІІ)/SO42-. Concentration of sulphide constantly increased and consisted on 15 day 91 mg/l and 45 mg/l at ratio of Fe(ІІІ)/SO42- 0.06 and 0.5. However, no production of dissolved sulphide was observed at ratio Fe(ІІІ)/SO42- 1 and 2. Maximum rates of total organic carbon removal were 0.75, 1.15, 1.39, 1.55 g TOC/g of volatile suspended solids (VVS) per hour; rates of methane production were 0.039, 0.047, 0.064 and 0.069 ml/g VVS per hour; contents of methane in biogas were 25, 41, 55 and 62 vol. % at the ratios of Fe(ІІІ)/SO42- 0.06, 0.5, 1 and 2, respectively. These data could be used for the development of a new technology for anaerobic treatment of sulphate containing wastewater.
The removal of nitrogen and phosphorus from reject water of municipal wastewater treatment plant using ferric and nitrate bioreductions
(2010) Guo, Cheng Hong; Stabnikov, Victor; Ivanov, Volodymyr M.
Reject water, which is the liquid fraction produced after dewatering of anaerobically digested activated sludge on the municipal wastewater treatment plants (MWWTPs), contributes up to 80% of the nitrogen and phosphorus loads to the MWWTP. It was proposed to combine the removal of nitrogen from reject water using the sequential biooxidation of and bioreduction of NO3- with precipitation of phosphate by Fe2+ ions produced due to bioreduction of Fe3+ in iron ore. Bioreduction of NO3- decreased Fe3+ bioreduction rate in reject water from 37 to 21 mg Fe2+/L d due to competition between NO3- and Fe3+ for electron donors. Addition of acetate as electron donor increased both bioreduction rates of Fe3+ and NO3- but acetate interfered with the competition between nitrate and phosphate anions reacting with ferrous cations decreasing efficiency of the phosphate removal from reject water. The stages of denitrification and ferric bioreduction/phosphate precipitation must be performed sequentially.
The removal of phosphate from wastewater using anoxic reduction of iron ore in the rotating reactor
(2009) Guo, Cheng Hong; Stabnikov, Victor; Kuang, Shengli; Ivanov, Volodymyr M.
The removal of phosphorus from reject water, which is the liquid fraction produced after dewatering of anaerobically digested activated sludge on the municipal wastewater treatment plants (MWWTPs), can significantly reduce the phosphorus load to the main stream of the MWWTPs. Ferric or ferrous reagents can be used for this removal but the significantly cheaper option could be the production of ferrous reagent using bioreduction of iron ore. The removal of phosphorus from reject water using anoxic bioreduction of iron ore was studied in the rotating reactor, which was selected to avoid the clogging of the pores between iron ore particles. The highest phosphorus removal rate from reject water in the rotating reactor, i.e. the parameter which can be used in the design of the continuous process, was 25mg P/L day. Significant role in the iron ore bioreduction is playing the formation of the fine particles from initially loaded coarse particles of iron ore during rotation of the reactor.
The removal of phosphorus from reject water of municipal wastewater treatment plant using iron ore
(2009) Guo, Cheng Hong; Stabnikov, Victor; Kuang, Shengli; Ivanov, Volodymyr M.
BACKGROUND: Reject water (return liquor) from dewatering of anaerobically digested activated sludge in municipal wastewater treatment plants contains from 10 to50%of the phosphorus load when being recycled to the aeration tank. Phosphorus removal from reject water could be an effective way to decrease phosphorus loads entering the aeration tank. An innovative approach involves the replacement of iron salts, which are commonly used for phosphorus removal, with ferrous ions produced by iron-reducing bacteria from iron ore. The aim of the research was to examine the feasibility of phosphorus removal from return liquor using bioreduction of iron ore.RESULTS: Ferrous production, phosphate and organic carbon removal rates were determined as a function of different iron ore particle sizes in batch experiments. Iron-reducing bacteria ensured the production of ferrous ions from iron ore up to concentrations of 550 mg L−1. The ferrous production rate was linearly dependent on the calculated specific surface area of the iron ore particles. The phosphorus concentration in the reject water was reduced by 90% during bioreduction of iron ore. The phosphorus removal rate did not depend on specific surface area of iron ore particles when the particle size of iron ore was smaller than 7 mm. The organic carbon removal rate did not seem to be dependent on iron ore particle size. CONCLUSION: Removal of phosphate using iron ore can be more economical than conventional chemical precipitation of phosphate using iron salts because of the lower cost of iron ore.
The structure of bacterial cell cycle and age structure of bacterial populations
(1995) Ivanov, Volodymyr M.; Svechnikova, Tatyana; Stabnikova, Elena; Gregirchak, Natalia
Вивчення синхронних і асинхронних культур Bacillus'tnegateriutn, Bacillus thuringiensis та Bacillus Ucheniformis показало, що тривалість періоду реплікації хромосомної ДНК (С-період) пропорційна часу генерації,а час між двома циклами реплікації ДНК (що зветься І-періодом) майже постійний та становить 0,5—1,0 год при варіації часу генерації від 1,5 до 2,75 год. Клітинний цикл (період між клітинними поділами) та цикл реплікації ДНК не синхронізовані між собою. Тому тривалість В-періоду (час між термінацією клітинного поділу та ініціацією реплікації ДНК),а також D-періоду (час між термінацією реплікації ДНК та ініціацією клітинного поділу) виявляються як стохастичні параметри в експериментах по синхронному культивуванню. Запропоновані теоретичні моделі клітинного циклу бактерій та вікові структури бактеріальних популяцій. Дані, що випливають з теоретичних моделей, узгоджуються з експериментальними даними проточного цитофлуорометричного аналізу синхронних та асинхронних культур бацил.
Trends and expected benefits of the breaking edge food technologies in 2021–2030
(2021) Ivanov, Volodymyr M.; Shevchenko, Oleksandr; Marynin, Andriy; Stabnikov, Victor; Stabnikova, Elena; Gubenia, Oleksii; Shevchenko, Anastasiia; Gavva, Oleksandr M.; Salyuk, Anatoly
The review considered the major trends in the world development of new food processing technologies in 2021–2030: more strict regulations of food safety including QPCR and DNA-sequencing detection of emerging food-borne pathogens, comprehensive control of minor chemical pollutants of food; production of functional food including food for babies, children, pregnant women, elderly, for sport activities, military food, meals ready-to-eat, microelements-enriched food, nutraceuticals, and clinical food; emerging environmentally-friendly and energy-saving food processing; biotechnological food processing using enzymes proteinases, glutamine transferases, galactosidases, enzymes, microbial metabolites, and new sources of food such as insects and artificial meat; personalization of food processing and distribution including adaptation of the food processing to the nutritional needs of different customer groups.