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Sample records for renewable flocculants electronic

  1. Polymeric polyelectrolytes obtained from renewable sources for biodiesel wastewater treatment by dual-flocculation

    Directory of Open Access Journals (Sweden)

    E. A. M. Ribeiro

    2017-06-01

    Full Text Available Biodiesel wastewater generally contains high levels of oils, soaps and glycerol residues. This needs wastewater treatment. In this study, the biodiesel wastewater treatment was tested (industrial wastewater (EFID and laboratory wastewater (EFLB from biodiesel by performing flocculation and dual-flocculation with renewable polymers. Tannin and cationic hemicellulose (CH were used as cationic flocculant, and cellulose acetate sulfate (CAS was used as an anionic flocculant. Polyacrylamide (PAM was used as a reference anionic flocculant for result efficiencies analysis obtained with CAS (renewable source flocculant. The treatment efficacy in wastewater was evaluated by: turbidity removal, sludge volume formed, chemical oxygen demand (COD and total suspended solids (TSS. The obtained sludge was studied using thermogravimetric analysis (TG. The dual-flocculation application condition of the 25% proportion of tannin (T and 75% proportion of cationic hemicelluloses (i.e., T25/CH75 showed EFLB turbidity removal of 89.1% and 89.5% for CAS and PAM additions respectively, and for EFID of 67% and 41% for CAS and PAM additions respectively. The dual-flocculation performance suggested that the polyelectrolytes obtained from renewable sources can be used for treating biodiesel wastewater.

  2. Flocculation of kaolin and lignin by bovine blood and hemoglobin

    Science.gov (United States)

    Polymeric flocculants are used extensively for water purification, inhibition of soil erosion, and reduction in water leakage from unlined canals. Production of highly active, renewable polymeric flocculants to replace synthetic flocculants is a priority. Using suspensions of kaolin, flocculation ...

  3. Power Electronics for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Choi, U. M.; Lee, K. B.; Blaabjerg, Frede

    2012-01-01

    The use of renewable energy sources are increased because of the depletion of natural resources and the increasing pollution level from energy production. The wind energy and the solar energy are most widely used among the renewable energy sources. Power electronics is needed in almost all kinds...... of renewable energy system. It controls the renewable source and interfaces with the load effectively, which can be grid-connected or van work in stand-alone mode. In this presentation, overview of wind and photovoltaic energy systems are introduced. Next, the power electronic circuits behind the most common...

  4. Power electronics for renewable energy systems

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede

    2009-01-01

    sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss some of the most emerging renewable energy sources......, wind energy and photovoltaics, which by means of power electronics are changing from being minor energy sources to be acting as important power sources in the energy system....

  5. Power Electronics, Energy Harvesting and Renewable Energies Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The research in the Power Electronics, Energy Harvesting and Renewable Energies Laboratory (PEHREL) is mainly focused on investigation, modeling, simulation, design,...

  6. Power Electronics for Renewable Energy Systems - Status and Trends

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ma, Ke; Yang, Yongheng

    2014-01-01

    electronics in generation, transmission/distribution and end-user application, together with advanced controls, can pave the way for renewable energy resources. In view of this, some of the most promising renewable candidates like wind power and photovoltaic, which are becoming a significant part...... in the electricity production, are explored in this paper. Issues like technology demands, power converter topologies, and control structures are addressed. Some special focuses are also paid on the emerging trends in power electronics development for those systems....

  7. International Conference on Power Electronics and Renewable Energy Systems

    CERN Document Server

    Suresh, L; Dash, Subhransu; Panigrahi, Bijaya

    2015-01-01

    The book is a collection of high-quality peer-reviewed research papers presented in Proceedings of International Conference on Power Electronics and Renewable Energy Systems (ICPERES 2014) held at Rajalakshmi Engineering College, Chennai, India. These research papers provide the latest developments in the broad area of Power Electronics and Renewable Energy. The book discusses wide variety of industrial, engineering and scientific applications of the emerging techniques. It presents invited papers from the inventors/originators of new applications and advanced technologies.

  8. Design for Reliability of Power Electronics in Renewable Energy Systems

    DEFF Research Database (Denmark)

    Ma, Ke; Yang, Yongheng; Wang, Huai

    2014-01-01

    Power electronics is the enabling technology for maximizing the power captured from renewable electrical generation, e.g., the wind and solar technology, and also for an efficient integration into the grid. Therefore, it is important that the power electronics are reliable and do not have too many...... failures during operation which otherwise will increase cost for operation, maintenance and reputation. Typically, power electronics in renewable electrical generation has to be designed for 20–30 years of operation, and in order to do that, it is crucial to know about the mission profile of the power...... electronics technology as well as to know how the power electronics technology is loaded in terms of temperature and other stressors relevant, to reliability. Hence, this chapter will show the basics of power electronics technology for renewable energy systems, describe the mission profile of the technology...

  9. Trends in Power Electronics and Control of Renewable Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Iov, Florin; Kerekes, Tamas

    2010-01-01

    term) based energy sources to renewable energy sources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss trends of the most emerging renewable energy sources, wind energy and photovoltaics, which...... by means of power electronics are changing the future electrical infrastructure but also contributes steadily more to non-carbon based electricity production. Most focus is on the power electronics technologies used. In the case of photovoltaics transformer-less systems are discussed as they have...

  10. Power Electronics and Reliability in Renewable Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ma, Ke; Zhou, Dao

    2012-01-01

    Power Electronics are needed in almost all kind of renewable energy systems. It is used both for controlling the renewable source and also for interfacing to the load, which can be grid-connected or working in stand-alone mode. More and more efforts are put into making renewable energy systems...... better in terms of reliability in order to ensure a high availability of the power sources, in this case the knowledge of mission profile of a certain application is crucial for the reliability evaluation/design of power electronics. In this paper an overview on the power electronic circuits behind...... the most common converter configurations for wind turbine and photovoltaic is done. Next different aspects of improving the system reliability are mapped. Further on examples of how to control the chip temperature in different power electronic configurations as well as operation modes for wind power...

  11. Effect of different flocculants on the flocculation performance of ...

    African Journals Online (AJOL)

    Effect of different flocculants on the flocculation performance of flocculation performance of microalgae, Chaetoceros calcitrans, cells. ZT Harith, FM Yusoff, MS Mohamed, M Shariff, M Din, AB Ariff ...

  12. Renewable Energy Systems in the Power Electronics Curriculum

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chen, Zhe; Teodorescu, Remus

    2005-01-01

    of the most important area is renewable energy systems. This paper will discuss the basic courses for the power electronics curriculum. It will also discuss how to teach power electronic systems efficiently through a projectoriented and problem-based learning approach with Aalborg University in Denmark...... as a full-scale example. Different project examples will be given as well as important laboratories for adjustable speed drives and renewable energy systems which are used at the university are described.......Power Electronics is still an emerging technology and its applications are increasing. The primary function is to convert electrical energy from one stage to another and it is used in many different applications. The power electronics curriculum is multidisciplinary covering fields like devices...

  13. Power electronics for renewable energy systems, transportation and industrial applications

    CERN Document Server

    Malinowski, Mariusz; Al-Haddad, Kamal

    2014-01-01

    Power Electronics for Renewable Energy, Transportation, and Industrial Applications combines state-of-the-art global expertise to present the latest research on power electronics and its application in transportation, renewable energy, and different industrial applications. This timely book aims to facilitate the implementation of cutting-edge techniques to design problems offering innovative solutions to the growing power demands in small- and large-size industries. Application areas in the book range from smart homes and electric and plug-in hybrid electrical vehicles (PHEVs), to smart distribution and intelligence operation centers where significant energy efficiency improvements can be achieved through the appropriate use and design of power electronics and energy storage devices.

  14. Power Electronics as Efficient Interface of Renewable Energy Sources

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chen, Zhe; Kjær, Søren Bækhøj

    2004-01-01

    The global electrical energy consumption is steadily rising and consequently there is a demand to increase the power generation capacity. A significant percentage of the required capacity increase can be based on renewable energy sources. Wind turbine technology, as the most cost effective...... renewable energy conversion system, will play an important part in our future energy supply. But other sources like microturbines, photovoltaics and fuel cell systems may also be serious contributor to the power supply. Characteristically, power electronics will be an efficient and important interface...... to the grid and this paper will first briefly discuss three different alternative/ renewable energy sources. Next, various configurations of the wind turbine technology are presented, as this technology seems to be most developed and cost-effective. Finally, the developments and requirements from the grid...

  15. Power electronics - key technology for renewable energy systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Iov, Florin; Kerekes, Tamas

    2011-01-01

    sources to renewable energy sources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss trends of the most emerging renewable energy sources, wind energy and photovoltaics, which by means of power electronics...... as efficient as possible. Further, the emerging climate changes is arguing to find sustainable future solutions. Of many options, two major technologies will play important roles to solve parts of those future problems. One is to change the electrical power production from conventional, fossil based energy......The electrical energy consumption continues to grow and more applications are based on electricity. We can expect that more 60% of all energy consumption will be converted and used as electricity. Therefore, it is a demand that production, distribution and use of electrical energy are done...

  16. Power electronics - The key technology for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ma, Ke; Yang, Yongheng

    2014-01-01

    The energy paradigms in many countries (e.g. Germany and Denmark) have experienced a significant change from fossil-based resources to clean renewables (e.g. wind turbines and photovoltaics) in the past few decades. The scenario of highly penetrated renewables is going to be further enhanced...... - Denmark expects to be 100 % fossil-free by 2050. Consequently, it is required that the production, distribution and use of the energy should be as technologically efficient as possible and incentives to save energy at the end-user should also be strengthened. In order to realize the transition smoothly...... and effectively, energy conversion systems, currently based on power electronics technology, will again play an essential role in this energy paradigm shift. Using highly efficient power electronics in power generation, power transmission/distribution and end-user application, together with advanced control...

  17. Microbial Flocculant for Nature Soda

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Peiyong; Zhang, Tong; Chen, Cuixian

    2004-03-31

    Microbial flocculant for nature soda has been studied. Lactobacillus TRJ21, which was able to produce an excellent biopolymer flocculant for nature soda, was obtained in our lab. The microbial flocculant was mainly produced when the bacteria laid in stationary growth phase. Fructose or glucose, as carbon sources, were more favorable for the bacterial growth and flocculant production. The bacteria was able to use ammonium sulfate or Urea as nitrogen to produce flocculant, but was not able to use peptone effectively. High C/N ratio was more favorable to Lactobacillus TRJ21 growth and flocculant production than low C/N ratio. The biopolymer flocculant was mainly composed of polysaccharide and protein with a molecular weight 1.38x106 by gel permeation chromatography. It was able to be easily purified from the culture medium by acetone. Protein in the flocculant was tested for the flocculating activity ingredient by heating the flocculant.

  18. Power electronics for renewable and distributed energy systems a sourcebook of topologies, control and integration

    CERN Document Server

    Chakraborty, Sudipta; Kramer, William E

    2013-01-01

    While most books approach power electronics and renewable energy as two separate subjects, Power Electronics for Renewable and Distributed Energy Systems takes an integrative approach; discussing power electronic converters topologies, controls and integration that are specific to the renewable and distributed energy system applications. An overview of power electronic technologies is followed by the introduction of various renewable and distributed energy resources that includes photovoltaics, wind, small hydroelectric, fuel cells, microturbines and variable speed generation. Energy storage s

  19. Power Electronics and Control of Renewable Energy Systems

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Sera, Dezso

    2007-01-01

    sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss some of the most emerging renewable energy sources......The global electrical energy consumption is still rising and there is a demand to double the power capacity within 20 years. The production, distribution and use of energy should be as technological efficient as possible and incentives to save energy at the end-user should also be set up....... Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources may be very high in the near future. Two major technologies will play important roles to solve the future problems. One is to change the electrical power production...

  20. A Flexible Power Electronics Configuration for Coupling Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    Mattia Filippini

    2015-05-01

    Full Text Available A combination of series, parallel and multilevel power electronics has been investigated as a potential interface for two different types of renewable energy sources and in order to reach higher power levels. Renewable energy sources are typically dispersed in a territory, and sources, like wind and solar, allow small to medium-scale generation of electricity. The configuration investigated in this article aims at adapting the coupling solution to the specific generation characteristics of the renewable energy source to make it fit the electrical network. The configuration consists of a combination of three-phase multilevel converters and single-phase inverters, which are designed to provide flexibility, high power quality and high efficiency. A detailed analysis and simulation is performed to identify the properties in conjunction with the electrical grid requirements and the potential challenges encountered during operation. An optimized operation example of wind generation combined with solar PV generation is presented to exemplify the flexibility and benefits of the proposed configuration.

  1. Enrichment of coal pulps by selective flocculation

    Energy Technology Data Exchange (ETDEWEB)

    Blaschke, Z

    1977-01-01

    The results are presented of selective flocculation of coal pulps using different reagents. In some tests the coal particles were flocculated, and in others the coal remained in suspension and the dirt was flocculated. Selective flocculation makes it possible to obtain coal concentrates with a very low ash content from slurries with a high ash content. (In Polish)

  2. Enrichment of coal pulps by selective flocculation

    Energy Technology Data Exchange (ETDEWEB)

    Blaschke, Z

    1977-01-01

    The results are presented of selective flocculation of coal pulps using different reagents. In some tests the coal particles were flocculated, and in others the coal remained in suspension and the dirt was flocculated. Selective flocculation makes it possible to obtain coal concentrates with a very low ash content from slurries with a high ash content.

  3. Renewal of beam position monitor electronics of the SPring-8 storage ring

    International Nuclear Information System (INIS)

    Sasaki, Shigeki; Fujita, Takahiro

    2007-01-01

    Signal processing electronics for the beam position monitors (BPM) of the SPring-8 Storage Ring were renewed during the summer shutdown period of 2006. The configurations of the electronics of before and after the alteration are described. The evaluation of the performance of the electronics is shown with the data taken by using the actual beams. (author)

  4. [Preparation and structural analysis of diatomite-supported SPFS flocculant].

    Science.gov (United States)

    Zheng, Huai-li; Fang, Hui-li; Jiang, Shao-jie; Yang, Chun; Ma, Jiang-ya; Zhang, Zhao-qing

    2011-07-01

    In the presetn study, polymerized ferric sulphate (PFS) flocculant was prepared and tested. In the preparation of PFS flocculant, industrial by-product ferrous sulfate heptahydrate (FeSO4.7H2O) was reused as the main material. By composition with diatomite and drying up at certain temperature in vacuum drying oven, solid PFS flocculant was produced. Structural characteristics of the new flocculant product were examined through infrared spectroscopy and scanning electron microscopy (SEM), which showed that by compositing with diatomite, new group bridging emerged in the structure of PFS, which made the bond of groups stronger. In addition, part of the metalic contents in diatomite was polymerized with PFS, the product of which was polymerized ferric complex. Furthermore, the absorbing and agglomerating capacity of the diatomite carrier was significant. Considering the factors listed above, the new solid polymerized ferric sulphate (SPFS) flocculant was characterized with a larger molecule structure and enhanced absorbing, bridging and rolling sweep capacities. Through orthogonal experiment, optimum conditions of synthesis were as follows: the ratio of FeSO4.7H2O/diatomite in weight was 43/1, the reaction time is 1 h and the reaction temperature is 55 degrees C. By wastewater treatment experiment, it was found that the synthetic products showed good flocculation performance in the treatment of domestic sewage, the removal of COD was 80.00% and the removal of turbidity was 99.98%.

  5. Extraction of flocculants from a strain of Bacillus thuringiensis and analysis of their properties

    Directory of Open Access Journals (Sweden)

    Jingrong Wu

    2017-07-01

    Full Text Available In a preliminary screening study, our laboratory isolated from the biofloc in aquaculture waters a strain of Bacillus thuringiensis, which produced highly efficient bio-flocculants. In the present study, we extracted the crude flocculants from this strain and analyzed their properties. Distribution analysis indicated that the flocculants were mainly distributed in the supernatant of the fermentation liquid. The flocculants were extracted using an ethanol extraction method, and the chemical compositions and morphology of the crude flocculants were analyzed using the Molish reaction, Fehling reaction, ninhydrin reaction, biuret reaction, phenol-sulfuric acid assay, Coomassie brilliant blue staining, ultraviolet scanning, infrared scanning and scanning electron microscopy. The carbohydrate composition of the polysaccharides in the flocculants was analyzed with thin layer chromatography. The results indicated that flocculants were solid substances with an ivory white color and their texture was loose and soft. Visualization under scanning electron microscopy revealed that their ultra-morphology consisted of small, long and fiber-like shapes. Chemical and physical analyses indicated that polysaccharides accounted for 34.5% of the components in the crude flocculants. The monosaccharides present in crude flocculants included mainly glucose, galactose and mannitose.

  6. Power Electronics – Key Technology for Renewable Energy Systems – Status and Future

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Yang, Yongheng; Ma, Ke

    2013-01-01

    play an essential role. Using highly efficient power electronics in power generation, power transmission/ distribution and end-user application, together with advanced control solutions, can pave the way for renewable energies. In view of this, some of the most emerging renewable energies, e.g. wind......The energy paradigms in many countries (e.g. Germany and Denmark) have experienced a significant change from fossil-based resources to clean renewables in the past few decades. The scenario of highly penetrated renewables is going to be further enhanced. This requires that the production......, distribution and use of the energy should be as technological efficient as possible and incentives to save energy at the end-user should also be streng-thened. In order to realize the transition smoothly and effectively, energy conversion systems, currently based on power electronics technology, will again...

  7. Power electronic converter systems for direct drive renewable energy applications

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    This chapter presents power electronic conversion systems for wind and marine energy generation applications, in particular, direct drive generator energy conversion systems. Various topologies are presented and system design optimization and reliability are briefly discussed....

  8. Flocculation Dynamics of cohesive sediment

    NARCIS (Netherlands)

    Maggi, F.

    2005-01-01

    Cohesive sediment suspended in natural waters is subject not only to transport and deposition processes but also to reactions of flocculation, \\textit{i.e.} aggregation of fine particles, and breakup of aggregates. Although aggregation and breakup occur at small and very small length scales compared

  9. A novel poly(acrylic acid-co-acrylamide)/diatomite composite flocculant with outstanding flocculation performance.

    Science.gov (United States)

    Xu, Kun; Liu, Yao; Wang, Yang; Tan, Ying; Liang, Xuecheng; Lu, Cuige; Wang, Haiwei; Liu, Xiusheng; Wang, Pixin

    2015-01-01

    Series of anionic flocculants with outstanding flocculation performance, poly(acrylic acid-co-acrylamide)/diatomite composite flocculants (PAAD) were successfully prepared through aqueous solution copolymerization and applied to flocculate from oil-field fracturing waste-water. The structure of PAAD was characterized by Fourier transform infra-red spectroscopy, (13)C nuclear magnetic resonance and X-ray diffraction tests, and its properties were systematically evaluated by viscometer, thermogravimetry analysis and flocculation measurements. Furthermore, the influences of various reaction parameters on the apparent viscosity of flocculant solution were studied, and the optimum synthesis condition was determined. The novel composite flocculants exhibited outstanding flocculation properties. Specifically, the dosage of composite flocculants that could make the transmittance of treated wastewater exceed 90% was only approximately 12-35 ppm, which was far lower than that of conventional flocculants. Meanwhile, the settling time was lower than 5 s, which was similar to that of conventional flocculants. This was because PAAD flocculants had a higher absorption capacity, and larger chain extending space than conventional linear flocculants, which could refrain from the entanglement of linear polymer chains and significantly improve flocculation capacity.

  10. Design for reliability in power electronics in renewable energy systems – status and future

    DEFF Research Database (Denmark)

    Wang, Huai; Blaabjerg, Frede; Ma, Ke

    2013-01-01

    Advances in power electronics enable efficient and flexible interconnection of renewable sources, loads and electric grids. While targets concerning efficiency of power converters are within reach, recent research endeavors to predict and improve their reliability to ensure high availability, low...... maintenance costs, and herefore, low Levelized-Cost-of-Energy (LCOE) of renewable energy systems. This paper presents the prior-art Design for Reliability (DFR) process for power converters and addresses the paradigm shift to Physics-of-Failure (PoF) approach and mission profile based analysis. Moreover...

  11. Power Electronics – The Key Technology for Renewable Energy System Integration

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Yang, Yongheng; Ma, Ke

    2015-01-01

    The energy paradigms in many countries (e.g. Germany and Denmark) have experienced a significant change from fossil-based resources to clean renewables (e.g. wind turbines and photovoltaics) in the past few decades. The scenario of highly penetrated renewables is going to be further enhanced...... – Denmark expects to be 100 % fossil-free by 2050. Consequently, it is required that the production, distribution and use of the energy should be as technologically efficient as possible and incentives to save energy at the end-user should also be strengthened. In order to realize the transition smoothly...... and effectively, energy conversion systems, currently based on power electronics technology, will again play an essential role in this energy paradigm shift. Using highly efficient power electronics in power generation, power transmission/distribution and end-user application, together with advanced control...

  12. Flocculation and consolidation of cohesive sediments under the influence of coagulant and flocculant

    NARCIS (Netherlands)

    Ibanez Sanz, M.E.

    2018-01-01

    This thesis focuses on the coagulation and flocculation processes of cohesive sediments under the influence of polyelectrolyte. For this study clay particles and anionic and cationic flocculants were used. The influence of the shear stresses on the flocculation demonstrated that the shear stress is

  13. Harvesting of microalgae by bio-flocculation

    NARCIS (Netherlands)

    Salim, S.; Bosma, R.; Vermuë, M.H.; Wijffels, R.H.

    2011-01-01

    The high-energy input for harvesting biomass makes current commercial microalgal biodiesel production economically unfeasible. A novel harvesting method is presented as a cost and energy efficient alternative: the bio-flocculation by using one flocculating microalga to concentrate the

  14. Yeast flocculation: New story in fuel ethanol production.

    Science.gov (United States)

    Zhao, X Q; Bai, F W

    2009-01-01

    Yeast flocculation has been used in the brewing industry to facilitate biomass recovery for a long time, and thus its mechanism of yeast flocculation has been intensively studied. However, the application of flocculating yeast in ethanol production garnered attention mainly in the 1980s and 1990s. In this article, updated research progress in the molecular mechanism of yeast flocculation and the impact of environmental conditions on yeast flocculation are reviewed. Construction of flocculating yeast strains by genetic approach and utilization of yeast flocculation for ethanol production from various feedstocks were presented. The concept of self-immobilized yeast cells through their flocculation is revisited through a case study of continuous ethanol fermentation with the flocculating yeast SPSC01, and their technical and economic advantages are highlighted by comparing with yeast cells immobilized with supporting materials and regular free yeast cells as well. Taking the flocculating yeast SPSC01 as an example, the ethanol tolerance of the flocculating yeast was also discussed.

  15. Flocculent Settling of Food Wastes.

    Science.gov (United States)

    Chowdhury, Mohammad Monirul Islam; Kim, Mingu; Haroun, Basem Mikhaeil; Nakhla, George; Keleman, Michael

    2016-07-01

    This study evaluated the flocculent settling in water and municipal wastewater (MWW) in a 10.6 ft deep column. A total of eight runs at three different testing conditions involving MWW alone, food waste (FW) alone, and FW in MWW (FW+MWW) were conducted. Total suspended solid (TSS), total BOD (TBOD), total COD (TCOD), total nitrogen (TN), and total phosphorous (TP) removal efficiencies after 3 hours of settling were 62%, 46%, 49%, 46% and 62% for FW, and 50%, 43%, 39%, 37% and 24% for MWW. Removal efficiencies of particulate COD (PCOD) and particulate BOD (PBOD) at the lowest surface overflow rate (SOR) of 1.1 m3/m2/hr corresponding to the longest settling time of 3 hours were 59% and 64% for FW, and 65% and 70% for FW with MWW samples. On the other hand, no significant variation between FW and FW with MWW was observed for PN removal after 3 hours of settling.

  16. Flocculation of retention pond water

    International Nuclear Information System (INIS)

    Hart, B.T.; McGregor, R.J.

    1982-05-01

    An integral part of the water management strategy proposed by Ranger Uranium Mining Pty. Ltd. involves the collection of runoff water in a series of retention ponds. This water will subsequently be used in the uranium milling plant or released to Magela Creek. Runoff water collected during the wet season caused a section of Magela Creek to become turbid when it was released. The eroded material causing the turbidity was very highly dispersed and showed little tendency to sediment out in the retention ponds. Results of a preliminary study to determine the feasibility of clarifying retention pond water by flocculation with alum are presented. A concentration of 30 Mg/L alum reduced turbidity from an initial 340 NTU to less than 30 NTU in four hours

  17. Power Electronics and Renewable Energy Systems – a perfect match for a sustainable society

    Directory of Open Access Journals (Sweden)

    Frede Blaabjerg

    2015-08-01

    Full Text Available The energy consumption is steadily increasing very rapid due to more people on the earth, betterliving conditions as well as we are trying to live in areas where the energy demand is high. Theeconomy growth in the last century has not been possible without low prize of energy which has beenachieved by fossil fuels. Looking into the future – the fossil fuel resources have a time limit – whichcan appear faster than expected – both because of the limited resources but also because the marketcan suddenly increase the prize. Therefore there is a demand to come up with sustainable energysolutions for energy production like wind turbines, hydro power as well as photovoltaics. At the sametime it is evident that by the use of new technology it is possible to make energy saving. In bothsituations power electronics are making this possible – we are using power electronics to interfacerenewable sources to maximize the energy yield from wind turbines and photovoltaics as well assmoothly integrate it to the grid. Also in many applications we use power electronics to interface a loadwith the grid and control the behavior of the electrical equipment according to the demand. In manycases power electronics is able to ensure a large amount of energy saving like in pumps, compressorsas well as in ventilation systems. Also the transportation gain a lot of using electricity instead of fossilfuel – clearly made possible due to the power electronics. Denmark is one of the societies which have been the frontier of implementing the renewabletechnology and has today covered more than 50 % of the electrical energy consumption by means ofrenewable and has as ambition to be fully independent on fossil fuels in 2050. Already in 2035 100 %of the electricity will be covered by renewables. At the same time the energy consumption has notreally increased for 20 years despite the GDP has grown by more than 60 % - much is enabled byenergy efficient technologies based on

  18. Better flocculants by radiation induced polymerization

    International Nuclear Information System (INIS)

    Laizier, J.; Gaussens, G.

    1978-01-01

    The use of radiation induced polymerization should theoritically allow to prepare better flocculants. The testings of several products prepared by such a process shows that better properties are indeed obtained: better efficiencies, lower amounts needed, better overall properties [fr

  19. Methylation of hemoglobin to enhance flocculant performance

    Science.gov (United States)

    An inexpensive bioflocculant, bovine hemoglobin (Hb), has been covalently modified through methylation of the side chain carboxyl groups of aspartic and glutamic acid residues to improve its flocculation activity. Potentiometric titration of the recovered products showed approximately 28% degree of ...

  20. Gravitational sedimentation of flocculated waste activated sludge.

    Science.gov (United States)

    Chu, C P; Lee, D J; Tay, J H

    2003-01-01

    The sedimentation characteristics of flocculated wastewater sludge have not been satisfactorily explored using the non-destructive techniques, partially owing to the rather low solid content (ca. 1-2%) commonly noted in the biological sediments. This paper investigated, for the first time, the spatial-temporal gravitational settling characteristics of original and polyelectrolyte flocculated waste activated sludge using Computerized Axial Tomography Scanner. The waste activated sludge possessed a distinct settling characteristic from the kaolin slurries. The waste activated sludges settled more slowly and reached a lower solid fraction in the final sediment than the latter. Flocculation markedly enhanced the settleability of both sludges. Although the maximum achievable solid contents for the kaolin slurries were reduced, flocculation had little effects on the activated sludge. The purely plastic rheological model by Buscall and White (J Chem Soc Faraday Trans 1(83) (1987) 873) interpreted the consolidating sediment data, while the purely elastic model by Tiller and Leu (J. Chin. Inst. Chem. Eng. 11 (1980) 61) described the final equilibrated sediment. Flocculation produced lower yield stress during transient settling, thereby resulting in the more easily consolidated sludge than the original sample. Meanwhile, the flocculated activated sludge was stiffer in the final sediment than in the original sample. The data reported herein are valuable to the theories development for clarifier design and operation.

  1. Current Harmonics Compensation in Microgrids Exploiting the Power Electronics Interfaces of Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    Ioannis Bouloumpasis

    2015-03-01

    Full Text Available This work presents a method of current harmonic reduction in a distorted distribution system. In order to evaluate the proposed method a grid with high-order current harmonics is assumed. The reduction of current distortion is feasible due to the pulse modulation of an active filter, which consists of a buck-boost converter connected back-to-back to a polarity swapping inverter. For a practical application, this system would be the power electronic interface of a Renewable Energy Source (RES and therefore it changes a source of harmonics to a damping harmonics system. Using the proposed method, the current Total Harmonic Distortion (THD of the grid is reduced below the acceptable limits and thus the general power quality of the system is improved. Simulations in the MATLAB/SIMULINK platform and experiments have been performed in order to verify the effectiveness of the proposed method.

  2. Characterization of the flocculating agent from the spontaneously flocculating microalga Chlorella vulgaris JSC-7.

    Science.gov (United States)

    Alam, Md Asraful; Wan, Chun; Guo, Suo-Lian; Zhao, Xin-Qing; Huang, Zih-You; Yang, Yu-Liang; Chang, Jo-Shu; Bai, Feng-Wu

    2014-07-01

    High cost of biomass recovery is one of the bottlenecks for developing cost-effective processes with microalgae, particularly for the production of biofuels and bio-based chemicals through biorefinery, and microalgal biomass recovery through cell flocculation is a promising strategy. Some microalgae are naturally flocculated whose cells can be harvested by simple sedimentation. However, studies on the flocculating agents synthesized by microalgae cells are still very limited. In this work, the cell flocculation of a spontaneously flocculating microalga Chlorella vulgaris JSC-7 was studied, and the flocculating agent was identified to be cell wall polysaccharides whose crude extract supplemented at low dosage of 0.5 mg/L initiated the more than 80% flocculating rate of freely suspended microalgae C. vulgaris CNW11 and Scenedesmus obliquus FSP. Fourier transform infrared (FTIR) analysis revealed a characteristic absorption band at 1238 cm(-1), which might arise from PO asymmetric stretching vibration of [Formula: see text] phosphodiester. The unique cell wall-associated polysaccharide with molecular weight of 9.86×10(3) g/mol, and the monomers consist of glucose, mannose and galactose with a molecular ratio of 5:5:2. This is the first time to our knowledge that the flocculating agent from C. vulgaris has been characterized, which could provide basis for understanding the cell flocculation of microalgae and breeding of novel flocculating microalgae for cost-effective biomass harvest. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Evaluation of flocculating performance of a thermostable bioflocculant produced by marine Bacillus sp.

    Science.gov (United States)

    Okaiyeto, Kunle; Nwodo, Uchechukwu U; Mabinya, Leonard V; Okoli, Arinze S; Okoh, Anthony I

    2016-01-01

    This study assessed the bioflocculant (named MBF-W7) production potential of a bacterial isolate obtained from Algoa Bay, Eastern Cape Province of South Africa. The 16S ribosomal deoxyribonucleic acids gene sequence analysis showed 98% sequence similarity to Bacillus licheniformis strain W7. Optimum culture conditions for MBF-W7 production include 5% (v/v) inoculum size, maltose and NH4NO3 as carbon and nitrogen sources of choice, medium pH of 6 as the initial pH of the growth medium. Under these optimal conditions, maximum flocculating activity of 94.9% was attained after 72 h of cultivation. Chemical composition analyses showed that the purified MBF-W7 was a glycoprotein which was predominantly composed of polysaccharides 73.7% (w/w) and protein 6.2% (w/w). Fourier transform infrared spectroscopy revealed the presence of hydroxyl, carboxyl and amino groups as the main functional groups identified in the bioflocculant molecules. Thermogravimetric analyses showed the thermal decomposition profile of MBF-W7. Scanning electron microscopy imaging revealed that bridging played an important role in flocculation. MBF-W7 exhibited excellent flocculating activity for kaolin clay suspension at 0.2 mg/ml over a wide pH range of 3-11; with the maximal flocculation rate of 85.8% observed at pH 3 in the presence of Mn(2+). It maintained and retained high flocculating activity of over 70% after heating at 100°C for 60 min. MBF-W7 showed good turbidity removal potential (86.9%) and chemical oxygen demand reduction efficiency (75.3%) in Tyume River. The high flocculating rate of MBF-W7 makes it an attractive candidate to replace chemical flocculants utilized in water treatment.

  4. Escherichia coli O157:H7 Acid Sensitivity Correlates with Flocculation Phenotype during Nutrient Limitation

    Directory of Open Access Journals (Sweden)

    Kathryn L. Kay

    2017-07-01

    Full Text Available Shiga toxin producing Escherichia coli (STEC strains vary in acid resistance; however, little is known about the underlying mechanisms that result in strain specific differences. Among 25 STEC O157:H7 strains tested, 7 strains flocculated when grown statically for 18 h in minimal salts medium at 37°C, while 18 strains did not. Interestingly, the flocculation phenotype (cells came out of suspension was found to correlate with degree of acid sensitivity in an assay with 400 mM acetic acid solution at pH 3.3 targeting acidified foods. Strains exhibiting flocculation were more acid sensitive and were designated FAS, for flocculation acid sensitive, while the acid resistant strain designated PAR for planktonic acid resistant. Flocculation was not observed for any strains during growth in complex medium (Luria Bertani broth. STEC strains B201 and B241 were chosen as representative FAS (2.4 log reduction and PAR (0.15 log reduction strains, respectively, due to differences in acid resistance and flocculation phenotype. Results from electron microscopy showed evidence of fimbriae production in B201, whereas fimbriae were not observed in B241.Curli fimbriae production was identified through plating on Congo red differential medium, and all FAS strains showed curli fimbriae production. Surprisingly, 5 PAR strains also had evidence of curli production. Transcriptomic and targeted gene expression data for B201 and B241indicated that csg and hde (curli and acid induced chaperone genes, respectively expression positively correlated with the phenotypic differences observed for these strains. These data suggest that FAS strains grown in minimal medium express curli, resulting in a flocculation phenotype. This may be regulated by GcvB, which positively regulates curli fimbriae production and represses acid chaperone proteins. RpoS and other regulatory mechanisms may impact curli fimbriae production, as well. These findings may help elucidate mechanisms

  5. Revisiting Coiled Flocculator Performance for Particle Aggregation.

    Science.gov (United States)

    2017-09-08

    This work summarizes recent studies evaluating the torsion and curvature parameters in the flocculation efficiency using a hydraulic plug-flow flocculator named as Flocs Generator Reactor (FGR). Colloidal Fe(OH)3 and coal particles were used as suspension models and a cationic polyacrylamide was used for the flocculation. The effectiveness of the aggregation process (in the distinct curvature and torsion parameters and hydrodynamic conditions) was evaluated by the settling rate of the Fe(OH)3 flocs and flocs size by photographic analysis. Due to curvature, a secondary flow is induced and the profiles of the flow quantities differ from those for a straight pipe. Results showed that the difference in the flocculator design influences the Fe(OH)3 flocs size and settling rates, reaching values about 13 and 4 mh-1, for the coiled and straight pipes respectively. Coal flocs generation also showed to be dependent on the flocculator design and shear rate. Results showed that turbulent kinetic energy increases due to curvature when the torsion parameter is kept constant (pitch close to zero) enhancing the flocs formation.

  6. Flocculation of chromite ore fines suspension using polysaccharide ...

    Indian Academy of Sciences (India)

    Unknown

    liquid separation. Keywords. Flocculation; graft copolymer; mineral industry effluent; chromite ore fines; ... work well as flocculating agent on coal washery effluent, copper and iron ore fines etc (Karmakar et al 1998, 1999;. Tripathy et al 2001).

  7. Polymeric flocculant based on cassava starch grafted polydiallyldimethylammonium chloride: Flocculation behavior and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Razali, M.A.A.; Ariffin, A., E-mail: srazlan@usm.my

    2015-10-01

    Graphical abstract: - Highlights: • Flocculation performance of cassava grafted polyDADMAC was studied. • Turbidity and TSS removal increased with increasing grafting percentage. • The grafted polymer showed good removal in acidic and neutral region. • Zeta potential results pointed to the charge neutralization mechanism. • Flocs increased with increasing grafting percentage and molecular weight. - Abstract: In this work, flocculation properties of cassava starch grafted polydiallyldimethylammonium chloride (polyDADMAC) with different grafting percentages were investigated. Flocculation performance was evaluated in simulated kaolin suspension. The grafting percentages used were 1.76 %, 14.84 %, and 21.98 %. The effectiveness of the flocculation was measured based on the reduction of the turbidity and total suspended solids (TSSs), zeta potential measurements, particle size, and atomic force microscopy imaging. Grafted polymers improved the removal rate of turbidity and TSS compared with gelatinized starch, and the removal rate increased with increasing grafting percentage and dosage.

  8. Polymeric flocculant based on cassava starch grafted polydiallyldimethylammonium chloride: Flocculation behavior and mechanism

    International Nuclear Information System (INIS)

    Razali, M.A.A.; Ariffin, A.

    2015-01-01

    Graphical abstract: - Highlights: • Flocculation performance of cassava grafted polyDADMAC was studied. • Turbidity and TSS removal increased with increasing grafting percentage. • The grafted polymer showed good removal in acidic and neutral region. • Zeta potential results pointed to the charge neutralization mechanism. • Flocs increased with increasing grafting percentage and molecular weight. - Abstract: In this work, flocculation properties of cassava starch grafted polydiallyldimethylammonium chloride (polyDADMAC) with different grafting percentages were investigated. Flocculation performance was evaluated in simulated kaolin suspension. The grafting percentages used were 1.76 %, 14.84 %, and 21.98 %. The effectiveness of the flocculation was measured based on the reduction of the turbidity and total suspended solids (TSSs), zeta potential measurements, particle size, and atomic force microscopy imaging. Grafted polymers improved the removal rate of turbidity and TSS compared with gelatinized starch, and the removal rate increased with increasing grafting percentage and dosage

  9. Red mud flocculation process in alumina production

    Science.gov (United States)

    Fedorova, E. R.; Firsov, A. Yu

    2018-05-01

    The process of thickening and washing red mud is a gooseneck of alumina production. The existing automated systems of the thickening process control involve stabilizing the parameters of the primary technological circuits of the thickener. The actual direction of scientific research is the creation and improvement of models and systems of the thickening process control by model. But the known models do not fully consider the presence of perturbing effects, in particular the particle size distribution in the feed process, distribution of floccules by size after the aggregation process in the feed barrel. The article is devoted to the basic concepts and terms used in writing the population balance algorithm. The population balance model is implemented in the MatLab environment. The result of the simulation is the particle size distribution after the flocculation process. This model allows one to foreseen the distribution range of floccules after the process of aggregation of red mud in the feed barrel. The mud of Jamaican bauxite was acting as an industrial sample of red mud; Cytec Industries of HX-3000 series with a concentration of 0.5% was acting as a flocculant. When simulating, model constants obtained in a tubular tank in the laboratories of CSIRO (Australia) were used.

  10. Electrokinetics and flocculation studies of coal

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, N. [Punjab Engineering College, Chandigarh (India). Dept. of Metallurgical Engineering

    2008-07-01

    Coal from India contains 25-35 per cent ash content. This leads to high slag volume, lower calorific value and inferior coke. In order to remove ash content, coal is washed, however, it retains some water that makes it difficult to process. Mechanical dewatering is performed in which a large portion of solids is removed while the remainder remains in centrifuge. There is therefore a need to recover solids and water. This paper discussed the use of flocculation and electrokinetic studies such as the determination of the point of zero charge. The experimental studies considered factors such as turbidity, faster settling, and compactness. Flocculation is brought about by the action of high molecular weight materials such as polyelectrolytes, where the material physically forms a bridge between two or more particles, uniting the sold particles into a random, three-dimensional structure, which is loose and porous. This paper also described the materials and methods of the electrokinetic studies on coal samples. Materials that were described included nephelometer, zeta meter, and a flocculator. It was concluded that in selecting the best flocculant, the preference order should be turbidity; settling rate; dosage; and moisture content. 3 refs., 2 tabs., 8 figs.

  11. Coagulation-flocculation studies of wastewaters

    NARCIS (Netherlands)

    Leentvaar, J.

    1982-01-01

    Although coagulation-flocculation processes have been practiced world-wide for almost a century in water treatment, several problems both in the theoretical and in the applied field have not been resolved yet. Especially interpretation of practical results with respect to governing

  12. Contribution To The Study Of Flocculation Of Digestate

    Directory of Open Access Journals (Sweden)

    Heviánková Silvie

    2015-09-01

    Full Text Available The paper deals with the intensification of separating the solid phase of digestate using flocculants only. The separated solid phase should subsequently be used in agriculture for fertilising. Flocculants (polyacrylamides are difficult to biodegrade. In this respect, they should not deteriorate the properties of the solid phase and the flocculant dose must be as low as possible. The research aimed to identify the optimal cationic flocculant and its application procedure which would enable a dosage that would be both economically and ecologically acceptable. We tested 21 cationic flocculants of different charge density and molecular weight and 1 mixture of two selected flocculants (Sokoflok 53 and Sokoflok 54 with the aim to discover the lowest possible dose of flocculating agent to achieve the effective aggregation of digestate particles. The lowest flocculant doses were obtained using the mixture of flocculants labelled Sokoflok 53 and Sokoflok 54 in 4:1 proportion, both of a low charge density and medium molecular weight, namely 14.54 g/kg of total solids for a digestate from the biogas plant Stonava and namely 11.80 g/kg of total solids for a digestate from the biogas plant Vrahovice. The findings also reveal that flocculation is most effective during two-stage flocculant dosing at different mixing time and intensity.

  13. Enhanced Harvesting of Chlorella vulgaris Using Combined Flocculants.

    Science.gov (United States)

    Ma, Xiaochen; Zheng, Hongli; Zhou, Wenguang; Liu, Yuhuan; Chen, Paul; Ruan, Roger

    2016-10-01

    In this study, a novel flocculation strategy for harvesting Chlorella vulgaris with combined flocculants, poly (γ-glutamic acid) (γ-PGA) and calcium oxide (CaO), has been developed. The effect of flocculant dosage, the order of flocculant addition, mixing speed, and growth stage on the harvesting efficiency was evaluated. Results showed that the flocculation using combined flocculants significantly decreases the flocculant dosage and settling time compared with control. It was also found that CaO and γ-PGA influenced microalgal flocculation by changing the zeta potential of cells and pH of microalgal suspension. The most suitable order of flocculant addition was CaO first and then γ-PGA. The optimal mixing speed was 200 rpm for 0.5 min, followed by 50 rpm for another 4.5 min for CaO and γ-PGA with the highest flocculation efficiency of 95 % and a concentration factor of 35.5. The biomass concentration and lipid yield of the culture reusing the flocculated medium were similar to those when a fresh medium was used. Overall, the proposed method requires low energy input, alleviates biomass and water contamination, and reduces utilization of water resources and is feasible for harvesting C. vulgaris for biofuel and other bio-based chemical production.

  14. UV-initiated template copolymerization of AM and MAPTAC: Microblock structure, copolymerization mechanism, and flocculation performance.

    Science.gov (United States)

    Li, Xiang; Zheng, Huaili; Gao, Baoyu; Sun, Yongjun; Liu, Bingzhi; Zhao, Chuanliang

    2017-01-01

    Flocculation as the core technology of sludge pretreatment can improve the dewatering performance of sludge that enables to reduce the cost of sludge transportation and the subsequent disposal costs. Therefore, synthesis of high-efficiency and economic flocculant is remarkably desired in this field. This study presents a cationic polyacrylamide (CPAM) flocculant with microblock structure synthesized through ultraviolet (UV)-initiated template copolymerization by using acrylamide (AM) and methacrylamido propyl trimethyl ammonium chloride (MAPTAC) as monomers, sodium polyacrylate (PAAS) as template, and 2,2'-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (VA-044) as photoinitiator. The microblock structure of the CPAM was observed through nuclear magnetic resonance ( 1 H NMR and 13 C NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) analyses. Furthermore, thermogravimetric/differential scanning calorimetry (TG/DSC) analysis was used to evaluate its thermal decomposition property. The copolymerization mechanism was investigated through the determination of the binding constant M K and study on polymerization kinetics. Results showed that the copolymerization was conducted in accordance with the I (ZIP) template polymerization mechanism, and revealed the coexistence of bimolecular termination free-radical reaction and mono-radical termination in the polymerization process. Results of sludge dewatering tests indicated the superior flocculation performance of microblock flocculant than random distributed CPAM. The residual turbidity, filter cake moisture content, and specific resistance to filtration reached 9.37 NTU, 68.01%, and 6.24 (10 12  m kg -1 ), respectively, at 40 mg L -1 of template poly(AM-MAPTAC) and pH 6.0. Furthermore, all flocculant except commercial CPAM showed a wide scope of pH application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Engineering and Design: Precipitation/Coagulation/Flocculation

    Science.gov (United States)

    2001-11-15

    Flocculation 7-3 7-3 Jar Test Analysis 10-1 10-3 Alternating Flow Diversion Equalization System 11-1 11-1 Intermittent Flow Diversion System...EM 1110-1-4012 15 NOV 01 (2) Polyaluminum chloride (PAC), another aluminum derivative, is a partially hydrolyzed aluminum chloride solution...derived from natural products include starch, starch derivatives, proteins, and tannins (EPA, 1987). Of these, starch is the most widely used. The

  16. One-step green synthesis of non-hazardous dicarboxyl cellulose flocculant and its flocculation activity evaluation

    International Nuclear Information System (INIS)

    Zhu, Hangcheng; Zhang, Yong; Yang, Xiaogang; Liu, Hongyi; Shao, Lan; Zhang, Xiumei; Yao, Juming

    2015-01-01

    The waste management of used flocculants is a thorny issue in the field of wastewater treatment. To natural cellulose based flocculants, utilization of hazardous cellulose solvent and simplification of synthetic procedure are the two urgent problems needing to be further improved. In this work, a series of natural dicarboxyl cellulose flocculants (DCCs) were one-step synthesized via Schiff-base route. The cellulose solvent (NaOH/Urea solution) was utilized during the synthesis process. The full-biodegradable flocculants avoid causing secondary pollution to environment. The chemical structure and solution property of the DCC products were characterized by FT-IR, 1 H NMR, 13 C NMR, TGA, FESEM, charge density and ζ-potential. Kaolin suspension and effluent from paper mill were selected to evaluate the flocculation activity of the DCCs. Their flocculation performance was compared with that of commercial cationic polyacrylamide and poly aluminium chloride flocculants. The positive results showed that the NaOH/Urea solvent effectively promoted the dialdehyde cellulose (DAC) conversion to DCC in the one-step synthesis reaction. The DCCs with the carboxylate content more than 1 mmol/g exhibited steady flocculation performance to kaolin suspension in the broad pH range from 4 to 10. Its flocculation capacity to the effluent from paper mill also showed excellent

  17. Synthesis of a Cationic Polyacrylamide under UV Initiation and Its Flocculation in Estrone Removal

    Directory of Open Access Journals (Sweden)

    Jiaoxia Sun

    2018-01-01

    Full Text Available A ternary cationic polyacrylamide (CPAM with the hydrophobic characteristic was prepared through ultraviolet- (UV- initiated polymerization technique for the estrone (E1 environmental estrogen separation and removal. The monomers of acrylamide (AM, acryloyloxyethyl-trimethyl ammonium chloride (DAC, and acryloyloxyethyl dimethylbenzyl ammonium chloride (AODBAC were used to synthesize the ternary copolymer (PADA. Fourier transform infrared spectroscopy (FT-IR, 1H nuclear magnetic resonance spectroscopy (1H NMR, thermogravimetry/differential scanning calorimetry (TG/DSC, and scanning electron microscopy (SEM were employed to characterize the structure, thermal decomposition property, and morphology of the polymers, respectively. FT-IR and 1H NMR results indicated the successful formation of the polymers. Besides, with the introduction of hydrophobic groups (phenyl group, an irregular and porous surface morphology and a favorable thermal stability of the PADA were observed by SEM and TG/DSC analyses, respectively. At the optimal condition (pH = 7, flocculant dosage = 4.0 mg/L and E1 concentration = 0.75 mg/L, an excellent E1 flocculation performance (E1 removal rate: 90.1%, floc size: 18.3 μm, and flocculation kinetics: 22.69×10-4 s−1 was acquired by using the efficient flocculant PADA-3 (cationic degree = 40%, and intrinsic viscosity = 6.30 dL·g−1. The zeta potential and floc size analyses were used to analyze the possible flocculation mechanism for the E1 removal. Results indicated that the charge neutralization, adsorption, and birding effects were dominant in the E1 removal progress.

  18. An overview of power electronic converter technology for renewable energy systems

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    This chapter presents power electronic technology which is an enabling tool for modern wind and marine energy conversion systems. In this chapter, the main power electronic devices are described. Various power electronic converter topologies are represented, and commonly used modulation schemes...

  19. Cake creep during filtration of flocculated manure

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    is filtered. Hence, it is not possible to scale up the experiments, and it is therefore difficult to optimize the flocculation and estimate the needed filter media area. Similar problems have been observed when sewage sludge and synthetic core-shell colloids are filtered, and it has been suggested......, and the mixing procedure affect the result, and lab-scale experiments are often used to study how these pre-treatments influence the filtration process. However, the existing mathematical filtration models are based on filtration of inorganic particles and cannot simulate the filtration data obtained when manure...

  20. Impact of flocculation on flotation tailing's hydro-cycloning properties

    Directory of Open Access Journals (Sweden)

    Knežević Dinko N.

    2014-01-01

    Full Text Available Research results of hydro-cycloning of flocculated and non-flocculated flotation tailing from the lead and zinc open pit mine 'Suplja stijena', Sula - Montenegro have been shown in this paper. Reason for this research was finding conditions in order to separate fraction that is suitable for embankment erection. Flotation tailings has been tested in the very state that it goes out from the flotation process and tailings which is flocculated by anionic flocculant. The object was to determine the impact of flocculation on properties of hydro-cycloning products and disposal process. In hydro-cycloning process greater underflow mass is being separated with non-flocculated tailing. Values of geomechanical parameters are significantly different, especially hydro-cyclone's underflow. All geomechanical parameters of hydro-cyclone's underflow are suitable for erecting embankment which shall be made from non-flocculated tailing. Underflow drainage of non-flocculated tailing is faster while overflow drainage is slower and problematic with both tailings.

  1. Prediction of parametric numbers in filterbed flocculation | Odira ...

    African Journals Online (AJOL)

    ... quality, turbidity breakthrough, etc) are due to insufficient flocculation in the filter bed. Such setbacks are probably due to the limited pore volume in the filter bed that would necessitate the settlement of flocculated water to reduce the sediment load applied to the filter. (Journal of Civil Engineering, JKUAT: 2002 7: 117-132) ...

  2. Nanocellulose size regulates microalgal flocculation and lipid metabolism

    Science.gov (United States)

    Yu, Sun Il; Min, Seul Ki; Shin, Hwa Sung

    2016-01-01

    Harvesting of microalgae is a cost-consuming step for biodiesel production. Cellulose has recently been studied as a biocompatible and inexpensive flocculant for harvesting microalgae via surface modifications such as cation-modifications. In this study, we demonstrated that cellulose nanofibrils (CNF) played a role as a microalgal flocculant via its network geometry without cation modification. Sulfur acid-treated tunicate CNF flocculated microalgae, but cellulose nanocrystals (CNC) did not. In addition, desulfurization did not significantly influence the flocculation efficiency of CNF. This mechanism is likely related to encapsulation of microalgae by nanofibrous structure formation, which is derived from nanofibrils entanglement and intra-hydrogen bonding. Moreover, flocculated microalgae were subject to mechanical stress resulting in changes in metabolism induced by calcium ion influx, leading to upregulated lipid synthesis. CNF do not require surface modifications such as cation modified CNC and flocculation is derived from network geometry related to nanocellulose size; accordingly, CNF is one of the least expensive cellulose-based flocculants ever identified. If this flocculant is applied to the biodiesel process, it could decrease the cost of harvest, which is one of the most expensive steps, while increasing lipid production. PMID:27796311

  3. Induced flocculation of Pachysolen tannophilus using the tower fermentor

    Energy Technology Data Exchange (ETDEWEB)

    Deverell, K.F.; Clark, T.A.

    1985-12-01

    This article reports the induction of flocculation with Pachysolen tannophilus by the use of controlled aeration in a tower fermentor. The observed environmental and physiological conditions for flocculent growth are described. Although most studies with P. tannophilus have used oxylose as substrate, a synthetic glucose medium was chosen for this study as the faster growth rate of the organism on glucose was considered to favor more rapid selection of a flocculent strain. Due to flocculation, the concentration of yeast cells retained in the tower was up to 16 times greater than in the overflow. Ethanol yields approaching theoretical were achieved at low specific oxygen uptake rates, conditions which also favored maximum flocculation. Future work will involve continuous tower fermentation of sugar mixtures representative of the composition of wood hydrolysates.

  4. Power Electronics Thermal Management R&D; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Waye, Scot

    2015-06-10

    Presentation containing an update for the Power Electronics Thermal Management project in the Electric Drive Train task funded by the Vehicle Technology Office of DOE. This presentation outlines the purpose, plan, and results of research thus far for cooling and material selection strategies to manage heat in power electronic assemblies such as inverters, converters, and chargers.

  5. Effect of flocculating agent dosages on the performance of red mud flocculation under shear conditions

    International Nuclear Information System (INIS)

    Gagnon, M.J.; Simard, G.; Leclerc, A.; Peloquin, G.

    2002-01-01

    The performance of different polymers used to flocculate red mud particulate materials in the Bayer process can be evaluated on the basis of their efficiency to achieve adequate settling velocities and turbidity levels. In this study, three commercially available flocculants are evaluated under typical conditions found in the last washer of a Bayer plant. The different shear levels are produced by using a modified Couette flow system. Great differences are noticed in the performance of the polymers when they are compared at different dosages and at different shear rate levels. The data collected also suggests that conventional cylinder settling tests may not be adequate to measure the performance of certain types of polymers. (author)

  6. Flocculation kinetics of kaolinite : role of aqueous phase species

    Energy Technology Data Exchange (ETDEWEB)

    House, P.; Wang, C.; Dhadli, N. [Shell Canada Ltd., Calgary, AB (Canada)

    2010-07-01

    Flocculation kinetics were used to study the rate-based processes that lead to aggregate growth and breakage of kaolinite in oil sands tailings. The role of aqueous phase species on aggregate growth, breakage and flocculant de-activation was studied. Collision efficiency and deactivation parameters were presented. The study showed that collisions can be efficient when the adsorption of the polymer is thermodynamically favorable. Up to 94 percent of adsorption takes place at the kaolinite edge. Studies have shown that hydrogen bonding sites on the kaolinite disappear with increases in pH values. The impact of molecular level interactions on flocculation kinetics were assessed in order to determine collision efficiencies and aggregate breakage rates. A focused beam reflectance model was used to monitor flocculation kinetics in situ. The period over which reflectance was observed was coupled with the laser velocity to determine the chord length of the particle. The kinetics of flocculation were observed for a 10 minute period. The effects of pH, calcium additions, and EDTA chelating agent additions were investigated. The study showed that calcium additions accelerate the rate of flocculant growth dramatically, and provide a much higher collision efficiency. Flocculants formed in the presence of calcium were weaker. The presence of salts promoted polymer adsorption by non-specific Van der Waals forces. tabs., figs.

  7. Imaging c-PAM-induced flocculation of paper fibers.

    Science.gov (United States)

    Hartley, William H; Banerjee, Sujit

    2008-04-01

    The flocculation of paper fibers by cationic polyacrylamides (c-PAM) was studied by imaging the fibers that remain free during flocculation. Studies with fibers of different lengths showed that the degree of flocculation increases with fiber length, with the best flocs being formed with mixtures of short and long fibers. Short fibers did not flocculate by themselves but were captured by flocs formed with longer fibers. The short fibers strengthen the floc and give it shear resistance. Shear had the expected effect of promoting flocculation at low Reynolds number but disrupting it at higher values. For a given polymer the maximum floc size for a mixture of fibers is dictated by the length distribution of the fibers. The polymer dose governs the rate of flocculation. The technique is especially useful in following the tail end of the flocculation process. At this stage a floc is almost fully grown and a small increase in its size would be very difficult to measure by conventional techniques. In contrast, the number of free fibers measured by single fiber imaging decreases rapidly at this point.

  8. Segregation and differential settling in flocculated tailings

    Energy Technology Data Exchange (ETDEWEB)

    Farinato, R.S.; Mahmoudkhani, A.; Fenderson, T.; Watson, P. [Kemira, Atlanta, GA (United States)

    2010-07-01

    Untreated oil sands tailings have a high solids content, have poor dewaterability, and contain no aggregates. This PowerPoint presentation investigated segregation and differential settling in flocculated tailings. Tailings were treated with gypsum and various polymers. Cylinder settling, dynamic rheometry, particle size analysis, and microscopy techniques were used to characterize the composite tailings. The particles sizes of the samples were evaluated in relation to shear rate, bed depth, and treatment. The study showed that the gypsum-treated tailings had small aggregates, size stratification, a high solids content, and poor dewaterability. The polymer N-treated tailings had the lowest solids content, good dewaterability, and weak aggregates. The polymer A-treated tailings had a low solids content, very good dewaterability, and strong aggregates. The addition of a coagulant to the polymer-A treated tailings provided weaker aggregates and a higher solids content. tabs., figs.

  9. Polyacrylamide-based inorganic hybrid flocculants with self-degradable property

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xinfang [Materials and Metallurgical College, Northeastern University, Shenyang 110819 (China); Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China); Tao, Junshi; Li, Mingzhi; Zhu, Bishan; Li, Xuan; Ma, Zhiyu; Zhao, Tingjie; Wang, Bingzhu; Suo, Biao [Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China); Wang, Haiwang, E-mail: whwdbdx@126.com [Materials and Metallurgical College, Northeastern University, Shenyang 110819 (China); State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China); Yang, Jun, E-mail: jyang@ipe.ac.cn [State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Ye, Li, E-mail: yeli@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190 (China); Qi, Xiwei, E-mail: qxw@mail.neuq.edu.cn [Materials and Metallurgical College, Northeastern University, Shenyang 110819 (China); Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China)

    2017-05-01

    Polyacrylamide (PAM)-based inorganic hybrid materials are of great potential as flocculants in soil-liquid separation. Herein, we reported the design of inorganic soil-TiO{sub 2}-PAM hybrid materials using a unique process, which involved coating of titanium dioxide (TiO{sub 2}) nanoparticles on the surface of inorganic soils and subsequent polymerization of acrylamide (AM) on these nanoparticles under visible light. Inorganic soils including kaolin, bentonite, montmorillonite and diatomaceous earth were used to control the volume and to reduce the cost, and the TiO{sub 2} nanoparticles accelerated PAM degradation. The nanoparticles initiated AM polymerization directly under visible light, thus providing a facile strategy for the synthesis of new organic-inorganic hybrid flocculants. The obtained hybrid materials were characterized using Fourier transform infrared spectroscopy and transmission electron microscopy. The degradation of PAM initiated by UV irradiation exceeded 24% in 2 h, depending on its initial concentration. - Highlights: • A new polyacrylamide (PAM)-based inorganic hybrid flocculants with self-degradable property was developed. • TiO{sub 2} nanoparticles show a unique surface-initiated property under the condition of visible light. • We designed a facile strategy for the synthesis of inorganic soil@TiO{sub 2}@PAM hybrid materials.

  10. Production of Flocculants, Adsorbents, and Dispersants from Lignin.

    Science.gov (United States)

    Chen, Jiachuan; Eraghi Kazzaz, Armin; AlipoorMazandarani, Niloofar; Hosseinpour Feizi, Zahra; Fatehi, Pedram

    2018-04-10

    Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.

  11. Production of Flocculants, Adsorbents, and Dispersants from Lignin

    Directory of Open Access Journals (Sweden)

    Jiachuan Chen

    2018-04-01

    Full Text Available Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.

  12. Effective flocculation of fine mineral suspensions using Moringa oleifera seeds

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, T.M. [Bureau of Mines, Reno, NV (United States)

    1995-12-31

    The purpose of this research was to investigate the feasibility of using Moringa oleifera seeds, or the active components of the seeds, in the clarification of waters containing suspended mineral fines. In comparative testing using a hematite suspension, the flocculating activity of Moringa oleifera seeds was better than alum. Twenty milligrams of seed powder was sufficient to clarify the hematite to near zero turbidity, while the same amount of alum had a minimal effect on turbidity. Extracts were prepared from the seeds in an attempt to separate the proteins. A crude protein extract was enriched by lowering the pH to 6.0. Only 0.08 mg/L of the enriched extract was required to flocculate a minusil suspension. Environmentally friendly protein flocculants could theoretically be produced and enhanced with recombinant DNA techniques as an alternative to chemical flocculants currently used in water treatment.

  13. A simple shear limited, single size, time dependent flocculation model

    Science.gov (United States)

    Kuprenas, R.; Tran, D. A.; Strom, K.

    2017-12-01

    This research focuses on the modeling of flocculation of cohesive sediment due to turbulent shear, specifically, investigating the dependency of flocculation on the concentration of cohesive sediment. Flocculation is important in larger sediment transport models as cohesive particles can create aggregates which are orders of magnitude larger than their unflocculated state. As the settling velocity of each particle is determined by the sediment size, density, and shape, accounting for this aggregation is important in determining where the sediment is deposited. This study provides a new formulation for flocculation of cohesive sediment by modifying the Winterwerp (1998) flocculation model (W98) so that it limits floc size to that of the Kolmogorov micro length scale. The W98 model is a simple approach that calculates the average floc size as a function of time. Because of its simplicity, the W98 model is ideal for implementing into larger sediment transport models; however, the model tends to over predict the dependency of the floc size on concentration. It was found that the modification of the coefficients within the original model did not allow for the model to capture the dependency on concentration. Therefore, a new term within the breakup kernel of the W98 formulation was added. The new formulation results is a single size, shear limited, and time dependent flocculation model that is able to effectively capture the dependency of the equilibrium size of flocs on both suspended sediment concentration and the time to equilibrium. The overall behavior of the new model is explored and showed align well with other studies on flocculation. Winterwerp, J. C. (1998). A simple model for turbulence induced flocculation of cohesive sediment. .Journal of Hydraulic Research, 36(3):309-326.

  14. Dielectric Properties of Flocculated Water-in-Oil Emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Skodvin, T.

    1995-12-31

    When an offshore oil field is near completion, water occupies a large fraction of the available pore volume. Thus, in collecting the oil and gas reserves, one has to deal with a high co-production of either formation- or injected water. This doctoral thesis focuses on the effect of water-in-oil emulsions on the dielectric properties, in particular the effect of flocculation. Various dielectric models are applied to obtain methods for qualitative and quantitative characterization of the flocculated state. Permittivity and measurement of dielectric properties are discussed as a basis for the interpretation of the dielectric properties of the emulsions. Various flocculation models are presented. It is concluded that the dielectric properties of water-in-oil emulsions are strongly influenced by continuously ongoing processes in the system. Because of flocculation and sedimentation the traditional dielectric mixture models cannot satisfactorily predict the dielectric behaviour. The experimentally obtained permittivities for the emulsions can be reproduced by including flocculation in the models and treating the floc aggregates as spheroids or subsystems with dielectric properties given by the degree of flocculation. The models discussed have difficulties reproducing the complete frequency behaviour found experimentally. This is probably because the dielectric relaxation may be influenced by processes not included in the models, such as the effects of dipolar or multipolar interactions between the droplets. For further research it is recommended that rheological and dielectric measurements be combined. 227 refs., 61 figs., 16 tabs.

  15. Enveloped virus flocculation and removal in osmolyte solutions.

    Science.gov (United States)

    Gencoglu, Maria F; Heldt, Caryn L

    2015-07-20

    Our ability to reduce infectious disease burden throughout the world has been greatly improved by the creation of vaccines. However, worldwide immunization rates are low. The two most likely reasons are the lack of sufficient distribution in underdeveloped countries and the high cost of vaccine products. The high costs are due to the difficulties of manufacturing individual vaccine products with specialized purification trains. In this study, we propose to use virus flocculation in osmolytes, followed by microfiltration, as an alternative vaccine purification operation. In our previous work, we demonstrated that osmolytes preferentially flocculate a non-enveloped virus, porcine parvovirus (PPV). In this work we show that osmolytes flocculate the enveloped virus, Sindbis virus heat resistant strain (SVHR), and demonstrate a >80% removal with a 0.2 μm microfilter membrane while leaving proteins in solution. The best osmolytes were tested for their ability to flocculate SVHR at different concentrations, pH and ionic strengths. Our best removal was 98% of SVHR in 0.3M mannitol at a pH of 5. We propose that osmolytes are able to flocculate hydrophobic non-enveloped and enveloped virus particles by the reduction of the hydration layer around the particles, which stimulates virus aggregation. Now that we have demonstrated that protecting osmolytes flocculate viruses, this method has the potential to be a future platform purification process for vaccines. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Dielectric Properties of Flocculated Water-in-Oil Emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Skodvin, T

    1996-12-31

    When an offshore oil field is near completion, water occupies a large fraction of the available pore volume. Thus, in collecting the oil and gas reserves, one has to deal with a high co-production of either formation- or injected water. This doctoral thesis focuses on the effect of water-in-oil emulsions on the dielectric properties, in particular the effect of flocculation. Various dielectric models are applied to obtain methods for qualitative and quantitative characterization of the flocculated state. Permittivity and measurement of dielectric properties are discussed as a basis for the interpretation of the dielectric properties of the emulsions. Various flocculation models are presented. It is concluded that the dielectric properties of water-in-oil emulsions are strongly influenced by continuously ongoing processes in the system. Because of flocculation and sedimentation the traditional dielectric mixture models cannot satisfactorily predict the dielectric behaviour. The experimentally obtained permittivities for the emulsions can be reproduced by including flocculation in the models and treating the floc aggregates as spheroids or subsystems with dielectric properties given by the degree of flocculation. The models discussed have difficulties reproducing the complete frequency behaviour found experimentally. This is probably because the dielectric relaxation may be influenced by processes not included in the models, such as the effects of dipolar or multipolar interactions between the droplets. For further research it is recommended that rheological and dielectric measurements be combined. 227 refs., 61 figs., 16 tabs.

  17. Characterization of specialized flocculent yeasts to improve sparkling wine fermentation.

    Science.gov (United States)

    Tofalo, R; Perpetuini, G; Di Gianvito, P; Arfelli, G; Schirone, M; Corsetti, A; Suzzi, G

    2016-06-01

    Flocculent wine yeasts were characterized for the expression of FLO1, FLO5, FLO8, AMN1 and RGA1 genes, growth kinetics and physicochemical properties of the cell surface during a 6-month sparkling wine fermentation period. The expression of FLO1, FLO5, FLO8, AMN1 and RGA1 genes was determined by RT-qPCR. The physicochemical characterization of yeast surface properties was evaluated by the microbial adhesion to solvents method. FLO5 gene was the most expressed one and a linear correlation with the flocculent degree was found. Flocculent strains were more hydrophobic than the commercial wine strain EC1118. Gene expressions and the ability to face secondary wine fermentation conditions were strain dependent. The importance of FLO5 gene in developing the high flocculent characteristic of wine yeasts was highlighted. Cell surface properties depended on the time of fermentation. Better knowledge about the expression of some genes encoding the flocculent phenotype which could be useful to select suitable starter cultures to improve sparkling wine technology was achieved. A step forward in understanding the complexity and strain-specific nature of flocculation phenotype was done. © 2016 The Society for Applied Microbiology.

  18. Analysis and optimization of flocculation activity and turbidity reduction in kaolin suspension using pectin as a biopolymer flocculant.

    Science.gov (United States)

    Ho, Y C; Norli, I; Alkarkhi, Abbas F M; Morad, N

    2009-01-01

    The performance of pectin in turbidity reduction and the optimum condition were determined using Response Surface Methodology (RSM). The effect of pH, cation's concentration, and pectin's dosage on flocculating activity and turbidity reduction was investigated at three levels and optimized by using Box-Behnken Design (BBD). Coagulation and flocculation process were assessed with a standard jar test procedure with rapid and slow mixing of a kaolin suspension (aluminium silicate), at 150 rpm and 30 rpm, respectively, in which a cation e.g. Al(3+), acts as coagulant, and pectin acts as the flocculant. In this research, all factors exhibited significant effect on flocculating activity and turbidity reduction. The experimental data and model predictions well agreed. From the 3D response surface graph, maximum flocculating activity and turbidity reduction are in the region of pH greater than 3, cation concentration greater than 0.5 mM, and pectin dosage greater than 20 mg/L, using synthetic turbid wastewater within the range. The flocculating activity for pectin and turbidity reduction in wastewater is at 99%.

  19. Flocculation of flotation tailings using thermosensitive polymers

    Directory of Open Access Journals (Sweden)

    Bogacz Wojciech

    2017-09-01

    Full Text Available The key feature of thermosensitive polymers is the reversible transition between the hydrophilic and hydrophopic forms depending on the temperature. Although the main research efforts are focused on their application in different kinds of drug delivery systems, this phenomenon also allows one to precisely control the stability of solid-liquid dispersions. In this paper research on the application of poly(N-isopropylacrylamide copolymers in processing of minerals is presented. In the experiments tailings from flotation plant of one of the coal mines of Jastrzębska Spółka Węglowa S.A. (Poland were used. A laser particle sizer Fritsch Analysette 22 was used in order to determine the Particle Size Distribution (PSD. It was proved that there are some substantial issues associated with the application of thermosensitive polymers in industrial practice which may exclude them from the common application. High salinity of suspension altered the value of Lower Critical Solution Temperature (LCST. Moreover, the co-polymers used in research proved to be efficient flocculating agents without any temperature rise. Finally, the dosage needed to achieve steric stabilization of suspension was greatly beyond economic justification.

  20. Temperature effects on flocculation, using different coagulants.

    Science.gov (United States)

    Fitzpatrick, C S B; Fradin, E; Gregory, J

    2004-01-01

    Temperature is known to affect flocculation and filter performance. Jar tests have been conducted in the laboratory, using a photometric dispersion analyser (PDA) to assess the effects of temperature on floc formation, breakage and reformation. Alum, ferric sulphate and three polyaluminium chloride (PACI) coagulants have been investigated for temperatures ranging between 6 and 29 degrees C for a suspension of kaolin clay in London tap water. Results confirm that floc formation is slower at lower temperatures for all coagulants. A commercial PACl product, PAX XL 19, produces the largest flocs for all temperatures; and alum the smallest. Increasing the shear rate results in floc breakage in all cases and the flocs never reform to their original size. This effect is most notable for temperatures around 15 degrees C. Breakage, in terms of floc size reduction, is greater for higher temperatures, suggesting a weaker floc. Recovery after increased shear is greater at lower temperatures implying that floc break-up is more reversible for lower temperatures.

  1. Flocculation of suspended matter in a crude wet phosphoric acid (Algeria)

    International Nuclear Information System (INIS)

    Brikci Nigassa, M.; Bensebaa, A.

    1994-11-01

    Prior to the recovery of uranium, a pre-treatment of the phosphoric acid is necessary to remove soluble impurities of different origins. In this work, synthetic flocculants have been used. the influence of operating conditions on flocculation and filtration, such as, type of flocculants, polymer concentration, temperature, mixing and time of agitation, has been studied for both aged and fresh phosphoric acid. It has been shown that synthetic flocculants can be used for flocculation ins a phosphoric acid medium and that flocculation and filtration processes are strongly linked

  2. On the perspectives of wide-band gap power devices in electronic-based power conversion for renewable systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos Araujo, Samuel

    2013-10-01

    The high breakdown field from WBG materials allows the construction of unipolar devices with very low specific chip resistance mainly characterized by very low conduction and switching losses, even at high blocking voltages. Suitable concepts for SiC and GaN range from traditional FET structures driven by a MOS interface or a PN-Junction, bipolar devices and even high-electron mobility transistors (HEMT). A detailed revision of the literature will be performed in this work with the objective of providing a broad overview of possible approaches, along with inherent advantages and limitations. In addition to this, a benchmarking of several SiC-based devices technologies rated for 1200 V and 1700 V will be performed against their state-of-the-art Silicon-counterparts. Concerning the application of wide band gap devices in renewable energy systems, a significant cost reduction potential can be obtained due to smaller expenditure with magnetic filters and cooling, alongside higher efficiency levels. These aspects will be discussed in details in order to identify constraints and bottlenecks at application level with special focus on photovoltaic and wind power systems.

  3. Adsorption and flocculation by polymers and polymer mixtures.

    Science.gov (United States)

    Gregory, John; Barany, Sandor

    2011-11-14

    Polymers of various types are in widespread use as flocculants in several industries. In most cases, polymer adsorption is an essential prerequisite for flocculation and kinetic aspects are very important. The rates of polymer adsorption and of re-conformation (relaxation) of adsorbed chains are key factors that influence the performance of flocculants and their mode of action. Polyelectrolytes often tend to adopt a rather flat adsorbed configuration and in this state their action is mainly through charge effects, including 'electrostatic patch' attraction. When the relaxation rate is quite low, particle collisions may occur while the adsorbed chains are still in an extended state and flocculation by polymer bridging may occur. These effects are now well understood and supported by much experimental evidence. In recent years there has been considerable interest in the use of multi-component flocculants, especially dual-polymer systems. In the latter case, there can be significant advantages over the use of single polymers. Despite some complications, there is a broad understanding of the action of dual polymer systems. In many cases the sequence of addition of the polymers is important and the pre-adsorbed polymer can have two important effects: providing adsorption sites for the second polymer or causing a more extended adsorbed conformation as a result of 'site blocking'. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Flocculation mechanism of the actinomycete Streptomyces sp. hsn06 on Chlorella vulgaris.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Zheng, Tianling; Wang, Hailei

    2017-09-01

    In this study, an actinomycete Streptomyces sp. hsn06 with the ability to harvest Chlorella vulgaris biomass was used to investigate the flocculation mechanism. Streptomyces sp. hsn06 exhibited flocculation activity on algal cells through mycelial pellets with adding calcium. Calcium was determined to promote flocculation activity of mycelial pellets as a bridge binding with mycelial pellets and algal cells, which implied that calcium bridging is the main flocculation mechanism for mycelial pellets. Characteristics of flocculation activity confirmed proteins in mycelial pellets involved in flocculation procedure. The morphology and structure of mycelial pellets also caused dramatic effects on flocculation activity of mycelial pellets. According to the results, Streptomyces sp. hsn06 can be used as a novel flocculating microbial resource for high-efficiency harvesting of microalgae biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Flocculation characteristics of polyacrylamide grafted cellulose from Phyllostachys heterocycla: An efficient and eco-friendly flocculant.

    Science.gov (United States)

    Liu, Hongyi; Yang, Xiaogang; Zhang, Yong; Zhu, Hangcheng; Yao, Juming

    2014-08-01

    This work presents a synthesis process and flocculation characteristics of an eco-friendly flocculant based on bamboo pulp cellulose (BPC) from Phyllostachys heterocycla. Ployacrylamide (PAM) was grafted onto the BPC by free-radical graft copolymerization in homogeneous aqueous solution. The optimal synthesis conditions of the bamboo pulp cellulose-graft-ployacrylamide flocculant (BPC-g-PAM) and its performance on wastewater treatments were investigated. A UV-based method was used to rapidly determine the degree of substitution (DS) of BPC. The results showed that, under the optimal synthesis conditions, the obtained BPC-g-PAM held a grafting ratio of 43.8% and DS of 1.31. Turbidity removal of the product reached 98.0% accompanying with the significant flocculation and sedimentation in target suspensions. The flocculation mechanism was explored by means of zeta potential method. For negatively charged contaminants, like kaolin clay particles, the BPC-g-PAM could remove the contaminants efficiently via bridging and charge neutralization in acidic or neutral environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Impact of dynamic distribution of floc particles on flocculation effect

    Institute of Scientific and Technical Information of China (English)

    NAN Jun; HE Weipeng; Song Xinin; LI Guibai

    2009-01-01

    Polyaluminum chloride (PAC) was used as coagulant and suspended particles in kaolin water. Online instruments including turbidimeter and particle counter were used to monitor the flocculation process. An evaluation model for demonstrating the impact on the flocculation effect was established based on the multiple linear regression analysis method. The parameter of the index weight of channels quantitatively described how the variation of floc particle population in different size ranges cause the decrement of turbidity. The study showed that the floc particles in different size ranges contributed differently to the decrement of turbidity and that the index weight of channel could excellently indicate the impact degree of floc particles dynamic distribution on flocculation effect. Therefore, the parameter may significantly benefit the development of coagulation and sedimentation techniques as well as the optimal coagulant selection.

  7. Chitosan as flocculant agent for clarification of stevia extract

    Directory of Open Access Journals (Sweden)

    Silvia P. D. de Oliveira

    2012-01-01

    Full Text Available Stevia is used as a sweetener due to its low calorific value and its taste, which is very similar to that of sucrose. After extraction from dried leaves, stevia extract is dark in colour, and therefore needs to be whitened to increase acceptance by consumers. In this study we tested chitosan, a cationic polyelectrolyte, as flocculant agent for the whitening of the Stevia extract. Positive charges of chitosan can interact electrostatically with a counter-ion, sodium tripolyphosphate (TPP, and then chitosan precipitates. A factorial design was used to study the whitening process, in which Glycosides Removal, Colour Removal, Turbidity Removal and Soluble Solids Removal were evaluated. The studied factors were Chitosan Mass and pH of the TPP solution. The results showed that chitosan is a good flocculant agent, being able to flocculate both the glycosides and the pigments that make the extract coloured.

  8. Impact of dynamic distribution of floc particles on flocculation effect.

    Science.gov (United States)

    Nan, Jun; He, Weipeng; Song, Xinin; Li, Guibai

    2009-01-01

    Polyaluminum chloride (PAC) was used as coagulant and suspended particles in kaolin water. Online instruments including turbidimeter and particle counter were used to monitor the flocculation process. An evaluation model for demonstrating the impact on the flocculation effect was established based on the multiple linear regression analysis method. The parameter of the index weight of channels quantitatively described how the variation of floc particle population in different size ranges cause the decrement of turbidity. The study showed that the floc particles in different size ranges contributed differently to the decrease of turbidity and that the index weight of channel could excellently indicate the impact degree of floc particles dynamic distribution on flocculation effect. Therefore, the parameter may significantly benefit the development of coagulation and sedimentation techniques as well as the optimal coagulant selection.

  9. Flocculation - Formation and structure of aggregates composed of polyelectrolyte chains and clay colloidal particles

    OpenAIRE

    Sakhawoth , Yasine

    2017-01-01

    Flocculation is a key process in numerous environmental and industrial technologies such as purification of waste-water or paper making. It is necessary to understand the formation and structure of the aggregates to control and optimize such a process. Most of the studies on flocculation involve spherical particles, but there is a clear need to understand the flocculation of anisotropic particles such as clay colloids, which are platelets. I studied the flocculation of montmorillonite clay su...

  10. Decontamination technology of contaminated water with flocculating and settling technology

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Adachi, Toshihiro; Watanabe, Noriyuki; Hosobuchi, Shigeki

    2012-01-01

    In the joint research and development of treatment systems of cooling water for cutting asphalt pavement surface with our authors' group, the liquid-solid separation technology by flocculating and settling technology, and the flocculants for the use of systems were developed. In this paper, the developed flocculating and settling technology and the flocculants are discussed first. Next, the demonstration tests of decontamination technology on the contaminated water in swimming pools in an elementary school located at Motomiya City, Fukushima Prefecture had been conducted by use of the stationary purification system of contaminated water and the flocculants compounding with or without iron ferrocianide developed by the preliminary test. It was clarified from the results that ionized cesium (Cs) rarely exists in the stagnant water in pools, ponds, lakes and so on at the time when nine months have passed since Fukushima Dai-ichi nuclear power plant accidents. Further, it is necessary to use the flocculants compounding iron ferrocianide in the case where ionized Cs exists in water. From the above-mentioned results, the following problems were pointed out: One problem was cyanide dissolution in the purified water and the other one was the dissolution from the dehydration sludge. Finally, the high-performance mobile purification units of contaminated water which is capable for carrying with trucks have been developed, and the demonstration test was performed in Minami-soma City, Fukushima Prefecture to purify the contaminated water in a pond and generated by the high-pressure water washing in a Public Hall. From the test results, it was made clear that the dehydration sludge separated by liquid-solid settling of the contaminated water of around 1,000Bq/l became a high radiation dose of about 185,000Bq/l. (author)

  11. Study of the hibiscus esculentus mucilage coagulation–flocculation ...

    African Journals Online (AJOL)

    The flocculent activity of Hibiscus esculentus (gombo) mucilage traditionally used for a local beer (Tchapalo) clarification in Côte d\\'Ivoire was studied using the method of the experimental designs. Of the three factors selected that are the volume of mucilage (X1), the temperature (X2) and the pH (X3), sole X1 and X3 ...

  12. Porcine parvovirus flocculation and removal in the presence of osmolytes.

    Science.gov (United States)

    Gencoglu, Maria F; Pearson, Eric; Heldt, Caryn L

    2014-09-30

    Viruses can be modified into viral vaccines or gene therapy vectors in order to treat acquired or genetic diseases. To satisfy the current market demand, an improvement in current vaccine manufacturing is needed. Chromatography and nanofiltration are not suitable for all types of viruses. In this study, we propose to use virus flocculation with osmolytes, followed by microfiltration, as a potential virus purification process. We hypothesize that osmolytes strongly bind to water, thus leading to the formation of a hydration layer around the virus particles and stimulation of aggregation. We have discovered that osmolytes, including sugars, sugar alcohols and amino acids, preferentially flocculate porcine parvovirus (PPV), and demonstrate a >80% removal with a 0.2 μm filter while leaving model proteins in solution. This large pore size filter increases the flux and decreases the transmembrane pressure of typical virus filters. The best flocculants were tested for their ability to aggregate PPV at different concentrations, shear stress, pH and ionic strength. We were able to remove 96% of PPV in 3.0M glycine at a pH of 5. Glycine is also an excipient, and therefore may not require removal later in the process. Virus flocculation using osmolytes, followed by microfiltration could be used as an integrated process for virus purification. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. OPTIMIZATION OF FLOCCULATION PROCESS BY MICROBIAL COAGULANT IN RIVER WATER

    Directory of Open Access Journals (Sweden)

    Fatin Nabilah Murad

    2017-12-01

    Full Text Available The existing process of coagulation and flocculation are using chemicals that known as cationic coagulant such as alum, ferric sulfate, calcium oxide, and organic polymers.  Thus, this study concentrates on optimizing of flocculation process by microbial coagulant in river water. Turbidity and suspended solids are the main constraints of river water quality in Malaysia. Hence, a study is proposed to produce microbial coagulants isolated locally for river water treatment. The chosen microbe used as the bioflocculant producer is Aspergillus niger. The parameters to optimization in the flocculation process were pH, bioflocculant dosage and effluent concentration. The research was done in the jar test process and the process parameters for maximum turbidity removal was validated. The highest flocculating activity was obtained on day seven of cultivation in the supernatant. The optimum pH and bioflocculant dosage for an optimize sedimentation process were between 4-5 and 2-3 mL for 0.3 g/L of effluent concentration respectively. The model was validated by using a river water sample from Sg. Pusu and the result showed that the model was acceptable to evaluate the bioflocculation process.

  14. The role of electrostatics in saliva-induced emulsion flocculation

    NARCIS (Netherlands)

    Silletti, Erika; Vingerhoeds, Monique H.; Norde, Willem; Van Aken, George A.

    Upon consumption food emulsions undergo different processes, including mixing with saliva. It has been shown that whole saliva induces emulsion flocculation [van Aken, G. A., Vingerhoeds, M. H., & de Hoog, E. H. A. (2005). Colloidal behaviour of food emulsions under oral conditions. In E. Dickinson

  15. Flocculation and dispersion behaviour of two kaolinitic soil clays as ...

    African Journals Online (AJOL)

    This showed that crystalline Fe oxides were important in stabilizing the structure of the soils studied. The amorphous Fe oxides, however, did not play a stabilizing role. The clays whose crystalline Fe oxides, amorphous Fe oxides and organic matter were successively removed were the most flocculated and therefore had ...

  16. Evaluation of the flocculating properties of Malvaviscus arboreus, Heliocarpus popayanensis and Hylocereus undatus for water clarification

    Directory of Open Access Journals (Sweden)

    Lina Marcela Ramírez Estrada

    2011-10-01

    Full Text Available The Malvaviscus arboreus, Heliocarpus popayanensis and Hylocereus undatus have been reported by river residents as natural flocculants. Waters were investigated in La Salada creek (in the municipality of Caldas, Colombia to see if the effects are modified by the flocculant species (Malvaviscus arboreus, Heliocarpus popayanensis and Hylocereus undatus, the type of vegetal material (dry or fresh and the concentration of organic flocculant (10, 20, 30, 40, 50 and 60 ml. JAR methodology was used, following the standard ASTM No. D2035-80. It was found that Heliocarpus popayanensis and Hylocereus undatus presented a flocculation power (P value: 0.017, that increasing the concentration of flocculent it increased the flocculation (P value: 0.08 and the storage did not alter the effects of species over the process of flocculation (P value: 0.7813.

  17. Polyacrylamide grafted cellulose as an eco-friendly flocculant: Key factors optimization of flocculation to surfactant effluent.

    Science.gov (United States)

    Zhu, Hangcheng; Zhang, Yong; Yang, Xiaogang; Shao, Lan; Zhang, Xiumei; Yao, Juming

    2016-01-01

    The discharge of effluents from surfactant manufacturers is giving rise to increasingly serious environmental problems. In order to develop the eco-friendly flocculation materials to achieve effective removal of pollutants from the surfactant effluents, the bamboo pulp cellulose from Phyllostachys heterocycla is employed as the skeleton material to synthesize an eco-friendly bamboo pulp cellulose-g-polyacrylamide (BPC-g-PAM) for flocculation. The BPC-g-PAM is used with the metal ions as the coagulant to treat the effluent from a surfactant manufacturer. The response surface methodology coupled with Box-behnken design is employed to optimize the key factors of coagulation-flocculation. The results show that the combination of Fe(3+) with BPC-g-PAM achieves the best coagulation-flocculation performance like, the fast treatment time, minimum coagulant and BPC-g-PAM dosages compared with the other two combinations of Al(3+) with BPC-g-PAM and Ca(2+) with BPC-g-PAM. Therefore, the combination of Fe(3+) with BPC-g-PAM is expected to promote its application for the pollution control in the surfactant manufacturers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Renewable energy resources

    DEFF Research Database (Denmark)

    Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

    2014-01-01

    Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

  19. Renewal processes

    CERN Document Server

    Mitov, Kosto V

    2014-01-01

    This monograph serves as an introductory text to classical renewal theory and some of its applications for graduate students and researchers in mathematics and probability theory. Renewal processes play an important part in modeling many phenomena in insurance, finance, queuing systems, inventory control and other areas. In this book, an overview of univariate renewal theory is given and renewal processes in the non-lattice and lattice case are discussed. A pre-requisite is a basic knowledge of probability theory.

  20. Synthesis, characterization, and secondary sludge dewatering performance of a novel combined silicon–aluminum–iron–starch flocculant

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Qintie, E-mail: qintlin@163.com; Peng, Huanlong; Zhong, Songxiong; Xiang, Jiangxin

    2015-03-21

    Highlights: • Silicon, aluminum, and iron were grafted onto starch chains to synthesize CSiAFS. • The sludge dewatering performance of CSiAFS was superior to PAC, PAM, and FeCl{sub 3}. • CSiAFS exhibited a good dewatering efficiency over a wide range of pH (3.0–11.0). • CSiAFS had a discontinuous surface with channels which helped to sludge dewatering. - Abstract: Flocculation is one of the most widely used cost-effective pretreatment method for sludge dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the sludge dewatering field. In this study, a novel combined silicon–aluminum–ferric–starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The dewatering performance of secondary sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good dewatering efficiency over a wide pH range of 3.0–11.0, (2) superior sludge dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary sludge dewatering applications.

  1. Removal of Cr(VI) from aqueous solution by flocculant with the capacity of reduction and chelation

    International Nuclear Information System (INIS)

    Wang, Gang; Chang, Qing; Han, Xiaoting; Zhang, Mingyue

    2013-01-01

    Highlights: ► We report a novel flocculant with the properties of reduction and chelation for Cr. ► The removal of Cr(VI) by the flocculant depends highly on pH value. ► Some coexisting ions inhibit Cr (VI) removal, but promote total Cr removal. ► Cr and turbidity can be removed simultaneously in the treated wastewater. ► The interaction mechanism is investigated by FTIR and SEM. -- Abstract: A novel agent polyethyleneimine-sodium xanthogenate (PEX) with the multifunction of reduction, chelation, flocculation and precipitation was synthesized by using polyethyleneimine (PEI), carbon disulfide (CS 2 ), and sodium hydroxide (NaOH). The effects of different important parameters, such as pH value, initial Cr(VI) concentration, coexisting ions and turbidity etc., on the removal of chromium from aqueous solution by PEX were investigated in flocculation experiments. The experiments results demonstrated that PEX could efficiently remove Cr(VI) and total Cr (Cr(VI) + Cr(III)) in strongly acidic media. It was proved that the presence of coexisting ions (Na + , Ca 2+ , F − , Cl − , and SO 4 2− ) in the solution had a little influence on the removal of chromium. Furthermore, it was conformed that Cr(VI) ions and turbidity could be simultaneously removed when water samples contained both Cr(VI) ions and turbidity. Finally, the mechanism of interaction between chromium and PEX was further confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results reveal that dithiocarboxylic acid groups on PEX macromolecule play a major role in Cr(VI) reduction and Cr(III) chelation, and the flocs formation is attributed to the interparticle bridging mechanism of PEX

  2. Renewable energy

    DEFF Research Database (Denmark)

    Olsen, Birgitte Egelund

    2016-01-01

    Renewable energy projects are increasingly confronted by local opposition, which delays and sometimes even prevents their implementation. This reflects the frequent gap between support for the general idea of renewables as a strategy for reducing carbon emissions, and acceptance of renewable energy...

  3. Synthesis of optimal digital controller of flocculant dosing

    Directory of Open Access Journals (Sweden)

    A.V. Pismenskiy

    2013-06-01

    Full Text Available Purpose. The task of automatic process control of the slime water thickening and flotation tailings clarification is the stabilization of thicken product density within the given range and keeping up the solids content in the overflow not above the permissible level with minimum use of the flocculants. In existing systems for automatic control the flocculant dosing is carried out according to the solids content in the device input (the principle of open-loop control. This leads to the excess consumption of the flocculants and increase the dispersion density of the overflow. To perform the synthesis of the optimal digital controller in order to minimize the deviations from the master control and ensure the specified quality of the transition process. Over controlling value should not exceed 5 %. To perform the system operation modeling in order to determine the quality of transient processes. Methodology. Synthesis of the optimal digital controller is based on the method of dynamic programming. Findings. A mathematical model of the object control is represented in the normal form of Cauchy and further in the form of differential equations. The optimum period of quantization as the function from specified error of control and the output coordinate change is calculated. The differential equation of Bellman is obtained and the condition for minimization of the quality functional. Bellman function is represented as a quadratic form from the variables of the system condition. In order to limit possible control, the weight coefficients of the functional are calculated based on maximum permitted values of the system condition variables and the control actions during the transient process. Practical value. Using the modeling of ACS of the flocculant dosing it was established that the over controlling amount is 3.5%, the transient process life 5.6 sec, the transient process is aperiodical, non-static control, which meets the requirements imposed on the

  4. Coagulation and flocculation of dissolved organic substances with organic polymers

    OpenAIRE

    Kvinnesland, Thomas

    2002-01-01

    Coagulation of natural organic matter (NOM) in water is a well-established process, enabling or enhancing the removal of these substances by different particle separation processes. The dominating coagulating agents used are, however, inorganic salts of iron (Fe3+) and aluminium (Al3+). The primary use of organic polymers is as flocculating agents for already coagulated aggregates. However, in recent years the use of cationic organic polymers have received increasing attent...

  5. Digital Imaging and Piezo-dispenser Actuator in Automatic Flocculation Control

    Directory of Open Access Journals (Sweden)

    Jani TOMPERI

    2012-01-01

    Full Text Available This study presents an image-based on-line control system for a coiled pipe flocculator. A digital imaging technique developed previously is utilized to measure the characteristic floc size and a high-pressure piezo-dispenser is introduced for accurate dosing and rapid mixing of the flocculant. The controller is a conventional PI controller. Step change experiments on feed water quality, flow rate and desired floc size have been carried out for controller tuning and testing. The paper shows that the piezo-dispenser provides better flocculation results than a conventional dosing pump, and the flocculation result can be automatically controlled even when the feed water quality rapidly changes. The proposed flocculator is a simple, inexpensive and practical system for long-term laboratory tests to investigate the functionality of flocculants on varying feed waters.

  6. EFFECT OF DEXTRAN-graft-POLYACRYLAMIDE INTERNAL STRUCTURE ON FLOCCULATION PROCESS PARAMETERS

    International Nuclear Information System (INIS)

    Bezugla, T.; Kutsevol, N.; Shyichuk, A.; Ziolkowska, D.

    2008-01-01

    Dextran-graft-Polyacrylamide copolymers (D-g-PAA) of brush-like architecture were tested as flocculation aids in the model kaolin suspensions. Due to expanded conformation the D-g-PAA copolymers are more effective flocculants than individual PAA with close molecular mass. The internal structure of D-g-PAA copolymers which is determined by number and length of grafted PAA chains, the distance between grafts, etc., has the significant influence on flocculation behavior of such polymers

  7. Renewable energy export network

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    A Renewable Energy Exporters Network (REEN) has recently been established, following a meeting of renewable energy exporters and government agencies on 30 October 2000. REEN will assist the Australian renewable energy industry to take advantage of the opportunities offered by the burgeoning global market for renewable energy goods and services. Recent estimates of the significant potential global growth is renewable energy demand have reinforced the industry and Government's view that, in the medium to long-term, growth in the Australian renewable energy industry will largely depend on capturing export market share. Expanding the export market was identified as a crucial component in the Renewable Energy Action Agenda, developed jointly by industry and Government and released in June 2000. It was estimated that, for the industry to achieve its vision of sales of $4 billion per year by 2010, exports would need to comprise approximately 50% of the forecast growth in sales. As such, the need for a specific export strategy for the Australian renewable energy industry was recognised in the Action Agenda, and the establishment of the REEN is one of the first initiatives undertaken as part of the Renewable Energy Export Strategy. The REEN comprises approximately 50 export-ready renewable energy companies, the Department of Industry, Science and Resources, Austrade, and Stage Government agencies such as NSW's Sustainable Energy Development Authority. The Export Network will operate electronically, with face-to-face meetings held as appropriate. The Department of Industry, Science and Resources will facilitate the Export Network and has published a website at www.isr.gov.au/industry/reen. The site includes: a members directory; a discussion forum; information on opportunities to showcase Australian renewable; energy products and services; and Iinks to sites containing information that may be useful to renewable energy exporters. Other actions that are being undertaken as

  8. Renewable enthusiasm

    International Nuclear Information System (INIS)

    Duffin, Tony

    2000-01-01

    A reduction in energy consumption by the energy intensive sectors will be rewarded by a tax credit. The advantages of renewable sources of energy in terms of reducing emissions of carbon dioxide are extolled. The Government will reward the use of renewables through exemption from the Climate Change Levy. Many major companies are now committed to renewables and Shell predict that 50% of world energy will come from renewables by 2050. World-wide there is now 10,000 MW of installed wind power and the annual rate of growth is more than 20%. Other renewables such as biomass, energy from waste, solar power, hydropower, wind power and tidal power are discussed. The Government would like to see 10% of the UK's electricity coming from renewables by 2010. (UK)

  9. Marine microalgae flocculation using plant: the case of Nannochloropsis oculata and Moringa oleifera

    International Nuclear Information System (INIS)

    Baharuddin, N.; Aziz, N. S.; Sohif, H. N.; Basiran, M. N.

    2016-01-01

    Marine microalgae have been commercially used as live feed for aquaculture and nutritional supplements. However, harvesting of marine microalgae is a major obstacle for industrial scale and one of the promising harvesting techniques is bio-flocculation. Nannochloropsis oculata from the culture broth was investigated. The potential of Moringa oleifera as a flocculant has been evaluated using jar test experiments. Moringa oleifera after oil extraction (MOAE) and with non-extracted Moringa oleifera (MOWE) have been studied and compared to chemical flocculant, aluminium sulphate. Three parameters involved: pH, settling time and flocculant dosage. When MOAE and MOWE were used as flocculants, the highest flocculation efficiency of Nannochloropsis oculata was observed at 93.77 percent (pH 7, 150 minutes, 5000 mg/L) and 70.56 percent (pH 7, 90 minutes, 4000 mg/L) respectively. Harvesting efficiency of 99.98 percent with short settling time, 30 minutes and 2000 mg/L of flocculant dosage at pH 6 was achieved using aluminium sulphate. The concentrated of Nannochloropsis oculata was then fed to the Brachionus plicatilis (rotifers) to observe the growth characteristics in 12 days period. Concentrates of MOWE gave better growth of Brachionus plicatilis than growth in concentrates of MOAE and live Nannochloropsis oculata. In contrast, growth of Brachionus plicatilis in aluminium sulphate was tremendously decline. In Conclusion, bio-flocculation using Moringa oleifera was rapid, inexpensive and eco-friendly technology as no addition of chemical flocculants was required. (author)

  10. Molecular mechanism of flocculation self-recognition in yeast and its role in mating and survival

    Data.gov (United States)

    National Aeronautics and Space Administration — Saccharomyces cerevisiae flocculation occurs when fermentable sugars are limiting and is therefore considered as a way to enhance the survival chance of...

  11. Some aspects related to stability, critical concentrations and kinetics of flocculation of the calcium phytate colloid

    International Nuclear Information System (INIS)

    Lucas, F.J.M.; Alvarez, J.G.; Sanchis, S.E.; Munoz, B.C.

    1986-01-01

    As sup(99m)Tc-Ca phytate is an important radiopharmaceutical and its colloidal nature presents problems, we investigated some of them. This work describes the study of the colloidal behaviour of the calcium phytate colloid in terms of its formation, stability and kinetics of flocculation. The study of spontaneous, and centrifugation-induced flocculation allows the determination of two critical concentrations of sol flocculation. The titrations of calcium phytate colloid at different concentrations provide information on the colloidal formation conditions. Moreover, a study on flocculation kinetics was made by turbidity measurements. (author)

  12. Renewable energy

    International Nuclear Information System (INIS)

    Yoon, Cheon Seok

    2009-09-01

    This book tells of renewable energy giving description of environment problem, market of renewable energy and vision and economics of renewable energy. It also deals with solar light like solar cell, materials performance, system and merit of solar cell, solar thermal power such as solar cooker and solar collector, wind energy, geothermal energy, ocean energy like tidal power and ocean thermal energy conversion, fuel cell and biomass.

  13. Influence of organic and inorganic flocculants on the formation of PCDD/Fs during sewage sludge incineration.

    Science.gov (United States)

    Lin, Xiaoqing; Li, Xiaodong; Lu, Shengyong; Wang, Fei; Chen, Tong; Yan, Jianhua

    2015-10-01

    Flocculants are widely used to improve the properties of sludge dewatering in industrial wastewater treatment. However, there have been no studies conducted on the influence of flocculants on the formation of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) during sewage sludge incineration. This paper selected three typical kinds of flocculants, including polyacrylamide (PAM), poly-ferric chloride (PFC), and polyaluminum chloride (PAC) flocculant, to study their influences on the formation of PCDD/Fs during sewage sludge incineration. The results indicated that PAM flocculant, which is an organic flocculant, inhibited the formation of PCDD/Fs in sewage sludge incineration, while inorganic flocculant, such as PFC and PAC flocculant, promoted the formation. The most probable explanation is that the amino content in the PAM flocculant acted as an inhibitor in the formation of PCDD/Fs, while the chlorine content, especially the metal catalyst in the PFC and PAC flocculants, increased the formation rate. The addition of flocculants nearly did not change the distribution of PCDD/F homologues. The PCDFs contributed the most toxic equivalent (TEQ) value, especially 2, 3, 4, 7, 8-PeCDF. Therefore, the use of inorganic flocculants in industrial wastewater treatment should be further assessed and possibly needs to be strictly regulated if the sludge is incinerated. From this aspect, a priority to the use of organic flocculants should be given.

  14. License renewal

    International Nuclear Information System (INIS)

    Newberry, S.

    1993-01-01

    This article gives an overview of the process of license renewal for nuclear power plants. It explains what is meant by license renewal, the significance of license renewal, and goes over key elements involved in the process of license renewal. Those key elements are NRC requirements embodied in 10 CFR Part 54 (Reactor Safety) and 10 CFR Part 51 (Environmental Issues). In addition Industry Reports must be developed and reviewed. License renewal is essentially the process of applying for a 20 year extension to the original 40 year operating license granted for the plant. This is a very long term process, which involves a lot of preparation, and compliance with regulatory rules and guidelines. In general it is a process which is expected to begin when plants reach an operating lifetime of 20 years. It has provisions for allowing the public to become involved in the review process

  15. Renewable Energy

    DEFF Research Database (Denmark)

    Sørensen, Bent Erik

    Bent Sorensen’s Renewable Energy: Physics, Engineering, Environmental Impacts, Economics and Planning, Fifth Edition, continues the tradition by providing a thorough and current overview of the entire renewable energy sphere. Since its first edition, this standard reference source helped put...... renewable energy on the map of scientific agendas. Several renewable energy solutions no longer form just a marginal addition to energy supply, but have become major players, with the promise to become the backbone of an energy system suitable for life in the sustainability lane. This volume is a problem...... structured around three parts in order to assist readers in focusing on the issues that impact them the most for a given project or question. PART I covers the basic scientific principles behind all major renewable energy resources, such as solar, wind, and biomass. PART II provides in-depth information...

  16. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Shuying [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Zhen, E-mail: yangzhen@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Ren, Kexin [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Tian, Ziqi [Department of Chemistry, University of California, Riverside, CA 92521 (United States); Dong, Chang; Ma, Ruixue; Yu, Ge [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Weiben, E-mail: yangwb007@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China)

    2016-11-05

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  17. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    International Nuclear Information System (INIS)

    Jia, Shuying; Yang, Zhen; Ren, Kexin; Tian, Ziqi; Dong, Chang; Ma, Ruixue; Yu, Ge; Yang, Weiben

    2016-01-01

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  18. New sizing agents and flocculants derived from chitosan

    International Nuclear Information System (INIS)

    Hebeish, A.; Higay, A.; El-Shafei, A.

    2005-01-01

    Novel approaches for development of new textile sizing agents and flocculants were undertaken. One of these approaches is based on acid hydrolysis of chitosan and the other involves its carboxy methylation. Characterization of the hydrolyzed chitosan was performed through monitoring nitrogen content and apparent viscosity, while carboxymethyl chitosan was analyzed for degree of substitution (DS) along with apparent viscosity. Factors affecting both hydrolysis and carboxy methylation were investigated. The nitrogen content and apparent viscosity of chitosan decrease variably by increasing HCl concentration as well as time and temperature of hydrolysis. On the other hand, the DS of carboxymethyl chitosan increases by increasing the concentration of both sodium hydroxide and monochloroacetic acid and similarly increases by prolonging the duration and raising the temperature of carboxy methylation; in contrast with apparent viscosity which is inversely related to these parameters. Aqueous solutions of hydrolyzed chitosan or carboxymethyl chitosan were applied to light cotton fabric with a view to envision the technical feasibility of such water soluble chitosan for textile sizing. The size add-on on the light fabric is directly related to the concentration of the hydrolyzed or carboxymethyl chitosan in the sizing solution and so does the apparent viscosity of the latter. Hundred percent size removals could be achieved with the hydrolyzed chitosan irrespective or the size solution concentration provided that the latter is not less than 8%. Different situation is encountered with carboxymethyl chitosan where the percent size removal increase from 81% to 95% by increasing its concentration in the sizing solution from 5 % to 15%. Drying the sized fabric at 80 degree C for 5 minutes or 120 degree C for 3 minutes has practically no effect on percent size removal. The same holds true for heat treatment of the sized fabric at higher temperatures (up to 160 degree C) for longer

  19. Arsenic removal in water by means of coagulation-flocculation processes

    International Nuclear Information System (INIS)

    Franco, M. F.; Carro P, M. E.

    2014-01-01

    Arsenic and arsenical compounds are considered as carcinogenic and risky for humans according to epidemiological evidence related with the ingestion of arsenical water during a long period. In many places the only source of drinking water contains arsenic and, therefore, removal strategies have to be investigated. This work shows experimental results of coagulation-flocculation processes implemented to evaluate the efficiency in the removal of arsenic from drinking water. The main objectives include the evaluation of the relevant aspect that controls the removal efficiency. Experimental tests were performed with coagulant concentrations from 5 to 500 mg/L, solid particle concentrations from 0 to 6000 mg/L, and initial arsenic concentrations from 0.5 to 5 mg/L. These variables were simultaneously varied in more than 100 experiments. The efficiency in remediation ranged from 0% to 95%. Removal efficiency near 95% was obtained when using ferric chloride as coagulant, and was close to 80% when using aluminium sulfate as coagulant in arsenate solutions. The remediation efficiency decreased significantly when the ferric chloride concentration was higher than 50 mg/L in relation to the obtained results for aluminum sulfate for different type and concentration of soil particles. The highest removal efficiency were obtained at ph between 3 and 5 in oxidized solutions. Obtained results simulated by means of multiple linear regression analysis (R>0.90) allow determining that the main parameters that control the removal of arsenic from drinking water are coagulant concentration, ph, and solid particles concentration. Conversely, particle mineralogy and coagulant type have less significant effect on the removal by means of coagulation-flocculation mechanisms. Obtained results are relevant for the removal of As in water treatment plants as well as for the development of small scale filters. The samples were studied by scanning electron microscopy and energy dispersive X

  20. Scaling Behavior of Delayed Demixing, Rheology, and Microstructure of Emulsions Flocculated by Depletion and Bridging

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Linden, van der E.; Vliet, van T.; Aken, van G.A.

    2004-01-01

    Abstract: This paper describes an experimental comparison of microstructure, rheology, and demixing of bridging- and depletion-flocculated oil-in-water emulsions. Confocal scanning laser microscopy imaging showed that bridging-flocculated emulsions were heterogeneous over larger length scales than

  1. Depletion - flocculation in oil-in-water emulsions using fibrillar protein assemblies

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Veerman, C.; Linden, van der E.

    2004-01-01

    This paper shows that low concentrations of -lactoglobulin fibrils can induce depletion-flocculation in -lactoglobulin-stabilized oil-in-water emulsions. The minimum required fibril concentration for flocculation was determined experimentally for fibril lengths of about 3 and 0.1 m. The minimum

  2. Serum separation and structure of depletion- and bridging-flocculated emulsions: a comparison

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Winden, van A.J.M.; Vliet, van T.; Aken, van G.A.

    2004-01-01

    Stability against demixing, rheology and microstructure of emulsions that were flocculated by depletion or bridging were compared. Flocculation by depletion and bridging was induced by addition of the polysaccharide carboxy-methylcellulose (CMC) to emulsions that were stabilised by ß-lactoglobulin

  3. Revealing the characteristics of a novel bioflocculant and its flocculation performance in Microcystis aeruginosa removal

    Science.gov (United States)

    Sun, Pengfei; Hui, Cai; Bai, Naling; Yang, Shengmao; Wan, Li; Zhang, Qichun; Zhao, Yuhua

    2015-12-01

    In the present work, a novel bioflocculant, EPS-1, was prepared and used to flocculate the kaolin suspension and Microcystis aeruginosa. We focused on the characteristics and flocculation performance of EPS-1, especially with regard to its protein components. An important attribute of EPS-1 was its protein content, with 18 protein types identified that occupied a total content of 31.70% in the EPS-1. Moreover, the flocculating activity of these protein components was estimated to be no less than 33.93%. Additionally, polysaccharides that occupied 57.12% of the total EPS-1 content consisted of four monosaccharides: maltose, D-xylose, mannose, and D-fructose. In addition, carbonyl, amino, and hydroxyl groups were identified as the main functional groups. Three main elements, namely C1s, N1s, and O1s, were present in EPS-1 with relative atomic percentages of 62.63%, 24.91%, and 10.5%, respectively. Zeta potential analysis indicated that charge neutralization contributed to kaolin flocculation, but was not involved in M. aeruginosa flocculation. The flocculation conditions of EPS-1 were optimized, and the maximum flocculating efficiencies were 93.34% within 2 min for kaolin suspension and 87.98% within 10 min for M. aeruginosa. These results suggest that EPS-1 could be an alternative to chemical flocculants for treating wastewaters and cyanobacterium-polluted freshwater.

  4. Cationic flocculants carrying hydrophobic functionalities: applications for solid/liquid separation.

    Science.gov (United States)

    Schwarz, S; Jaeger, W; Paulke, B-R; Bratskaya, S; Smolka, N; Bohrisch, J

    2007-07-26

    The flocculation behaviors of three series of polycations with narrow molecular weight distributions carrying hydrophobic substituents on their backbones [poly(N-vinylbenzyl-N,N,N-trimethylammonium chloride), poly(N-vinylbenzyl-N,N-dimethyl-N-butylammonium chloride), and poly(N-vinylbenzylpyridinium chloride)] were investigated in dispersions of monodisperse polystyrene latexes and kaolin. Apparently, the charge density of the polycations decreases with increasing substituent hydrophobicity and increasing molecular weight of the polyelectrolytes. The necessary amount of flocculant for phase separation in dispersions with high substrate surface charge densities increases with increasing hydrophobicity of the polyelectrolyte. Nevertheless, the introduction of hydrophobic functionalities is beneficial, resulting in a substantial broadening of the range between the minimum and maximum amounts of flocculant necessary for efficient flocculation (flocculation window). An increase in ionic strength supports this effect. When the substrate has a low charge density, the hydrophobic interactions play a much more significant role in the flocculation process. Here, the minimum efficient doses remained the same for all three polyelectrolytes investigated, but the width of the flocculation window increased as the polycation hydrophobicity and the molecular weight increased. The necessary amount of flocculant increased with an increase in particle size at constant solid content of the dispersion, as well as with a decreasing number of particles at a constant particle size.

  5. Renewable energy

    International Nuclear Information System (INIS)

    Berghmans, J.

    1994-01-01

    Renewable energy sources have a small environmental impact and can be easily integrated within existing structures. Moreover, the use of renewable energy sources can contribute to achieve a zero emission of carbon dioxide by 2100, provided an efficient environmental policy during the next 40 years. This includes a correct pricing policy of renewable energy sources with respect to nuclear energy and fossil fuel. The latter energy sources have been favoured in the past. In addition, an open market policy, the restructuring or conversion of existing international energy institutes, and international treaties for the protection of the natural environment are needed in view of achieving the zero carbon dioxide emission objective. (A.S.)

  6. The use of dielectric spectroscopy for the characterization of polymer-induced flocculation of polystyrene particles

    DEFF Research Database (Denmark)

    Christensen, Peter Vittrup; Keiding, Kristian

    2008-01-01

    in dilute suspensions. Thus, techniques usable for flocculation characterization in high-solids suspensions are desirable. This study investigates the use of dielectric spectroscopy to monitor the flocculation of polystyrene particles with a cationic polymer. The frequency-dependent permittivity is modeled......The flocculation of colloidal suspensions is an important unit operation in many industries, as it greatly improves the performance of solid separation processes. The number of available techniques for evaluating flocculation processes on line is limited, and most of these are only functional...... as a decrease in the magnitude of the dielectric dispersion. The use of dielectric spectroscopy is found to be valuable for assessing flocculation processes in high-solids suspensions, as changes in parameters Such as floc size and charge can be detected....

  7. The relationship between extent of hemoglobin purification and the performance characteristics of a blood-based flocculant

    Science.gov (United States)

    Whole blood is a highly complex substance. Hemoglobin, the most abundant blood protein, can function as a flocculant of colloidal clay; most of the other blood components exhibit poor flocculant activity. For the purpose of processing raw whole blood into a flocculant product, the practical value of...

  8. Plasma-initiated polymerization of chitosan-based CS-g-P(AM-DMDAAC) flocculant for the enhanced flocculation of low-algal-turbidity water.

    Science.gov (United States)

    Sun, Yongjun; Zhu, Chengyu; Sun, Wenquan; Xu, Yanhua; Xiao, Xuefeng; Zheng, Huaili; Wu, Huifang; Liu, Cuiyun

    2017-05-15

    In this work, a highly efficient and environmentally friendly chitosan-based graft flocculant, namely, acrylamide- and dimethyl diallyl ammonium chloride-grafted chitosan [CS-g-P(AM-DMDAAC)], was prepared successfully through plasma initiation. FTIR results confirmed the successful polymerization of CS-g-P(AM-DMDAAC) and P(AM-DMDAAC). P(AM-DMDAAC) was the copolymer of acrylamide- and dimethyl diallyl ammonium chloride. SEM results revealed that a densely cross-linked network structure formed on the surface. XRD results verified that the ordered crystal structure of chitosan in CS-g-P(AM-DMDAAC) was changed into an amorphous structure after plasma-induced polymerization. The flocculation results of low-algal-turbidity water further showed the optimal flocculation efficiency of turbidity removal rate, COD removal rate, and Chl-a removal rate were 99.02%, 96.11%, and 92.20%, respectively. The flocculation efficiency of CS-g-P(AM-DMDAAC) were significantly higher than those obtained by cationic polyacrylamide (CPAM) and Polymeric aluminum and iron (PAFC). This work provided a valuable basis for the design of eco-friendly naturally modified polymeric flocculants to enhance the flocculation of low-algal-turbidity water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Renewable energy.

    Science.gov (United States)

    Destouni, Georgia; Frank, Harry

    2010-01-01

    The Energy Committee of the Royal Swedish Academy of Sciences has in a series of projects gathered information and knowledge on renewable energy from various sources, both within and outside the academic world. In this article, we synthesize and summarize some of the main points on renewable energy from the various Energy Committee projects and the Committee's Energy 2050 symposium, regarding energy from water and wind, bioenergy, and solar energy. We further summarize the Energy Committee's scenario estimates of future renewable energy contributions to the global energy system, and other presentations given at the Energy 2050 symposium. In general, international coordination and investment in energy research and development is crucial to enable future reliance on renewable energy sources with minimal fossil fuel use.

  10. Flocculent killer yeast for ethanol fermentation of beet molasses

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Kazuhito; Shimoii, Hitoshi; Sato, Shun' ichi; Saito, Kazuo; Tadenuma, Makoto

    1987-09-25

    When ethanol is produced using beet molasses, the concentration of ethanol is lower than that obtained using suger cane molasses. Yeast strain improvement was conducted to enhance ethanol production from beet molasses. The procedures and the results are as follows: (1) After giving ethanol tolerance to the flocculent yeast, strain 180 and the killer yeast, strain 909-1, strain 180-A-7, and strain 909-1-A-4 were isolated. These ethanol tolerant strains had better alcoholic fermentation capability and had more surviving cells in mash in the later process of fermentation than the parental strains. (2) Strain H-1 was bred by spore to cell mating between these two ethanol tolerant strains. Strain H-1 is both flocculent and killer and has better alcoholic fermentation capability than the parental strains. (3) In the fermentation test of beet molasses, strain H-1 showed 12.8% of alcoholic fermentation capability. It is equal to that of sugar cane molasses. Fermentation with reused cells were also successful. (5 figs, 21 refs)

  11. Processing of miscellaneous radioactive effluents by continous flocculation decantation

    International Nuclear Information System (INIS)

    Lundy, D.; Matton, P.; Petteau, J.L.; Roofthooft, R.

    1985-01-01

    In the nuclear power plant of Chooz an installation for flocculation and chemical precipitation has been built to treat miscellaneous radioactive effluents continuously. It is an industrial prototype of 5 m 3 /h resulting of several years of research, first on lab scale in a discontinous system and finally in a continuous pilot plant of small size (500 l/h). The process is based on the adsorption of radioactivity on a floc of copper-ferrocyanide precipitated by ferric chloride. The water is then filtered. After a series of preliminary tests and modifications, it has been possible to develop a technique which satisfies the specified decontamination conditions and to reduce the discharges of radioactivity to the Meuse to only 5 - 10% of the authorized limits. The process aims principally at the treatment of laundry waste, but other effluents such as drains from the rocks, pool water and used decontamination solutions (of the primary pumps) have been treated. A technico-economic evaluation of the process in comparison with evaporation is clearly in favour of the flocculation. 31 figs, 40 tables, 12 refs

  12. Inhibition of Alkaline Flocculation by Algal Organic Matter for Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Vandamme, Dries; Beuckels, Annelies; Vadelius, Eric; Depraetere, Orily; Noppe, Wim; Dutta, Abhishek; Foubert, Imogen; Laurens, Lieve; Muylaert, Koenraad

    2016-01-01

    Alkaline flocculation is a promising strategy for the concentration of microalgae for bulk biomass production. However, previous studies have shown that biological changes during the cultivation negatively affect flocculation efficiency. The influence of changes in cell properties and in the quality and composition of algal organic matter (AOM) were studied using Chlorella vulgaris as a model species. In batch cultivation, flocculation was increasingly inhibited over time and mainly influenced by changes in medium composition, rather than biological changes at the cell surface. Total carbohydrate content of the organic matter fraction sized bigger than 3 kDa increased over time and this fraction was shown to be mainly responsible for the inhibition of alkaline flocculation. The monosaccharide identification of this fraction mainly showed the presence of neutral and anionic monosaccharides. An addition of 30–50 mg L-1 alginic acid, as a model for anionic carbohydrate polymers containing uronic acids, resulted in a complete inhibition of flocculation. Furthermore, these results suggest that inhibition of alkaline flocculation was caused by interaction of anionic polysaccharides leading to an increased flocculant demand over time.

  13. Flocculation of Clay Colloids Induced by Model Polyelectrolytes: Effects of Relative Charge Density and Size.

    Science.gov (United States)

    Sakhawoth, Yasine; Michot, Laurent J; Levitz, Pierre; Malikova, Natalie

    2017-10-06

    Flocculation and its tuning are of utmost importance in the optimization of several industrial protocols in areas such as purification of waste water and civil engineering. Herein, we studied the polyelectrolyte-induced flocculation of clay colloids on a model system consisting of purified clay colloids of well-defined size fractions and ionene polyelectrolytes presenting regular and tunable chain charge density. To characterize ionene-induced clay flocculation, we turned to the combination of light absorbance (turbidity) and ζ-potential measurements, as well as adsorption isotherms. Our model system allowed us to identify the exact ratio of positive and negative charges in clay-ionene mixtures, the (c+/c-) ratio. For all samples studied, the onset of efficient flocculation occurred consistently at c+/c- ratios significantly below 1, which indicated the formation of highly ionene-deficient aggregates. At the same time, the ζ-potential measurements indicated an apparent zero charge on such aggregates. Thus, the ζ-potential values could not provide the stoichiometry inside the clay-ionene aggregates. The early onset of flocculation in clay-ionene mixtures is reminiscent of the behavior of multivalent salts and contrasts that of monovalent salts, for which a large excess amount of ions is necessary to achieve flocculation. Clear differences in the flocculation behavior are visible as a function of the ionene charge density, which governs the conformation of the ionene chains on the clay surface. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. First evidence of bioflocculant from Shinella albus with flocculation activity on harvesting of Chlorella vulgaris biomass.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Liu, Lei; Jiang, Xiaobing; Zhang, Kun; Zheng, Tianling; Wang, Hailei

    2016-10-01

    Bioflocculant from Shinella albus xn-1 could be used to harvest energy-producing microalga Chlorella vulgaris biomass for the first time. In this study, we investigated the flocculation activity and mode of strain xn-1, the characteristics of bioflocculant, the effect of flocculation conditions and optimized the flocculation efficiency. The results indicated that strain xn-1 exhibited flocculation activity through secreting bioflocculant; the bioflocculant with high thermal stability, pH stability and low molecular weight was proved to be not protein and polysaccharide, and flocculation active component was confirmed to contain triple bond and cumulated double bonds; algal pH, temperature and metal ions showed great impacts on the flocculation efficiency of bioflocculant; the maximum flocculation activity of bioflocculant reached 85.65% after the response surface optimization. According to the results, the bioflocculant from S. albus xn-1 could be a good potential in applications for high-efficiency harvesting of microalgae. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Comparison of different artificial neural network architectures in modeling of Chlorella sp. flocculation.

    Science.gov (United States)

    Zenooz, Alireza Moosavi; Ashtiani, Farzin Zokaee; Ranjbar, Reza; Nikbakht, Fatemeh; Bolouri, Oberon

    2017-07-03

    Biodiesel production from microalgae feedstock should be performed after growth and harvesting of the cells, and the most feasible method for harvesting and dewatering of microalgae is flocculation. Flocculation modeling can be used for evaluation and prediction of its performance under different affective parameters. However, the modeling of flocculation in microalgae is not simple and has not performed yet, under all experimental conditions, mostly due to different behaviors of microalgae cells during the process under different flocculation conditions. In the current study, the modeling of microalgae flocculation is studied with different neural network architectures. Microalgae species, Chlorella sp., was flocculated with ferric chloride under different conditions and then the experimental data modeled using artificial neural network. Neural network architectures of multilayer perceptron (MLP) and radial basis function architectures, failed to predict the targets successfully, though, modeling was effective with ensemble architecture of MLP networks. Comparison between the performances of the ensemble and each individual network explains the ability of the ensemble architecture in microalgae flocculation modeling.

  16. Development of Graft Copolymer Flocculant Based on Acrylamide and Acrylic Acid for the dewatering of coal

    International Nuclear Information System (INIS)

    Mahmoud, G.A.; Abdel Khalek, M.A

    2012-01-01

    Most coal preparation processes were carried out in water medium. The water content of coal product has a negative impact on handling and specific energy value. The moisture content may be attributed to the proportion of fine coal, which presents the greatest dewatering problem. A novel polymeric flocculant has been developed by graft copolymerization of acrylamide (AAm) with acrylic acid (AAc) using gamma irradiation technique. The grafted copol621621ymer P(AAm/AAc) was characterized by Fourier-transform infrared spectroscopy (FTIR), and thermo-gravimetric analysis (TGA). The effects of reaction parameters, such as total absorbed dose, and monomer concentration on grafting yield were investigated. The flocculation performance of the graft copolymer P(AAm/AAc) was investigated in coal suspension. It was observed that the grafting ratio was one of the key factors for the flocculating effects. The copolymers with various grafting ratios showed different flocculating properties. It was found that as the grafting ratio increased, the flocculating effect also increased. The flocculation performance of the grafted copolymer was better than that of the commercial flocculant, poly-acrylamide (Magnafloc 1011).

  17. Synthesis, characterization and flocculation activity of novel Fe(OH){sub 3}-polyacrylamide hybrid polymer

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huilong; Cui Jinyan [Department of Chemistry, Dalian University of Technology, Dalian 116023 (China); Jiang Wenfeng, E-mail: dlutjiangwf@yahoo.com.cn [Department of Chemistry, Dalian University of Technology, Dalian 116023 (China)

    2011-11-01

    Highlights: {yields} The preparation of a novel Fe(OH){sub 3}-PAM hybrid polymer flocculant is achieved via free radical solution polymerization. {yields} Flocculation of kaolin suspensions using this novel Fe(OH){sub 3}-PAM hybrid polymer flocculant is revealed in this study. {yields} The statistical model was first applied for calculating the thermodynamic parameters for the kaolin flocculating process. - Abstract: A novel Fe(OH){sub 3}-polyacrylamide inorganic-organic hybrid polymer (FHPAM) was synthesized via free radical solution polymerization initiated by a redox initiation system ((NH{sub 4}){sub 2}S{sub 2}O{sub 8}-NaHSO{sub 3}) in an aqueous medium. Reaction parameters influencing the intrinsic viscosity and the yield of the hybrid polymer, such as initiator concentration, monomer mass fraction, temperature and reaction time were investigated and optimized. The results show that the maximum intrinsic viscosity and up to 94% yields of the hybrid polymer can be achieved using initiator concentration of 0.3% with acrylamide monomer mass fraction of 20% under solution polymerization at 40 deg. C for 7 h. The physicochemical properties of this hybrid flocculant were characterized with TEM, FTIR spectra, TGA, and conductivity. It was found that a chemical bond exists between Fe(OH){sub 3} colloid and polyacrylamide chains in the FHPAM. The application of the hybrid polymer for the treatment of 2.5 g L{sup -1} kaolin suspension indicates that it had an excellent flocculation capacity and its flocculation efficiency was much better than that of commercial available polyacrylamide (PAM) and polymeric ferric sulfate (PFS). The optimal conditions for the flocculation treatment of kaolin suspension were the FHPAM dosage of 40 mg L{sup -1} at pH 7.0. The thermodynamic parameters for the flocculation process were calculated based on a statistical model. Interpretation of the results was given.

  18. Synthesis, characterization and flocculation activity of novel Fe(OH)3-polyacrylamide hybrid polymer

    International Nuclear Information System (INIS)

    Wang Huilong; Cui Jinyan; Jiang Wenfeng

    2011-01-01

    Highlights: → The preparation of a novel Fe(OH) 3 -PAM hybrid polymer flocculant is achieved via free radical solution polymerization. → Flocculation of kaolin suspensions using this novel Fe(OH) 3 -PAM hybrid polymer flocculant is revealed in this study. → The statistical model was first applied for calculating the thermodynamic parameters for the kaolin flocculating process. - Abstract: A novel Fe(OH) 3 -polyacrylamide inorganic-organic hybrid polymer (FHPAM) was synthesized via free radical solution polymerization initiated by a redox initiation system ((NH 4 ) 2 S 2 O 8 -NaHSO 3 ) in an aqueous medium. Reaction parameters influencing the intrinsic viscosity and the yield of the hybrid polymer, such as initiator concentration, monomer mass fraction, temperature and reaction time were investigated and optimized. The results show that the maximum intrinsic viscosity and up to 94% yields of the hybrid polymer can be achieved using initiator concentration of 0.3% with acrylamide monomer mass fraction of 20% under solution polymerization at 40 deg. C for 7 h. The physicochemical properties of this hybrid flocculant were characterized with TEM, FTIR spectra, TGA, and conductivity. It was found that a chemical bond exists between Fe(OH) 3 colloid and polyacrylamide chains in the FHPAM. The application of the hybrid polymer for the treatment of 2.5 g L -1 kaolin suspension indicates that it had an excellent flocculation capacity and its flocculation efficiency was much better than that of commercial available polyacrylamide (PAM) and polymeric ferric sulfate (PFS). The optimal conditions for the flocculation treatment of kaolin suspension were the FHPAM dosage of 40 mg L -1 at pH 7.0. The thermodynamic parameters for the flocculation process were calculated based on a statistical model. Interpretation of the results was given.

  19. Renewable energy

    DEFF Research Database (Denmark)

    Olsen, Birgitte Egelund

    2016-01-01

    Renewable energy projects are increasingly confronted by local opposition, which delays and sometimes even prevents their implementation. This reflects the frequent gap between support for the general idea of renewables as a strategy for reducing carbon emissions, and acceptance of renewable energy...... installations in the local landscape. A number of countries have introduced financial incentives to promote community acceptance. The tool box of incentives is still limited but in recent years it has been expanded to address local concerns. Certain general characteristics can be identified, suggesting...... that there are at least three distinct categories of incentives: individual compensation, community benefits and ownership measures. Local opposition must be approached with caution, as financial incentives to promote local acceptance can be seen as buying consent or even ‘bribery’, stirring up further opposition....

  20. Energy-producing electro-flocculation for harvest of Dunaliella salina.

    Science.gov (United States)

    Liu, Qing; Zhang, Meng; Lv, Tao; Chen, Hongjun; Chika, Anthony Okonkwo; Xiang, Changli; Guo, Minxue; Wu, Minghui; Li, Jianjun; Jia, Lishan

    2017-10-01

    In this study, an efficient electro-flocculation process for Dunaliella salina with energy production by aluminum-air battery has been successfully applied. The formed aluminum hydroxide hydrates during discharging of battery were positively charged, which have a great potential for microalgae flocculation. The precipitation of aluminum hydroxide hydrates by algae also could improve the performance of aluminum-air battery. The harvesting efficiency could reach 97% in 20mins with energy production of 0.11kWh/kg. This discharging electro-flocculation (DEF) technology provides a new energy producing process to effectively harvest microalgae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Pilot-scale study of ballasted-flocculation technology

    International Nuclear Information System (INIS)

    Liem, L.E.; Brant, W.H.; Gagne, B.; Michaud, J.; Beaudet, J.-F.; Landry, D.; Braden, K.; Campbell, D.

    2002-01-01

    A ballasted-flocculation pilot-scale study was undertaken to treat a wide-range river water turbidity (17 to 2,608 NTU). The pilot-scale unit was operated at flowrates of 30 to 63 m 3 /h, which corresponded to loading rates of 40 to 84 m/h. Coagulants, polymers, and microsand were added to enhance the floc agglomeration. The weighted flocs settled rapidly resulting in excellent turbidity removals of 94.7 to 99.9%. At the peak turbidity, the unit had a 99.9% removal performance (2.7 from 2,608 NTU) at a loading rate of 40 m/h. In this case, polyaluminum silicosulfate and anionic polymer dosages were 82 and 1 mg/L, respectively. The microsand recycle rate was kept constant at 4.5 m 3 /h, and 1mg microsand was added for each liter of water treated. (author)

  2. Removal of Pyrethrin from Aqueous Effluents by Adsorptive Micellar Flocculation

    Directory of Open Access Journals (Sweden)

    Pardon K. Kuipa

    2015-01-01

    Full Text Available The equilibrium adsorption of pyrethrin onto aggregates formed by the flocculation of micelles of the surfactant sodium dodecyl sulphate (SDS with aluminium sulphate is reported. The experimental results were analysed using different adsorption isotherms (Langmuir, Freundlich, Redlich-Peterson, Sips, Radke-Prausnitz, Temkin, linear equilibrium, and the Dubin-Radushkevich isotherms. The Freundlich and linear equilibrium isotherms best describe the adsorption of pyrethrin onto SDS micellar flocs, with the Freundlich adsorption constant, KF, and the mass distribution coefficient, KD, of 64.266 ((mg/g(L/mg1/n and 119.65 L/g, respectively. Applicability of the Freundlich adsorption model suggests that heterogeneous surface adsorption affects the adsorption. The mean free energy value estimated using the Dubinin-Radushkevich isotherm was 0.136 kJ/mol indicating that physisorption may be predominant in the adsorption process.

  3. Renewable Energy

    NARCIS (Netherlands)

    Turkenburg, W.C.; Arent, D.; Bertani, R.; Faaij, A.P.C.; Hand, M.; Krewitt, W.; Larson, E.D.; Lund, J.; Mehos, M.; Merrigan, T.; Mitchell, C.; Moreira, J.R.; Sinke, W.C.; Sonntag-O'Brien, V.; Thresher, B.; Sark, W.G.J.H.M. van; Usher, E.

    2012-01-01

    This chapter presents an in-depth examination of major renewable energy technologies, including their installed capacity and energy supply in 2009 , the current state of market and technology development, their economic and financial feasibility in 2009 and in the near future, as well as major

  4. Characterization and flocculation properties of a carbohydrate bioflocculant from a newly isolated Bacillus velezensis 40B.

    Science.gov (United States)

    Zaki, Sahar A; Elkady, Marwa F; Farag, Soha; Abd-El-Haleem, Desouky

    2013-01-01

    In this study, a bioflocculant with a high flocculation activity (> 98%) produced by strain 40B, which was isolated from a brackish water was investigated By 16S rDNA sequence analysis, strain 40B was identified as Bacillus velezensis. Chemical analysis of the bioflocculant 40B indicated that it contained 2% protein and 98% carbohydrates. FTIR analysis showed the presence of carboxyl, hydroxyl and amino groups, which were preferred for the flocculation process. The optimal concentration for the flocculation activity was 3.5 mg (-1). This polysaccharide could also flocculate kaolin suspension over a wide range of pH (1-10) and temperature (5-85 degrees C) in the presence of CaCl2. The stability of the bioflocculant 40B under various conditions suggests its possible use in the industries and environmental applications. However, no previous report exists on the isolation and characterization of a bioflocculant from the Bacillus velezensis.

  5. Ratio between autoflocculating and target microalgae affects the energy-efficient harvesting by bio-flocculation

    NARCIS (Netherlands)

    Salim, S.; Vermuë, M.H.; Wijffels, R.H.

    2012-01-01

    The effect of ratio between autoflocculating and target microalgae in bio-flocculation was studied with emphasis on the recovery, sedimentation rate and energy demand for harvesting the target microalgae. When the autoflocculating microalgae Ettlia texensis, Ankistrodesmus falcatus and Scenedesmus

  6. Effect of sepiolite on the flocculation of suspensions of fibre-reinforced cement

    International Nuclear Information System (INIS)

    Jarabo, Rocio; Fuente, Elena; Moral, Ana; Blanco, Angeles; Izquierdo, Laura; Negro, Carlos

    2010-01-01

    Sepiolite is used to increase thixotropy of cement slurries for easier processing, to prevent sagging and to provide a better final quality in the manufacture of fibre-reinforced cement products. However, the effect of sepiolite on flocculation and its interactions with the components of fibre cement are yet unknown. The aim of this research is to study the effects of sepiolite on the flocculation of different fibre-reinforced cement slurries induced by anionic polyacrylamides (A-PAMs). Flocculation and floc properties were studied by monitoring the chord size distribution in real time employing a focused beam reflectance measurement (FBRM) probe. The results show that sepiolite increases floc size and floc stability in fibre-cement suspensions. Sepiolite competes with fibres and clay for A-PAMs adsorption and its interaction with A-PAM improves flocculation of mineral particles.

  7. Demonstration test on decontamination of contaminated pool water using liquid-solid settling technology with flocculants

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Adachi, Toshihiro; Watanabe, Noriyuki; Tagawa, Akihiro; Hosobuchi, Shigeki; Takanashi, Junko

    2013-01-01

    For the purpose of supplying agricultural water, a stationary purification system for contaminated water had been developed on the basis of the liquid-solid settling technology using flocculants. Two kinds of flocculants had been developed on the basis of preliminary tests: one that compounds iron ferrocyanide and the other that does not. With the use of this system and flocculants, a demonstration test was conducted to apply the decontamination technology on contaminated water in two swimming pools in an elementary school located at Motomiya City, Fukushima Prefecture, Japan. It is proved from the results that both the developed purification system and the flocculants can be established as a practicable decontamination technology for contaminated water: the treatment rate was 10 m 3 /hour and the elimination factor of radioactive materials was higher than 99%. (author)

  8. Development and Optimization of a Flocculation Procedure for Improved Solid-Liquid Separation of Digested Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Caroline; Lischeske, James J.; Sievers, David A.

    2015-11-03

    One viable treatment method for conversion of lignocellulosic biomass to biofuels begins with saccharification (thermochemical pretreatment and enzymatic hydrolysis), followed by fermentation or catalytic upgrading to fuels such as ethanol, butanol, or other hydrocarbons. The post-hydrolysis slurry is typically 4-8 percent insoluble solids, predominantly consisting of lignin. Suspended solids are known to inhibit fermentation as well as poison catalysts and obstruct flow in catalyst beds. Thus a solid-liquid separation following enzymatic hydrolysis would be highly favorable for process economics, however the material is not easily separated by filtration or gravimetric methods. Use of a polyacrylamide flocculant to bind the suspended particles in a corn stover hydrolyzate slurry into larger flocs (1-2mm diameter) has been found to be extremely helpful in improving separation. Recent and ongoing research on novel pretreatment methods yields hydrolyzate material with diverse characteristics. Therefore, we need a thorough understanding of rapid and successful flocculation design in order to quickly achieve process design goals. In this study potential indicators of flocculation performance were investigated in order to develop a rapid analysis method for flocculation procedure in the context of a novel hydrolyzate material. Flocculation conditions were optimized on flocculant type and loading, pH, and mixing time. Filtration flux of the hydrolyzate slurry was improved 170-fold using a cationic polyacrylamide flocculant with a dosing of approximately 22 mg flocculant/g insoluble solids at an approximate pH of 3. With cake washing, sugar recovery exceeded 90 percent with asymptotic yield at 15 L wash water/kg insoluble solids.

  9. Flocculation of Chlamydomonas reinhardtii with Different Phenotypic Traits by Metal Cations and High pH

    Directory of Open Access Journals (Sweden)

    Jianhua Fan

    2017-11-01

    Full Text Available Concentrating algal cells by flocculation as a prelude to centrifugation could significantly reduce the energy and cost of harvesting the algae. However, how variation in phenotypic traits such as cell surface features, cell size and motility alter the efficiency of metal cation and pH-induced flocculation is not well understood. Our results demonstrate that both wild-type and cell wall-deficient strains of the green unicellular alga Chlamydomonas reinhardtii efficiently flocculate (>90% at an elevated pH of the medium (pH 11 upon the addition of divalent cations such as calcium and magnesium (>5 mM. The trivalent ferric cation (at 10 mM proved to be essential for promoting flocculation under weak alkaline conditions (pH ∼8.5, with a maximum efficiency that exceeded 95 and 85% for wild-type CC1690 and the cell wall-deficient sta6 mutant, respectively. Near complete flocculation could be achieved using a combination of 5 mM calcium and a pH >11, while the medium recovered following cell removal could be re-cycled without affecting algal growth rates. Moreover, the absence of starch in the cell had little overall impact on flocculation efficiency. These findings contribute to our understanding of flocculation in different Chlamydomonas strains and have implications with respect to inexpensive methods for harvesting algae with different phenotypic traits. Additional research on the conditions (e.g., pH and metal ions used for efficient flocculation of diverse algal groups with diverse characteristics, at both small and large scale, will help establish inexpensive procedures for harvesting cell biomass.

  10. Chitosan-magnesium aluminum silicate composite dispersions: characterization of rheology, flocculate size and zeta potential.

    Science.gov (United States)

    Khunawattanakul, Wanwisa; Puttipipatkhachorn, Satit; Rades, Thomas; Pongjanyakul, Thaned

    2008-03-03

    Composite dispersions of chitosan (CS), a positively charged polymer, and magnesium aluminum silicate (MAS), a negatively charged clay, were prepared and rheology, flocculate size and zeta potential of the CS-MAS dispersions were investigated. High and low molecular weights of CS (HCS and LCS, respectively) were used in this study. Moreover, the effects of heat treatment at 60 degrees C on the characteristics of the CS-MAS dispersions and the zeta potential of MAS upon addition of CS at different pHs were examined. Incorporation of MAS into CS dispersions caused an increase in viscosity and a shift of CS flow type from Newtonian to pseudoplastic flow with thixotropic properties. Heat treatment brought about a significant decrease in viscosity and hysteresis area of the composite dispersions. Microscopic studies showed that flocculation of MAS occurred after mixing with CS. The size and polydispersity index of the HCS-MAS flocculate were greater than those of the LCS-MAS flocculate. However, a narrower size distribution and the smaller size of the HCS-MAS flocculate were found after heating at 60 degrees C. Zeta potentials of the CS-MAS flocculates were positive and slightly increased with increasing MAS content. In the zeta potential studies, the negative charge of the MAS could be neutralized by the addition of CS. Increasing the pH and molecular weight of CS resulted in higher CS concentrations required to neutralize the charge of MAS. These findings suggest that the electrostatic interaction between CS and MAS caused a change in flow behavior and flocculation of the composite dispersions, depending on the molecular weight of CS. Heat treatment affected the rheological properties and the flocculate size of the composite dispersions. Moreover, pH of medium and molecular weight of CS influence the zeta potential of MAS.

  11. Qualitative changes of riverine dissolved organic matter at low salinities due to flocculation

    Science.gov (United States)

    Asmala, Eero; Bowers, David G.; Autio, Riitta; Kaartokallio, Hermanni; Thomas, David N.

    2014-10-01

    The flocculation of dissolved organic matter (DOM) was studied along transects through three boreal estuaries. Besides the bulk concentration parameters, a suite of DOM quality parameters were investigated, including colored DOM (CDOM), fluorescent DOM, and the molecular weight of DOM as well as associated dissolved iron concentrations. We observed significant deviations from conservative mixing at low salinities (DOC), UV absorption (a(CDOM254)), and humic-like fluorescence. The maximum deviation from conservative mixing for DOC concentration was -16%, at salinities between 1 and 2. An associated laboratory experiment was conducted where an artificial salinity gradient between 0 and 6 was created. The experiment confirmed the findings from the estuarine transects, since part of the DOC and dissolved iron pools were transformed to particulate fraction (>0.2 µm) and thereby removing them from the dissolved phase. We also measured flocculation of CDOM, especially in the UV region of the absorption spectrum. Protein-like fluorescence of DOM decreased, while humic-like fluorescence increased because of salt-induced flocculation. Additionally, there was a decrease in molecular weight of DOM. Consequently, the quantity and quality of the remaining DOM pool was significantly changed after influenced to flocculation. Based on these results, we constructed a mechanistic, two-component flocculation model. Our findings underline the importance of the coastal filter, where riverine organic matter is flocculated and exported to the sediments.

  12. Turbidity and chlorine demand reduction using alum and moringa flocculation before household chlorination in developing countries.

    Science.gov (United States)

    Preston, Kelsey; Lantagne, Daniele; Kotlarz, Nadine; Jellison, Kristen

    2010-03-01

    Over 1.1 billion people in the world lack access to improved drinking water. Diarrhoeal and other waterborne diseases cause an estimated 1.87 million deaths per year. The Safe Water System (SWS) is a household water treatment intervention that reduces diarrhoeal disease incidence among users in developing countries. Turbid waters pose a particular challenge to implementation of SWS programmes; although research shows that a 3.75 mg l(-1) sodium hypochlorite dose effectively treats turbid waters, users sometimes object to the strong chlorine taste and prefer to drink water that is more aesthetically pleasing. This study investigated the efficacy of two locally available chemical water treatments-alum and Moringa oleifera flocculation-to reduce turbidity and chlorine demand at turbidities of 10, 30, 70, 100 and 300 NTU. Both treatments effectively reduced turbidity (alum flocculation 23.0-91.4%; moringa flocculation 14.2-96.2%). Alum flocculation effectively reduced chlorine demand compared with controls at 30, 70, 100 and 300 NTU (p=0.01-0.06). Moringa flocculation increased chlorine demand to the point where adequate free chlorine residual was not maintained for 24 hours after treatment. Alum pretreatment is recommended in waters>or=30 NTU for optimum water disinfection. Moringa flocculation is not recommended before chlorination.

  13. First-principles flocculation as the key to low energy algal biofuels processing.

    Energy Technology Data Exchange (ETDEWEB)

    Hewson, John C.; Wyatt, Nicholas B.; Pierce, Flint; Brady, Patrick Vane; Dwyer, Brian P.; Grillet, Anne; Hankins, Matthew G; Hughes, Lindsey Gloe; Lechman, Jeremy B.; Mondy, Lisa Ann; Murton, Jaclyn K.; O' Hern, Timothy J; Parchert, Kylea Joy; Pohl, Phillip Isabio; Williams, Cecelia Victoria; Zhang, Xuezhi; Hu, Qiang; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton

    2012-09-01

    This document summarizes a three year Laboratory Directed Research and Development (LDRD) program effort to improve our understanding of algal flocculation with a key to overcoming harvesting as a techno-economic barrier to algal biofuels. Flocculation is limited by the concentrations of deprotonated functional groups on the algal cell surface. Favorable charged groups on the surfaces of precipitates that form in solution and the interaction of both with ions in the water can favor flocculation. Measurements of algae cell-surface functional groups are reported and related to the quantity of flocculant required. Deprotonation of surface groups and complexation of surface groups with ions from the growth media are predicted in the context of PHREEQC. The understanding of surface chemistry is linked to boundaries of effective flocculation. We show that the phase-space of effective flocculation can be expanded by more frequent alga-alga or floc-floc collisions. The collision frequency is dependent on the floc structure, described in the fractal sense. The fractal floc structure is shown to depend on the rate of shear mixing. We present both experimental measurements of the floc structure variation and simulations using LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). Both show a densification of the flocs with increasing shear. The LAMMPS results show a combined change in the fractal dimension and a change in the coordination number leading to stronger flocs.

  14. SODIUM TITANATE NANOBELT AS A MICROPARTICLE TO INDUCE CLAY FLOCCULATION WITH CPAM

    Directory of Open Access Journals (Sweden)

    Wenxia Liu

    2010-07-01

    Full Text Available Sodium titanate nanobelt was synthesized by treating titanium dioxide hydrothermally in concentrated sodium hydroxide solution. The product was characterized by SEM analysis and zeta potential measurement. It served as a microparticle to constitute a microparticle retention system with cationic polyacrylamide (CPAM, while the microparticle system was employed to induce the flocculation of kaolin clay. The flocculation behavior of kaolin clay in such a system was investigated by using a photometric dispersion analyzer connected with a dynamic drainage jar. It was found that the sodium titanate nanobelt carried negative charges and had a lower zeta potential at higher pH. It gave a large synergistic flocculation effect with CPAM at a very low dosage, and showed higher flocculation effect with CPAM under neutral and weak alkaline conditions. A suitably high shear level was helpful for the re-flocculation of clay by sodium titanate nanobelt. The clay flocculation induced by CPAM/titanate nanobelt system demonstrated high shear resistance and also generated dense flocs.

  15. Kaolinite flocculation induced by smectite addition - a transmission X-ray microscopic study.

    Science.gov (United States)

    Zbik, Marek S; Song, Yen-Fang; Frost, Ray L

    2010-09-01

    The influence of smectite addition on kaolinite suspensions in water was investigated by transmission X-ray microscopy (TXM) and Scanning Electron Microscopy (SEM). Sedimentation test screening was also conducted. Micrographs were processed by the STatistic IMage Analysing (STIMAN) program and structural parameters were calculated. From the results of the sedimentation tests important influences of small smectite additions to about 3wt.% on kaolinite suspension flocculation has been found. In order to determine the reason for this smectite impact on kaolinite suspension, macroscopic behaviour micro-structural examination using Transmission X-ray Microscope (TXM) and SEM has been undertaken. TXM & SEM micrographs of freeze-dried kaolinite-smectite suspensions with up to 20% smectite showed a high degree of orientation of the fabric made of highly oriented particles and greatest density when 3wt.% of smectite was added to the 10wt.% dense kaolinite suspension. In contrast, suspensions containing pure kaolinite do not show such platelet mutual orientation but homogenous network of randomly oriented kaolinite platelets. This suggests that in kaolinite-smectite suspensions, smectite forms highly oriented basic framework into which kaolinite platelets may bond in face to face preferential contacts strengthening structure and allowing them to show plastic behaviour which is cause of platelets orientation. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Flocculation in ale brewing strains of Saccharomyces cerevisiae: re-evaluation of the role of cell surface charge and hydrophobicity.

    Science.gov (United States)

    Holle, Ann Van; Machado, Manuela D; Soares, Eduardo V

    2012-02-01

    Flocculation is an eco-friendly process of cell separation, which has been traditionally exploited by the brewing industry. Cell surface charge (CSC), cell surface hydrophobicity (CSH) and the presence of active flocculins, during the growth of two (NCYC 1195 and NCYC 1214) ale brewing flocculent strains, belonging to the NewFlo phenotype, were examined. Ale strains, in exponential phase of growth, were not flocculent and did not present active flocculent lectins on the cell surface; in contrast, the same strains, in stationary phase of growth, were highly flocculent (>98%) and presented a hydrophobicity of approximately three to seven times higher than in exponential phase. No relationship between growth phase, flocculation and CSC was observed. For comparative purposes, a constitutively flocculent strain (S646-1B) and its isogenic non-flocculent strain (S646-8D) were also used. The treatment of ale brewing and S646-1B strains with pronase E originated a loss of flocculation and a strong reduction of CSH; S646-1B pronase E-treated cells displayed a similar CSH as the non-treated S646-8D cells. The treatment of the S646-8D strain with protease did not reduce CSH. In conclusion, the increase of CSH observed at the onset of flocculation of ale strains is a consequence of the presence of flocculins on the yeast cell surface and not the cause of yeast flocculation. CSH and CSC play a minor role in the auto-aggregation of the ale strains since the degree of flocculation is defined, primarily, by the presence of active flocculins on the yeast cell wall.

  17. Treatment of waste water by coagulation and flocculation using biomaterials

    Science.gov (United States)

    Muruganandam, L.; Saravana Kumar, M. P.; Jena, Amarjit; Gulla, Sudiv; Godhwani, Bhagesh

    2017-11-01

    The present study deals with the determination of physical and chemical parameters in the treatment process of waste water by flocculation and coagulation processes using natural coagulants and assessing their feasibility for water treatment by comparing the performance with each other and with a synthetic coagulant. Initial studies were done on the synthetic waste water to determine the optimal pH and dosage, the activity of natural coagulant, followed by the real effluent from tannery waste. The raw tannery effluent was bluish-black in colour, mildly basic in nature, with high COD 4000mg/l and turbidity in the range 700NTU, was diluted and dosed with organic coagulants, AloeVera, MoringaOleifera and Cactus (O.ficus-indica). The study observed that coagulant Moringa Oleifera of 15 mg/L dose at 6 pH gave the best reduction efficiencies for major physicochemical parameters followed by Aloe Vera and Cactus under identical conditions. The study reveals that the untreated tannery effluents can be treated with environmental confirmative naturally occurring coagulants.

  18. Automation of a flocculation test for syphilis on Groupamatic equipment.

    Science.gov (United States)

    Garretta, M; Paris-Hamelin, A; Gener, J; Muller, A; Matte, C; Vaisman, A

    1975-01-01

    A flocculation reaction employing a cardiolipid antigen was used for syphilis screening on Groupamatic equipment in parallel with conventional screening reactions: Kolmer CF, RPCF, Kahn, Kline, and RPR. The positive samples were confirmed by FTA-200, FTA-ABS, TPI, and in some cases by TPHA. There were 5,212 known samples which had already been tested by all methods and of which 1,648 were positive, and 58,636 screened samples including 65 positives. Half of the samples in the first series were taken without anticoagulant; the remainder were collected in potassium EDTA. The percentage of false positives with the Groupamatic was about 1-4 per cent. The percentage of false negatives among positve (greater than or equal+) samples varied from 0-18 to 1-3 per cent.; on the other hand the sensitivity was less good for samples giving doubtful and/or dissociated reactions in conventional screening reactions. The specificity and sensitivity of this technique are acceptable for a blood transfusion centre. The reproducibility is excellent and the automatic reading of results accurate. Additional advantages are rapidity (340 samples processed per hour); simultaneous performance of eleven other immunohaematological reactions; no contamination between samples; automatic reading, interpretation, and print-out of results; and saving of time because samples are not filed sequentially and are automatically identified when the results are obtained. Although the importance of syphilis in blood transfusion seems small, estimates of the risk are difficult and further investigations are planned. Images PMID:1098731

  19. Evaluation of Flocculation and Filtration Procedures Applied to WSRC Sludge: A Report from B. Yarar, Colorado School of Mines

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.R.

    2001-06-04

    This report, addresses fundamentals of flocculation processes shedding light on why WSRC researchers have not been able to report the discovery of a successful flocculant and acceptable filtration rates. It also underscores the importance of applying an optimized flocculation-testing regime, which has not been adopted by these researchers. The final part of the report proposes a research scheme which should lead to a successful choice of flocculants, filtration aids (surfactants) and a filtration regime, as well recommendations for work that should be carried out to make up for the deficiencies of the limited WSRC work where a better performance should be the outcome.

  20. Introduction to Renewable Energy Systems

    DEFF Research Database (Denmark)

    Ma, Ke; Yang, Yongheng; Blaabjerg, Frede

    2014-01-01

    . It is concluded that as the quick development of renewable energy, wind power and PV power both show great potential to be largely integrated into the power grid. Power electronics is playing essential role in both of the systems to achieve more controllable, efficient, and reliable energy production......In this chapter, the state-of-the-arts developments of renewable energy are reviewed in respect to the installed power and market share, where wind power and photovoltaic power generation are the main focuses due to the fast growing speed and large share of installed capacity. Some basic principles...... of operation, mission profiles, as well as power electronics solutions and corresponding controls are discussed respectively in the case of wind power and photovoltaic power systems. Finally a few development trends for renewable energy conversions are also given from a power electronics point of view...

  1. Operating Conditions of Coagulation-Flocculation Process for High Turbidity Ceramic Wastewater

    Directory of Open Access Journals (Sweden)

    Sameer Al-Asheh

    2017-04-01

    Full Text Available This work attempted to determine the optimum conditions required for the coagulation and flocculation process as an essential stage of the ceramic wastewater treatment. Coagulation and flocculation is a very necessary step in industries as it lessens turbidity, color, and odor of wastewater. The experimental work was performed in several runs. The volume of wastewater used in each run was 200 mL and was kept at this value throughout. In certain runs, the speed of the mixer was varied while keeping the quantity of coagulant and flocculant constant in order to determine the optimum speed that resulted in the least turbidity. A speed of 5% was chosen as the ideal process speed according to the results obtained. Next, experiments were operated at this optimum speed while changing the dosage of coagulant and flocculant in order to decide the optimum dosage. Coagulant and flocculent amounts of 0.4 g (without booster and 0.2 g (with booster selected after the readings were taken. For all the readings, a turbidity meter was used providing results in Nephelometric Turbidity Units (NTU. Lowest turbidity was achieved when using 5% speed with 0.4 grams of coagulant and 0.4 grams of flocculant, or 5% speed with 0.2 grams of coagulant, 0.2 grams of flocculant and 0.25 g/L of booster coagulant. According to factorial design analysis, such as parameters as impeller speed and dosage have an influential impact on the turbidity; while the booster has insignificant influence and other interactions between parameters are important.

  2. Front-face fluorescence spectroscopy study of globular proteins in emulsions: influence of droplet flocculation.

    Science.gov (United States)

    Rampon, V; Genot, C; Riaublanc, A; Anton, M; Axelos, M A V; McClements, D J

    2003-04-23

    Measurement of the intensity (I(MAX)) and/or wavelength (lambda(MAX)) of the maximum in the tryptophan (TRP) emission spectrum using front-face fluorescence spectroscopy (FFFS) can be used to provide information about the molecular environment of proteins in nondiluted emulsions. Many protein-stabilized emulsions in the food industry are flocculated, and therefore, we examined the influence of droplet flocculation on FFFS. Stock oil-in-water emulsions stabilized by bovine serum albumin were prepared by high-pressure valve homogenization (30 wt % n-hexadecane, 0.35 wt % BSA, pH 7). These emulsions were used to create model systems with different degrees of droplet flocculation, either by changing the pH, adding surfactant, or adding xanthan. Emulsions (21 wt % n-hexadecane, 0.22 wt % BSA) with different pH (5 and 7) and molar ratios of Tween 20 to BSA (R = 0-131) were prepared by dilution of the stock emulsion. As the surfactant concentration was increased, the protein was displaced from the droplet surfaces, which caused an increase in both I(MAX) and lambda(MAX), because of the change in TRP environment. The dependence of I(MAX) and lambda(MAX) on surfactant concentration followed a similar pattern in emulsions that were initially flocculated (pH 5) and nonflocculated (pH 7). Relatively small changes in FFFS emission spectra were observed in emulsions (21 wt % n-hexadecane, 0.22 wt % BSA, pH 7) with different levels of depletion flocculation induced by adding xanthan. These results suggested that droplet flocculation did not have a major impact on FFFS. This study shows that FFFS is a powerful technique for nondestructively providing information about the molecular environment of proteins in concentrated and flocculated protein-stabilized emulsions. Nevertheless, in general the suitability of the technique may also depend on protein type and the nature of the physicochemical matrix surrounding the proteins.

  3. Rapid removal of fine particles from mine water using sequential processes of coagulation and flocculation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, M.; Lee, H.J.; Shim, Y. [Korean Mine Reclamation Corporation MIRECO, Seoul (Republic of Korea)

    2010-07-01

    The processes of coagulation and flocculation using high molecular weight long-chain polymers were applied to treat mine water having fine flocs of which about 93% of the total mass was less than 3.02 {mu} m, representing the size distribution of fine particles. Six different combinations of acryl-type anionic flocculants and polyamine-type cationic coagulants were selected to conduct kinetic tests on turbidity removal in mine water. Optimization studies on the types and concentrations of the coagulant and flocculant showed that the highest rate of turbidity removal was obtained with 10 mg L{sup -1} FL-2949 (coagulant) and 12 mg L{sup -1} A333E (flocculant), which was about 14.4 and 866.7 times higher than that obtained with A333E alone and that obtained through natural precipitation by gravity, respectively. With this optimized condition, the turbidity of mine water was reduced to 0 NTU within 20 min. Zeta potential measurements were conducted to elucidate the removal mechanism of the fine particles, and they revealed that there was a strong linear relationship between the removal rate of each pair of coagulant and flocculant application and the zeta potential differences that were obtained by subtracting the zeta potential of flocculant-treated mine water from the zeta potential of coagulant-treated mine water. Accordingly, through an optimization process, coagulation-flocculation by use of polymers could be advantageous to mine water treatment, because the process rapidly removes fine particles in mine water and only requires a small-scale plant for set-up purposes owing to the short retention time in the process.

  4. Rapid removal of fine particles from mine water using sequential processes of coagulation and flocculation.

    Science.gov (United States)

    Jang, Min; Lee, Hyun-Ju; Shim, Yonsik

    2010-04-01

    The processes of coagulation and flocculation using high molecular weight long-chain polymers were applied to treat mine water having fine flocs of which about 93% of the total mass was less than 3.02 microm, representing the size distribution of fine particles. Six different combinations of acryl-type anionic flocculants and polyamine-type cationic coagulants were selected to conduct kinetic tests on turbidity removal in mine water. Optimization studies on the types and concentrations of the coagulant and flocculant showed that the highest rate of turbidity removal was obtained with 10 mg L(-1) FL-2949 (coagulant) and 12 mg L(-1) A333E (flocculant), which was about 14.4 and 866.7 times higher than that obtained with A333E alone and that obtained through natural precipitation by gravity, respectively. With this optimized condition, the turbidity of mine water was reduced to 0 NTU within 20 min. Zeta potential measurements were conducted to elucidate the removal mechanism of the fine particles, and they revealed that there was a strong linear relationship between the removal rate of each pair of coagulant and flocculant application and the zeta potential differences that were obtained by subtracting the zeta potential of flocculant-treated mine water from the zeta potential of coagulant-treated mine water. Accordingly, through an optimization process, coagulation-flocculation by use of polymers could be advantageous to mine water treatment, because the process rapidly removes fine particles in mine water and only requires a small-scale plant for set-up purposes owing to the short retention time in the process.

  5. The renewable alternative

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses renewable energy sources as an alternative to a fossil fuel based economy. The topics discussed in the chapter include the historic aspects and current status of use of renewable energy, status of the renewable energy industry, market barriers to renewable energy, research and development and commercialization of renewable energy, the environmental and social costs associated with renewable energy, valuing future costs and benefits of energy use, and the potential market of renewable energy

  6. Co-Flocculation of Yeast Species, a New Mechanism to Govern Population Dynamics in Microbial Ecosystems.

    Directory of Open Access Journals (Sweden)

    Debra Rossouw

    Full Text Available Flocculation has primarily been studied as an important technological property of Saccharomyces cerevisiae yeast strains in fermentation processes such as brewing and winemaking. These studies have led to the identification of a group of closely related genes, referred to as the FLO gene family, which controls the flocculation phenotype. All naturally occurring S. cerevisiae strains assessed thus far possess at least four independent copies of structurally similar FLO genes, namely FLO1, FLO5, FLO9 and FLO10. The genes appear to differ primarily by the degree of flocculation induced by their expression. However, the reason for the existence of a large family of very similar genes, all involved in the same phenotype, has remained unclear. In natural ecosystems, and in wine production, S. cerevisiae growth together and competes with a large number of other Saccharomyces and many more non-Saccharomyces yeast species. Our data show that many strains of such wine-related non-Saccharomyces species, some of which have recently attracted significant biotechnological interest as they contribute positively to fermentation and wine character, were able to flocculate efficiently. The data also show that both flocculent and non-flocculent S. cerevisiae strains formed mixed species flocs (a process hereafter referred to as co-flocculation with some of these non-Saccharomyces yeasts. This ability of yeast strains to impact flocculation behaviour of other species in mixed inocula has not been described previously. Further investigation into the genetic regulation of co-flocculation revealed that different FLO genes impact differently on such adhesion phenotypes, favouring adhesion with some species while excluding other species from such mixed flocs. The data therefore strongly suggest that FLO genes govern the selective association of S. cerevisiae with specific species of non-Saccharomyces yeasts, and may therefore be drivers of ecosystem organisational

  7. Flocculation-coagulation behaviour study of tailings of a fluorspar mineral processing plant

    International Nuclear Information System (INIS)

    Dzioba, B. R.; Diaz, A. A.; Menendez-Aguado, J. M.

    2004-01-01

    The objective of this work is to carry out a selection study of the most adequate flocculation-coagulation reagents to reduce the solids content in the overflow from the settling lagoons of a fluorspar processing plant. This overflow has 1/ solids content, clarified from a feed of 25% solids in the settling lagoons, and is pilled into a river. The importance of this work is enhanced by the fact that the plant is located in a low water resources area, and that eventually the water from the river is used for agriculture or even human consumption. It is relevant to find a working methodology which allow to improve the efficiency of the clarifying process and minimize the environmental impact. Regarding the research methodology, a series of trials were made at natural pH and 25 degree centigree to evaluate the action of those reagents which previously probed to be more efficient in this case: as flocculants were tried BOZEFLOC C 65, SEPARAN AP 273 P. SEPARAN MG 200, and as coagulant aluminium sulfate. The possible interaction of flocculation-coagulation processes was also studied, to obtain optimum result. As analysis criterium the total flocculation time was used, and as all essays were made in 100 ml probes, it corresponds with flocculation rate. As result of this study it can be concluded that the most efficient floculant was SEPARAN MG 200, at 4 g/T. with the observation that an excess of aluminium sulfate gets down the efficiency. (Author) 6 refs

  8. Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling during ethanol fermentation

    Directory of Open Access Journals (Sweden)

    Lili Li

    2017-03-01

    Full Text Available Objectives: To improve ethanolic fermentation performance of self-flocculating yeast, difference between a flocculating yeast strain and a regular industrial yeast strain was analyzed by transcriptional and metabolic approaches. Results: The number of down-regulated (industrial yeast YIC10 vs. flocculating yeast GIM2.71 and up-regulated genes were 4503 and 228, respectively. It is the economic regulation for YIC10 that non-essential genes were down-regulated, and cells put more “energy” into growth and ethanol production. Hexose transport and phosphorylation were not the limiting-steps in ethanol fermentation for GIM2.71 compared to YIC10, whereas the reaction of 1,3-disphosphoglycerate to 3-phosphoglycerate, the decarboxylation of pyruvate to acetaldehyde and its subsequent reduction to ethanol were the most limiting steps. GIM2.71 had stronger stress response than non-flocculating yeast and much more carbohydrate was distributed to other bypass, such as glycerol, acetate and trehalose synthesis. Conclusions: Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling will provide clues for improving the fermentation performance of GIM2.71.

  9. Flocculation of colloidal clay by bacterial polysaccharides: effect of macromolecule charge and structure.

    Science.gov (United States)

    Labille, J; Thomas, F; Milas, M; Vanhaverbeke, C

    2005-04-01

    The molecular mechanism of montmorillonite flocculation by bacterial polysaccharides was investigated, with special emphasis on the effect of carboxylic charges in the macromolecules on the mechanisms of interaction with the clay surface. An indirect way to quantify the energy of interaction was used, by comparing the flocculation ability of variously acidic polysaccharides. Data on tensile strength of aggregates in diluted suspension were collected by timed size measurements in the domain 0.1-600 microm, using laser diffraction. The flow behavior of settled aggregates was studied by rheology measurements. Flocculation of colloidal clay suspension by polysaccharides requires cancelling of the electrostatic repulsions by salts, which allows approach of clay surfaces close enough to be bridged by adsorbing macromolecules. The amount of acidic charges of the polysaccharides, and especially their location in the molecular structure, governs the bridging mechanism and the resulting tensile strength of the aggregates. The exposure of carboxylate groups located on side chains strongly promotes flocculation. In turn, charges located on the backbone of the polysaccharide are less accessible to interaction, and the flocculation ability of such polysaccharides is lowered. Measurements at different pH indicate that adsorption of acidic polysaccharides occurs via electrostatic interactions on the amphoteric edge surface of clay platelets, whereas neutral polysaccharides rather adsorb via weak interactions. Increased tensile strength in diluted aggregates due to strong surface interactions results in proportionally increased viscosity of the concentrated aggregates.

  10. Effective flocculation of Chlorella vulgaris using chitosan with zeta potential measurement

    Science.gov (United States)

    Low, Y. J.; Lau, S. W.

    2017-06-01

    Microalgae are considered as one promising source of third-generation biofuels due to their fast growth rates, potentially higher yield rates and wide ranges of growth conditions. However, the extremely low biomass concentration in microalgae cultures presents a great challenge to the harvesting of microalgae because a large volume of water needs to be removed to obtain dry microalgal cells for the subsequent oil extraction process. In this study, the fresh water microalgae Chlorella vulgaris (C. vulgaris) was effectively harvested using both low molecular weight (MW) and high MW chitosan flocculants. The flocculation efficiency was evaluated by physical appearance, supernatant absorbance, zeta potential and solids content after centrifugal dewatering. High flocculation efficiency of 98.0-99.0% was achieved at the optimal dosage of 30-40 mg/g with formation of large microalgae flocs. This study suggests that the polymer bridging mechanism was governing the flocculation behaviour of C. vulgaris using high MW chitosan. Besides, charge patch neutralisation mechanism prevailed at low MW chitosan where lower dosage was sufficient to reach near-zero zeta potential compared with the high MW chitosan. The amount of chitosan polymer present in the culture may also affect the mechanism of flocculation.

  11. Chemical modification of cobalt ferrite nanoparticles with possible application as asphaltene flocculant agent

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, G.E.; Clarindo, J.E.S.; Santo, K.S.E., E-mail: geiza.oliveira@ufes.br [Universidade Federal do Espirito Santo (CCE/DQUI/UFES), Vitoria, ES (Brazil). Centro de Ciencias Exatas. Dept. de Quimica; Souza Junior, F.G. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas

    2013-11-01

    Asphaltenes can cause enormous losses in the oil industry, because they are soluble only in aromatic solvents. Therefore, they must be removed from the petroleum before it is refined, using flocculant agents. Aiming to find new materials that can work as flocculant agents to asphaltenes, cobalt ferrite nanoparticles were chemically modified through acid-base reactions using dodecylbenzene sulfonic acid (DBSA) to increase their lipophilicity. Nanoparticle synthesis was performed using the co-precipitation method followed by annealing of these nanoparticles, aiming to change the structural phase. Modified and unmodified nanoparticles were tested by FTIR-ATR, XRD and TGA/DTA. In addition, precipitation onset of the asphaltenes was performed using modified and unmodified nanoparticles. These tests showed that modified nanoparticles have a potential application as flocculant agents used to remove asphaltenes before oil refining, since the presence of nanoparticles promotes the asphaltene precipitation onset with the addition of a small amount of non-solvent (author)

  12. Chemical modification of cobalt ferrite nanoparticles with possible application as asphaltene flocculant agent

    International Nuclear Information System (INIS)

    Oliveira, G.E.; Clarindo, J.E.S.; Santo, K.S.E.; Souza Junior, F.G.

    2013-01-01

    Asphaltenes can cause enormous losses in the oil industry, because they are soluble only in aromatic solvents. Therefore, they must be removed from the petroleum before it is refined, using flocculant agents. Aiming to find new materials that can work as flocculant agents to asphaltenes, cobalt ferrite nanoparticles were chemically modified through acid-base reactions using dodecylbenzene sulfonic acid (DBSA) to increase their lipophilicity. Nanoparticle synthesis was performed using the co-precipitation method followed by annealing of these nanoparticles, aiming to change the structural phase. Modified and unmodified nanoparticles were tested by FTIR-ATR, XRD and TGA/DTA. In addition, precipitation onset of the asphaltenes was performed using modified and unmodified nanoparticles. These tests showed that modified nanoparticles have a potential application as flocculant agents used to remove asphaltenes before oil refining, since the presence of nanoparticles promotes the asphaltene precipitation onset with the addition of a small amount of non-solvent (author)

  13. Particle-level simulations of flocculation in a fiber suspension flowing through a diffuser

    Directory of Open Access Journals (Sweden)

    Andrić Jelena S.

    2017-01-01

    Full Text Available We investigate flocculation in dilute suspensions of rigid, straight fibers in a decelerating flow field of a diffuser. We carry out numerical studies using a particle-level simulation technique that takes into account the fiber inertia and the non-creeping fiber-flow interactions. The fluid flow is governed by the Reynolds-averaged Navier-Stokes equations with the standard k-omega eddy-viscosity turbulence model. A one-way coupling between the fibers and the flow is considered with a stochastic model for the fiber dispersion due to turbulence. The fibers interact through short-range attractive forces that cause them to aggregate into flocs when fiber-fiber collisions occur. We show that ballistic deflection of fibers greatly increases the flocculation in the diffuser. The inlet fiber kinematics and the fiber inertia are the main parameters that affect fiber flocculation in the prediffuser region.

  14. Synthesis of carboxyl superparamagnetic ultrasmall iron oxide (USPIO) nanoparticles by a novel flocculation-redispersion process

    International Nuclear Information System (INIS)

    Cheng Changming; Kou Geng; Wang Xiaoliang; Wang Shuhui; Gu Hongchen; Guo Yajun

    2009-01-01

    We report a novel flocculation-redispersion method to synthesize and purify the biocompatible superparamagnetic ultrasmall iron oxide (USPIO) nanoparticles coated with carboxyl dextran derivative. First, USPIO nanoparticles were synthesized and flocculated to form the large clusters through bridging effect of polyvinyl alcohol (PVA) during coprecipitation process. Then the flocculated USPIO was separated and purified from the solution conveniently through magnetic sedimentation. Finally, USPIO in the clusters were released again and well dispersed through electrostatic repelling effect of citric acid with the aid of ultrasonic. The dispersed carboxyl-functionalized USPIO was conjugated with the monoclonal antibodies. And it has been proved that the antibodies anchored on USPIO still retained their bioactivity after the conjugation. These results implied that the USPIO synthesized have good potential as active targeting molecular probe in biomedical application.

  15. Sludge dewatering in a decanter centrifuge aided by cationic flocculant Praestol 855BS and essential oil of waste orange peels

    Directory of Open Access Journals (Sweden)

    Kowalczyk Anna

    2016-03-01

    Full Text Available In the study the comparative analysis of test results of drainage of municipal wastewater sludge was conducted with the use of flocculant Praestol 855BS and the mixture of flocculant Praestol 855BS 50% + orange essential oil 50%, as the reagents supporting this process. It was also attempted to reduce unpleasant smells exuding from the drained sludge.

  16. Flocculation of wheat straw soda lignin by hemoglobin and chicken blood: Effects of cationic polymer or calcium chloride

    Science.gov (United States)

    Flocculation can be used to separate non-sulfonated lignin from base hydrolyzed biomass. In the industrial process, the lignin is isolated by filtration and washed with water. Some of the lignin is lost in the wash water, and flocculation can be used to recover this lignin. Several ways of enhanc...

  17. Enhancing the auto-flocculation of photosynthetic bacteria to realize biomass recovery in brewery wastewater treatment.

    Science.gov (United States)

    Lu, Haifeng; Dong, Shan; Zhang, Guangming; Han, Ting; Zhang, Yuanhui; Li, Baoming

    2018-02-15

    Photosynthetic bacteria (PSB) wastewater treatment technology can simultaneously realize wastewater purification and biomass production. The produced biomass contains high value-added products, which can be used in medical and agricultural industry. However, because of the small size and high electronegativity, PSB are hard to be collected from wastewater, which hampers the commercialization of PSB-based industrial processes. Auto-flocculation is a low cost, energy saving, non-toxic biomass collection method for microbiology. In this work, the influence factors with their optimal levels and mechanism for enhancing the auto-flocculation of PSB were investigated in pure cultivation medium. Then PSB auto-flocculation performance in real brewery wastewater was probed. Results showed that Na + concentration, pH and light intensity were three crucial factors except the initial inoculum sizes and temperature. In the pure medium cultivation system, the optimal condition for PSB auto-flocculation was as follows: pH was 9.5, inoculum size was 420 mg l -1 , Na + concentration was 0.067 mol l -1 , light intensity was 5000 lux, temperature was 30°C. Under the optimal condition, the auto-flocculation ratio and biomass recovery reached 85.0% and 1488 mg l -1 , which improved by 1.67-fold and 2.14-fold compared with the PSB enrichment cultivation conditions, respectively. Mechanism analysis showed that the protein/polysaccharides ratio and absolute Zeta potential value had a liner relationship. For the brewery wastewater treatment, under the above optimal condition, the chemical oxygen demand removal reached 94.3% with the auto-flocculation ratio and biomass recovery of 89.6% and 1510 mg l -1 , which increased 2.75-fold and 2.77-fold, respectively.

  18. Flocculation kinetics and aggregate structure of kaolinite mixtures in laminar tube flow.

    Science.gov (United States)

    Vaezi G, Farid; Sanders, R Sean; Masliyah, Jacob H

    2011-03-01

    Flocculation is commonly used in various solid-liquid separation processes in chemical and mineral industries to separate desired products or to treat waste streams. This paper presents an experimental technique to study flocculation processes in laminar tube flow. This approach allows for more realistic estimation of the shear rate to which an aggregate is exposed, as compared to more complicated shear fields (e.g. stirred tanks). A direct sampling method is used to minimize the effect of sampling on the aggregate structure. A combination of aggregate settling velocity and image analysis was used to quantify the structure of the aggregate. Aggregate size, density, and fractal dimension were found to be the most important aggregate structural parameters. The two methods used to determine aggregate fractal dimension were in good agreement. The effects of advective flow through an aggregate's porous structure and transition-regime drag coefficient on the evaluation of aggregate density were considered. The technique was applied to investigate the flocculation kinetics and the evolution of the aggregate structure of kaolin particles with an anionic flocculant under conditions similar to those of oil sands fine tailings. Aggregates were formed using a well controlled two-stage aggregation process. Detailed statistical analysis was performed to investigate the establishment of dynamic equilibrium condition in terms of aggregate size and density evolution. An equilibrium steady state condition was obtained within 90 s of the start of flocculation; after which no further change in aggregate structure was observed. Although longer flocculation times inside the shear field could conceivably cause aggregate structure conformation, statistical analysis indicated that this did not occur for the studied conditions. The results show that the technique and experimental conditions employed here produce aggregates having a well-defined, reproducible structure. Copyright © 2011

  19. The treatment of low level effluents by flocculation and settling at the Chooz nuclear power plant

    International Nuclear Information System (INIS)

    Petteau, J.L.; Roofthooft, R.

    1989-01-01

    At the Chooz plant, radioactive effluents were formerly treated by evaporation, but because throughput was low, another method was studied. After laboratory tests, a 500 L/h flocculation and settling pilot plant was constructed, followed later by a 5 m 3 /h installation. The main isotopes eliminated are caesium-134 and caesium-137. Flocculation with copper ferrocyanide reduces the total activity to less than 500 Bq/L. The installation described in the paper was commissioned in 1984 and has been in industrial operation since 1985, processing all types of effluent. The evaporator can be set aside for boric acid recovery. (author). 3 figs, 1 tab

  20. Understanding flocculation mechanism of graphene oxide for organic dyes from water: Experimental and molecular dynamics simulation

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2015-11-01

    Full Text Available Flocculation treatment processes play an important role in water and wastewater pretreatment. Here we investigate experimentally and theoretically the possibility of using graphene oxide (GO as a flocculant to remove methylene blue (MB from water. Experimental results show that GO can remove almost all MB from aqueous solutions at its optimal dosages and molecular dynamics simulations indicate that MB cations quickly congregate around GO in water. Furthermore, PIXEL energy contribution analysis reveals that most of the strong interactions between GO and MB are of a van der Waals (London dispersion character. These results offer new insights for shedding light on the molecular mechanism of interaction between GO and organic pollutants.

  1. Very high gravity ethanol fermentation by flocculating yeast under redox potential-controlled conditions

    Directory of Open Access Journals (Sweden)

    Liu Chen-Guang

    2012-08-01

    Full Text Available Abstract Background Very high gravity (VHG fermentation using medium in excess of 250 g/L sugars for more than 15% (v ethanol can save energy consumption, not only for ethanol distillation, but also for distillage treatment; however, stuck fermentation with prolonged fermentation time and more sugars unfermented is the biggest challenge. Controlling redox potential (ORP during VHG fermentation benefits biomass accumulation and improvement of yeast cell viability that is affected by osmotic pressure and ethanol inhibition, enhancing ethanol productivity and yield, the most important techno-economic aspect of fuel ethanol production. Results Batch fermentation was performed under different ORP conditions using the flocculating yeast and media containing glucose of 201 ± 3.1, 252 ± 2.9 and 298 ± 3.8 g/L. Compared with ethanol fermentation by non-flocculating yeast, different ORP profiles were observed with the flocculating yeast due to the morphological change associated with the flocculation of yeast cells. When ORP was controlled at −100 mV, ethanol fermentation with the high gravity (HG media containing glucose of 201 ± 3.1 and 252 ± 2.9 g/L was completed at 32 and 56 h, respectively, producing 93.0 ± 1.3 and 120.0 ± 1.8 g/L ethanol, correspondingly. In contrast, there were 24.0 ± 0.4 and 17.0 ± 0.3 g/L glucose remained unfermented without ORP control. As high as 131.0 ± 1.8 g/L ethanol was produced at 72 h when ORP was controlled at −150 mV for the VHG fermentation with medium containing 298 ± 3.8 g/L glucose, since yeast cell viability was improved more significantly. Conclusions No lag phase was observed during ethanol fermentation with the flocculating yeast, and the implementation of ORP control improved ethanol productivity and yield. When ORP was controlled at −150 mV, more reducing power was available for yeast cells to survive, which in turn improved their viability and VHG

  2. An evaluation of soluble cations and anions on the conductivity and rate of flocculation of kaolins

    Science.gov (United States)

    Fulton, Deborah Lee

    1998-10-01

    The focus of this project was to learn how ionic concentrations and their contributions to electric conductivity influence the flocculation behavior of kaolin/water suspensions. Sodium silicate, calcium chloride, and magnesium sulfate were used as chemical additives. The specific surface areas, particle size distributions, and methylene blue indices for two kaolins were measured. The SSA and MBI for these kaolins indicated that they possessed inherent differences in SSA and flocculation behaviors. Rheological studies were also performed. Testing included simultaneous gelation, deflocculation, and pH tests. Viscosity, pH, temperature, and chemical additive concentrations were monitored at each point. Testing was performed at 45/55 wt% solids. Effects of additions of various levels of deflocculant and flocculant to each of the kaolin/water suspensions were studied by making several suspensions from each kaolin. The concentrations of dispersant, and flocculant levels and types were varied to produce suspensions with different chemical additive "histories," but all with similar final apparent viscosities. Slurry filtrates were analyzed for conductivity, pH, temperature, and ion concentrations of (Al3+, Fe2+,3+, Ca 2+, Mg+, Na+, SO4 2--, and Cl--). Plastic properties were calculated to determine how variations in suspension histories affected conductivities, pH, and detectable ion contents of the suspensions. These analyses were performed on starting slurries which were under-, completely-, and over-deflocculated before further additions of flocculants and deflocculant were added to tune the slurries to the final, constant, target viscosity. Results showed that rates of flocculation and conductivities increased as concentrations of ions increased. By increasing conductivity correlations with increases in flocculation occurs, which yields higher rates of buildup, or RBU [1]. This is the single most important slip control property in the whitewares industry. Shear

  3. Renewing governance.

    Science.gov (United States)

    Loos, Gregory P

    2003-01-01

    Globalization's profound influence on social and political institutions need not be negative. Critics of globalization have often referred to the "Impossible Trinity" because decision-making must 1. respect national sovereignty, 2. develop and implement firm regulation, and 3. allow capital markets to be as free as possible. To many, such goals are mutually exclusive because history conditions us to view policy-making and governance in traditional molds. Thus, transnational governance merely appears impossible because current forms of governance were not designed to provide it. The world needs new tools for governing, and its citizens must seize the opportunity to help develop them. The rise of a global society requires a greater level of generality and inclusion than is found in most policy bodies today. Politicians need to re-examine key assumptions about government. States must develop ways to discharge their regulatory responsibilities across borders and collaborate with neighboring jurisdictions, multilateral bodies, and business. Concepts such as multilateralism and tripartism show great promise. Governments must engage civil society in the spirit of shared responsibility and democratic decision-making. Such changes will result in a renewal of the state's purpose and better use of international resources and expertise in governance.

  4. Coagulation-flocculation process applied to wastewaters generated in hydrocarbon-contaminated soil washing: Interactions among coagulant and flocculant concentrations and pH value.

    Science.gov (United States)

    Torres, Luis G; Belloc, Claudia; Vaca, Mabel; Iturbe, Rosario; Bandala, Erick R

    2009-11-01

    Wastewater produced in the contaminated soil washing was treated by means of coagulation-flocculation (CF) process. The wastewater contained petroleum hydrocarbons, a surfactant, i.e., sodium dodecyl sulfate (SDS) as well as salts, brownish organic matter and other constituents that were lixiviated from the soil during the washing process. The main goal of this work was to develop a process for treating the wastewaters generated when washing hydrocarbon-contaminated soils in such a way that it could be recycled to the washing process, and also be disposed at the end of the process properly. A second objective was to study the relationship among the coagulant and flocculant doses and the pH at which the CF process is developed, for systems where methylene blue active substances (MBAS) as well as oil and greases were present. The results for the selection of the right coagulant and flocculant type and dose, the optimum pH value for the CF process and the interactions among the three parameters are detailed along this work. The best coagulant and flocculant were FeCl(3) and Tecnifloc 998 at doses of 4,000 and 1 mg/L, correspondingly at pH of 5. These conditions gave color, turbidity, chemical oxygen demand (COD) and conductivity removals of 99.8, 99.6, 97.1 and 35%, respectively. It was concluded that it is feasible to treat the wastewaters generated in the contaminated soil washing process through CF process, and therefore, wastewaters could be recycled to the washing process or disposed to drainage.

  5. Production of extracellular polymeric substances (EPS) by Serratia sp.1 using wastewater sludge as raw material and flocculation activity of the EPS produced.

    Science.gov (United States)

    Bezawada, J; Hoang, N V; More, T T; Yan, S; Tyagi, N; Tyagi, R D; Surampalli, R Y

    2013-10-15

    Growth profile and extracellular polymeric substances (EPS) production of Serratia sp.1 was studied in shake flask fermentation for 72 h using wastewater sludge as raw material. Maximum cell concentration of 6.7 × 10(9) cfu/mL was obtained at 48 h fermentation time. EPS dry weight, flocculation activity and dewaterability of different EPS (tightly bound or TB-EPS, loosely bound or LB-EPS and broth-EPS or B-EPS) were also measured. The highest concentration of LB-EPS (2.45 g/L) and TB-EPS (0.99 g/L) were attained at 48 h of fermentation. Maximum flocculation activity and dewaterability (ΔCST) of TB-EPS (76.4%, 14.5s and 76.5%, 15.5s), LB-EPS (67.8%, 8.1s and 64.7%, 7.6s) and broth EPS (61%, 6.1s and 70.4%, 6.8s) were obtained at 36 and 48 h of growth. Higher flocculation activity and dewaterability were achieved with TB-EPS than with the two other EPS. Characterization of TB-EPS and LB-EPS was done in terms of their protein and carbohydrate content. Protein content was much higher in TB-EPS where as carbohydrate content was only slightly higher in TB-EPS than LB-EPS. Morphology of the Serratia strain after fermentation in sludge and TSB was observed under a scanning electron microscope and the cell size was found to be bigger in the sludge medium than the TSB medium. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Polyelectrolyte flocculation of grain stillage for improved clarification and water recovery within bioethanol production facilities.

    Science.gov (United States)

    Menkhaus, Todd J; Anderson, Jason; Lane, Samuel; Waddell, Evan

    2010-04-01

    Polyelectrolytes were investigated for flocculation of a corn whole stillage stream to improve solid-liquid clarification operations and reduce downstream utility requirements for evaporation and drying within a bioethanol process. Despite a negative zeta potential for the stillage solids, an anionic polyelectrolyte was found to provide the best flocculation. At the optimal dosage of 1.1mg polymer/g dry suspended solids, an anionic flocculant provided a clarified stream with only 0.15% w/w suspended solids (equivalent to a total dissolved solid to total suspended solid ratio greater than 40, and a viscosity reduction of 39% compared to an unflocculated "clarified" stream). The resulting solids cake had greater than 40% w/w solids, and more than 80% water recovery was found in the clarified stream. Addition of flocculant improved filtration flux by six fold and/or would allow for up to a 4-times higher flow rate if using a decanting centrifuge for clarification of corn stillage. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Assessment of the shelf-life of Nannochloropsis oculata flocculates stored at different temperatures

    Directory of Open Access Journals (Sweden)

    Constanza Low

    2015-05-01

    Full Text Available The cell and culture viability of concentrates of the microalga Nannochloropsis oculata were assessed after storage for a period of 16 weeks at -18, 0 and 5°C. The concentrates were obtained from the crop of N. oculata, which was harvested at the start of the seasonal growth period using a process of flocculation. Flocotac Plus was used as the flocculation agent, achieving flocculation of 90% of the suspended microalgae. It was observed that the chemical process did not affect the number of live cells. The concentrate stored at -18°C presented slow freezing, which deteriorated the cells and therefore reduced cell viability after five weeks (75%. The concentrates stored at 0 and 5°C showed cell viability over 97% after the 16 weeks. Culture viability was only seen in the concentrates stored at 0 and 5°C, which showed specific growth rates similar to those of the control culture. It may be concluded that it is possible to use flocculates stored at 0 and 5°C after 16 weeks as inoculum for mass crops of N. oculata for food, green water and other uses.

  8. Biodiversity of autolytic ability in flocculent Saccharomyces cerevisiae strains suitable for traditional sparkling wine fermentation.

    Science.gov (United States)

    Perpetuini, Giorgia; Di Gianvito, Paola; Arfelli, Giuseppe; Schirone, Maria; Corsetti, Aldo; Tofalo, Rosanna; Suzzi, Giovanna

    2016-07-01

    Yeasts involved in secondary fermentation of traditional sparkling wines should show specific characteristics, such as flocculation capacity and autolysis. Recently it has been postulated that autophagy may contribute to the outcome of autolysis. In this study, 28 flocculent wine Saccahromyces cerevisiae strains characterized by different flocculation degrees were studied for their autolytic and autophagic activities. Autolysis was monitored in synthetic medium through the determination of amino acid nitrogen and total proteins released. At the same time, novel primer sets were developed to determine the expression of the genes ATG1, ATG17 and ATG29. Twelve strains were selected on the basis of their autolytic rate and ATG gene expressions in synthetic medium and were inoculated in a base wine. After 30, 60 and 180 days the autolytic process and ATG gene expressions were evaluated. The obtained data showed that autolysis and ATG gene expressions differed among strains and were independent of the degree of flocculation. This biodiversity could be exploited to select new starter stains to improve sparkling wine production. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Assessing the effectiveness and environmental impacts of using natural flocculants to manage turbidity.

    Science.gov (United States)

    2005-08-01

    The objective of this research was to determine the feasibility of using chitosan as a natural flocculant to control : turbidity during in-stream construction work. A series of field tests in Oak Creek, Corvallis, OR were conducted in : order to test...

  10. Biodegradable flocculants based on polyacrylamide and poly(N,N-dimethylacrylamide) grafted amylopectin.

    Science.gov (United States)

    Kolya, Haradhan; Tripathy, Tridib

    2014-09-01

    Synthesis of amylopectin grafted polyacrylamide (AP-g-PAM) and poly(N,N-dimethylacrylamide) (AP-g-PDMA) was carried out by Ce4+ in water medium. The reaction conditions for maximum grafting was optimized by varying the reaction variables, including the concentration of monomers, ceric ammonium nitrate (CAN), amylopectin, reaction time and temperature. The graft copolymers were characterized by FTIR spectroscopy, NMR (both 1H and 13C) spectroscopy, molecular weight determination and molecular weight distribution by using size exclusion chromatography (SEC), thermal analysis (TGA), SEM studies. Biodegradation of the graft copolymers was carried out by enzyme hydrolysis. Flocculation performances of the graft copolymers were evaluated in 1.0 wt% coal and 1.0 wt% silica suspensions. A comparative study of the flocculation performances of AP-g-PDMA and AP-g-PAM was also made. It shows that the flocculation performance of AP-g-PDMA was better than that of AP-g-PAM. AP-g-PDMA performed best when compared with other commercial flocculants in the same suspensions. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Effects of combined flocculant – Lanthanum modified bentonite treatment on aquatic macroinvertebrate fauna

    NARCIS (Netherlands)

    Waajen, G.; Pauwels, M.; Lürling, M.

    2017-01-01

    A low dose flocculant (FeCl3), combined with lanthanum modified bentonite (LMB) as phosphate-binding agent, has been applied for eutrophication management in Lake De Kuil (The Netherlands). After the treatment, the state of the lake shifted from hypertrophic to mesotrophic. Although

  12. Effect of flocculation on performance of arming yeast in direct ethanol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Khaw Teik Seong; Katakura, Yoshio; Ninomiya, Kazuaki; Shioya, Suteaki [Osaka Univ. (Japan). Dept. of Biotechnology; Bito, Yohei; Katahira, Satoshi; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering; Ueda, Mitsuyoshi [Kyoto Univ. (Japan). Div. of Applied Life Sciences

    2006-11-15

    In the direct ethanol fermentation of raw starch by arming yeast with {alpha}-amylase and glucoamylase, it is preferable to use a flocculent yeast because it can be recovered without centrifugation. Three types of arming yeast system, I (nonflocculent), II (mildly flocculent), and III (heavily flocculent), were constructed and their fermentation performances were compared. With an increase in the degree of flocculation, specific ethanol production rate for soluble starch decreased (0.19, 0.17, and 0.12 g g-dry-cell{sup -1} h{sup -1} for systems I, II, and III, respectively), but that for raw starch did not decrease as much as expected (0.06, 0.06, and 0.04 g g-dry-cell{sup -1} h{sup -1} for systems I, II and III, respectively). Microscopic observation revealed that many starch granules were captured in the yeast flocs in system III during the direct ethanol fermentation of raw starch. It was suggested that the capture of starch granules increases apparent substrate concentration for amylolytic enzymes in arming yeast cell flocs; thus, the specific ethanol production rate of system III was kept at a level comparable to those of the other systems. (orig.)

  13. APPLICATION OF ESSENTIAL OILS EXTRACTED FROM PEELS OF ORANGES AS A PARTIAL SUBSTITUTE OF FLOCCULANT

    Directory of Open Access Journals (Sweden)

    Anna Kowalczyk

    2016-05-01

    Full Text Available The study attempts to determine the optimum conditions of the process of mechanical dewatering of municipal sewage sludge and reduction of odours emitted during this process. The process of dewatering of municipal sewage sludge was carried out using laboratory sedimentation centrifuge of MPW-350 type. Municipal sewage sludge stabilized during anaerobic digestion, taken from Wastewater Treatment Plant Jamno. The dewatering process was aided by cationic flocculant Praestol 855BS of real solution concentration 0.3% and essential oil from orange, which was extracted from orange peels in the process of steam distillation. Constant parameters of dewatering process were: pH, temperature, colour, texture, smell, water content and dry matter content. Independent variables of dewatering process were: centrifugation time (in the range 1–10 min, centrifugation speed (in the range 1000–3000 rotations/min and dose of mixture of flocculant Praestol 855BS (79% + essential oil of orange (21% in the range 0–48 ml/dm3. Water content in the sludge after the process, dry matter content in the effluent and the duration of the smell of oil in the sediment were determined. Studies showed that the essential oil from orange may be used as a partial substitute of flocculant Praestol 855BS in the process of centrifugal sedimentation. Essential oil of orange significantly reduces unpleasant odours which are emitted from sludge during mechanical dewatering. Simultaneous application of both reagents, ie. flocculant Praestol 855BS 79%, and essential oil of orange 21% of volume is recommended.

  14. Toxicity of clay flocculation of the toxic dinoflagellate, Karenia brevis, to estuarine invertebrates and fish

    Science.gov (United States)

    The benthic environmental effects of proposed control procedures for red tide events are relatively unknown but important to understand. The objective of this study was to determine the laboratory-derived toxicities of a clay flocculation technique proposed for the Florida red ti...

  15. Enhanced removal of Zn(2+) or Cd(2+) by the flocculating Chlorella vulgaris JSC-7.

    Science.gov (United States)

    Alam, Md Asraful; Wan, Chun; Zhao, Xin-Qing; Chen, Li-Jie; Chang, Jo-Shu; Bai, Feng-Wu

    2015-05-30

    Microalgae are attracting attention due to their potentials in mitigating CO2 emissions and removing environmental pollutants. However, harvesting microalgal biomass from diluted cultures is one of the bottlenecks for developing economically viable processes for this purpose. Microalgal cells can be harvested by cost-effective sedimentation when flocculating strains are used. In this study, the removal of Zn(2+) and Cd(2+) by the flocculating Chlorella vulgaris JSC-7 was studied. The experimental results indicated that more than 80% Zn(2+) and 60% Cd(2+) were removed by the microalgal culture within 3 days in the presence up to 20.0mg/L Zn(2+) and 4.0mg/L Cd(2+), respectively, which were much higher than that observed with the culture of the non-flocculating C. vulgaris CNW11. Furthermore, the mechanism underlying this phenomenon was explored by investigating the effect of Zn(2+) and Cd(2+) on the growth and metabolic activities of the microalgal strains. It was found that the flocculation of the microalga improved its growth, synthesis of photosynthetic pigments and antioxidation activity under the stressful conditions, indicating a better tolerance to the heavy metal ions for a potential in removing them more efficiently from contaminated wastewaters, together with a bioremediation of other nutritional components contributed to the eutrophication of aquatic ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Batch Sedimentation Studies for Freshwater Green Alga Scenedesmus abundans Using Combination of Flocculants

    Directory of Open Access Journals (Sweden)

    Raghu K. Moorthy

    2017-06-01

    Full Text Available Microalga is the only feedstock that has the theoretical potential to completely replace the energy requirements derived from fossil fuels. However, commercialization of this potential source for fuel applications is hampered due to many technical challenges with harvesting of biomass being the most energy intensive process among them. The fresh water microalgal species, Scenedesmus abundans, has been widely recognized as a potential feedstock for production of biodiesel (Mandotra et al., 2014. The present work deals with sedimentation of algal biomass using extracted chitosan and natural bentonite clay powder as flocculant. The effect of flocculant combination and different factors such as temperature, pH, and concentration of algal biomass on sedimentation rates has been analyzed. A high flocculation efficiency of 76.22 ± 7.81% was obtained at an algal biomass concentration of 1 ± 0.05 g/L for a settling time of 1 h at 50 ± 5°C with a settling velocity of 103.2 ± 0.6 cm/h and a maximum surface conductivity of 2,260 ± 2 μS/cm using an optimal design in response surface methodology (RSM. Biopolymer flocculant such as chitosan exhibited better adsorption property along with bentonite clay powder that reduced the settling time significantly.

  17. Optimization of Alkaline Flocculation for Harvesting of Scenedesmus quadricauda #507 and Chaetoceros muelleri #862

    Directory of Open Access Journals (Sweden)

    Shuhao Huo

    2014-09-01

    Full Text Available A response surface methodology (RSM was used to evaluate the effects of pH and microalgal biomass concentration (BC on alkaline flocculating activity for harvesting one freshwater green algae Scenedesmus quadricauda #507 and one marine diatom Chaetoceros muelleri #862. The pH value and BC were in range of 9.0–12.0 and 0.20–2.30 g/L, respectively. Very high regression coefficient between the variables and the response indicates excellent evaluation of experimental data by second-order regressions. Optimum conditions for flocculating activity were estimated as follows: (i pH 11.6, BC 0.54 g/L for strain #507 and (ii pH 11.5, BC 0.42 g/L for strain #862. The maximum flocculating activity was around 94.7% and 100%, respectively. Furthermore, the addition of synthetic ocean water (SOW to the freshwater #507 culture can increase the flocculating activity from 82.13%–88.79% in low algae concentration (0.52 g/L and 82.92%–95.60% in high concentration (2.66 g/L.

  18. Synthesis and flocculation properties of gum ghatti andpoly(acrylamide-co-acrylonitrile) based biodegradable hydrogels

    CSIR Research Space (South Africa)

    Mittal, H

    2014-12-01

    Full Text Available This article reports the development of biodegradable flocculants based on graft co-polymers of gum ghatti (Gg) and a mixture of acrylamide and acrylonitrile co-monomers (AAm-co-AN). The hydrogel polymer exhibited an excellent swelling capacity...

  19. Coagulation and flocculation in the preparation of drinking water in a pilot plant

    Directory of Open Access Journals (Sweden)

    Iličić Gordana

    2005-01-01

    Full Text Available The objective of the practical part in this article was to explore the influence of different parameters on coagulation and flocculation processes as well as the influence of this stage on other stages in water purification. Analysis of the water samples was conducted in the chemical laboratory of Banja Luka Municipal Waterworks using standard methods for analyzing drinking water. The results are presented as diagrams that show the dependence of different parameters as a function of the residual turbidity and the content of natural organic matters in water. The following conclusions were drawn It is necessary to conduct the chemical treatment of raw water with the aim to satisfy chemical and bacteriological standards for drinking water. The best results were achieved with Al2(SO4s as coagulant,. Counterrecoil sludge in an amount of 2-3% in relation with the total quantity of water has a positive impacts on coagulation-flocculation processes. 4. For effective purification, all the conditions for coagulation-flocculation must be adjusted for the filter to have a longer useful life. One of example is correction of the pH to pH=7, coagulant dose 20 mg/L Al2(SO4s, flocculant dose 0.1 mg/L PE, counterrecoil sludge dose 90 L/h PM.

  20. TREATMENT OF LANDFILL LEACHATE BY COUPLING COAGULATION-FLOCCULATION OR OZONATION TO GRANULAR ACTIVATED CARBON ADSORPTION.

    Science.gov (United States)

    Oloibiri, Violet; Ufomba, Innocent; Chys, Michael; Audenaert, Wim; Demeestere, Kristof; Van Hulle, Stijn W H

    2015-01-01

    A major concern for landfilling facilities is the treatment of their leachate. To optimize organic matter removal from this leachate, the combination of two or more techniques is preferred in order to meet stringent effluent standards. In our study, coagulation-flocculation and ozonation are compared as pre- treatment steps for stabilized landfill leachate prior to granular activated carbon (GAC) adsorption. The efficiency of the pre treatment techniques is evaluated using COD and UVA254 measurements. For coagulation- flocculation, different chemicals are compared and optimal dosages are determined. After this, iron (III) chloride is selected for subsequent adsorption studies due to its high percentage of COD and UVA254 removal and good sludge settle-ability. Our finding show that ozonation as a single treatment is effective in reducing COD in landfill leachate by 66% compared to coagulation flocculation (33%). Meanwhile, coagulation performs better in UVA254 reduction than ozonation. Subsequent GAC adsorption of ozonated effluent, coagulated effluent and untreated leachate resulted in 77%, 53% and 8% total COD removal respectively (after 6 bed volumes). The effect of the pre-treatment techniques on GAC adsorption properties is evaluated experimentally and mathematically using Thomas and Yoon-Nelson models. Mathematical modelling of the experimental GAC adsorption data shows that ozonation increases the adsorption capacity and break through time with a factor of 2.5 compared to coagulation-flocculation.

  1. Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes

    Institute of Scientific and Technical Information of China (English)

    ZAYAS Pérez Teresa; GEISSLER Gunther; HERNANDEZ Fernando

    2007-01-01

    The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculatio and advanced oxidation processes(AOP)had been studied.The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H202,UVO3 and UV/H-H202/O3 processes was determined under acidic conditions.For each of these processes,different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater.Coffee wastewater is characterized by a high chemical oxygen demand(COD)and low total suspended solids.The outcomes of coffee wastewater reeatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD,color,and turbidity.It was found that a reductiOn in COD of 67%could be realized when the coffee wastewater was treated by chemical coagulation-flocculatlon witll lime and coagulant T-1.When coffee wastewater was treated by coagulation-flocculation in combination with UV/H202,a COD reduction of 86%was achieved,although only after prolonged UV irradiation.Of the three advanced oxidation processes considered,UV/H202,uv/03 and UV/H202/03,we found that the treatment with UV/H2O2/O3 was the most effective,with an efficiency of color,turbidity and further COD removal of 87%,when applied to the flocculated coffee wastewater.

  2. DMC-grafted cellulose as green-based flocculants for agglomerating fine kaolin particles

    Directory of Open Access Journals (Sweden)

    Meng Li

    2018-04-01

    Full Text Available Novel cellulose based flocculants C-g-P (DMC with various chain architectures are synthesized through a situ graft copolymerization. The cationic ammonium chloride group (DMC is grafted onto cellulose by two separate inverse emulsion polymerization with γ-methacryloxypropyl trimethoxy silane (KH-570 and double bond addition reactions, which is a new and simple method to employ KH-570 as a bridge for the connection of cellulose matrix and DMC group. The effects of pH, flocculant dose, standing time on turbidity of kaolin suspensions and particle sizes have been studied systematically. In addition, the response surface methodology (RSM study confirms that PAC and C-g-P (DMC have synergy in turbidity removal with a higher removal efficiency of 98.32%. Moreover, C-g-P (DMC 1 has higher removal efficiency with 96.5% at a low dosage of 0.6 mg L−1 and better floc properties than C-g-P (DMC 2 and C-g-P (DMC 3, suggesting that the length and quantity of cationic branch chains play a crucial role in Kaolin flocculation due to their dramatically enhanced bridging effects. Keywords: Cellulose, Cationic flocculant, Inverse emulsion polymerization, Kaolin suspension

  3. Dextran-induced depletion flocculation in oil-water emulsions in the presence of sucrose

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Zoet, F.D.; Vliet, van T.; Linden, van der E.; Aken, van G.A.

    2004-01-01

    The phase behaviour and mechanical properties of 10 wt% oil-in-water emulsions, stabilised by ß-lactoglobulin (ß-lg) and flocculated by the polysaccharide dextran were studied as a function of sucrose concentration. The sucrose concentration affected neither the polysaccharide concentration above

  4. Recovery of kaolinite from tailings of Zonouz kaolin-washing plant by flotation-flocculation method

    Directory of Open Access Journals (Sweden)

    Kianoush Barani

    2018-04-01

    Full Text Available The traditional processing of kaolin is achieved by dispersion of the mined ore and classification by multistage hydrocyclone plants. The inefficiencies inherent to cyclones produce a middling product that is commonly disposed back into the quarry. In this research, recovery of kaolinite from tailings of Zonouz kaolin washing plant, which is located in Iran was investigated by flotation and flotation- flocculation. Flotation experiments show that the flotation of kaolinite from the tailings is better in an acidic than in an alkaline medium containing cationic collectors. Flotation under acidic condition causes problems such as equipment corrosion at industrial scale. As a result, the cationic flotation of kaolinite is enhanced by addition of polyacrylamide as a flocculant. The results showed flocculation by polyacrylamide improved flotation of kaolinite within a range of pH. With 300 g/t dodecylamine, 500 g/t aluminum chloride, 50 g/t pine oil (frother, 15 g/t polyacrylamide, at pH = 7 and without de-slimming a product has 37.19% Al2O3, 54.19% SiO2 and 34.43% mass recovery was archived. Keywords: Kaolinite, Flotation, Flocculation, Cetylpyridinium chloride, Dodecylamine, Aluminum chloride, Polyacrylamide

  5. Impacts of flocculation on the distribution and diagenesis of iron in boreal estuarine sediments

    Directory of Open Access Journals (Sweden)

    T. Jilbert

    2018-03-01

    Full Text Available Iron (Fe plays a key role in sedimentary diagenetic processes in coastal systems, participating in various redox reactions and influencing the burial of organic carbon. Large amounts of Fe enter the marine environment from boreal river catchments associated with dissolved organic matter (DOM and as colloidal Fe oxyhydroxides, principally ferrihydrite. However, the fate of this Fe pool in estuarine sediments has not been extensively studied. Here we show that flocculation processes along a salinity gradient in an estuary of the northern Baltic Sea efficiently transfer Fe and OM from the dissolved phase into particulate material that accumulates in the sediments. Flocculation of Fe and OM is partially decoupled. This is likely due to the presence of discrete colloidal ferrihydrite in the freshwater Fe pool, which responds differently from DOM to estuarine mixing. Further decoupling of Fe from OM occurs during sedimentation. While we observe a clear decline with distance offshore in the proportion of terrestrial material in the sedimentary particulate organic matter (POM pool, the distribution of flocculated Fe in sediments is modulated by focusing effects. Labile Fe phases are most abundant at a deep site in the inner basin of the estuary, consistent with input from flocculation and subsequent focusing. The majority of the labile Fe pool is present as Fe (II, including both acid-volatile sulfur (AVS-bound Fe and unsulfidized phases. The ubiquitous presence of unsulfidized Fe (II throughout the sediment column suggests Fe (II-OM complexes derived from reduction of flocculated Fe (III-OM, while other Fe (II phases are likely derived from the reduction of flocculated ferrihydrite. Depth-integrated rates of Fe (II accumulation (AVS-Fe + unsulfidized Fe (II + pyrite for the period 1970–2015 are greater in the inner basin of the estuary with respect to a site further offshore, confirming higher rates of Fe reduction in near-shore areas

  6. Impacts of flocculation on the distribution and diagenesis of iron in boreal estuarine sediments

    Science.gov (United States)

    Jilbert, Tom; Asmala, Eero; Schröder, Christian; Tiihonen, Rosa; Myllykangas, Jukka-Pekka; Virtasalo, Joonas J.; Kotilainen, Aarno; Peltola, Pasi; Ekholm, Päivi; Hietanen, Susanna

    2018-03-01

    Iron (Fe) plays a key role in sedimentary diagenetic processes in coastal systems, participating in various redox reactions and influencing the burial of organic carbon. Large amounts of Fe enter the marine environment from boreal river catchments associated with dissolved organic matter (DOM) and as colloidal Fe oxyhydroxides, principally ferrihydrite. However, the fate of this Fe pool in estuarine sediments has not been extensively studied. Here we show that flocculation processes along a salinity gradient in an estuary of the northern Baltic Sea efficiently transfer Fe and OM from the dissolved phase into particulate material that accumulates in the sediments. Flocculation of Fe and OM is partially decoupled. This is likely due to the presence of discrete colloidal ferrihydrite in the freshwater Fe pool, which responds differently from DOM to estuarine mixing. Further decoupling of Fe from OM occurs during sedimentation. While we observe a clear decline with distance offshore in the proportion of terrestrial material in the sedimentary particulate organic matter (POM) pool, the distribution of flocculated Fe in sediments is modulated by focusing effects. Labile Fe phases are most abundant at a deep site in the inner basin of the estuary, consistent with input from flocculation and subsequent focusing. The majority of the labile Fe pool is present as Fe (II), including both acid-volatile sulfur (AVS)-bound Fe and unsulfidized phases. The ubiquitous presence of unsulfidized Fe (II) throughout the sediment column suggests Fe (II)-OM complexes derived from reduction of flocculated Fe (III)-OM, while other Fe (II) phases are likely derived from the reduction of flocculated ferrihydrite. Depth-integrated rates of Fe (II) accumulation (AVS-Fe + unsulfidized Fe (II) + pyrite) for the period 1970-2015 are greater in the inner basin of the estuary with respect to a site further offshore, confirming higher rates of Fe reduction in near-shore areas. Mössbauer 57Fe

  7. PDADMAC flocculation of Chinese hamster ovary cells: enabling a centrifuge-less harvest process for monoclonal antibodies.

    Science.gov (United States)

    McNerney, Thomas; Thomas, Anne; Senczuk, Anna; Petty, Krista; Zhao, Xiaoyang; Piper, Rob; Carvalho, Juliane; Hammond, Matthew; Sawant, Satin; Bussiere, Jeanine

    2015-01-01

    High titer (>10 g/L) monoclonal antibody (mAb) cell culture processes are typically achieved by maintaining high viable cell densities over longer culture durations. A corresponding increase in the solids and sub-micron cellular debris particle levels are also observed. This higher burden of solids (≥15%) and sub-micron particles typically exceeds the capabilities of a continuous centrifuge to effectively remove the solids without a substantial loss of product and/or the capacity of the harvest filtration train (depth filter followed by membrane filter) used to clarify the centrate. We discuss here the use of a novel and simple two-polymer flocculation method used to harvest mAb from high cell mass cell culture processes. The addition of the polycationic polymer, poly diallyldimethylammonium chloride (PDADMAC) to the cell culture broth flocculates negatively-charged cells and cellular debris via an ionic interaction mechanism. Incorporation of a non-ionic polymer such as polyethylene glycol (PEG) into the PDADMAC flocculation results in larger flocculated particles with faster settling rate compared to PDADMAC-only flocculation. PDADMAC also flocculates the negatively-charged sub-micron particles to produce a feed stream with a significantly higher harvest filter train throughput compared to a typical centrifuged harvest feed stream. Cell culture process variability such as lactate production, cellular debris and cellular densities were investigated to determine the effect on flocculation. Since PDADMAC is cytotoxic, purification process clearance and toxicity assessment were performed.

  8. The use of laminar tube flow in the study of hydrodynamic and chemical influences on polymer flocculation of Escherichia coli.

    Science.gov (United States)

    Whittington, P N; George, N

    1992-08-05

    The optimization of microbial flocculation for subsequent biomass separation must relate the floc properties to separation process criteria. The effects of flocculant type, dose, and hydrodynamic conditions on floc formation in laminar tube flow were determined for an Escherichia coli system. Combined with an on-line aggregation sensor, this technique allows the flocculation process to be rapidly optimized. This is important, because interbatch variation in fermentation broth has consequences for flocculation control and subsequent downstream processing. Changing tube diameter and length while maintaining a constant flow rate allowed independent study of the effects of shear and time on the flocculation rate and floc characteristics. Tube flow at higher shear rates increased the rate and completeness of flocculation, but reduced the maximum floc size attained. The mechanism for this size limitation does not appear to be fracture or erosion of existing flocs. Rearrangement of particles within the flocs appears to be most likely. The Camp number predicted the extent of flocculation obtained in terms of the reduction in primary particle number, but not in terms of floc size.

  9. Fusion fuel and renewables

    International Nuclear Information System (INIS)

    Entler, Slavomir

    2015-01-01

    It is shown that fusion fuel meets all aspects applied when defining renewables. A table of definitions of renewables is presented. The sections of the paper are as follows: An industrial renewable source; Nuclear fusion; Current situation in research; Definitions of renewable sources; Energy concept of nuclear fusion; Fusion fuel; Natural energy flow; Environmental impacts; Fusion fuel assessment; Sustainable power; and Energy mix from renewables. (P.A.)

  10. Optimal Water Recovery with Emphasis on Flocculant Consumption Rate in the Thickener

    Directory of Open Access Journals (Sweden)

    Marzieh Hosseininasab

    2017-11-01

    Full Text Available Water plays a vital role in mineral processing as evidenced by the approximately 2 to 3 tons of water used for the treatment of one ton of ore. A major portion of this water may be recovered in thickeners. This study aimed to control the wet tailings output of the Hematite Gol-e-Gohar plant by changing  flocculant dosage and type and solid percentage in the feed in order to enhance effluent clarity and reduce water consumption. Materials and A series of settling experiments were performed using different combinations of the flocculants (A25, A26 Yazd, A26 Esfahan, A27, and A28, flocculant doses (20, 25, 30, 35, and 40 gr/ton, and solid loads in the feed (5, 7, 9, 10, and 11% to the thickener. The L25 Taguchi design method was chosen to handle the five different levels of the three factors. Adopting a 95% confidence interval, the results of analysis of variance (ANOVA revealed that flocculant consumption rate had a high effect on settling velocity (p = 0.006 while flocculant type and solid percentage in the feed had no significant effects. Moreover, it was found that A26 (Akhtar-chemistry Company, Yazd used at a rate of 40 g/ton improved the settling performance to yield an optimal water clarity. Using the findings of this study in process planning at the plant led to a considerable reduction (from the original 0.86 to 0.49 m3 in average water consumption per ton of input material so that the solid content of the thickener underflow rose from 7 to 45%.

  11. Flocculating performance of a bioflocculant produced by Arthrobacter humicola in sewage waste water treatment.

    Science.gov (United States)

    Agunbiade, Mayowa Oladele; Van Heerden, Esta; Pohl, Carolina H; Ashafa, Anofi Tom

    2017-06-12

    The discharge of poorly treated effluents into the environment has far reaching, consequential impacts on human and aquatic life forms. Thus, we evaluated the flocculating efficiency of our test bioflocculant and we report for the first time the ability of the biopolymeric flocculant produced by Arthrobacter humicola in the treatment of sewage wastewater. This strain was isolated from sediment soil sample at Sterkfontein dam in the Eastern Free State province of South Africa. Basic Local Alignment Search Tool (BLAST) analysis of the nucleotide sequence of the 16S rDNA revealed the bacteria to have 99% similarity to Arthrobacter humicola strain R1 and the sequence was deposited in the Gene bank as Arthrobacter humicola with accession number KC816574.1. Flocculating activity was enhanced with the aid of divalent cations, pH 12, at a dosage concentration of 0.8 mg/mL. The purified bioflocculant was heat stable and could retain more than 78% of its flocculating activity after heating at 100 °C for 25 min. Fourier Transform Infrared Spectroscopy analysis demonstrated the presence of hydroxyl and carboxyl moieties as the functional groups. The thermogravimetric analysis was used to monitor the pyrolysis profile of the purified bioflocculant and elemental composition revealed C: O: Na: P: K with 13.90: 41.96: 26.79: 16.61: 0.74 weight percentage respectively. The purified bioflocculant was able to remove chemical oxygen demand, biological oxygen demand, suspended solids, nitrate and turbidity from sewage waste water at efficiencies of 65.7%, 63.5%, 55.7%, 71.4% and 81.3% respectively. The results of this study indicate the possibility of using the bioflocculant produced by Arthrobacter humicola as a potential alternative to synthesized chemical flocculants in sewage waste water treatment and other industrial waste water.

  12. Renewable Energy Devices and Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ionel, Dan M.

    2015-01-01

    In this paper, essential statistics demonstrating the increasing role of renewable energy generation are firstly discussed. A state of the art review section covers fundamentals of wind turbines and PV systems. Included are schematic diagrams illustrating the main components and system topologies...... and the fundamental and increasing role of power electronics as an enabler for renewable energy integration, and for the future power system and smart grid. Recent examples of research and development, including new devices and system installations for utility power plants, as well for as residential and commercial......, fuel cells, and storage with batteries and hydrogen, respectively. Recommended further readings on topics of electric power engineering for renewable energy are included in a final section. This paper also represents an editorial introduction for two special issues of the Electric Power Component...

  13. Flocculation and floc break-up related to tidally induced turbulent shear in a low-turbidity, microtidal estuary

    DEFF Research Database (Denmark)

    Markussen, Thor Nygaard; Andersen, Thorbjørn Joest

    2014-01-01

    flocculation and floc break-up dynamics in the lower part of the water column in the period around slack water. These dynamics were confirmed in the Eulerian deployments and were reoccurring in every tidal cycle. The dynamics were mostly governed by changes in turbulent shear. Strong microflocs with a lower...... mean threshold diameter of 50–60 μm present at high turbulent shear flocculated to form fragile macroflocs with sizes of several hundred microns and mean diameters above 80 μm around slack water periods. A hysteresis in floc break-up and flocculation was found at high water slack (HWS), as flocs formed...

  14. Renewable target in sight

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    Australia's renewable energy industry is expecting several billion dollars of investment over the next 10 years following passage in December last year of the Renewable Energy Electricity) Act 2000 through Federal Parliament. The Act requires an additional 9500GWh of Australia's electricity production to be sourced from renewables by the year 2010. It also establishes a market for the 'green' component of the energy separate from the electricity itself, through a Renewable Energy Certificate (REC), whereby an accredited generator of renewable energy is able to issue one REC for each megawatt-hour of renewable energy generated

  15. Renewable energy annual 1996

    International Nuclear Information System (INIS)

    1997-03-01

    This report presents summary data on renewable energy consumption, the status of each of the primary renewable technologies, a profile of each of the associated industries, an analysis of topical issues related to renewable energy, and information on renewable energy projects worldwide. It is the second in a series of annual reports on renewable energy. The renewable energy resources included in the report are biomass (wood and ethanol); municipal solid waste, including waste-to-energy and landfill gas; geothermal; wind; and solar energy, including solar thermal and photovoltaic. The report also includes various appendices and a glossary

  16. Renewable energy annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report presents summary data on renewable energy consumption, the status of each of the primary renewable technologies, a profile of each of the associated industries, an analysis of topical issues related to renewable energy, and information on renewable energy projects worldwide. It is the second in a series of annual reports on renewable energy. The renewable energy resources included in the report are biomass (wood and ethanol); municipal solid waste, including waste-to-energy and landfill gas; geothermal; wind; and solar energy, including solar thermal and photovoltaic. The report also includes various appendices and a glossary.

  17. Environmental impact of a flocculant used to enhance solids transport during well bore clean-up operations

    International Nuclear Information System (INIS)

    Yunus, M.N.M.; Procyk, A.D.; Malbrel, C.A.; Ling, K.L.C.

    1995-01-01

    This paper investigates particle flocculation as a mechanism to remove residual contaminants in well bores during completion operations. Laboratory tests and field trials were conducted demonstrating the ability of flocculating polymer sweeps to improve well bore cleaning efficiency. This process reduces the volume of fluid accumulated in the well bore that is discharged to the environment and minimizes the risk of formation damage by residuals left in the well bore. In addition, a comprehensive environmental impact study was performed on the flocculating polymers which included 72 hrs-EC50, 48 hrs-LC50, 10 day- LC50 tests on a variety of marine organisms, and bioaccumulation and biodegradability tests. In all cases, the flocculating polymers were shown to be environmentally safe at the recommended concentrations

  18. Flocculation alters the distribution and flux of melt-water supplied sediments and nutrients in the Arctic

    DEFF Research Database (Denmark)

    Markussen, Thor Nygaard; Andersen, Thorbjørn Joest; Ernstsen, Verner Brandbyge

    In the Arctic, thawing permafrost and increased melting of glaciers are important drivers for changes in fine-grained sediment supply and biogeochemical fluxes from land to sea. Flocculation of particles is a controlling factor for the magnitude of fluxes and deposition rates in the marine...... environment but comparatively little is known about the flocculation processes in the Arctic. We investigated flocculation dynamics from a melt-water river in the inner Disko Fjord, West Greenland. A novel, laser-illuminated camera system significantly improved the particle size measurement capabilities...... and settling tubes were sampled to enable sub-sampling of different floc size fractions. Flocculation was observed during periods with low turbulent shear and also at the front of the fresh water plume resulting in significant volumes of large sized flocs at depth below the plume. The floc sizes and volumes...

  19. Effect of mineral nutrients on cell growth and self-flocculation of Tolypothrix tenuis for the production of a biofertilizer.

    Science.gov (United States)

    Silva, P G; Silva, H J

    2007-02-01

    The influence of mineral nutrients on the growth and self-flocculation of Tolypothrix tenuis was studied. The identification of possible limiting nutrients in the culture medium was performed by the biomass elemental composition approach. A factorial experimental design was used in order to estimate the contribution of macronutrients and micronutrients, as well as their interactions. Iron was identified to be limiting in the culture medium. The micronutrients influenced mainly cellular growth without effects on self-flocculation. Conversely, the self-flocculation capacity of the biomass increased at higher concentrations of macronutrients. The optimization of mineral nutrition of T. tenuis allowed a 73% increase in the final biomass level and 3.5 times higher flocculation rates.

  20. Photon Science for Renewable Energy

    International Nuclear Information System (INIS)

    Hussain, Zahid; Tamura, Lori; Padmore, Howard; Schoenlein, Bob; Bailey, Sue

    2010-01-01

    Our current fossil-fuel-based system is causing potentially catastrophic changes to our planet. The quest for renewable, nonpolluting sources of energy requires us to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels. Light-source facilities - the synchrotrons of today and the next-generation light sources of tomorrow - are the scientific tools of choice for exploring the electronic and atomic structure of matter. As such, these photon-science facilities are uniquely positioned to jump-start a global revolution in renewable and carbonneutral energy technologies. In these pages, we outline and illustrate through examples from our nation's light sources possible scientific directions for addressing these profound yet urgent challenges.

  1. Improving the Efficiency of a Coagulation-Flocculation Wastewater Treatment of the Semiconductor Industry through Zeta Potential Measurements

    OpenAIRE

    López-Maldonado, Eduardo Alberto; Oropeza-Guzmán, Mercedes Teresita; Ochoa-Terán, Adrián

    2014-01-01

    Efficiency of coagulation-flocculation process used for semiconductor wastewater treatment was improved by selecting suitable conditions (pH, polyelectrolyte type, and concentration) through zeta potential measurements. Under this scenario the zeta potential, ζ, is the right parameter that allows studying and predicting the interactions at the molecular level between the contaminants in the wastewater and polyelectrolytes used for coagulation-flocculation. Additionally, this parameter is a k...

  2. [The toxic and hygienic characteristics of the new synthetic organic flocculants AES-5, AES-7 and AES-10].

    Science.gov (United States)

    Prokopov, V A; Nekrasova, L S; Mudryĭ, I V

    2000-03-01

    A toxicological and hygienic characterization is submitted of novel synthetic organic flocculant AEC-5, AEC-7, AEC-10 which are low-toxicity substances and are classified under the fourth class of hazards. They have no skin-resorptive, locally irritative action and are endowed with a weak cumulative activity of functional character. The AEC-5 flocculant exerts a moderately manifest sensitizing effect in the dermal route of entry.

  3. Effects of flocculants on lipid extraction and fatty acid composition of the microalgae Nannochloropsis oculata and Thalassiosira weissflogii

    International Nuclear Information System (INIS)

    Borges, Lucelia; Moron-Villarreyes, Joaquin A.; D'Oca, Marcelo G. Montes; Abreu, Paulo Cesar

    2011-01-01

    The aim of this study was to investigate the possible interference of anionic and cationic flocculants in the lipid extraction and fatty acid profiles of two species of marine microalgae: Nannochloropsis oculata and Thalassiosira weissflogii. Cells were grown in batch cultures (f/2 medium, salinity of 28, temperature of 20 o C, light intensity of 40 μmol photons m -2 s -1 and 12/12 h L/D photoperiod) and concentrated using sodium hydroxide (control), sodium hydroxide and the anionic polyacrylamide flocculant Magnafloc ® LT-25 (APF treatment) and sodium hydroxide plus the cationic polyacrylamide flocculant Flopam ® (CPF treatment). There were no statistically significant differences among treatments with respect to lipid extraction for both species. However, N. oculata which presented higher percentages of C16:0, C16:1 and C20:5 fatty acids showed an increase of C14:0 and a decrease of C20:5 with the use of anionic flocculant. Additionally, T. weissflogii which had high percentages of C16:0, C16:1, C16:3 and C20:5, showed a decrease of C18:0 and C18:1n9c when both flocculants were used and a small decrease of C16:0 in the APF treatment. The results indicate that the choice of flocculant should be based on the level of saturation desirable, i.e., if the goal is to produce more stable biodiesel, with low percentage unsaturated fatty acids, then anionic flocculants should be used. On the other hand, if the aim is to produce unsaturated fatty acids for commercial uses in the pharmacy or food industries, then anionic polymers should be avoided. -- Highlights: → Interference of flocculants on biochemical of two marine microalgae. → Lipids extraction and fatty acids profile from Nannochloropsis oculata and Thalassiosira weissflogii. → No differences in the lipids but some differences on fatty acids profile.

  4. Renewable Energy Certificates (RECs)

    Science.gov (United States)

    Renewable Energy Certificates (RECs), are tradable, non-tangible energy commodities in the United States that represent proof that 1 megawatt-hour (MWh) of electricity was generated from an eligible renewable energy resource.

  5. Online driver's license renewal.

    Science.gov (United States)

    2015-09-01

    The Kentucky Department of Vehicle Regulation is exploring the possibility of developing and implementing online : drivers license renewal. The objective of this project was to: 1) evaluate online drivers license and REAL ID renewal : programs ...

  6. Effect of viscosity, basicity and organic content of composite flocculant on the decolorization performance and mechanism for reactive dyeing wastewater

    Institute of Scientific and Technical Information of China (English)

    Yuanfang Wang; Baoyu Gao; Qinyan Yue; Yah Wang

    2011-01-01

    A coagulation/flocculation process using the composite floceulant polyaluminum chloride-epichlorohydrin dimethylamine (PAC-EPI-DMA) was employed for the treatment of an anionic azo dye (Reactive Brilliant Red K-2BP dye).The effect of viscosity (η),basicity (B =[OH]/[Al]) and organic content (Wp) on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated.The η was the key factor affecting the dye removal efficiency of PAC-EPI-DMA.PAC-EPI-DMA with an intermediate η (2400 mPa-sec) gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers.The Wp of the composite flocculant was a minor important factor for the flocculation.The adsorption bridging of PAC-EPI-DMA with η of 300 or 4300 mPa.sec played an important role with the increase of Wp,whereasthe charge neutralization of them was weaker with the increase of Wp.There was interaction between Wp and B on the removal of reactive dye.The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater,which could achieve high reactive dye removal efficiency with low organic dosage.

  7. Bioethanol production by a flocculent hybrid, CHFY0321 obtained by protoplast fusion between Saccharomyces cerevisiae and Saccharomyces bayanus

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gi-Wook; Kang, Hyun-Woo; Kim, Yule [Changhae Institute of Cassava and Ethanol Research, Changhae Ethanol Co., LTD, Palbok-Dong 829, Dukjin-Gu, Jeonju 561-203 (Korea); Um, Hyun-Ju; Kim, Mina; Kim, Yang-Hoon [Department of Microbiology, Chungbuk National University, 410 Sungbong-Ro, Heungduk-Gu, Cheongju 361-763 (Korea)

    2010-08-15

    Fusion hybrid yeast, CHFY0321, was obtained by protoplast fusion between non-flocculent-high ethanol fermentative Saccharomyces cerevisiae CHY1011 and flocculent-low ethanol fermentative Saccharomyces bayanus KCCM12633. The hybrid yeast was used together with the parental strains to examine ethanol production in batch fermentation. Under the conditions tested, the fusion hybrid CHFY0321 flocculated to the highest degree and had the capacity to ferment well at pH 4.5 and 32 C. Simultaneous saccharification and fermentation for ethanol production was carried out using a cassava (Manihot esculenta) powder hydrolysate medium containing 19.5% (w v{sup -1}) total sugar in a 5 l lab scale jar fermenter at 32 C for 65 h with an agitation speed of 2 Hz. Under these conditions, CHFY0321 showed the highest flocculating ability and the best fermentation efficiency for ethanol production compared with those of the wild-type parent strains. CHFY0321 gave a final ethanol concentration of 89.8 {+-} 0.13 g l{sup -1}, a volumetric ethanol productivity of 1.38 {+-} 0.13 g l{sup -1} h{sup -1}, and a theoretical yield of 94.2 {+-} 1.58%. These results suggest that CHFY0321 exhibited the fermentation characteristics of S. cerevisiae CHY1011 and the flocculent ability of S. bayanus KCCM12633. Therefore, the strong highly flocculent ethanol fermentative CHFY0321 has potential for improving biotechnological ethanol fermentation processes. (author)

  8. Bioethanol production by a flocculent hybrid, CHFY0321 obtained by protoplast fusion between Saccharomyces cerevisiae and Saccharomyces bayanus

    International Nuclear Information System (INIS)

    Choi, Gi-Wook; Um, Hyun-Ju; Kang, Hyun-Woo; Kim, Yule; Kim, Mina; Kim, Yang-Hoon

    2010-01-01

    Fusion hybrid yeast, CHFY0321, was obtained by protoplast fusion between non-flocculent-high ethanol fermentative Saccharomyces cerevisiae CHY1011 and flocculent-low ethanol fermentative Saccharomyces bayanus KCCM12633. The hybrid yeast was used together with the parental strains to examine ethanol production in batch fermentation. Under the conditions tested, the fusion hybrid CHFY0321 flocculated to the highest degree and had the capacity to ferment well at pH 4.5 and 32 o C. Simultaneous saccharification and fermentation for ethanol production was carried out using a cassava (Manihot esculenta) powder hydrolysate medium containing 19.5% (w v -1 ) total sugar in a 5 l lab scale jar fermenter at 32 o C for 65 h with an agitation speed of 2 Hz. Under these conditions, CHFY0321 showed the highest flocculating ability and the best fermentation efficiency for ethanol production compared with those of the wild-type parent strains. CHFY0321 gave a final ethanol concentration of 89.8 ± 0.13 g l -1 , a volumetric ethanol productivity of 1.38 ± 0.13 g l -1 h -1 , and a theoretical yield of 94.2 ± 1.58%. These results suggest that CHFY0321 exhibited the fermentation characteristics of S. cerevisiae CHY1011 and the flocculent ability of S. bayanus KCCM12633. Therefore, the strong highly flocculent ethanol fermentative CHFY0321 has potential for improving biotechnological ethanol fermentation processes.

  9. Resilient Renewable Energy Microgrids

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Katherine H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); DiOrio, Nicholas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Butt, Robert S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cutler, Dylan S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Allison [Unaffiliated

    2017-11-14

    This presentation for the Cable-Tec Expo 2017 offers information about how renewable microgrids can be used to increase resiliency. It includes information about why renewable energy battery diesel hybrids microgrids should be considered for backup power, how to estimate economic savings of microgrids, quantifying the resiliency gain of microgrids, and where renewable microgrids will be successful.

  10. Impulsive control of a continuous-culture and flocculation harvest chemostat model

    Science.gov (United States)

    Zhang, Tongqian; Ma, Wanbiao; Meng, Xinzhu

    2017-12-01

    In this paper, a new mathematical model describing the process of continuous culture and harvest of microalgaes is proposed. By inputting medium and flocculant at two different fixed moments periodically, continuous culture and harvest of microalgaes is implemented. The mathematical analysis is conducted and the whole dynamics of model is investigated by using theory of impulsive differential equations. We find that the model has a microalgaes-extinction periodic solution and it is globally asymptotically stable when some certain threshold value is less than the unit. And the model is permanent when some certain threshold value is larger than the unit. Then, according to the threshold, the control strategies of continuous culture and harvest of microalgaes are discussed. The results show that continuous culture and harvest of microalgaes can be archived by adjusting suitable input time, input amount of medium or flocculant. Finally, some numerical simulations are carried out to verify the control strategy.

  11. A mathematical model for batch and continuous thickening of flocculent suspensions in vessels with varying section

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, R.; Damasceno, J.J.R.; Karlesen, K.H.

    2001-10-01

    The phenomenological theory of continuous thickening of flocculated suspensions in an ideal cylindrical thickener is extended to vessels having varying cross-section, including divergent or convergent conical vessels. The purpose of this contribution is to draw attention to the corresponding mathematical model, whose key ingredient is a strongly degenerate parabolic partial differential equation. For ideal (non-flocculated) suspensions, which do not form co compressible sediments, the mathematical model reduces to the kinematic approach by Anestis, who developed a method of construction of exact solution by the method of characteristics. The difficulty lies in the fact that characteristics and iso-concentration lines, unlike the conventional Kynch model for cylindrical vessels, do not coincide, and one has to resort to numerical methods to simulate the thickening process. A numerical algorithm is presented and employed for simulations of continuous thickening. Implications of the mathematical model are also demonstrated by steady-state calculations, which lead to new possibilities in thickener design. (author)

  12. Increase of ethanol productivity by cell-recycle fermentation of flocculating yeast.

    Science.gov (United States)

    Wang, F Z; Xie, T; Hui, M

    2011-01-01

    Using the recombinant flocculating Angel yeast F6, long-term repeated batch fermentation for ethanol production was performed and a high volumetric productivity resulted from half cells not washed and the optimum opportunity of residual glucose 20 g l(-1) of last medium. The obtained highest productivity was 2.07 g l-(1) h(-1), which was improved by 75.4% compared with that of 1.18 g l(-1) h(-1) in the first batch fermentation. The ethanol concentration reached 8.4% corresponding to the yield of 0.46 g g(-1). These results will contribute greatly to the industrial production of fuel ethanol using the commercial method with the flocculating yeast.

  13. Improvement of the flocculation process in water treatment by using moringa oleifera seeds extract

    Directory of Open Access Journals (Sweden)

    J. Sánchez-Martín

    2012-09-01

    Full Text Available Water scarcity encourages researchers to keep working on natural coagulant agents such as Moringa oleifera seed extract, that could be used even in developing countries. With this scope, this investigation is focused on the optimization of certain parameters affecting the use of this coagulant product in the clarification of real surface water. Acidic pH levels seem to enhance the coagulation performance and the turbidity removal increases as the stirring period becomes longer (up to 95% with 40 min. The optimum stirring rate is identified as 80 rpm. Water clarified with this optimum coagulation and flocculation process is turbidity-competitive with other well known coagulants and flocculants and its quality is inside standard ranges for clarified water. No microbial growth is observed within the first 72 hours after the coagulant trials.

  14. Removal of sodium lauryl sulphate by coagulation/flocculation with Moringa oleifera seed extract.

    Science.gov (United States)

    Beltrán-Heredia, J; Sánchez-Martín, J

    2009-05-30

    Among other natural flocculant/coagulant agents, Moringa oleifera seed extract ability to remove an anionic surfactant has been evaluated and it has been found to be very interesting. Sodium lauryl sulphate was removed from aqueous solutions up to 80% through coagulation/flocculation process. pH and temperature were found to be not very important factors in removal efficiency. Freundlich (F), Frumkin-Fowler-Guggenheim (FFG) and Gu-Zhu (GZ) models were used to adjust experimental data in a solid-liquid adsorption hypothesis. Last one resulted to be the most accurate one. Several data fit parameters were determined, as Freundlich order, which was found to be 1.66, Flory-Huggins interaction parameter from FFG model, which was found to be 4.87; and limiting Moringa surfactant adsorption capacity from GZ model, which was found to be 2.13 x 10(-3)mol/g.

  15. Design for Reliability in Renewable Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Zhou, Dao; Sangwongwanich, Ariya

    2017-01-01

    Power electronics are widely used in renewable energy systems to achieve lower cost of energy, higher efficiency and high power density. At the same time, the high reliability of the power electronics products is demanded, in order to reduce the failure rates and ensure cost-effective operation...... of the renewable energy systems. This paper thus describes the basic concepts used in reliability engineering, and presents the status and future trends of Design for Reliability (DfR) in power electronics, which is currently undergoing a paradigm shift to a physics-of-failure approach. Two case studies of a 2 MW...

  16. Study and simulation of the resistance of floccules to shear breakage in a centrifuge

    International Nuclear Information System (INIS)

    Touron, E.

    1995-01-01

    In France, spent fuels are in most cases reprocessed. The aim of the reprocessing is to separate the recyclable fissile materials (uranium, plutonium for instance) of radioactive wastes. The industrial process used until now is the Purex (Plutonium Uranium Refining by EXtraction) process. The two main first steps of this process are nowadays industrially completely controlled. Nevertheless, it exists several secondary operations which can interfere with the good unfolding of this process main steps as for instance, the clarification of the dissolution liquors. The aim of this work is then to improve particularly the separation efficiency between small particles and the associated dissolution liquors. The experimental study of the flow inside the rotor shows complex hydrodynamics arising from turbulence and secondary flows. This turbulent flow is likely to be capable of re-suspending small and flow density particles. The use of flocculants is a way of improving separation efficiencies. In gravity sedimentation, flocculants are frequently used to improve settling of fine particles, by causing them to aggregate behaving as if they were larger. Under slight turbulence, the flocs, which may be fragile, remain intact. In centrifugal sedimentation, shear rates are high and may result in complete floc breakup. Choice of the correct flocculant, proper dosage and right conditioning time result in strong, compact flocs so that flocculants can be used successfully. A diminution of the centrifugal shield from nominal conditions results in a diminution of shear breakage (in the feed zone) so that a total recover of solids may be obtained.(author). 122 refs., 95 figs., 28 tabs

  17. Ecotoxicological assessment of flocculant modified soil for lake restoration using an integrated biotic toxicity index.

    Science.gov (United States)

    Wang, Zhibin; Zhang, Honggang; Pan, Gang

    2016-06-15

    Flocculant modified soils/clays are being increasingly studied as geo-engineering materials for lake restoration and harmful algal bloom control. However, the potential impacts of adding these materials in aquatic ecological systems remain unclear. This study investigated the potential effects of chitosan, cationic starch, chitosan modified soils (MS-C) and cationic starch modified soils (MS-S) on the aquatic organisms by using a bioassay battery. The toxicity potential of these four flocculants was quantitatively assessed using an integrated biotic toxicity index (BTI). The test system includes four aquatic species, namely Chlorella vulgaris, Daphnia magna, Cyprinus carpio and Limnodrilus hoffmeisteri, which represent four trophic levels in the freshwater ecosystem. Results showed that median effect concentrations (EC50) of the MS-C and MS-S were 31-124 times higher than chitosan and cationic starch, respectively. D. magna was the most sensitive species to the four flocculants. Histological examination of C. carpio showed that significant pathological changes were found in gills. Different from chitosan and cationic starch, MS-C and MS-S significantly alleviated the acute toxicities of chitosan and cationic starch. The toxicity order of the four flocculants based on BTI were cationic starch > chitosan > MS-S > MS-C. The results suggested that BTI can be used as a quantitative and comparable indicator to assess biotic toxicity for aquatic geo-engineering materials. Chitosan or cationic starch modified soil/clay materials can be used at their optimal dosage without causing substantial adverse effects to the bioassay battery in aquatic ecosystem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Rheological behavior and stability of ciprofloxacin suspension: Impact of structural vehicles and flocculating agent

    Directory of Open Access Journals (Sweden)

    Eskandar Moghimipour

    2013-01-01

    Full Text Available Ciprofloxacin is a fluoroquinolone and is used against a broad spectrum of gram-negative and gram-positive bacteria. The aim of the study is to investigate the effect of structural vehicles and other formulating factors on physical stability and rheological behavior of ciprofloxacin suspension. To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated. Then to achieve controlled flocculation, different concentrations of sodium chloride and calcium chloride were added. After choosing suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose (NaCMC, hydroxypropylmethylcellulose (HPMC and Veegum were evaluated. Physical stability parameters such as sedimentation volume, the degree of flocculation and the ease of redispersion of the suspensions and growth of crystals were evaluated. After incorporation of structural vehicles, the rheological properties of formulations containing were also studied to find out their rheological behavior. According to the results, suspension containing glycerin (0.2% w/v and sodium chloride (0.05% w/v as wetting agent and flocculating agent, respectively, were the most stable formulations regarding their F and N. Microscopic observations showed the growth of crystals in ciprofloxacin suspension in formulation without excipients and the minimum amount of crystal growth was seen in suspension containing NaCMC (0.25% w/v, Veegum (0.1% w/v and NaCl (0.05% w/v. Rheological studies showed that almost all of the formulations had psuedoplastic behavior with different degree of thixotropy. The formulation containing NaCMC (0.25% w/v, Veegum (0.1% w/v and NaCl (0.05% w/v was the most stable formulation. It may be concluded that by altering the amount ratios of formulation factors, the best rheological behavior and the most proper thixotropy may be achieved.

  19. Rheological behavior and stability of ciprofloxacin suspension: Impact of structural vehicles and flocculating agent.

    Science.gov (United States)

    Moghimipour, Eskandar; Rezaee, Saeed; Salimi, Anayatollah; Asadi, Elham; Handali, Somayeh

    2013-07-01

    Ciprofloxacin is a fluoroquinolone and is used against a broad spectrum of gram-negative and gram-positive bacteria. The aim of the study is to investigate the effect of structural vehicles and other formulating factors on physical stability and rheological behavior of ciprofloxacin suspension. To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated. Then to achieve controlled flocculation, different concentrations of sodium chloride and calcium chloride were added. After choosing suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose (NaCMC), hydroxypropylmethylcellulose (HPMC) and Veegum were evaluated. Physical stability parameters such as sedimentation volume, the degree of flocculation and the ease of redispersion of the suspensions and growth of crystals were evaluated. After incorporation of structural vehicles, the rheological properties of formulations containing were also studied to find out their rheological behavior. According to the results, suspension containing glycerin (0.2% w/v) and sodium chloride (0.05% w/v) as wetting agent and flocculating agent, respectively, were the most stable formulations regarding their F and N. Microscopic observations showed the growth of crystals in ciprofloxacin suspension in formulation without excipients and the minimum amount of crystal growth was seen in suspension containing NaCMC (0.25% w/v), Veegum (0.1% w/v) and NaCl (0.05% w/v). Rheological studies showed that almost all of the formulations had psuedoplastic behavior with different degree of thixotropy. The formulation containing NaCMC (0.25% w/v), Veegum (0.1% w/v) and NaCl (0.05% w/v) was the most stable formulation. It may be concluded that by altering the amount ratios of formulation factors, the best rheological behavior and the most proper thixotropy may be achieved.

  20. Colorimetric Analysis on Flocculation of Bioinspired Au Self-Assembly for Biophotonic Application

    Directory of Open Access Journals (Sweden)

    Wan-Joong Kim

    2009-01-01

    Full Text Available Gold nanoparticles exhibited strong surface plasmon absorption and couplings between neighboring particles within bioactivated self-assembly modified their optical properties. Colorimetric analysis on the optical modification of surface plasmon resoanance (SPR shift and flocculation parameter functionalized bioinspired gold assembly for biophotonic application. The physical origin of bioinspired gold aggregation-induced shifting, decreasing, or broadening of the plasmon absorption spectra could be explained in terms of dynamic depolarization, collisional damping, and shadowing effects.

  1. Gelation of Soy Milk with Hagfish Exudate Creates a Flocculated and Fibrous Emulsion- and Particle Gel.

    Directory of Open Access Journals (Sweden)

    Lukas Böni

    Full Text Available Hagfish slime is an ultra dilute, elastic and cohesive hydrogel that deploys within milliseconds in cold seawater from a glandularly secreted exudate. The slime is made of long keratin-like fibers and mucin-like glycoproteins that span a network which entraps water and acts as a defense mechanism against predators. Unlike other hydrogels, the slime only confines water physically and is very susceptible to mechanical stress, which makes it unsuitable for many processing operations and potential applications. Despite its huge potential, little work has been done to improve and functionalize the properties of this hydrogel. To address this shortcoming, hagfish exudate was mixed with a soy protein isolate suspension (4% w/v and with a soy emulsion (commercial soy milk to form a more stable structure and combine the functionalities of a suspension and emulsion with those of the hydrogel. Hagfish exudate interacted strongly with the soy systems, showing a markedly increased viscoelasticity and water retention. Hagfish mucin was found to induce a depletion and bridging mechanism, which caused the emulsion and suspension to flocculate, making "soy slime", a cohesive and cold-set emulsion- and particle gel. The flocculation network increases viscoelasticity and substantially contributes to liquid retention by entrapping liquid in the additional confinements between aggregated particles and protein fibers. Because the mucin-induced flocculation resembles the salt- or acid-induced flocculation in tofu curd production, the soy slime was cooked for comparison. The cooked soy slime was similar to conventional cooked tofu, but possessed a long-range cohesiveness from the fibers. The fibrous, cold-set, and curd-like structure of the soy slime represents a novel way for a cold coagulation and fiber incorporation into a suspension or emulsion. This mechanism could be used to efficiently gel functionalized emulsions or produce novel tofu-like structured food

  2. Gelation of Soy Milk with Hagfish Exudate Creates a Flocculated and Fibrous Emulsion- and Particle Gel

    Science.gov (United States)

    Böni, Lukas; Rühs, Patrick A.; Windhab, Erich J.; Fischer, Peter; Kuster, Simon

    2016-01-01

    Hagfish slime is an ultra dilute, elastic and cohesive hydrogel that deploys within milliseconds in cold seawater from a glandularly secreted exudate. The slime is made of long keratin-like fibers and mucin-like glycoproteins that span a network which entraps water and acts as a defense mechanism against predators. Unlike other hydrogels, the slime only confines water physically and is very susceptible to mechanical stress, which makes it unsuitable for many processing operations and potential applications. Despite its huge potential, little work has been done to improve and functionalize the properties of this hydrogel. To address this shortcoming, hagfish exudate was mixed with a soy protein isolate suspension (4% w/v) and with a soy emulsion (commercial soy milk) to form a more stable structure and combine the functionalities of a suspension and emulsion with those of the hydrogel. Hagfish exudate interacted strongly with the soy systems, showing a markedly increased viscoelasticity and water retention. Hagfish mucin was found to induce a depletion and bridging mechanism, which caused the emulsion and suspension to flocculate, making “soy slime”, a cohesive and cold-set emulsion- and particle gel. The flocculation network increases viscoelasticity and substantially contributes to liquid retention by entrapping liquid in the additional confinements between aggregated particles and protein fibers. Because the mucin-induced flocculation resembles the salt- or acid-induced flocculation in tofu curd production, the soy slime was cooked for comparison. The cooked soy slime was similar to conventional cooked tofu, but possessed a long-range cohesiveness from the fibers. The fibrous, cold-set, and curd-like structure of the soy slime represents a novel way for a cold coagulation and fiber incorporation into a suspension or emulsion. This mechanism could be used to efficiently gel functionalized emulsions or produce novel tofu-like structured food products. PMID

  3. Study on Treatment of Landfill Leachate by Electrochemical, Flocculation and Photocatalysis

    Science.gov (United States)

    Yang, Yue; Jin, Xiuping; Pan, Yunbo; Zuo, Xiaoran

    2018-01-01

    In this study, the landfill leachate of different seasons in Liaoyang City is as the research object, and COD removal rate is as the main indicator. The electrochemical section’s results show that the optimal treatment conditions for the water of 2016 summer are as follows: voltage is 7.0V, current density is 40.21 A/m2, pH is equal to the raw water, electrolysis time is 1h, and the COD removal rate is 80.41%. The optimal treatment conditions for the 2017 fall’s water are: electrolysis voltage is 7.0 V, current density is 45.06 A/m2, electrolysis time is 4 hours, and COD removal rate is 28.03%. The flow rate of continuous electrolysis is 6.4 L/h using the water of 2016 fall, and the COD removal rate is 10.28%. The results of the flocculation process show that the optimal treatment conditions are as follows: pH is equal to the raw water; the optimal flocculant species is Fe-Al composite flocculant, wherein the optimal ratio of Fe-Al is n (Fe):n (Al)=0.5:1; the best dosage of flocculant is 2.0 g/L and COD removal rate is of 21.11%. The results of photocatalytic show that the optimal conditions are: pH is 4.5, Al2(SO4)3 is 1.0 g/L, FeSO4.7H2O is 700mg/L, H2O2(30%) is 4 mL/L, stirring and standing UV lamp light irradiation 3 hours, and adjusting pH to 6.0 or so, COD removal rate is 36.15%. +

  4. Metabolic adaptations of Azospirillum brasilense to oxygen stress by cell-to-cell clumping and flocculation.

    Science.gov (United States)

    Bible, Amber N; Khalsa-Moyers, Gurusahai K; Mukherjee, Tanmoy; Green, Calvin S; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B; Alexandre, Gladys

    2015-12-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. Recovery of kaolinite from tailings of Zonouz kaolin-washing plant by flotation-flocculation method

    OpenAIRE

    Kianoush Barani; Masoud Kalantari

    2018-01-01

    The traditional processing of kaolin is achieved by dispersion of the mined ore and classification by multistage hydrocyclone plants. The inefficiencies inherent to cyclones produce a middling product that is commonly disposed back into the quarry. In this research, recovery of kaolinite from tailings of Zonouz kaolin washing plant, which is located in Iran was investigated by flotation and flotation- flocculation. Flotation experiments show that the flotation of kaolinite from the tailings i...

  6. A highly efficient flocculant for graphene oxide recycling and its applications

    Science.gov (United States)

    Luan, Ruiying; Pan, Hui; Ma, Yuning; Mao, Lin; Li, Yao; Wang, Dawei; Zhang, Di; Zhu, Shenmin

    2018-01-01

    In this study, we found a novel and efficient way of recycling graphene oxide (GO) by adding ZnO colloid into the GO solution. GO flocculates immediately when mixed with ZnO colloids. Interestingly, the flocculation would disappear and disperse homogeneously in solution if a certain amount of HCl is added. The study offers a solution to recover and reuse GO throughout its production procedures. More importantly, in the obtained reduced GO/ZnO (rGO/ZnO) flocculant, ZnO nanorods are observed self-assembled into an ordered structure in between the rGO sheets. This prevents the rGO sheets from re-stacking and facilitates the movement of the electrolyte into ZnO if the prepared rGO/ZnO is used as an electrode for supercapacitor. Electrochemical measurements have proved that the rGO/ZnO composite with a weight ratio of 1:1 exhibits a gravimetric specific capacitance of 175 F g-1 and the rGO/ZnO electrode maintains 89.6% of the initial capacitance after 5000 cycles of uses.

  7. On the Kaolinite Floc Size at the Steady State of Flocculation in a Turbulent Flow.

    Science.gov (United States)

    Zhu, Zhongfan; Wang, Hongrui; Yu, Jingshan; Dou, Jie

    2016-01-01

    The flocculation of cohesive fine-grained sediment plays an important role in the transport characteristics of pollutants and nutrients absorbed on the surface of sediment in estuarine and coastal waters through the complex processes of sediment transport, deposition, resuspension and consolidation. Many laboratory experiments have been carried out to investigate the influence of different flow shear conditions on the floc size at the steady state of flocculation in the shear flow. Most of these experiments reported that the floc size decreases with increasing shear stresses and used a power law to express this dependence. In this study, we performed a Couette-flow experiment to measure the size of the kaolinite floc through sampling observation and an image analysis system at the steady state of flocculation under six flow shear conditions. The results show that the negative correlation of the floc size on the flow shear occurs only at high shear conditions, whereas at low shear conditions, the floc size increases with increasing turbulent shear stresses regardless of electrolyte conditions. Increasing electrolyte conditions and the initial particle concentration could lead to a larger steady-state floc size.

  8. Upgrading secondary wastewater plant effluent by modified coagulation and flocculation, for water reuse in irrigation

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Ghaneian

    2017-09-01

    Full Text Available In this study, the feasibility of using coagulation, flocculation, and sedimentation (CF-S for advanced treatment of secondary effluent released from the Yazd Intermittent Cycle Extended Aeration System was investigated. Four coagulants including ferric chloride (FeCl3, polyaluminum chloride (PAC, ferrous sulfate (FeSo4, and potassium ferrate (K2FeSo4 along with Gflog C-150 as flocculant polymer were used. In this study, returned chemical sludge was considered as a modification. Preliminary CF-S processes showed that FeSO4 and K2FeO4 had low removal efficiencies. Thus, these two coagulants were abandoned and CF-S processes were continued only with PAC and FeCl3 coagulants which had higher efficiencies in the removal of biological oxygen demand (BOD5, chemical oxygen demand (COD, total suspended solids (TSS, and turbidity. Removal efficiency was higher when half of the chemical producing sludge was returned as compared with using both coagulants simultaneously along with 2 mg L−1 of C-150 as flocculant. In the optimum dosage, when half of PAC and FeCl3 sludge were returned, the volume of produced sludge was reduced by 40% and 28%, respectively, as compared without returned sludge. For the PAC coagulant in the optimum dosage with half of the sludge returned, all 2012 EPA standards of irrigation were met for both ‘processed and non-processed type’ agricultural crops.

  9. Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth

    Energy Technology Data Exchange (ETDEWEB)

    Degreif, Daniel [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Technical Univ. of Darmstadt (Germany); de Rond, Tristan [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States); Bertl, Adam [Technical Univ. of Darmstadt (Germany); Keasling, Jay D. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Technical Univ. of Denmark, Lyngby (Denmark); Budin, Itay [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States)

    2017-03-18

    Cells modulate lipid metabolism in order to maintain membrane homeostasis. In this paper, we use a metabolic engineering approach to manipulate the stoichiometry of fatty acid unsaturation, a regulator of cell membrane fluidity, in Saccharomyces cerevisiae. Unexpectedly, reduced lipid unsaturation triggered cell-cell adhesion (flocculation), a phenomenon characteristic of industrial yeast but uncommon in laboratory strains. We find that ER lipid saturation sensors induce expression of FLO1 – encoding a cell wall polysaccharide binding protein – independently of its canonical regulator. In wild-type cells, Flo1p-dependent flocculation occurs under oxygen-limited growth, which reduces unsaturated lipid synthesis and thus serves as the environmental trigger for flocculation. Transcriptional analysis shows that FLO1 is one of the most highly induced genes in response to changes in lipid unsaturation, and that the set of membrane fluidity-sensitive genes is globally activated as part of the cell's long-term response to hypoxia during fermentation. Finally, our results show how the lipid homeostasis machinery of budding yeast is adapted to carry out a broad response to an environmental stimulus important in biotechnology.

  10. A novel acrylamide-free flocculant and its application for sludge dewatering.

    Science.gov (United States)

    Lu, Lianghua; Pan, Zhida; Hao, Nan; Peng, Wenqing

    2014-06-15

    In the present research, copolymers of methyl acrylate (MA) with anionic or cationic monomers were synthesized via emulsion polymerization, and used as sludge dewatering aids in wastewater treatment. The copolymerization of different stoichiometry of two monomers afforded a variety of water soluble copolymers with charge densities ranging from 40% to 80%, which align with the charge density of current flocculant products. These copolymers resemble current commercial products, but provide a greener solution by eliminating acrylamide monomer, which is a suspected carcinogen. High molecular weight copolymers were achieved by applying powder-like synthesis process with intrinsic viscosity of final products as high as 12.98 dl/g for anionic flocculant and 10.74 dl/g for cationic flocculant. The copolymers of methyl acrylate and [2-(Acryloyloxy)ethyl]trimethylammonium chloride (AETAC) with 55% charge density exhibited comparable performance in clay settling test, real water jar test, and sludge dewatering, when compared to AM-based commercial product in the real wastewater treatment application. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Winnowing and Flocculation in Bio-physical Cohesive Substrate: A Flume Experimental and Estuarine Study

    Science.gov (United States)

    Ye, L.; Parsons, D. R.; Manning, A. J.

    2016-12-01

    Cohesive sediment, or mud, is ubiquitously found in most aqueous environments, such as coasts and estuaries. The study of cohesive sediment behaviors requires the synchronous description of mutual interactions of grains (e.g., winnowing and flocculation), their physical properties (e.g., grain size) and also the ambient water. Herein, a series of flume experiments (14 runs) with different substrate mixtures of sand-clay-EPS (Extracellular Polymeric Substrates: secreted by aquatic microorganisms) are combined with an estuarine field survey (Dee estuary, NW England) to investigate the behavior of suspensions over bio-physical cohesive substrates. The experimental results indicate that winnowing and flocculation occur pervasively in bio-physical cohesive flow systems. Importantly however, the evolution of the bed and bedform dynamics and hence turbulence production can be lower when cohesivity is high. The estuarine survey also revealed that the bio-physical cohesion provided by both the clay and microorganism fractions in the bed, that pervasively exists in many natural estuarine systems, plays a significant role in controlling the interactions between bed substrate and sediment suspension and deposition, including controlling processes such as sediment winnowing, flocculation and re-deposition. Full understanding of these processes are essential in advancing sediment transport modelling and prediction studies across natural estuarine systems and the work will report on an improved conceptual model for sediment sorting deposition in bio-physical cohesive substrates.

  12. Improvement of water treatment pilot plant with Moringa oleifera extract as flocculant agent.

    Science.gov (United States)

    Beltrán-Heredia, J; Sánchez-Martín, J

    2009-05-01

    Moringa oleifera extract is a high-capacity flocculant agent for turbidity removal in surface water treatment. A complete study of a pilot-plant installation has been carried out. Because of flocculent sedimentability of treated water, a residual turbidity occured in the pilot plant (around 30 NTU), which could not be reduced just by a coagulation-flocculation-sedimentation process. Because of this limitation, the pilot plant (excluded filtration) achieved a turbidity removal up to 70%. A slow sand filter was put in as a complement to installation. A clogging process was characterized, according to Carman-Kozeny's hydraulic hypothesis. Kozeny's k parameter was found to be 4.18. Through fouling stages, this k parameter was found to be up to 6.36. The obtained data are relevant for the design of a real filter in a continuous-feeding pilot plant. Slow sand filtration is highly recommended owing to its low cost, easy-handling and low maintenance, so it is a very good complement to Moringa water treatment in developing countries.

  13. Mapping of renewable energies

    International Nuclear Information System (INIS)

    Boulanger, V.

    2013-01-01

    Germany is the champion of green energy in Europe: the contribution of renewable energies to electricity generation reached about 20% in 2011. This article describes the situation of renewable energies in Germany in 2011 with the help of 2 maps, the first one gives the installed electrical generation capacity for each region and for each renewable energy source (wind power, hydro-electricity, biomass, photovoltaic energy and biogas) and the second one details the total number of jobs (direct and indirect) for each renewable energy source and for each region. In 2011 about 372000 people worked in the renewable energy sector in Germany. (A.C.)

  14. Renewable energy annual 1995

    International Nuclear Information System (INIS)

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic

  15. Renewable energy annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic.

  16. Renewable Energy: Policy Considerations for Deploying Renewables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This information paper accompanies the IEA publication Deploying Renewables 2011: Best and Future Policy Practice (IEA, 2011a). It provides more detailed data and analysis on policies for Deploying Renewables, and is intended to complement the main publication. It provides an account of the strategic drivers underpinning renewable energy (RE) technology deployment (energy security, economic development and environment protection) and assesses RE technologies with respect to these drivers, including an estimate of GHG emissions reductions due to RE technologies. The paper also explores the different barriers to deploying renewables at a given stage of market maturity and discusses what tools policy makers can avail of to succeed in removing deployment barriers. An additional topical highlight explores the challenges associated with accelerating the diffusion of RE technologies in developing countries.

  17. VT Renewable Energy Sites - Renewable Energy Professionals

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  18. RENEWAL PROCESS IN QUEUING PROBLEM AND REPLACEMENT OF MACHINE

    OpenAIRE

    Hala Abbas Laz*, Mohamed Gomma Elnour

    2016-01-01

    The paper is studying the renewal process. There are many fields in which it’s used for example: the renewable energy (solar energy, wind energy), maintenance and replacement decision models, queuing system and other field in electronics. In this study our objective is to find the probability density function related to a renewal at a given time. Also to drive the renewal equation, how to find the current lifetime and residual life time. We obtain that as expected value of a renewal process w...

  19. Recovery of Bacillus sphaericus spores by flocculation/sedimentation and flotation

    Directory of Open Access Journals (Sweden)

    Christine Lamenha Luna

    2005-06-01

    Full Text Available The aim of this work was use flocculation/sedimentation and flotation for recovery of spores of the Bacillus sphaericus. Microorganism was produced batchwise using culture medium based skimmed milk, corn steep liquor and mineral salts. The best results of flocculation were obtained using CaCl2.2H2O, FeCl3.6H2O, Al2(SO43 and tannin as flocculating agents, with optimal flocculation concentrations of 1,500, 3,000, 2,000 and 1,700ppm, respectively. Flocculent suspensions were characterized based on floc diameter and density. Settling tests were performed in batch at different concentrations of the cellular suspensions and revealed high recovery of the solids in suspension in all cases. Flotation tests were accomplished using a mechanical agitated flotation cell and the process was favoured by the increase of the system agitation and for the presence of a cationic collector.O trabalho aborda a recuperação de esporos da bactéria Bacillus sphaericus por floculação/sedimentação e flotação. O microrganismo foi produzido em batelada, utilizando-se meio de cultivo à base de leite desnatado, milhocina e sais minerais. Os melhores resultados de floculação foram obtidos com os floculantes CaCl2.2H2O, FeCl3.6H2O, Al2(SO43 e tanino, com concentrações ótimas de 1.500, 3.000, 2.000 e 1.700ppm, respectivamente. Os sistemas floculentos foram caracterizados através da determinação da densidade e do diâmetro médio dos flocos. Testes de sedimentação em batelada a diferentes concentrações das suspensões celulares revelaram elevados índices de recuperação dos sólidos em suspensão em todos os casos. Os ensaios de flotação foram realizados em célula de flotação mecânica, e o processo foi favorecido pelo aumento da agitação do sistema e pela presença de um coletor catiônico.

  20. Production, Characterization, and Flocculation Mechanism of Cation Independent, pH Tolerant, and Thermally Stable Bioflocculant from Enterobacter sp. ETH-2

    Science.gov (United States)

    Tang, Wei; Song, Liyan; Li, Dou; Qiao, Jing; Zhao, Tiantao; Zhao, Heping

    2014-01-01

    Synthetic high polymer flocculants, frequently utilized for flocculating efficiency and low cost, recently have been discovered as producing increased risk to human health and the environment. Development of a more efficient and environmentally sound alternative flocculant agent is investigated in this paper. Bioflocculants are produced by microorganisms and may exhibit a high rate of flocculation activity. The bioflocculant ETH-2, with high flocculating activity (2849 mg Kaolin particle/mg ETH-2), produced by strain Enterobacter sp. isolated from activated sludge, was systematically investigated with regard to its production, characterization, and flocculation mechanism. Analyses of microscopic observation, zeta potential and ETH-2 structure demonstrates the bridging mechanism, as opposed to charge neutralization, was responsible for flocculation of the ETH-2. ETH-2 retains high molecular weight (603 to 1820 kDa) and multi-functional groups (hydroxyl, amide and carboxyl) that contributed to flocculation. Polysaccharides mainly composed of mannose, glucose, and galactose, with a molar ratio of 1∶2.9∶9.8 were identified as the active constituents in bioflocculant. The structure of the long backbone with active sites of polysaccharides was determined as a primary basis for the high flocculation activity. Bioflocculant ETH-2 is cation independent, pH tolerant, and thermally stable, suggesting a potential fit for industrial application. PMID:25485629

  1. Production, characterization, and flocculation mechanism of cation independent, pH tolerant, and thermally stable bioflocculant from Enterobacter sp. ETH-2.

    Directory of Open Access Journals (Sweden)

    Wei Tang

    Full Text Available Synthetic high polymer flocculants, frequently utilized for flocculating efficiency and low cost, recently have been discovered as producing increased risk to human health and the environment. Development of a more efficient and environmentally sound alternative flocculant agent is investigated in this paper. Bioflocculants are produced by microorganisms and may exhibit a high rate of flocculation activity. The bioflocculant ETH-2, with high flocculating activity (2849 mg Kaolin particle/mg ETH-2, produced by strain Enterobacter sp. isolated from activated sludge, was systematically investigated with regard to its production, characterization, and flocculation mechanism. Analyses of microscopic observation, zeta potential and ETH-2 structure demonstrates the bridging mechanism, as opposed to charge neutralization, was responsible for flocculation of the ETH-2. ETH-2 retains high molecular weight (603 to 1820 kDa and multi-functional groups (hydroxyl, amide and carboxyl that contributed to flocculation. Polysaccharides mainly composed of mannose, glucose, and galactose, with a molar ratio of 1:2.9:9.8 were identified as the active constituents in bioflocculant. The structure of the long backbone with active sites of polysaccharides was determined as a primary basis for the high flocculation activity. Bioflocculant ETH-2 is cation independent, pH tolerant, and thermally stable, suggesting a potential fit for industrial application.

  2. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    OpenAIRE

    Srinivasan, Ravi; Campbell, Daniel; Wang, Wei

    2015-01-01

    In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. Such progressive disinvestment in the non-renewable resources that may be substituted with renewable resources is referred to as “Renewable Substitutability” and if implemented, this process will lead to a paradigm sh...

  3. Policies for Renewable Heat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This paper builds on IEA publications, Deploying Renewables, Principles for Effective Policies and Deploying Renewables, Best and Future Policy Practice, that discuss the 'integrated policy approach,' whereby renewable energy technologies require different support policies at different stages of their maturity pathways. The paper discusses how the integrated policy approach applies to renewable heat. It attempts to provide guidance for policy-makers on renewable heat throughout the different phases of the policy lifecycle, allowing for the specific challenges of renewable heat and needs of the many stakeholders involved. Stimulating a market for heat involves challenges that are different and, often, more difficult to overcome than in the electricity and transport sectors.

  4. China's renewables law

    International Nuclear Information System (INIS)

    Zhu Li

    2005-01-01

    The paper discusses China's Renewable Energy Promotion Law which will come into force in January 2006. The law shows China's commitment to renewable energy sources. The target is to raise the country's energy consumption from renewables to 10% by 2020. Data for current capacity, and expected capacity by 2020, are given for wind power, solar power, biomass and hydroelectric power. The financial and technological hurdles which China must overcome are mentioned briefly

  5. Renewable energy resources

    CERN Document Server

    Twidell, John

    2015-01-01

    Renewable Energy Resources is a numerate and quantitative text covering the full range of renewable energy technologies and their implementation worldwide. Energy supplies from renewables (such as from biofuels, solar heat, photovoltaics, wind, hydro, wave, tidal, geothermal, and ocean-thermal) are essential components of every nation's energy strategy, not least because of concerns for the local and global environment, for energy security and for sustainability. Thus in the years between the first and this third edition, most renewable energy technologies have grown from fledgling impact to s

  6. The renewable chemicals industry

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Rass-Hansen, J.; Marsden, Charlotte Clare

    2008-01-01

    per kilogram of desired product to illustrate in which processes the use of renewable resources lead to the most substantial reduction of CO2 emissions. The steps towards a renewable chemicals industry will most likely involve intimate integration of biocatalytic and conventional catalytic processes......The possibilities for establishing a renewable chemicals industry featuring renewable resources as the dominant feedstock rather than fossil resources are discussed in this Concept. Such use of biomass can potentially be interesting from both an economical and ecological perspective. Simple...

  7. Renewables. The clean advantage

    International Nuclear Information System (INIS)

    Klein, A.

    2006-01-01

    Europe's big utilities are increasingly seeing renewable energy as a viable alternative to conventional forms of power generation which at present have disadvantages in terms of cost and/or environment. Europe's biggest 20 utilities aim to double their renewables capacity in the next five years and nearly 20 billion US dollars have been earmarked for such projects. This report by Emerging Energy Research discusses the likely trends for the next five years. The various sources of renewable energy and how they might be developed are discussed. The companies leading exploitation of renewables and their market share are named

  8. Influence of flocculating agents and structural vehicles on the physical stability and rheological behavior of nitrofurantoin suspension.

    Science.gov (United States)

    Moghimipour, Eskandar; Salimi, Anayatollah; Rezaee, Saeed; Balack, Maryam; Handali, Somayeh

    2014-05-01

    Nitrofurantoin is a nitrofuran antibiotic that has been used for treatment of urinary tract against positive and negative bacteria. The aim of this study was to evaluate the effect of structural vehicles and flocculating agents on physical stability and rheological behavior of nitrofurantoin suspension. To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated and their particle sizes were determined using the sieve method. Then to achieve controlled flocculation, sodium citrate and aluminum chloride were added. After choosing the suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose and Veegum were evaluated individually and in combination. In addition, the effect of sorbitol on density of continuous phase and some physical stability parameters such as sedimentation volume, degree of flocculation and ease of redispersion of the suspensions were evaluated. After incorporation of structural vehicles, the rheological properties of formulations were also determined to find their flow behavior. According to the results, glycerin (0.2%) and sodium citrate (0.3%) had the best effect on the suspension stability as wetting and flocculating agents, respectively. Rheological properties of formulations showed pseudoplastic behavior with some degree of thixotropy. In conclusion, the suspension containing Veegum 1%, sodium carboxy methyl cellulose 1%, glycerine 0.2%, sodium citrate 0.3% and sorbitol 20 % was chosen as the most physically stable formulation.

  9. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection

    Directory of Open Access Journals (Sweden)

    Lisa M. Casanova

    2015-11-01

    Full Text Available Point of use (POU household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions.

  10. Use of natural pH variation to increase the flocculation of the marine microalgae Nannochloropsis oculata.

    Science.gov (United States)

    Sales, Rafael; Abreu, Paulo Cesar

    2015-02-01

    Microalgae is largely used in aquaculture as feed. More recently, these microorganisms have been considered as an important feedstock for biodiesel production. However, the concentration of produced biomass represents a large parcel of production costs. In this study, we have evaluated the influence of natural pH variation of culture medium, caused by photosynthetic activity, on the flocculation of the marine microalgae Nannochloropsis oculata. Experiments were conducted with the same culture with different pH values (8.5 and 9.6), obtained after exposing the cells to different light conditions. For each pH value, different treatments were composed by adding 0, 5, 10, and 30 mM of NaOH and the flocculant Flopam® (FO4800 SH) at concentrations of 0, 0.5, 1, and 5 ppm. Higher flocculation efficiencies were obtained for the culture with pH 9.6 in comparison to 8.5 for the same NaOH and Flopam concentrations. Lower concentrations of base and flocculant were needed for flocculating the culture in higher pH, representing an economy of 20 % in the costs of crop harvesting.

  11. Modeling of microalgal shear-induced flocculation and sedimentation using a coupled CFD-population balance approach.

    Science.gov (United States)

    Golzarijalal, Mohammad; Zokaee Ashtiani, Farzin; Dabir, Bahram

    2018-01-01

    In this study, shear-induced flocculation modeling of Chlorella sp. microalgae was conducted by combination of population balance modeling and CFD. The inhomogeneous Multiple Size Group (MUSIG) and the Euler-Euler two fluid models were coupled via Ansys-CFX-15 software package to achieve both fluid and particle dynamics during the flocculation. For the first time, a detailed model was proposed to calculate the collision frequency and breakage rate during the microalgae flocculation by means of the response surface methodology as a tool for optimization. The particle size distribution resulted from the model was in good agreement with that of the jar test experiment. Furthermore, the subsequent sedimentation step was also examined by removing the shear rate in both simulations and experiments. Consequently, variation in the shear rate and its effects on the flocculation behavior, sedimentation rate and recovery efficiency were evaluated. Results indicate that flocculation of Chlorella sp. microalgae under shear rates of 37, 182, and 387 s -1 is a promising method of pre-concentration which guarantees the cost efficiency of the subsequent harvesting process by recovering more than 90% of the biomass. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:160-174, 2018. © 2017 American Institute of Chemical Engineers.

  12. Improving the Efficiency of a Coagulation-Flocculation Wastewater Treatment of the Semiconductor Industry through Zeta Potential Measurements

    Directory of Open Access Journals (Sweden)

    Eduardo Alberto López-Maldonado

    2014-01-01

    Full Text Available Efficiency of coagulation-flocculation process used for semiconductor wastewater treatment was improved by selecting suitable conditions (pH, polyelectrolyte type, and concentration through zeta potential measurements. Under this scenario the zeta potential, ζ, is the right parameter that allows studying and predicting the interactions at the molecular level between the contaminants in the wastewater and polyelectrolytes used for coagulation-flocculation. Additionally, this parameter is a key factor for assessing the efficiency of coagulation-flocculation processes based on the optimum dosages and windows for polyelectrolytes coagulation-flocculation effectiveness. In this paper, strategic pH variations allowed the prediction of the dosage of polyelectrolyte on wastewater from real electroplating baths, including the isoelectric point (IEP of the dispersions of water and commercial polyelectrolytes used in typical semiconductor industries. The results showed that there is a difference between polyelectrolyte demand required for the removal of suspended solids, turbidity, and organic matter from wastewater (23.4 mg/L and 67 mg/L, resp.. It was also concluded that the dose of polyelectrolytes and coagulation-flocculation window to achieve compliance with national and international regulations as EPA in USA and SEMARNAT in Mexico is influenced by the physicochemical characteristics of the dispersions and treatment conditions (pH and polyelectrolyte dosing strategy.

  13. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  14. Assessment of impact of culture conditions on capability of wastewater's microorganisms to flocculation

    Directory of Open Access Journals (Sweden)

    Il'inskiy V. V.

    2017-06-01

    Full Text Available Wastewater is one of the significant sources of pollution of the aquatic ecosystems of the Kola North. Sewage coming to the ground waters, surface waters and near shore marine basin have a complex negative impact on the biocenosis of water objects. Considering the fact that basin self-purification process in climatic environment of the Far North is slow, it seems to be current problem to research influence of external factors on the native microorganisms involved in the biological transformation of most pollutants. Along with oxygenizing activity microorganisms are able to accumulate pollutant in the cells and to form floccules. As a result, microorganisms fix the dissolved contaminants that may be mechanically derived from water. Using the data on the chemical makeup of some urban and domestic sewage, nutrient media have been developed where microorganisms isolated from effluents have been cultivated. As major characteristics of the cultivation media affecting the intensity and direction of metabolic processes in microorganisms, the ratios C / N, C / P and N / P have been chosen. Intensity growth of bacteria in experimental nutrient media has been studied and the flocculating activity of bacterial suspensions has been determined. The rate of these microorganisms (Pseudomonas spp. and cultures of bacteria of Enterobacteriaceae family average has been 70∙103 and 117∙103 cells/h respectively. The growth rate of each culture on different composition nutrient media has varied within three orders, and has correlated with the relative content of phosphates in the nutrient media. The flocculating potential does not depend on the ratio of biogenic elements C / N, C / P and N / P. Both cultures have shown the ability to precipitate suspended matter at the level of 50 % or more after cultivation on nutrient media similar in composition to habitat conditions.

  15. Coagulation-flocculation process applied to wastewaters generated in hydrocarbon-contaminated soil washing

    International Nuclear Information System (INIS)

    Torres, L. g.; Belloc, C.; Iturbe, R.; Bandala, E.

    2009-01-01

    A wastewater produced in the contaminated soil washing was treated by means of coagulation-flocculation (CF) process. the wastewater treatment in this work continued petroleum hydrocarbons, a surfactant, i. e., sodium dodecyl sulphate (SDS) as well as salts, humic acids and other constituents that were lixiviated rom the soil during the washing process. The aim of this work was to develop a process for treating the wastewaters generated when washing hydrocarbon-contaminated soils in such a way that it could be recycled to the washing process, and at the end of the cleaning up, the waters could be disposed properly. (Author)

  16. Marine Renewable Energies

    DEFF Research Database (Denmark)

    Azzellino, Arianna; Conley, Daniel; Vicinanza, Diego

    2013-01-01

    Countries with coastlines may have valuable renewable energy resources in the form of tides, currents, waves, and offshorewind.The potential to gather energy from the sea has recently gained interest in several nations, so Marine Renewable Energy Installations (hereinafter MREIs) will likely become...

  17. Renewable Resources in SA

    CSIR Research Space (South Africa)

    Mushwana, C

    2015-02-01

    Full Text Available Renewable energy is derived form natural resources that are replenished at a faster rate than they are consumed, and thus cannot be depleted. Solar, wind, geothermal, hydro, and some forms of biomass are common sources of renewable energy. Almost 90...

  18. Renewable Energy in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  19. Renewable Energy Technology

    Science.gov (United States)

    Daugherty, Michael K.; Carter, Vinson R.

    2010-01-01

    In many ways the field of renewable energy technology is being introduced to a society that has little knowledge or background with anything beyond traditional exhaustible forms of energy and power. Dotson (2009) noted that the real challenge is to inform and educate the citizenry of the renewable energy potential through the development of…

  20. Algae separation from urban landscape water using a high density microbubble layer enhanced by micro-flocculation.

    Science.gov (United States)

    Chen, Shuwen; Xu, Jingcheng; Liu, Jia; Wei, Qiaoling; Li, Guangming; Huang, Xiangfeng

    2014-01-01

    Eutrophication of raw water results in outbreaks of algae, which hinders conventional water treatment. In this study, high density microbubble layers combined with micro-flocculation was adopted to remove algae from urban landscape water, and the effects of pressure, hydraulic loading, microbubble layer height and flocculation dosage on the removal efficiency for algae were studied. The greatest removal efficiency for algae, chemical oxygen demand, nitrogen and phosphorus was obtained at 0.42 MPa with hydraulic loading at 5 m/h and a flocculation dosage of 4 mg/L using a microbubble layer with a height of 130 cm. Moreover, the size, clearance distance and concentration of microbubbles were found to be affected by pressure and the height of the microbubble layer. Based on the study, this method was an alternative for algae separation from urban landscape water and water purification.

  1. Arsenic removal in water by means of coagulation-flocculation processes; Remocion de arsenico en agua mediante procesos de coagulacion-floculacion

    Energy Technology Data Exchange (ETDEWEB)

    Franco, M. F.; Carro P, M. E., E-mail: ffrancis@efn.uncor.edu [Universidad Nacional de Cordoba, Facultad de Ciencias Exactas, Fisicas y Naturales, Departamento de Construcciones Civiles, Av. Velez Sarsfield 1611, Cordoba (Argentina)

    2014-10-01

    Arsenic and arsenical compounds are considered as carcinogenic and risky for humans according to epidemiological evidence related with the ingestion of arsenical water during a long period. In many places the only source of drinking water contains arsenic and, therefore, removal strategies have to be investigated. This work shows experimental results of coagulation-flocculation processes implemented to evaluate the efficiency in the removal of arsenic from drinking water. The main objectives include the evaluation of the relevant aspect that controls the removal efficiency. Experimental tests were performed with coagulant concentrations from 5 to 500 mg/L, solid particle concentrations from 0 to 6000 mg/L, and initial arsenic concentrations from 0.5 to 5 mg/L. These variables were simultaneously varied in more than 100 experiments. The efficiency in remediation ranged from 0% to 95%. Removal efficiency near 95% was obtained when using ferric chloride as coagulant, and was close to 80% when using aluminium sulfate as coagulant in arsenate solutions. The remediation efficiency decreased significantly when the ferric chloride concentration was higher than 50 mg/L in relation to the obtained results for aluminum sulfate for different type and concentration of soil particles. The highest removal efficiency were obtained at ph between 3 and 5 in oxidized solutions. Obtained results simulated by means of multiple linear regression analysis (R>0.90) allow determining that the main parameters that control the removal of arsenic from drinking water are coagulant concentration, ph, and solid particles concentration. Conversely, particle mineralogy and coagulant type have less significant effect on the removal by means of coagulation-flocculation mechanisms. Obtained results are relevant for the removal of As in water treatment plants as well as for the development of small scale filters. The samples were studied by scanning electron microscopy and energy dispersive X

  2. The Use of an Edible Mushroom-Derived Renewable Carbon Material as a Highly Stable Electrocatalyst towards Four-Electron Oxygen Reduction

    Directory of Open Access Journals (Sweden)

    Chaozhong Guo

    2015-12-01

    Full Text Available The development of highly stable and efficient electrocatalysts for sluggish oxygen reduction reaction (ORR is exceedingly significant for the commercialization of fuel cells but remains a challenge. We here synthesize a new nitrogen-doped biocarbon composite material (N-BC@CNP-900 as a nitrogen-containing carbon-based electrocatalyst for the ORR via facile all-solid-state multi-step pyrolysis of bioprotein-enriched enoki mushroom as a starting material, and inexpensive carbon nanoparticles as the inserting matrix and conducting agent at controlled temperatures. Results show that the N-BC@CNP-900 catalyst exhibits the best ORR electrocatalytic activity with an onset potential of 0.94 V (versus reversible hydrogen electrode, RHE and high stability. Meanwhile, this catalyst significantly exhibits good selectivity of the four-electron reaction pathway in an alkaline electrolyte. It is notable that pyridinic- and graphtic-nitrogen groups that play a key role in the enhancement of the ORR activity may be the catalytically active structures for the ORR. We further propose that the pyridinic-nitrogen species can mainly stabilize the ORR activity and the graphitic-nitrogen species can largely enhance the ORR activity. Besides, the addition of carbon support also plays an important role in the pyrolysis process, promoting the ORR electrocatalytic activity.

  3. The Use of an Edible Mushroom-Derived Renewable Carbon Material as a Highly Stable Electrocatalyst towards Four-Electron Oxygen Reduction.

    Science.gov (United States)

    Guo, Chaozhong; Sun, Lingtao; Liao, Wenli; Li, Zhongbin

    2015-12-23

    The development of highly stable and efficient electrocatalysts for sluggish oxygen reduction reaction (ORR) is exceedingly significant for the commercialization of fuel cells but remains a challenge. We here synthesize a new nitrogen-doped biocarbon composite material (N-BC@CNP-900) as a nitrogen-containing carbon-based electrocatalyst for the ORR via facile all-solid-state multi-step pyrolysis of bioprotein-enriched enoki mushroom as a starting material, and inexpensive carbon nanoparticles as the inserting matrix and conducting agent at controlled temperatures. Results show that the N-BC@CNP-900 catalyst exhibits the best ORR electrocatalytic activity with an onset potential of 0.94 V ( versus reversible hydrogen electrode, RHE) and high stability. Meanwhile, this catalyst significantly exhibits good selectivity of the four-electron reaction pathway in an alkaline electrolyte. It is notable that pyridinic- and graphtic-nitrogen groups that play a key role in the enhancement of the ORR activity may be the catalytically active structures for the ORR. We further propose that the pyridinic-nitrogen species can mainly stabilize the ORR activity and the graphitic-nitrogen species can largely enhance the ORR activity. Besides, the addition of carbon support also plays an important role in the pyrolysis process, promoting the ORR electrocatalytic activity.

  4. Nuclear plant license renewal

    International Nuclear Information System (INIS)

    Gazda, P.A.; Bhatt, P.C.

    1991-01-01

    During the next 10 years, nuclear plant license renewal is expected to become a significant issue. Recent Electric Power Research Institute (EPRI) studies have shown license renewal to be technically and economically feasible. Filing an application for license renewal with the Nuclear Regulatory Commission (NRC) entails verifying that the systems, structures, and components essential for safety will continue to perform their safety functions throughout the license renewal period. This paper discusses the current proposed requirements for this verification and the current industry knowledge regarding age-related degradation of structures. Elements of a license renewal program incorporating NRC requirements and industry knowledge including a schedule are presented. Degradation mechanisms for structural components, their significance to nuclear plant structures, and industry-suggested age-related degradation management options are also reviewed

  5. New renewable energy sources

    International Nuclear Information System (INIS)

    2001-06-01

    This publication presents a review of the technological, economical and market status in the field of new renewable energy sources. It also deals briefly with the present use of energy, external conditions for new renewable energy sources and prospects for these energy sources in a future energy system. The renewable energy sources treated here are ''new'' in the sense that hydroelectric energy technology is excluded, being fully developed commercially. This publication updates a previous version, which was published in 1996. The main sections are: (1) Introduction, (2) Solar energy, (3) Bio energy, (4) Wind power, (5) Energy from the sea, (6) Hydrogen, (7) Other new renewable energy technologies and (8) New renewable s in the energy system of the future

  6. NRC's license renewal regulations

    International Nuclear Information System (INIS)

    Akstulewicz, Francis

    1991-01-01

    In order to provide for the continuity of the current generation of nuclear power plant operating licenses and at the same time ensure the health and safety of the public, and the quality of the environment, the US Nuclear Regulatory Commission (NRC) established a goal of developing and issuing regulations and regulatory guidance for license renewal in the early 1990s. This paper will discuss some of those activities underway to achieve this goal. More specifically, this paper will discuss the Commission's regulatory philosophy for license renewal and the two major license renewal rule makings currently underway. The first is the development of a new Part 54 to address procedural and technical requirements for license renewal; the second is a revision to existing Part 51 to exclude environmental issues and impacts from consideration during the license renewal process. (author)

  7. Sustainable polymers from renewable resources.

    Science.gov (United States)

    Zhu, Yunqing; Romain, Charles; Williams, Charlotte K

    2016-12-14

    Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

  8. Development of a flocculation sub-model for a 3-D CFD model based on rectangular settling tanks.

    Science.gov (United States)

    Gong, M; Xanthos, S; Ramalingam, K; Fillos, J; Beckmann, K; Deur, A; McCorquodale, J A

    2011-01-01

    To assess performance and evaluate alternatives to improve the efficiency of rectangular Gould II type final settling tanks (FSTs), New York City Department of Environmental Protection and City College of NY developed a 3D computer model depicting the actual structural configuration of the tanks and the current and proposed hydraulic and solids loading rates. Fluent 6.3.26™ was the base platform for the computational fluid dynamics (CFD) model, for which sub-models of the SS settling characteristics, turbulence, flocculation and rheology were incorporated. This was supplemented by field and bench scale experiments to quantify the coefficients integral to the sub-models. The 3D model developed can be used to consider different baffle arrangements, sludge withdrawal mechanisms and loading alternatives to the FSTs. Flocculation in the front half of the rectangular tank especially in the region before and after the inlet baffle is one of the vital parameters that influences the capture efficiency of SS. Flocculation could be further improved by capturing medium and small size particles by creating an additional zone with an in-tank baffle. This was one of the methods that was adopted in optimizing the performance of the tank where the CCNY 3D CFD model was used to locate the in-tank baffle position. This paper describes the development of the flocculation sub-model and the relationship of the flocculation coefficients in the known Parker equation to the initial mixed liquor suspended solids (MLSS) concentration X0. A new modified equation is proposed removing the dependency of the breakup coefficient to the initial value of X0 based on preliminary data using normal and low concentration mixed liquor suspended solids values in flocculation experiments performed.

  9. Compositional thermodynamic model of asphaltenes flocculation out of crudes; Modelisation thermodynamique compositionnelle de la floculation des bruts asphalteniques

    Energy Technology Data Exchange (ETDEWEB)

    Szewczyk, V

    1997-12-02

    The aim of this work is to propose to the oil industry a compositional thermodynamic model able to predict the operating conditions which induce asphaltenes flocculation out of crudes. In this study, various analytical methods (calorimetry, elemental analysis, {sup 13}C nuclear magnetic resonance, neutron diffusion,...) have been used in order to get a better description of the asphaltene fraction to infer its flocculation mechanism. The proposed model describes this flocculation as a thermodynamic transition inducing the formation of a new liquid phase with a high asphaltene content and formed by all the components initially in the crude: the asphaltene deposit. Asphaltenes are represented as a pseudo-component essentially made of carbon and hydrogen. The analytical modelling of the F11-F20 light fraction is the one proposed by Jaubert (1993). The F20+ heavy fraction is represented by four pseudo-components, their physical properties are calculated using the group contribution methods of Avaullee (1995) and of Rogalski and Neau (1990). The Peng-Robinson equation of state (1976) combined with the Abdoul and Peneloux group contribution mixing rules (1989) is used in order to restitute the gas-liquid-asphaltene deposit phase equilibria. This model not being able to compute flocculation conditions on a predictive manner, the method consists in fitting some physical properties of the pseudo-components introduced in the analytical representation of the asphaltene crudes. he obtained results show results show that the proposed flocculation model is then well adapted to the description of the thermodynamic properties (saturation pressures, relative volumes, flocculation curves) of asphaltene crudes within a relatively large range of temperature (30-150 deg C) and pressure (0.1-50 MPa), covering the majority of conditions met in oil production. (author) 109 refs.

  10. Improvement of the coagulation/flocculation process using a combination of Moringa oleifera lam with anionic polymer in water treatment.

    Science.gov (United States)

    Bongiovani, Milene Carvalho; Camacho, Franciele Pereira; Nishi, Letícia; Coldebella, Priscila Ferri; Valverde, Karina Cardoso; Vieira, Angélica Marquetotti Salcedo; Bergamasco, Rosângela

    2014-01-01

    The objective of this study is to investigate the impacts of anionic polymer as a flocculant aid on the coagulation/flocculation performance with a saline solution of Moringa oleifera as a coagulant to provide larger flocs and decrease the time sedimentation. For the tests, raw water was used from Pirapó River Basin (Maringá, Paraná, Brazil). Optimization of coagulation/flocculation tests was initially performed in a jar-test with a dosage of M. oleifera Lam (crude extract--MO, oil-extracted with ethanol--MO (et) and hexane--MO (hex) 1% m/v) as the coagulant that ranged from 10 to 60 mg L(-1) and of the anionic polymer 0.1% as a flocculant aid with a dosage that ranged from 0 to 0.4 mg L(-1). The parameters analysed were colour, turbidity and compounds with absorption in UV254nm. In view of the statistical analysis results, MO (hex) with a dosage of 30 mg L(-1) was chosen as a coagulant for the next tests of coagulation/flocculation. When anionic polymer was used alone (0.0 mg L(-1) of MO (hex)), parameters were not removed and there was no generation of heavy flocs as compared with the combination of MO (hex) with the anionic polymer. Statistical analysis showed that MO (hex) obtained the highest removals of the parameters analysed in lower dosages and no significant increase in parameters removal was observed when the polymer dosage was increased. The efficacy of the coagulant +/- anionic polymer was optimal when 30mg L(-1) of MO (hex) was used as a coagulant and 0.1 mg L(-1) of the anionic polymer was used as a flocculant aid, decreasing the time sedimentation from 1 h to 15 min.

  11. Smart grid and renewable energy systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Guerrero, Josep M.

    2011-01-01

    conventional, fossil based energy sources to renewable energy sources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discus trends of the future grid infrastructure as well as the most emerging renewable energy...... as efficient as possible. Further, the recent challenges with nuclear power plants are arguing to find more sustainable energy generation solutions. Of many options, two major technologies will play important roles to solve parts of those future challenges. One is to change the electrical power production from...... sources, wind energy and photovoltaics. Then main focus is on the power electronics and control technology for wind turbines as they are the largest renewable power contributor, allowing their penetration into a SmartGrid to be even higher in the future....

  12. Treatment of Industrial Liquid Waste of Steel Plating by Coagulation-Flocculation Using Sodium Biphosphate

    International Nuclear Information System (INIS)

    Subiarto; Herlan Martono

    2007-01-01

    Research about treatment of industrial liquid waste of steel plating by coagulation-flocculation using sodium biphosphate have been conducted. The purpose of the treatment was the content reduction of Cr, Ni, and Cu in the liquid waste, so that produced effluent with Cr, Ni, and Cu content until they laid under mutual standard. The variables studied in this process were the solution pH, the coagulant/waste volume comparison, the speed of the fast stirring, and the time of the fast stirring. Optimum separation efficiency on coagulation-flocculation process of liquid waste of steel plating using sodium biphosphate at the condition of solution ph 9, coagulant/waste volume comparation 1.50, the speed of the fast stirring 400 rpm, and the time of fast stirring is 5 minute. Low stirring was conducted at 60 rpm for 60 minute. The yields of optimum separation efficiency in this condition were 99.48 % for Cr, 99.51 % for Ni, and 99.03 % for Cu. (author)

  13. Transmission X-ray Microscopy—A New Tool in Clay Mineral Floccules Characterization

    Directory of Open Access Journals (Sweden)

    Ray L. Frost

    2012-10-01

    Full Text Available Effective flocculation and dewatering of mineral processing streams containing clays are microstructure dependent in clay-water systems. Initial clay flocculation is crucial in the design and for the development of a new methodology of gas exploitation. Microstructural engineering of clay aggregates using covalent cations and Keggin macromolecules have been monitored using the new state of the art Transmission X-ray Microscope (TXM with 60 nm tomography resolution installed in a Taiwanese synchrotron. The 3-D reconstructions from TXM images show complex aggregation structures in montmorillonite aqueous suspensions after treatment with Na+, Ca2+ and Al13 Keggin macromolecules. Na-montmorillonite displays elongated, parallel, well-orientated and closed-void cellular networks, 0.5–3 µm in diameter. After treatment by covalent cations, the coagulated structure displays much smaller, randomly orientated and openly connected cells, 300–600 nm in diameter. The average distances measured between montmorillonite sheets was around 450 nm, which is less than half of the cell dimension measured in Na-montmorillonite. The most dramatic structural changes were observed after treatment by Al13 Keggin; aggregates then became arranged in compacted domains of a 300 nm average diameter composed of thick face-to-face oriented sheets, which forms porous aggregates with larger intra-aggregate open and connected voids.

  14. Treatment of Surface water in lebanon by using the coagulation-flocculation procedure

    International Nuclear Information System (INIS)

    SLIM, K.; Saad, Z.; Kazpard, V.; El Samarani, A.

    2005-01-01

    In the absence of application of environmental protection laws in Lebanon. Anthropic effluents are directly discharged in the course of rivers. More specially two coastal rivers (GHadir and Ibrahim)located near Beirut. Treatment of these surface waters is done by coagulation-flocculation process by using Al13 coagulant. The elimination of suspended matters in Ghadir and Ibrahim rivers is studied by simple jar test coupled to measurement of supernatant turbidity and sediment volume. Physical and chemical parameters of water before and after treatment are given by Atomic absorption and ion chromatography analysis. The optimal coagulation concentration of Al was defined relatively to lowest concentration of Aluminum needed for maximum turbidity removal in treated water. This study showed that hydrolysis of aluminum salts before adding to water is relevant to the use of similar quantities of Al for the coagulation-flocculation process that eliminates primarily suspended matter in river. Restabilisation is shown in all Jar tests of Ibrahim river, but not in Ghadir where buffering effect is elevated. Results also showed that waters with low turbidity request low concentration of aluminum for the destabilization process. For this, Ibrahim water treatment was found better than river Ghadir characterized by higher inputs of anthropogenic effluents in its course. In all cases, cationic exchanges with Al 1 3 polycations within the sediments caused the release of calcium and the elevation of its concentration in the supernatant. Sulfate concentration diminished continuously in supernatant after the addition of the optimal coagulation concentration of aluminum. (author)

  15. Flocculation of Pyrite Fines in Aqueous Suspensions with Corn Starch to Eliminate Mechanical Entrainment in Flotation

    Directory of Open Access Journals (Sweden)

    Wei Ge

    2015-10-01

    Full Text Available The hydrophilic flocculation of pyrite fines in aqueous suspensions with corn starch was studied by measuring particle size distribution, microscopy observation and micro-flotation. Furthermore, the interaction of corn starch with pyrite was investigated by determining the adsorption density and based on zeta potential measurements and X-ray photoelectron spectrometer (XPS analysis in this work. The results of the particle size distribution measurement show that corn starch can effectively aggregate pyrite fines, and the pyrite floccules (flocs are sensitive to mechanical stirring. The micro-flotation results suggest that the mechanical entrainment of pyrite fines in flotation can be effectively eliminated through the formation of large-size flocs. The zeta potential of pyrite particles decreases with the addition of corn starch. The XPS results prove that carboxyl groups are generated on the digested corn starch, and both iron hydroxyl compounds and ferrous disulfide on the pyrite surface can chemically interact with the corn starch digested by sodium hydroxide.

  16. Performance optimization of coagulant/flocculant in the treatment of wastewater from a beverage industry.

    Science.gov (United States)

    Amuda, O S; Amoo, I A; Ajayi, O O

    2006-02-28

    This study investigated the effect of coagulation/flocculation treatment process on wastewater of Fumman Beverage Industry, Ibadan, Nigeria. The study also compared different dosages of coagulant, polyelectrolyte (non-ionic polyacrylamide) and different pH values of the coagulation processes. The effect of different dosages of polyelectrolyte in combination with coagulant was also studied. The results reveal that low pH values (3-8), enhance removal efficiency of the contaminants. Percentage removal of 78, 74 and 75 of COD, TSS and TP, respectively, were achieved by the addition of 500 mg/L Fe2(SO4)3.3H2O and 93, 94 and 96% removal of COD, TSS and TP, respectively, were achieved with the addition of 25 mg/L polyelectrolyte to the coagulation process. The volume of sludge produced, when coagulant was used solely, was higher compared to the use of polyelectrolyte combined with Fe2(SO4)3.3H2O. This may be as a result of non-ionic nature of the polyelectrolyte; hence, it does not chemically react with solids of the wastewater. Coagulation/flocculation may be useful as a pre-treatment process for beverage industrial wastewater prior to biological treatment.

  17. Raise of efficiency of flocculation-precipitation treatment of exuding water from reclaimed land by irradiation

    International Nuclear Information System (INIS)

    Sawai, Teruko; Yamazaki, Masao; Sawai, Takeshi

    1984-01-01

    When rain falls on the coastal reclaimed land filled with home garbage in Tokyo, a large quantity of water containing much organic contaminant flows out. It is difficult to treat this water exuding from reclaimed land by conventional method. Because the water with low BOD which is difficult to treat by biological process flows out for long period after the stabilization of reclaimed land. When the water is treated by flocculation and precipitation, the substances with high molecular weight are easily removed, but the rate of removal of fulvic acid with low molecular weight, which accounts for more than 60% of the composition of the water, is very poor. Therefore, it was examined to change the fulvic acid to high molecular weight by irradiation, and to improve the efficiency of the flocculation-precipitation treatment of exuding water. Exuding water was sampled in Tokyo Bay No.15 reclaimed land, and it was separated into humic acid and fulvic acid. The Co-60 gamma ray of 5 kCi was irradiated to the samples. The experimental method and the results are reported. The change of fulvic acid to high molecular weight by irradiation was most efficient at pH 2.2. More than 90% of organic contaminants was able to be removed. (Kako, I.)

  18. Design of amphoteric chitosan flocculants for phosphate and turbidity removal in wastewater.

    Science.gov (United States)

    Agbovi, Henry K; Wilson, Lee D

    2018-06-01

    An amphoteric flocculant (CMC-CTA) was synthesized by grafting 3-chloro-2-hydroxypropyl trimethylammonium chloride onto carboxymethyl chitosan (CMC). The turbidity and orthophosphate (P i ) removal properties of chitosan (CHI), CMC, and CMC-CTA were compared in the presence (and absence) of FeCl 3 coagulant. At a fixed FeCl 3 dosage, the effects of flocculant dosage, pH and settling time were evaluated. Turbidity removal (%) and optimal dosage (FeCl 3 ; mg/L) was determined: CMC-CTA (95.8%;5), CHI (88.8%;7.0) and CMC (68.8%;9.0). The corresponding P i removal (%) and dosage (mg/L) are listed: (93.4%;10), (90.6%;10), and (67.4%;5). Optimal turbidity and P i removal occurred at pH 4, where CMC-CTA had greater efficiency over CMC and CHI. The turbidity removal kinetics was described by the pseudo-second-order model, while P i removal followed the pseudo-first-order model. The removal process involves cooperative Coulombic interactions between the biopolymer/Fe(III)/P i and/or kaolinite colloids, along with polymer bridging effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Computer Simulation Elucidates Yeast Flocculation and Sedimentation for Efficient Industrial Fermentation.

    Science.gov (United States)

    Liu, Chen-Guang; Li, Zhi-Yang; Hao, Yue; Xia, Juan; Bai, Feng-Wu; Mehmood, Muhammad Aamer

    2018-05-01

    Flocculation plays an important role in the immobilized fermentation of biofuels and biochemicals. It is essential to understand the flocculation phenomenon at physical and molecular scale; however, flocs cannot be studied directly due to fragile nature. Hence, the present study is focused on the morphological specificities of yeast flocs formation and sedimentation via the computer simulation by a single floc growth model, based on Diffusion-Limited Aggregation (DLA) model. The impact of shear force, adsorption, and cell propagation on porosity and floc size is systematically illustrated. Strong shear force and weak adsorption reduced floc size but have little impact on porosity. Besides, cell propagation concreted the compactness of flocs enabling them to gain a larger size. Later, a multiple flocs growth model is developed to explain sedimentation at various initial floc sizes. Both models exhibited qualitative agreements with available experimental data. By regulating the operation constraints during fermentation, the present study will lead to finding optimal conditions to control the floc size distribution for efficient fermentation and harvesting. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Landfill leachate treatment by coagulation/flocculation combined with microelectrolysis-Fenton processes.

    Science.gov (United States)

    Luo, Kun; Pang, Ya; Li, Xue; Chen, Fei; Liao, Xingsheng; Lei, Min; Song, Yong

    2018-02-07

    Landfill leachate was pretreated by chemical flocculation with polyaluminum chloride (PAC) as a flocculant, and subsequently purified by the microelectrolysis-Fenton (MEF) process. Response surface methodology was employed to optimize the MEF process, and the optimal conditions were initial pH 3.20, H 2 O 2 concentration 3.57 g/L, and Fe-C dosage 104.52 g/L. The PAC coagulation combined with MEF processes obtained a superior decontamination performance, and the predicted chemical oxygen demand (COD) and humic acids (HA) removal were respectively 90.27% and 93.79%. The strong fluorescence peak at 425 nm and the trapping experiment showed that [Formula: see text] was generated during MEF, which had a strong oxidation ability to degrade organic recalcitrant pollutants. The ultraviolet-visible spectra and three-dimensional excitation-emission matrices spectra (3D-EEMs) indicated that PAC coagulation could preferentially remove protein-like substances, while the MEF process was effective in destructing organic recalcitrant pollutants, especially humic-like and fulvic-like substances.

  1. Separation and purification of γ-aminobutyric acid from fermentation broth by flocculation and chromatographic methodologies.

    Science.gov (United States)

    Gao, Qiang; Duan, Qiang; Wang, Depei; Zhang, Yunze; Zheng, Chunyang

    2013-02-27

    To date, the multifunctional γ-aminobutyric acid (GABA) is mainly produced by microbial fermentation in industry. The purpose of this study was to find an effective method for separation and purification of 31.2 g/L initial GABA from the fermentation broth of Enterococcus raffinosus TCCC11660. To remove the impurities from fermentation broth, flocculation pretreatment using chitosan and sodium alginate was first implemented to facilitate subsequent filtration. Ultrafiltration followed two discontinuous diafiltration steps to effectively remove proteins and macromolecular pigments, and the resulting permeate was further decolored by DA201-CII resin at a high decoloration ratio and GABA recovery. Subsequently, ion exchange chromatography (IEC) with Amberlite 200C resin and gradient elution were applied for GABA separation from glutamate and arginine. Finally, GABA crystals of 99.1% purity were prepared via warm ethanol precipitation twice. Overall, our results reveal that the successive process including flocculation, filtration, ultrafiltration, decoloration, IEC, and crystallization is promising for scale-up GABA extraction from fermentation broth.

  2. New insights about flocculation process in sodium caseinate-stabilized emulsions.

    Science.gov (United States)

    Huck-Iriart, Cristián; Montes-de-Oca-Ávalos, Juan; Herrera, María Lidia; Candal, Roberto Jorge; Pinto-de-Oliveira, Cristiano Luis; Linares-Torriani, Iris

    2016-11-01

    Flocculation process was studied in emulsions formulated with 10wt.% sunflower oil, 2, 5 or 7.5wt.% NaCas, and with or without addition of sucrose (0, 5, 10, 15, 20 or 30wt.%). Two different processing conditions were used to prepare emulsions: ultraturrax homogenization or further homogenization by ultrasound. Emulsions with droplets with diameters above (coarse) or below (fine) 1μm were obtained. Emulsions were analyzed for droplet size distribution by static light scattering (SLS), stability by Turbiscan, and structure by confocal laser scanning microscopy (CLSM) and small angle X-ray scattering (SAXS). SAXS data were fitted by a theoretical model that considered a system composed of poly dispersed spheres with repulsive interaction and presence of aggregates. Flocculation behavior was caused by the self-assembly properties of NaCas, but the process was more closely related to interfacial protein content than micelles concentration in the aqueous phase. The results indicated that casein aggregation was strongly affected by disaccharide addition, hydrophobic interaction of the emulsion droplets, and interactions among interfacial protein molecules. The structural changes detected in the protein micelles in different environments allowed understanding the macroscopic physical behavior observed in concentrated NaCas emulsions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effect of chemical composition on the flocculation dynamics of latex-based synthetic activated sludge

    International Nuclear Information System (INIS)

    Tan Phong Nguyen; Hankins, Nicholas P.; Hilal, Nidal

    2007-01-01

    This study investigates the effect of calcium, alginate, fibrous cellulose, and pH on the flocculation dynamics and final properties of synthetic activated sludges. A laboratory-scale batch reactor, fed with standard synthetic sludges was used. The effects of varying calcium concentration (5-25 mM), alginate concentration (25-125 mg/L), fibrous cellulose concentration (0.2-0.8 g/L) and pH (3-9) on the sludge characteristics were studied by varying one parameter whilst keeping the others constant. The results from experiments indicated that the calcium, alginate, fibrous cellulose, and pH had the critical effect on the aggregation rate, flocs size, and made the improvement of the final properties of sludge. Dynamic measurements have established the optimum conditions for floc formation and can accurately reflect the state of formation of the synthetic activated sludge flocs. These correlate well with measurements of settleability and turbidity of the synthetic activated sludge. The results of this study support the bonding theory and indicate that formation of cations-polymer complexes and polymer gelation are important means of flocculation. The development of synthetic activated sludges is suggested also to be a possible surrogate for studying the final properties of activated sludge

  4. REMOVAL OF PHENOL AND SURFACTANT FROM LANDFILL LEACHATE BY COAGULATION-FLOCCULATION PROCESS

    Directory of Open Access Journals (Sweden)

    H. BAKRAOUY

    2016-02-01

    Full Text Available Following the action of rainfall and natural fermentation, the stored waste produces a liquid fraction called leachate. This leachate is rich in organic matter (biodegradable but also refractory and trace elements. There are many techniques of treating the leachate, in particular, biological, physicochemical, membrane processes. The choice of a technique instead of another depends on several parameters including: the age of the leachate, composition... In this work we applied a coagulation-flocculation process to treat intermediate landfill leachate of Rabat city with a combined ferric chloride coagulant and a polymer flocculant. We were inspired by full factorial design, including twenty five experiments, to determine optimal dosages of coagulant and flocculant. We operate at pH 8.4, the best removal efficiencies obtained were 88 % for Turbidity, 98 % for Phenol and 82 % for surfactant. The optimum dosages values determined by this study were 13.2 g∙L-1 of coagulant, 62 mL∙L-1 of flocculant.

  5. Variables in the process of coagulation / flocculation / settling of leachate of municipal landfills

    Directory of Open Access Journals (Sweden)

    José Fernando Thomé Jucá

    2012-08-01

    Full Text Available The careless disposal of waste may generate tremendous environmental and social impacts. For the treatment of landfill leachate, biological and physic-chemical treatments are routinely used. Chemical precipitation using calcium hydroxide has been used with great effectiveness in treating effluent with high concentrations of organic compounds and heavy metals. The leachate used in this study was collected from a flow box of the Muribeca landfill, located in the city of Jaboatão Guararapes, PE. Commercial calcium hydroxide was used as coagulant in aqueous solution. The experiment was implemented using a fractional factorial design, followed by a complete planning 24. It was observed that the lowest turbidity and color were obtained at the highest flocculation speeds. Color removal was favored by long flocculation time whereas this did not occur for turbidity removal. For the optimal point, a reduction of 52% of the color and a NTU turbidity within the standards established in Brazilian Laws (CONAMA 357/05 and CONAMA 430/11 were obtained.

  6. Renewable Energy Operation and Conversion Schemes

    DEFF Research Database (Denmark)

    Spagnuolo, Giovanni; Petrone, Giovanni; Araujo, Samuel Vasconcelos

    2010-01-01

    A short summary of some speeches given during Seminar on Renewable Energy system (SERENE) is presented. The contributions have been mainly focused on power electronics for photovoltaic (PV) and sea wave energies, pointing out some aspects related to efficiency, reliability, and grid integration. ...

  7. Renewables in the Midwest

    International Nuclear Information System (INIS)

    Wager, J.S.

    1994-01-01

    Over the past three years, the Union of Concerned Scientists (UCS) has evaluated the potential for using renewable energy for electricity in the Midwest, and has been carrying out a multifaceted effort to expand the use of renewables in the region. The UCS study presents a strategy for developing renewable-electric technologies and resources in 12 midwestern states. UCS analysts used a geographic information system (GIS) to create data-bases of renewable resources, land uses, vegetation cover, terrain elevation and locations of utility transmission lines, and to analyze and present information on a .6 mi x .6 mi (1 km x 1 km) grid scale. In addition, UCS developed a model to calculate the net employment impact of renewable versus conventional electricity technologies on a state-by-state basis. In evaluating the costs and benefits of renewable energy sources, UCS analysts explored a cost assessment that accounted for the impact of pollution from fossil fuels on energy resource cost. Researchers also considered the risks associated with fuel-price volatility, environmental regulation, construction lead times and other uncertainties. Finally, UCS researchers suggested steps to remove the institutional, regulatory and legislative barriers that inhibit renewable energy development, and proposed policies to expand the use of the region's renewable resources. The UCS analysis showed that wind is currently the least expensive renewable resource. UCS also found numerous opportunities to expand biomass-electric generation in the near term, such as converting small coal-fired power plants to wood fuel, making greater use of logging residues and co-firing a small percentage of biomass with fossil fuel at large power plants

  8. Damn renewable energies

    International Nuclear Information System (INIS)

    Gay, Michel

    2017-01-01

    In this book, the author describes how renewable energies have been developed in a way he considers as scandalous, whereas they are a technical, financial and ecological dead end. He also explains how ecologists (notably the ADEME) manipulate figures to make believe that these energies could be an answer to the needs of France, of Europe and of humanity. In a first chapter, he criticises the influence of a so-called green ideology on the design of energy transition. In the second one, he denounces twelve tales about energy transition. In the next chapters, he denounces the sham of renewable energies, and finally tells some unfortunate renewable experiments

  9. Renewable energies - Alain Chardon

    International Nuclear Information System (INIS)

    Anon.

    2012-01-01

    In an interview, the chairman of Cleantechs and Decarbonate, Capgemini Consulting, comments the challenge of the struggle against global warming, discusses the role of gas on the way towards a de-carbonated economy, the cost of renewable energies compared to that of fossil and nuclear energies. He outlines other brakes upon the development of renewable energies, discusses the political issues and the challenge of meeting European objectives with respect with the share of renewable energies in the energy mix and the electricity mix by 2020

  10. Renewable energy in Taiwan

    International Nuclear Information System (INIS)

    Chen, Falin; Lu, Shyi-Min; Wang, Eric; Tseng, Kuo-Tung

    2010-01-01

    With limited indigenous conventional energy resources, Taiwan imports over 99% of its energy supply from foreign countries, mostly from the Middle East. Developing independent renewable energy resources is thus of priority concern for the Taiwanese government. A medium subtropical island surrounded by the Pacific Ocean, Taiwan has enormous potential to develop various renewable energies, such as solar energy, biomass energy, wind power, geothermal energy, hydropower, etc. However, owing to the importance of conventional fossil energy in generating exceptionally cheap electricity, renewable energy has not yet fully developed in Taiwan, resulting from a lack of market competition. Consequently, numerous promotional and subsidy programs have recently been proclaimed by the Taiwanese government, focused on the development of various renewables. This study reviews the achievements, polices and future plans in this area. (author)

  11. The value of renewables

    International Nuclear Information System (INIS)

    Koch, H.J.

    2001-01-01

    The article extols the virtues of renewable energy sources. Based largely on the outcome of an IAE meeting in May 2001, the author has outlined an approach for accelerating the development of renewables. The article quotes several statements made by the IAE with respect to the need for a secure supply of affordable energy, sustainable development, diversification, the value of renewables and challenges confronting developers of renewables. The article is presented under the sub-headings of: (i) harnessing energy market forces; (ii) understanding costs in the context of diversification; (iii) economic performance; (iv) environmental protection; (v) an IAE action plan and (vi) conclusions. The author was once the IAE's director for energy efficiency, technology and R and D

  12. Biotechnology for renewable chemicals

    DEFF Research Database (Denmark)

    Borodina, Irina; Kildegaard, Kanchana Rueksomtawin; Jensen, Niels Bjerg

    2014-01-01

    The majority of the industrial organic chemicals are derived from fossil sources. With the oil and gas resources becoming limiting, biotechnology offers a sustainable alternative for production ofchemicals from renewable feedstocks. Yeast is an attractive cell factory forsustainable production...

  13. Foundations for renewables

    Energy Technology Data Exchange (ETDEWEB)

    Neidlein, H.C. [German Agency Scherer Schnell Walser und Partner (Germany)

    2007-07-01

    In Germany, 77 foundations promote renewable energy technology with around Euro 25 million annually. The most important internationally active foundations, however, can be found in the Anglo-Saxon countries. (orig.)

  14. Renewable resources - future possibilities

    International Nuclear Information System (INIS)

    Thomas, Martin H.

    1998-01-01

    The paper describes the Australian Cooperative Research Centre for Renewable Energy and Related Greenhouse Gas Abatement Technologies (ACRE), its technologies, commercial relationships and markets. The relevance of ACRE to developing country communities which lack reliable, adequate power supplies, is discussed. The opportunities for mutual collaboration between Australia and the developing countries in the application of renewable energy have never been stronger. Renewable energy promises real advantages to those who deploy it wisely, as well as significant job creation. Education at all level together with operational training, public awareness of what is possible and increased system reliability, are also vital ingredients for acceptance of these new technologies. They underpin successful commercialisation. The author concludes with the hope for a united international cooperative approach to the development of the renewable energy industry. (author)

  15. Promoting renewable energy technologies

    International Nuclear Information System (INIS)

    Grenaa Jensen, S.

    2004-06-01

    Technologies using renewable energy sources are receiving increasing interest from both public authorities and power producing companies, mainly because of the environmental advantages they procure in comparison with conventional energy sources. These technologies can be substitution for conventional energy sources and limit damage to the environment. Furthermore, several of the renewable energy technologies satisfy an increasing political goal of self-sufficiency within energy production. The subject of this thesis is promotion of renewable technologies. The primary goal is to increase understanding on how technological development takes place, and establish a theoretical framework that can assist in the construction of policy strategies including instruments for promotion of renewable energy technologies. Technological development is analysed by through quantitative and qualitative methods. (BA)

  16. Renewable Heating And Cooling

    Science.gov (United States)

    Renewable heating and cooling is a set of alternative resources and technologies that can be used in place of conventional heating and cooling technologies for common applications such as water heating, space heating, space cooling and process heat.

  17. Renewable Energy Tracking Systems

    Science.gov (United States)

    Renewable energy generation ownership can be accounted through tracking systems. Tracking systems are highly automated, contain specific information about each MWh, and are accessible over the internet to market participants.

  18. Renewable energy in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Falin; Lu, Shyi-Min; Wang, Eric; Tseng, Kuo-Tung [Institute of Applied Mechanics, National Taiwan University, Taipei 10617 (China)

    2010-09-15

    With limited indigenous conventional energy resources, Taiwan imports over 99% of its energy supply from foreign countries, mostly from the Middle East. Developing independent renewable energy resources is thus of priority concern for the Taiwanese government. A medium subtropical island surrounded by the Pacific Ocean, Taiwan has enormous potential to develop various renewable energies, such as solar energy, biomass energy, wind power, geothermal energy, hydropower, etc. However, owing to the importance of conventional fossil energy in generating exceptionally cheap electricity, renewable energy has not yet fully developed in Taiwan, resulting from a lack of market competition. Consequently, numerous promotional and subsidy programs have recently been proclaimed by the Taiwanese government, focused on the development of various renewables. This study reviews the achievements, polices and future plans in this area. (author)

  19. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    Science.gov (United States)

    In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. ...

  20. License renewal process

    International Nuclear Information System (INIS)

    Fable, D.; Prah, M.; Vrankic, K.; Lebegner, J.

    2004-01-01

    The purpose of this paper is to provide information about license renewal process, as defined by Nuclear Regulatory Commission (NRC). The Atomic Energy Act and NRC regulations limit commercial power reactor licenses to an initial 40 years but also permit such licenses to be renewed. This original 40-year term for reactor licenses was based on economic and antitrust considerations not on limitations of nuclear technology. Due to this selected time period; however, some structures and components may have been engineered on the basis of an expected 40-year service life. The NRC has established a timely license renewal process and clear requirements codified in 10 CFR Part 51 and 10 CFR Part 54, that are needed to assure safe plant operation for extended plant life. The timely renewal of licenses for an additional 20 years, where appropriate to renew them, may be important to ensuring an adequate energy supply during the first half of the 21st Century. License renewal rests on the determination that currently operating plants continue to maintain adequate levels of safety, and over the plant's life, this level has been enhanced through maintenance of the licensing bases, with appropriate adjustments to address new information from industry operating experience. Additionally, NRC activities have provided ongoing assurance that the licensing bases will continue to provide an acceptable level of safety. This paper provides additional discussion of license renewal costs, as one of key elements in evaluation of license renewal justifiability. Including structure of costs, approximately value and two different approaches, conservative and typical. Current status and position of Nuclear Power Plant Krsko, related to license renewal process, will be briefly presented in this paper. NPP Krsko is designed based on NRC Regulations, so requirements from 10 CFR 51, and 10 CFR 54, are applicable to NPP Krsko, as well. Finally, this paper will give an overview of current status of

  1. Processes of Strategic Renewal,

    OpenAIRE

    Harald Aadne, John; Mahnke, Volker

    2010-01-01

    We discuss strategic renewal from a competence perspective. We argue that the management of speed and timing in this process is viewed distinctively when perceived through a cognitive lens. Managers need more firmly grounded process-understanding. The key idea of this paper is to dynamically conceptualize key activities of strategic renewal, and possible sources of break-down as they relate to the managment of speed and timing. Based on a case from the media industry, we identi...

  2. Promoting renewable energy technologies

    DEFF Research Database (Denmark)

    Olsen, O.J.; Skytte, K.

    2004-01-01

    % of its annual electricity production. In this paper, we present and discuss the Danish experience as a case of promoting renewable energy technologies. The development path of the two technologies has been very different. Wind power is considered an outright success with fast deployment to decreasing...... technology and its particular context, it is possible to formulate some general principles that can help to create an effective and efficient policy for promoting new renewable energy technologies....

  3. Renewable energy in Europe

    International Nuclear Information System (INIS)

    Deshaies, M.

    2009-01-01

    Europe's increasing demand for energy and its environmental preoccupations are creating a favourable environment for the development of renewable energy sources. This article stated that although many European countries have adopted voluntary policies since the 1990s to increase the use of renewable energy sources, they have not been developed in an equal or consistent manner. A table was included to show the consumption of renewable energies by country; the percentage of renewable energies in 1995 as compared to 2006; and the consumption of primary energy resources. Combined, Germany, Spain and Denmark produce 75 per cent of wind energy in Europe, while 75 per cent of Europe's hydroelectricity is produced in Norway, Sweden, France, Italy, Austria and Switzerland. Germany has also made significant contributions in developing biomass energy. The article emphasized that the development of renewable energy sources is limited by the fact that it cannot keep up with growing energy demands. In addition, renewable energies cannot yet replace all fossil fuel consumption in Europe because of the variation in development from one country to another. 1 ref., 2 tabs., 4 figs.

  4. Impact of coagulant and flocculant addition to an anaerobic dynamic membrane bioreactor (AnDMBR) treating waste-activated sludge

    NARCIS (Netherlands)

    Kooijman, G.; Lopes, Wilton; Zhou, Z.; Guo, H.; de Kreuk, M.K.; Spanjers, H.L.F.M.; van Lier, J.B.

    2017-01-01

    In this work, we investigated the effects of flocculation aid (FA) addition to an anaerobic dynamic membrane bioreactor (AnDMBR) (7 L, 35°C) treating waste-activated sludge (WAS). The experiment consisted of three distinct periods. In period 1 (day 1–86), the reactor was operated as a

  5. Surface water coagulation-flocculation models. Modelos para el proceso de coagulacion-floculacion de aguas superficiales

    Energy Technology Data Exchange (ETDEWEB)

    Oropesa Rodriguez, I.; Alvarez Rosell, S.; Marin Llanes, L.; Marquez Canosa, E.

    1994-01-01

    Modelling of water treatment processes have been studied ultimately. In the present work, three of the models that are used generally to represent the physical-chemical phenomenum that occur during the coagulation-flocculation process, are compared. The best result are obtained with Freundlich model although the new model gives adequate results too. (Author) 4 refs.

  6. Smectite flocculation structure modified by Al13 macro-molecules--as revealed by the transmission X-ray microscopy (TXM).

    Science.gov (United States)

    Zbik, Marek S; Martens, Wayde N; Frost, Ray L; Song, Yen-Fang; Chen, Yi-Ming; Chen, Jian-Hua

    2010-05-01

    The aggregate structure which occurs in aqueous smectitic suspensions is responsible for poor water clarification, difficulties in sludge dewatering and the unusual rheological behaviour of smectite rich soils. These macroscopic properties are dictated by the 3D structural arrangement of smectite finest fraction within flocculated aggregates. Here, we report results from a relatively new technique, transmission X-ray microscopy (TXM), which makes it possible to investigate the internal structure and 3D tomographic reconstruction of the smectite clay aggregates modified by Al(13) Keggin macro-molecule [Al(13)(O)(4)(OH)(24)(H(2)O)(12)](7+). Three different treatment methods were shown resulted in three different micro-structural environments of the resulting flocculation. In case of smectite sample prepared in Methods 1 and 3 particles fall into the primary minimum where Van der Waals forces act between FF oriented smectite flakes and aggregates become approach irreversible flocculation. In case of sample prepared using Method 2, particles contacting by edges (EE) and edge to face (EF) orientation fell into secondary minimum and weak flocculation resulted in severe gelation and formation of the micelle-like texture in fringe superstructure, which was first time observed in smectite based gel. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Dynamics of polyelectrolyte adsorption and colloidal flocculation upon mixing studied using mono-dispersed polystyrene latex particles

    NARCIS (Netherlands)

    Feng, Lili; Cohen Stuart, Martien; Adachi, Yasuhisa

    2015-01-01

    The dynamic behavior of polyelectrolytes just after their encounter with the surface of bare colloidal particles is analyzed, using the flocculation properties of mono-dispersed polystyrene latex (PSL) particles. Applying a Standardized Colloid Mixing (SCM) approach, effects of ionic strength and

  8. Flocculation and adsorption properties of biodegradable gum-ghatti-grafted poly(acrylamide-co-methacrylic acid) hydrogels

    CSIR Research Space (South Africa)

    Mittal, H

    2015-01-01

    Full Text Available This study reports the microwave-assisted synthesis of gum-ghatti (Gg)-grafted poly(acrylamide-co-methacrylic acid) (AAm-co-MAA) hydrogels for the development of biodegradable flocculants and adsorbents. The synthesized hydrogels were characterized...

  9. Investigation of Self-Assembly Processes for Chitosan-Based Coagulant-Flocculant Systems: A Mini-Review

    Directory of Open Access Journals (Sweden)

    Savi Bhalkaran

    2016-09-01

    Full Text Available The presence of contaminants in wastewater poses significant challenges to water treatment processes and environmental remediation. The use of coagulation-flocculation represents a facile and efficient way of removing charged particles from water. The formation of stable colloidal flocs is necessary for floc aggregation and, hence, their subsequent removal. Aggregation occurs when these flocs form extended networks through the self-assembly of polyelectrolytes, such as the amine-based polysaccharide (chitosan, which form polymer “bridges” in a floc network. The aim of this overview is to evaluate how the self-assembly process of chitosan and its derivatives is influenced by factors related to the morphology of chitosan (flocculant and the role of the solution conditions in the flocculation properties of chitosan and its modified forms. Chitosan has been used alone or in conjunction with a salt, such as aluminum sulphate, as an aid for the removal of various waterborne contaminants. Modified chitosan relates to grafted anionic or cationic groups onto the C-6 hydroxyl group or the amine group at C-2 on the glucosamine monomer of chitosan. By varying the parameters, such as molecular weight and the degree of deacetylation of chitosan, pH, reaction and settling time, dosage and temperature, self-assembly can be further investigated. This mini-review places an emphasis on the molecular-level details of the flocculation and the self-assembly processes for the marine-based biopolymer, chitosan.

  10. The effect of global velocity gradient on the character and filterability of aggregates formed during the coagulation/flocculation process

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Martin; Bubáková, Petra; Pivokonská, Lenka; Hnaťuková, Petra

    2011-01-01

    Roč. 32, č. 12 (2011), s. 1355-1366 ISSN 0959-3330 R&D Projects: GA AV ČR IAA200600902 Institutional research plan: CEZ:AV0Z20600510 Keywords : aggregate size distribution * flocculation * mixing * fractal dimension * filtration Subject RIV: BK - Fluid Dynamics Impact factor: 1.406, year: 2011

  11. The chemical and mechanical differences between alginate-like exopolysaccharides isolated from aerobic flocculent sludge and aerobic granular sludge

    NARCIS (Netherlands)

    Lin, Y. M.; Sharma, P. K.; van Loosdrecht, M. C. M.

    2013-01-01

    This study aimed to investigate differences in the gel matrix of aerobic granular sludge and normal aerobic flocculent sludge. From both types of sludge that fed with the same municipal sewage, the functional gel-forming exopolysaccharides, alginate-like exopolysaccharides, were isolated. These two

  12. 2016 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    2017-12-29

    The 2016 Renewable Energy Data Book provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  13. 2015 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-11-01

    The Renewable Energy Data Book for 2015 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  14. 2015 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp; Tian, Tian

    2016-11-01

    The 2015 Renewable Energy Data Book provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  15. 2014 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp

    2015-11-01

    The Renewable Energy Data Book for 2014 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  16. Suspended particulate matter flocculation in a natural tidal wetland located in the San Francisco Estuary

    Science.gov (United States)

    Saraceno, J.; Bergamaschi, B. A.; Wright, S. A.; Boss, E.; Downing, B. D.; Fleck, J.; Ganju, N. K.

    2011-12-01

    flocculation. Additionally, the timing of flocculation was coincident with periods of elevated dissolved organic matter, suggesting organic matter played a role in the formation of large aggregates. Measurements of SPM organic content in ebb water revealed that SPM was enriched in organic matter by up to 50% following interaction with the wetland. Newly formed aggregates were carried out to the estuary with the ebb tide. These results indicate that the Browns Island wetland (and presumably other similar wetlands throughout the San Francisco Bay-Delta) plays an important role in estuarine biogeochemistry and particle cycling because flocculated particles have higher settling velocities and optical properties than their component particles and will behave differently. The implications of these findings are relevant to several tidal wetland management concerns such as the maintenance of marsh elevation, the cycling and transport of contaminants, and water clarity.

  17. Physicochemical properties of cross-linked poly-gamma-glutamic acid and its flocculating activity against kaolin suspension

    International Nuclear Information System (INIS)

    Taniguchi, M.; Kato, K.; Shimauchi, A.; Ping, X.; Fujita, K.; Tanaka, T.; Tarui, Y.; Hirasawa, E.

    2005-01-01

    Cross-linked poly-Gamma-glutamic acid (C-L Gamma-PGA) was prepared with Gamma-PGA irradiated with Gamma-PGA at various kGy values. The physicochemical properties including viscosity and water absorption capacity were compared between C-L Gamma-PGA and several typical flocculating agents. The viscosity of C-L Gamma-PGA increased with the dose of Gamma-lrradiatio, although the water absorption capacity of C-L Gamma-PGA did not, which showed a maximum of 1005.6 ml/g at 20 kGy. Flocculating activity against kaolin suspension was not observed for any of the test compounds when used singly. However, the activity of C-L Gamma-PGA markedly increased following the addition of polyaluminum chloride. The activity increased with temperature up to 80deg C and remained at 80 deg C of heat pretreatment for 1 h, but did not at more than 50 deg C of beat pretreatment for 24 h. The activity was also observed within a pH range of 4.5-10.0. Roth the water absorption capacity and flocculating activity of C-L Gamma-PGA decreased in parallel with increasing NaCl concentration, suggesting that the hocculating activity of C-L Gamma-PGA was associated with its water absorption capacity, rather than viscosity. An investigation of the effects of various cations on the flocculating activity of C-L Gamma-PGA showed that only trivalent catlons had a synergistic effect. The mechanism of C-L Gamma-PGA flocculating activity is discussed based on the results of preliminary experiments

  18. Mature landfill leachate treatment by coagulation/flocculation combined with Fenton and solar photo-Fenton processes.

    Science.gov (United States)

    Amor, Carlos; De Torres-Socías, Estefanía; Peres, José A; Maldonado, Manuel I; Oller, Isabel; Malato, Sixto; Lucas, Marco S

    2015-04-09

    This work reports the treatment of a mature landfill leachate through the application of chemical-based treatment processes in order to achieve the discharge legal limits into natural water courses. Firstly, the effect of coagulation/flocculation with different chemicals was studied, evaluating the role of different initial pH and chemicals concentration. Afterwards, the efficiency of two different advanced oxidation processes for leachate remediation was assessed. Fenton and solar photo-Fenton processes were applied alone and in combination with a coagulation/flocculation pre-treatment. This physicochemical conditioning step, with 2 g L(-1) of FeCl3 · 6H2O at pH 5, allowed removing 63% of COD, 80% of turbidity and 74% of total polyphenols. Combining the coagulation/flocculation pre-treatment with Fenton reagent, it was possible to reach 89% of COD removal in 96 h. Moreover, coagulation/flocculation combined with solar photo-Fenton revealed higher DOC (75%) reductions than single solar photo-Fenton (54%). In the combined treatment (coagulation/flocculation and solar photo-Fenton), it was reached a DOC reduction of 50% after the chemical oxidation, with 110 kJ L(-1) of accumulated UV energy and a H2O2 consumption of 116 mM. Toxicity and biodegradability assays were performed to evaluate possible variations along the oxidation processes. After the combined treatment, the leachate under study presented non-toxicity but biodegradability increased. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. [Process development for continuous ethanol fermentation by the flocculating yeast under stillage backset conditions].

    Science.gov (United States)

    Zi, Lihan; Liu, Chenguang; Bai, Fengwu

    2014-02-01

    Propionic acid, a major inhibitor to yeast cells, was accumulated during continuous ethanol fermentation from corn meal hydrolysate by the flocculating yeast under stillage backset conditions. Based on its inhibition mechanism in yeast cells, strategies were developed for alleviating this effect. Firstly, high temperature processes such as medium sterilization generated more propionic acid, which should be avoided. Propionic acid was reduced significantly during ethanol fermentation without medium sterilization, and concentrations of biomass and ethanol increased by 59.3% and 7.4%, respectively. Secondly, the running time of stillage backset should be controlled so that propionic acid accumulated would be lower than its half inhibition concentration IC50 (40 mmol/L). Finally, because low pH augmented propionic acid inhibition in yeast cells, a higher pH of 5.5 was validated to be suitable for ethanol fermentation under the stillage backset condition.

  20. CHEMICAL INTERACTIONS TO CLEANUP HIGHLY POLLUTED AUTOMOBILE SERVICE STATION WASTEWATER BY BIOADSORPTION-COAGULATION-FLOCCULATION

    Directory of Open Access Journals (Sweden)

    Carlos Banchon

    2017-01-01

    Full Text Available The present study addresses an ecofriendly solution to treat automobile service stations effluents with high concentrations of oily substances, surfactants, organic matter and heavy metals. Bioadsorption using sawdust from pine trees, sugar cane bagasse and coconut coir without any chemical modification removed colloidal contamination up to 70%. Polyaluminium chloride, ferric chloride and polyacrylamide were applied to remove dissolved and colloidal pollutants under saline conditions without change of initial pH. Both bioadsorption and coagulation-flocculation removed up to 97.8% of BOD, COD, surfactants and heavy metals at a saline concentration of 1.5% NaCl. The increase of ionic strength promoted a high sludge index and a representative cost saving in chemicals consumption of almost 70%. High levels of pollution removal with the minimal use of chemicals is herein presented.

  1. Comparison and analysis of membrane fouling between flocculent sludge membrane bioreactor and granular sludge membrane bioreactor.

    Directory of Open Access Journals (Sweden)

    Wang Jing-Feng

    Full Text Available The goal of this study is to investigate the effect of inoculating granules on reducing membrane fouling. In order to evaluate the differences in performance between flocculent sludge and aerobic granular sludge in membrane reactors (MBRs, two reactors were run in parallel and various parameters related to membrane fouling were measured. The results indicated that specific resistance to the fouling layer was five times greater than that of mixed liquor sludge in the granular MBR. The floc sludge more easily formed a compact layer on the membrane surface, and increased membrane resistance. Specifically, the floc sludge had a higher moisture content, extracellular polymeric substances concentration, and negative surface charge. In contrast, aerobic granules could improve structural integrity and strength, which contributed to the preferable permeate performance. Therefore, inoculating aerobic granules in a MBR presents an effective method of reducing the membrane fouling associated with floc sludge the perspective of from the morphological characteristics of microbial aggregates.

  2. NGC2403: a flocculent galaxy with two principal centres of star formation

    International Nuclear Information System (INIS)

    Beckman, J.; Cepa, J.; Prieto, M.; Munoz Tunon, C.

    1987-01-01

    We have mapped the nearby flocculent spiral galaxy in the visible U, B and V bands, as well as in the near infrared J, H and K bands, with a linear resolution of 900 pc. The galaxy, which does not show marked spiral structure in visible photographs (Tammann and Sandage, 1968) nor in the 21 cm line of HI (Wevers, 1984) is found to have two principal current centres of large-scale star formation, signposted by centres of ultraviolet and blue flux. One is in the nucleus, defined by the geometrical centre of the HI emission, and the other at some 1.5 kpc radial distance away. The outer star-forming region is the more intense and the younger of the two, and corresponds to a local peak in the HI surface density. We use the colours of the star-forming regions and of the integrated galaxy to make a first order estimate of the stellar population distribution. (Author)

  3. Bedform development and morphodynamics in mixed cohesive sediment substrates: the importance of winnowing and flocculation

    Science.gov (United States)

    Ye, Leiping; Parsons, Daniel; Manning, Andrew

    2016-04-01

    There remains a lack of process-based knowledge of sediment dynamics within flows over bedforms generated in complex mixtures of cohesionless sand and biologically-active cohesive muds in natural estuarine flow systems. The work to be presented forms a part of the UK NERC "COHesive BEDforms (COHBED)" project which aims to fill this gap in knowledge. Herein results from a field survey in sub-tidal zone of Dee estuary (NW, England) and a set of large-scale laboratory experiments, conducted using mixtures of non-cohesive sands, cohesive muds and Xanthan gum (as a proxy for the biological stickiness of Extracellular Polymeric Substances (EPS)) will be presented. The results indicate the significance of biological-active cohesive sediments in controlling winnowing rates and flocculation dynamics, which contributes significantly to rates of bedform evolution.

  4. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  5. Renewable Energy in China

    Directory of Open Access Journals (Sweden)

    Valery I. Salygin

    2015-01-01

    Full Text Available China is the most densely populated country in the world with high rate of economic growth resulting in higher demand for energy resources and in strive to guarantee stable supply of these resources. Chinese annual GDP growth in 2012 and 2013 was down to 7.7% comparing to 10% in 2000-2011 [7]. In 2012 and 2013 economic growth stumbled because of slowdown in manufacturing and exports, taking into account that Chinese government was eager to cut inflation and excessive investments in some segments of the market. Speaking about energy sector Chinese government is aimed at promotion of market-based pricing systems, activities for advanced energy efficiency and higher competition between energy companies, and increased investment in renewable energy resources. Considering renewables as one of many ways to diversify energy supplies, lower dependence on coal and improve environmental situation Chinese government actively supports and develops programs aimed at support of renewable energy industry in China. Chinese economic development is tightly attached to five-year plans. It seems important to mention the fact that main energy goals for current 12-th "five-year plan" are to achieve 15% renewables consumption and CO2 sequestration up to 40-45% by2020 in order to lower dependency on coal and improve environmental situation. As a result of Chinese state policy to develop renewables China achieved certain results in wind energy, helioenergetics, hydroenergetics and energy from waste recycling.

  6. Renewable energy handbook

    Energy Technology Data Exchange (ETDEWEB)

    Fine, R

    1976-01-01

    The potential for renewable energy use in Canada is examined. It is pointed out that Canada can choose to begin to diversify its energy supply now, moving rapidly and smoothly towards an efficient energy society based on renewable energy sources; or, it can continue on its present course and face the possibility of being forced by necessity to make a later transition to renewable sources, probably with a great deal of economic and political disruption. The handbook begins with a discussion on major issues and options available. This second section deals with the technology, applications, and costs of direct solar energy utilization, solar thermal electricity generation, photovoltaic conversion, wind energy, biomass energy, tidal power, wave energy, ocean thermal energy, geothermal energy, heat pumps, and energy storage. Section three discusses how renewable energy might realistically supply Canada's energy requirements within a reasonable period of time. Some issues on how government, industry, and the individual may become involved to make this happen are suggested. A list of resource people and renewable energy businesses is provided in the last section. A recommended reading list and bibliography complete the handbook. (MCW)

  7. Art : accessible, renewable technology

    International Nuclear Information System (INIS)

    Middleton, C.D.

    2004-01-01

    This paper focuses on the role of non-governmental organization (NGO) citizen groups in Ontario in the use and production of electricity. NGOs have the potential to act both directly on their own accord, and indirectly by pressuring government and others. Current demand for electricity is divided between industrial, commercial and residential users. Citizens have an important role to play in reducing energy demand. On the supply side, there is a revival of interest in renewable energy based on wind, photovoltaic and local-hydro technologies as a result of the escalating environmental and economic costs of coal and nuclear generation. However, citizen groups have greater interest and enthusiasm than technical expertise, creating a mismatch between technological solutions and human need or use of them. This paper discusses how this mismatch applies to renewable-energy technologies, many of which are not especially user-friendly, or accessible. While alternative technologies are increasingly welcomed by government, industry is developing a large and growing array of technological devices. In between this is the citizen, who, despite keen interest, can be overwhelmed by the complexity of the situation. This paper links the theoretical perspective to the real world with a discussion of the dynamics between people and renewable energy in citizen groups and makes particular reference to one group, Citizens for Renewable Energy, that has been making renewable energy technology more accessible to its members for over a decade

  8. Subsidies for renewable energy?

    International Nuclear Information System (INIS)

    Skytte, K.; Grenaa Jensen, S.; Morthorst, P.E.; Olsen, O.J.

    2004-01-01

    Ambitious Danish and European energy and environment objectives make a point of using renewable energy sources in the electricity supply. Denmark has been leading country in successful development and commercialization of wind turbines and is as yet one of the leading manufacturers of the world. Danish governments have successfully invested a lot in this development. Other countries have spent more money without achieving a similar success. The questions are why things have gone so well in Denmark and if the Danish success can be repeated for other renewable energy technologies. The starting point of this book is that a political decision on subsidizing the developmental process of a specific technology not in itself guarantees that the technology will turn out reliable and efficient enough to compete successfully in a liberalized electricity market. An understanding of this development is necessary in order to affect a technological development. This book goes through the development of different renewable energy technologies and two theories used for discussing the technological development: experience curves and innovation theory. Based on the discussions and a description of causal relations, an analytical model for different phases of renewable energy technologies' developmental progress and technological life cycle is made. The model is used for evaluating the subsidies for chosen renewable technologies in Denmark. With wind energy as example an analysis of what went well or badly, what might be done and which actions might be efficient is made. (BA)

  9. Polymer-grafted cellulose nanocrystals as pH-responsive reversible flocculants.

    Science.gov (United States)

    Kan, Kevin H M; Li, Jian; Wijesekera, Kushlani; Cranston, Emily D

    2013-09-09

    Cellulose nanocrystals (CNCs) are a sustainable nanomaterial with applications spanning composites, coatings, gels, and foams. Surface modification routes to optimize CNC interfacial compatibility and functionality are required to exploit the full potential of this material in the design of new products. In this work, CNCs have been rendered pH-responsive by surface-initiated graft polymerization of 4-vinylpyridine with the initiator ceric(IV) ammonium nitrate. The polymerization is a one-pot, water-based synthesis carried out under sonication, which ensures even dispersion of the cellulose nanocrystals during the reaction. The resultant suspensions of poly(4-vinylpyridine)-grafted cellulose nanocrystals (P4VP-g-CNCs) show reversible flocculation and sedimentation with changes in pH; the loss of colloidal stability is visible by eye even at concentrations as low as 0.004 wt %. The presence of grafted polymer and the ability to tune the hydrophilic/hydrophobic properties of P4VP-g-CNCs were characterized by Fourier transform infrared spectroscopy, elemental analysis, electrophoretic mobility, mass spectrometry, transmittance spectroscopy, contact-angle measurements, thermal analysis, and various microscopies. Atomic force microscopy showed no observable changes in the CNC dimensions or degree of aggregation after polymer grafting, and a liquid crystalline nematic phase of the modified CNCs was detected by polarized light microscopy. Controlled stability and wettability of P4VP-g-CNCs is advantageous both in composite design, where cellulose nanocrystals generally have limited dispersibility in nonpolar matrices, and as biodegradable flocculants. The responsive nature of these novel nanoparticles may offer new applications for CNCs in biomedical devices, as clarifying agents, and in industrial separation processes.

  10. Sedimentation from flocculated suspensions in the presence of settling-driven gravitational interface instabilities

    Science.gov (United States)

    Rouhnia, Mohamad; Strom, Kyle

    2015-09-01

    We experimentally examine sedimentation from a freshwater suspension of clay flocs overlying saltwater in the presence of gravitational instabilities. The study seeks to determine: (1) if flocculation hampers or alters interface instability formation; (2) how the removal rates of sediment from the buoyant layer compare to those predicted by individual floc settling; and (3) whether or not it is possible to develop a model for effective settling velocity. The experiments were conducted in a tank at isothermal conditions. All experiments were initially stably stratified but later developed instabilities near the interface that grew into downward convecting plumes of fluid and sediment. Throughout, we measured sediment concentration in the upper and lower layers, floc size, and plume descent rates. The data showed that flocculation modifies the mixture settling velocity, and therefore shifts the mode of interface instability from double-diffusive (what one would expect from unflocculated clay) to settling-driven leaking and Rayleigh-Taylor instability formation. Removal rates of sediment from the upper layer in the presence of these instabilities were on the same order of magnitude as those predicted by individual floc settling. However, removal rates were found to better correlate with the speed of the interface plumes. A simple force-balance model was found to be capable of reasonably describing plume velocity based on concentration in the buoyant layer. This relation, coupled with a critical Grashof number and geometry relations, allowed us to develop a model for the effective settling velocity of the mixture based solely on integral values of the upper layer.

  11. Renewability of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    O' Sullivan, Michael; Yeh, Angus [Department of Engineering Science, University of Auckland, Auckland (New Zealand); Mannington, Warren [Contact Energy Limited, Taupo (New Zealand)

    2010-12-15

    In almost all geothermal projects worldwide, the rate of extraction of heat energy exceeds the pre-exploitation rate of heat flow from depth. For example, current production of geothermal heat from the Wairakei-Tauhara system exceeds the natural recharge of heat by a factor of 4.75. Thus, the current rate of heat extraction from Wairakei-Tauhara is not sustainable on a continuous basis, and the same statement applies to most other geothermal projects. Nevertheless, geothermal energy resources are renewable in the long-term because they would fully recover to their pre-exploitation state after an extended shut-down period. The present paper considers the general issue of the renewability of geothermal resources and uses computer modeling to investigate the renewability of the Wairakei-Tauhara system. In particular, modeling is used to simulate the recovery of Wairakei-Tauhara after it is shut down in 2053 after a hundred years of production. (author)

  12. People and renewable energy

    International Nuclear Information System (INIS)

    Rosenvald, Avo

    2002-01-01

    The use of renewable energy is tightly connected to solving social problems in Estonia by creating more new jobs. It is essential that Estonia should increase the use of biofuels. One of the biofuels, firewood, has been used already for centuries. For wider use of renewable energy in Estonia, it is not enough to rely only on enterprices. Rather, before any serious progress can take place, the state should create the appropriate legal environment. Due to its many social and environmental aspects, renewable energy is more important to the state than a sole enterprice. Unfortunately, Estonian government has been delaying its duties. Estonia has two resources that should be taken advantage of, fertile spare land and people still used to the country life. The country people would get work by growing different energy crops on the spare land. (author)

  13. Understanding renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Quaschning, Volker

    2005-01-15

    Beginning with an overview of renewable energy sources including biomass, hydroelectricity, geothermal, tidal, wind and solar power, this book explores the fundamentals of different renewable energy systems. The main focus is on technologies with high development potential such as solar thermal systems, photovoltaics and wind power. This text not only describes technological aspects, but also deals consciously with problems of the energy industry. In this way, the topics are treated in a holistic manner, bringing together maths, engineering, climate studies and economics, and enabling readers to gain a broad understanding of renewable energy technologies and their potential. The book also contains a free CD-ROM resource, which includes a variety of specialist simulation software and detailed figures from the book. (Author)

  14. Renewables vs fossil fuels

    Energy Technology Data Exchange (ETDEWEB)

    Adams, K. (Energy Research and Development Corporation (Australia))

    1992-01-01

    The paper examines some of the factors which will influence the future mix of energy from fossil fuels and renewable sources in Australia. Aspects covered include: the present energy situation; impact of environmental issues; potential for renewable energy; motivators for change; and research and development. It is concluded that the future for fossil fuels and renewable energy is dependent on a number of complex factors, many of which are currently unknown. The key factor is economic viability and that will be influenced by a range of factors such as policies of the Australian and overseas governments in relation to pollution and environment protection (reflected in the cost of meeting such requirements), exploration and production costs (also influenced by government policies), availability of supply, rate of technological development and the size of export markets. 8 refs., 2 figs., 1 tab.

  15. Raw and renewable polymers

    CSIR Research Space (South Africa)

    Joseph, S

    2010-01-01

    Full Text Available in the permeability of the membrane and HO H3C H3C H2C H2C HO OH NH NH OH O OC C n O O O O Fig. 4 Structure of Chitin Raw and Renewable Polymers promoting internal osmotic imbalances. This results in leaching of electrolytes and proteins. 2... is often lost. In most cases this denaturation is not reversible. R-CH-COOH NH2 w Amino acid H2N COOHR a Amino acid Fig. 5 Structure of amino acid Raw and Renewable Polymers The solubilities of proteins vary considerably based on compositions...

  16. Renewable energy sources (promotion)

    International Nuclear Information System (INIS)

    Cook, F.

    1986-01-01

    Permission to present a Bill to establish an independent commission directly responsible for the research, development and demonstration of clean, renewable, alternative sources of energy (to nuclear energy) is requested. The paragraphs of the preamble to the Bill are summarized by the Member seeking permission. The main reason for promoting renewable energy sources is opposition to the nuclear industry. One objection was raised. However, permission was granted to present the Bill and it was read for the first time with a second reading ordered for 7 March 1986. The Bill itself is not reprinted but the permission and question are reported verbatim. (U.K.)

  17. Renewable Electricity Futures (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Mai, T.

    2012-08-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented at the 2012 RE AMP Annual Meeting. RE-AMP is an active network of 144 nonprofits and foundations across eight Midwestern states working on climate change and energy policy with the goal of reducing global warming pollution economy-wide 80% by 2050.

  18. Demonstration of Parallel Algal Processing: Production of Renewable Diesel Blendstock and a High-Value Chemical Intermediate

    Energy Technology Data Exchange (ETDEWEB)

    Knoshaug, Eric P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mohagheghi, Ali [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nagle, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stickel, Jonathan J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dong, Tao [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Karp, Eric M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kruger, Jacob S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brandner, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manker, Lorenz [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rorrer, Nicholas [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hyman, Deborah A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Christensen, Earl D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pienkos, Philip T [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-19

    Co-production of high-value chemicals such as succinic acid from algal sugars is a promising route to enabling conversion of algal lipids to a renewable diesel blendstock. Biomass from the green alga Scenedesmus acutus was acid pretreated and the resulting slurry separated into its solid and liquor components using charged polyamide induced flocculation and vacuum filtration. Over the course of a subsequent 756 hours continuous fermentation of the algal liquor with Actinobacillus succinogenes 130Z, we achieved maximum productivity, process conversion yield, and titer of 1.1 g L-1 h-1, 0.7 g g-1 total sugars, and 30.5 g L-1 respectively. Succinic acid was recovered from fermentation media with a yield of 60% at 98.4% purity while lipids were recovered from the flocculated cake at 83% yield with subsequent conversion through deoxygenation and hydroisomerization to a renewable diesel blendstock. This work is a first-of-its-kind demonstration of a novel integrated conversion process for algal biomass to produce fuel and chemical products of sufficient quality to be blend-ready feedstocks for further processing.

  19. Amino acids in cell wall of Gram-positive bacterium Micrococcus sp. hsn08 with flocculation activity on Chlorella vulgaris biomass.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Zheng, Tianling; Wang, Hailei

    2018-02-01

    The aim of this work was to investigate the flocculation mechanism by Gram-positive bacterium, Micrococcus sp. hsn08 as a means for harvesting Chlorella vulgaris biomass. Bacterial cells of Micrococcus sp. hsn08 were added into algal culture to harvest algal cells through direct contacting with algae to form flocs. Viability dependence test confirmed that flocculation activity does not depend on live bacteria, but on part of the peptidoglycan. The further investigation has determined that amino acids in cell wall play an important role to flocculate algal cells. Positively charged calcium can combine bacterial and algal cells together, and form a bridge between them, thereby forming the flocs, suggesting that ions bridging is the main flocculation mechanism. These results suggest that bacterial cells of Micrococcus sp. hsn08 can be applied to harvest microalgae biomass with the help of amino acids in cell wall. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Differential sedimentation and selective flocculation in the desulfurization of Teruel lignite. Sedimentacion diferencial y floculacion selectiva en la desulfuracion de los lignitos de Teruel

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, R.; Clemente, C.; Gomez-Limon, D. (Escuela Tecnica Superior de Ingenieros de Minas de Madrid, Madrid (Spain))

    1988-01-01

    At the time of researching the possibility to remove the sulfur of the lignites located in the Teruel area via selective flocculation, it has been proved that in the case of the sulfur on its sulfur form, there's a pronounced interference with the differential sedimentation between coal and sulfur, increased by the fact of a selective liberation. This differential sedimentation shows better results on the sulfur removal process than that obtained by selective flocculation. 8 refs., 12 tabs.

  1. [Isolation of an excellent bio-flocculant-producing strain and its application in the treatment of cold-rolling waste oily water].

    Science.gov (United States)

    Lei, Guo-Yuan; Ding, Cui-Ping; Yang, Jia-Xuan

    2011-09-01

    An excellent strain (designated as T-3) which produces bio-flocculants was isolated from soil samples, and identified as Klebsiella sp. species based on the analysis of morphology, physiology and biochemistry and 16S rDNA sequences measurement. The effects of culture conditions such as pH values, temperature, carbon sources and nitrogen sources on bio-flocculants production by T-3 strain were studied. The experiment results show that T-3 strain has better adaptability to carbon sources and nitrogen sources, and higher capacity of bio-flocculants was obtained when the initial pH value of culture and temperature were 9 and 25 degrees C respectively. Based on the colorimetric reactions of proteins and polysaccharide substance, ultraviolet scanning analysis and Fourier Transform Infrared Spectroscopy analysis, it is found that the bio-flocculants produced by T-3 strain contains -OH and -COO(-) groups and belongs to anionic type flocculant. Moreover, the main component is polysaccharides. The treatment of oily cold-rolling wastewater by the bio-flocculant was investigated and the better result was obtained. When the dosages of CaCl2, bio-flocculants and poly aluminium chloride were 4 g x L(-1), 10% (volume fraction) and 1 g x L(-1) respectively, and the pH value was 7.0, the oil concentration, COD and turbidity were decreased to 10 mg x L(-1), 218.4 mg x L(-1) and 1.36 from 4 819 mg x L(-1), 28 456.8 mg x L(-1) and 3 950 with the removal efficiencies of 99.79%, 92.32% and 99.97% respectively. The interaction between flocculant and oily droplets is achieved by the interaction of Van der Waals force, hydrogen bond and the bridged coordination of Ca2+, in which the bridged coordination of Ca2+ is the dominant.

  2. Report on the effectiveness of flocculation for removal of 239Pu at concentrations of 1 pCi/L and 0.1 pCi/L

    International Nuclear Information System (INIS)

    Triay, I.R.; Bayhurst, G.K.; Mitchell, A.J.; Cisneros, M.R.; Efurd, D.W.; Roensch, F.R.; Rokop, D.J.; Aguilar, R.D.; Attrep, M.; Nuttall, H.E.

    1993-01-01

    The objective of this work is to assess the effectiveness of flocculation for the removal of Pu from Rocky Flats Plant (RFP) pond waters spiked with 239 Pu at the 1.0 and 0.1 pCi/L level. The flocculation treatment procedure is described in detail. Results are presented for treatment studies for the removal of Pu from C-2 pond water spiked with 239 Pu and from distilled water spiked with 239 Pu

  3. Nontraditional renewable energy sources

    International Nuclear Information System (INIS)

    Shpil'rajn, Eh.Eh.

    1997-01-01

    The paper considers the application possibilities of nontraditional renewable energy sources to generate electricity, estimates the potential of nontraditional sources using energy of Sun, wind, biomass, as well as, geothermal energy and presents the results of economical analysis of cost of electricity generated by solar electrical power plants, geothermal and electrical plants and facilities for power reprocessing of biomass. 1 tab

  4. The wood, renewable energy

    International Nuclear Information System (INIS)

    Acket, C.

    2006-12-01

    This document evaluates the french forest situation and its future. Indeed, the wood energy constitutes in France the first renewable energy after the hydraulic. It presents the today situation of the french forest providing statistical data, evaluation of the energy estimation, the carbon fixation, the resources, the perspectives wood energy for 2050, the biofuels and an economic analysis. (A.L.B.)

  5. Information for Institutional Renewal.

    Science.gov (United States)

    Spencer, Richard L.

    1979-01-01

    Discusses a planning, management, and evaluation system, an objective-based planning process, research databases, analytical reports, and transactional data as state-of-the-art tools available to generate data which link research directly to planning for institutional renewal. (RC)

  6. Renewable Energies, Present & Future

    Institute of Scientific and Technical Information of China (English)

    X. S. Cai

    2005-01-01

    Fossil fuels are major cause of environmental destruction in pollutions. It has created much needed momentum for renewable energies, which are environmentally benign, generated locally, and can play a significant role in developing economy. As a sustainable energy sources, it can grow at a rapid pace to meet increasing demands for electricity in a cost-effective way.

  7. Renewable Energy for Microenterprise

    Energy Technology Data Exchange (ETDEWEB)

    Allderdice, A.; Rogers, J.H.

    2000-11-28

    This guide provides readers with a broad understanding of the potential benefits that current renewable energy technologies can offer rural microenterprises. It also introduces the institutional approaches that have been developed to make RE technologies accessible to microentrepreneurs and the challenges that these entrepreneurs have encountered.

  8. Renewable material resource potential

    NARCIS (Netherlands)

    van Weenen, H.; Wever, R.; Quist, J.; Tukker, A.; Woudstra, J.; Boons, F.A.A.; Beute, N.

    2010-01-01

    Renewable material resources, consist of complex systems and parts. Their sub-systems and sub-sub-systems, have unique, specific, general and common properties. The character of the use that is made of these resources, depends on the availability of knowledge, experience, methods, tools, machines

  9. Renewable Energy Essentials: Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Hydropower is currently the most common form of renewable energy and plays an important part in global power generation. Worldwide hydropower produced 3 288 TWh, just over 16% of global electricity production in 2008, and the overall technical potential for hydropower is estimated to be more than 16 400 TWh/yr.

  10. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    Directory of Open Access Journals (Sweden)

    Ravi S. Srinivasan

    2015-05-01

    Full Text Available In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. Such progressive disinvestment in the non-renewable resources that may be substituted with renewable resources is referred to as “Renewable Substitutability” and if implemented, this process will lead to a paradigm shift in the way building materials are manufactured. This paper discusses the development of a Renewable Substitutability Index (RSI that is designed to maximize the use of renewable resources in a building and quantifies the substitution process using solar emergy (i.e., the solar equivalent joules required for any item. The RSI of a building or a building component, i.e., floor or wall systems, etc., is the ratio of the renewable resources used during construction, including replacement and maintenance, to the building’s maximum renewable emergy potential. RSI values range between 0 and 1.0. A higher RSI achieves a low-energy building strategy promoting a higher order of sustainability by optimizing the use of renewables over a building’s lifetime from formation-extraction-manufacturing to maintenance, operation, demolition, and recycle.

  11. The Renewable Energy Data Explorer: Mapping Our Renewable Energy Future

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-13

    The Renewable Energy (RE) Data Explorer, developed by the National Renewable Energy Laboratory, is an innovative web-based platform that allows users to visualize and analyze renewable energy potential. The RE Data Explorer informs prospecting, integrated planning, and policymaking to enable low emission development.

  12. EVALUATION OF THE FLOCCULATION EFFICIENCY OF Chlorella vulgaris MEDIATED BY Moringa oleifera SEED UNDER DIFFERENT FORMS: FLOUR, SEED CAKE AND EXTRACTS OF FLOUR AND CAKE

    Directory of Open Access Journals (Sweden)

    C. M. L. Lapa Teixeira

    Full Text Available Abstract Flocculation as a pre-separation method can help make production of biodiesel from microalgae economically feasible. In a previous study, Moringa oleifera seed flour (1 g.L-1 was shown to be a very efficient flocculant for Chlorella vulgaris, a microalga with high potential for biodiesel production. In this study, several aspects of C vulgaris flocculation mediated by Moringa were investigated in order to optimize the separation of this biomass. Flocculation efficiency was the same with seeds from different origins and lots. The stationary growth stage was best for harvesting C vulgaris cells to carry out flocculation efficiently (93%. The use of flour extracts and cake extracts generated the best cost-benefit ratio (flocculation efficiency from 78 to 97% with a saving in mass of seed of 75%. The highest efficiency was reached with extracts prepared with seawater and NaCl solutions which have high salt concentration. Reasonable stability of the extract allows its use for up to two weeks, provided it is kept at low temperature (4 ºC.

  13. Renewable Energy on Tribal Lands

    Science.gov (United States)

    This page contains presentations from the Brown to Green: Make the Connection to Renewable Energy workshop held in Santa Fe, New Mexico, during December 10-11, 2008 regarding Renewable Energy on Tribal Lands.

  14. Non-renewal of contracts

    CERN Multimedia

    Association du personnel

    2007-01-01

    A new illegal practice is appearing in certain sectors of the Organization: the non-renewal of renewable three-year limited-duration (LD) contracts, despite a more than satisfactory performance and an obvious commitment to the Organization.

  15. Many Drops Interactions I: Simulation of Coalescence, Flocculation and Fragmentation of Multiple Colliding Drops with Smoothed Particle Hydrodynamics

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2012-06-01

    Full Text Available Smoothed Particle Hydrodynamics (SPH is a Lagrangian mesh-free formalism and has been useful to model continuous fluid. This formalism is employed to solve the Navier-Stokes equations by replacing the fluid with a set of particles. These particles are interpolation points from which properties of the fluid can be determined. In this study, the SPH method is applied to simulate the hydrodynamics interaction of many drops, showing some settings for the coalescence, fragmentation and flocculation problem of equally sized liquid drops in three-dimensional spaces. For small velocities the drops interact only through their deformed surfaces and the flocculation of the droplets arises. This result is very different if the collision velocity is large enough for the fragmentation of droplets takes place. We observe that for velocities around 15 mm/ms the coalescence of droplets occurs. The velocity vector fields formed inside the drops during the collision process are shown.

  16. Complete genome sequence of Klebsiella pneumoniae J1, a protein-based microbial flocculant-producing bacterium.

    Science.gov (United States)

    Pang, Changlong; Li, Ang; Cui, Di; Yang, Jixian; Ma, Fang; Guo, Haijuan

    2016-02-20

    Klebsiella pneumoniae J1 is a Gram-negative strain, which belongs to a protein-based microbial flocculant-producing bacterium. However, little genetic information is known about this species. Here we carried out a whole-genome sequence analysis of this strain and report the complete genome sequence of this organism and its genetic basis for carbohydrate metabolism, capsule biosynthesis and transport system. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Technological applications of organo-montmorillonites in the removal of pyrimethanil from water: adsorption/desorption and flocculation studies.

    Science.gov (United States)

    Flores, Federico M; Undabeytia, Tomas; Morillo, Esmeralda; Torres Sánchez, Rosa M

    2017-06-01

    Pyrimethanil (2-aniline-4, 6-dimethylpyrimidine, PRM) is used in fruit packing plants to control fungal infections and diseases. The effluents greatly polluted with this fungicide, as a point source contamination, need to be technologically treated for their regeneration before they reach water bodies. This work evaluates the use of organo-montmorillonites, synthetized in our laboratory, for their application in adsorption and coagulation/flocculation processes for the removal of PRM from water. The adsorption-desorption performance of PRM in a raw montmorillonite (Mt) and several organo-montmorillonites (organo-Mt) obtained by different amounts and types of exchanged surfactants (octadecyltrimethylammonium (ODTMA) and didodecyldimethylammonium (DDAB) bromides and benzyltrimethylammonium chloride (BTMA)) was studied. The PRM adsorption on raw Mt was assigned mainly to an interlayer occupancy, while hydrophobic interactions between PRM and the surfactants in the exchanged samples increased PRM adsorption, which was correlated with the surfactant loading. PRM desorption showed irreversible behavior in raw Mt, which changed to reversible for organo-Mt samples, and was also correlated with the increase of surfactant loading.Two of the organo-Mt with high surfactant loading (twice the CEC) were assayed for the removal of commercial PRM in coagulation/flocculation tests, and their performance was compared to that of the native clay (Mt). The use of the organo-Mt produced flocculation at a very low ratio (0.5 g L -1 ), whereas no flocculation was observed with Mt. These results proved the feasibility of the use of organo-Mt for the treatment of wastewater contaminated with PRM using a low organo-Mt/liquid ratio.

  18. Preparation of poly(acrylamide-co-acrylic acid)-grafted gum and its flocculation and biodegradation studies.

    Science.gov (United States)

    Mittal, H; Mishra, Shivani B; Mishra, A K; Kaith, B S; Jindal, R; Kalia, S

    2013-10-15

    Biodegradation studies of Gum ghatti (Gg) and acrylamide-co-acrylic acid based flocculants [Gg-cl-poly(AAm-co-AA)] have been reported using the soil composting method. Gg-cl-poly(AAm-co-AA) was found to degrade 89.76% within 60 days. The progress of biodegradation at each stage was monitored through FT-IR and SEM. Polymer was synthesized under pressure using potassium persulphate-ascorbic acid as a redox initiator and N,N'-methylene-bis-acrylamide as a crosslinker. Synthesized polymer was found to show pH, temperature and ionic strength of the cations dependent swelling behavior. Gg-cl-poly(AAm-co-AA) was utilized for the selective absorption of saline from different petroleum fraction-saline emulsions. The flocculation efficiency of the polymer was studied as a function of polymer dose, temperature and pH of the solution. Gg-cl-poly(AAm-co-AA) showed maximum flocculation efficiency with 20 mol L(-1) polymer dose in acidic medium at 50 °C. Copyright © 2013. Published by Elsevier Ltd.

  19. High-level ethanol production from starch by a flocculent Saccharomyces cerevisiae strain displaying cell-surface glucoamylase

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, A.; Shigechi, H.; Abe, M.; Uyama, K. [Dept. of Chemical Science and Engineering, Kobe Univ., Nadaku, Kobe (Japan); Matsumoto, T.; Fukuda, H. [Div. of Molecular Science, Kobe Univ., Nadaku, Kobe (Japan); Takahashi, S.; Ueda, M.; Tanaka, A. [Dept. of Synthetic Chemistry and Biological Chemistry, Kyoto Univ., Sakyoku, Kyoto (Japan); Kishimoto, M. [Dept. of Biotechnology, Osaka Univ., Osaka (Japan)

    2002-07-01

    A Strain of host yeast YF207, which is a tryptophan auxotroph and shows strong flocculation ability, was obtained from Saccharomyces diastaticus ATCC60712 and S. cerevisiae W303-1B by tetrad analysis. The plasmid pGA11, which is a multicopy plasmid for cell-surface expression of the Rhyzopus oryzae glucoamylase/{alpha}-agglutinin fusion protein, was then introduced into this flocculent yeast strain (YF207/pGA11). Yeast YF207/pGA11 grew rapidly under aerobic condition (dissolved oxygen 2.0 ppm), using soluble starch. The harvested cells were used for batch fermentation of soluble starch to ethanol under anaerobic condition and showed high ethanol production rates (0.71 g h{sup -1} I{sup -1}) without a time lag, because glucoamylase was immobilized on the yeast cell surface. During repeated utilization of cells for fermentation, YF207/pGA11 maintained high ethanol production rates over 300 h. Moreover, in fed-batch fermentation with YF207/pGA11 for approximately 120 h, the ethanol concentration reached up to 50 g I{sup -1}. In conclusion, flocculent yeast cells displaying cell-surface glucoamylase are considered to be very effective for the direct fermentation of soluble starch to ethanol. (orig.)

  20. Clay-oil flocculation and its role in natural cleansing in Prince William Sound following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Bragg, J.R.; Yang, S.H.

    1995-01-01

    Natural interactions of fine mineral particles with residue oil and seawater, in a process called clay-oil flocculation, were found to create solids-stabilized oil-in-water emulsions on shoreline sediments at numerous locations in Prince William Sound following the Exxon Valdez spill. In laboratory tests using oiled sediment samples from Prince William Sound, these emulsions were shown to facilitate natural cleansing and dispersion of oil from sediments by moving water. To investigate the effect of flocculation on natural cleansing, studies were conducted to determine the hydrodynamic energy needed for seawater to remove flocculated oil residues from sediments sampled from shorelines. Water was pumped at different velocities through a column packed with oiled sediment, and the amount and composition of oil removed from the sediment were measured as functions of water velocity and sediment movement. In separate tests, oil removal was observed in a wave tank that generated wave heights less than and greater than needed to move sediments. 28 refs., 13 figs., 7 tabs

  1. Flocculating Zymomonas mobilis is a promising host to be engineered for fuel ethanol production from lignocellulosic biomass.

    Science.gov (United States)

    Zhao, Ning; Bai, Yun; Liu, Chen-Guang; Zhao, Xin-Qing; Xu, Jian-Feng; Bai, Feng-Wu

    2014-03-01

    Whereas Saccharomyces cerevisiae uses the Embden-Meyerhof-Parnas pathway to metabolize glucose, Zymomonas mobilis uses the Entner-Doudoroff (ED) pathway. Employing the ED pathway, 50% less ATP is produced, which could lead to less biomass being accumulated during fermentation and an improved yield of ethanol. Moreover, Z. mobilis cells, which have a high specific surface area, consume glucose faster than S. cerevisiae, which could improve ethanol productivity. We performed ethanol fermentations using these two species under comparable conditions to validate these speculations. Increases of 3.5 and 3.3% in ethanol yield, and 58.1 and 77.8% in ethanol productivity, were observed in ethanol fermentations using Z. mobilis ZM4 in media containing ∼100 and 200 g/L glucose, respectively. Furthermore, ethanol fermentation bythe flocculating Z. mobilis ZM401 was explored. Although no significant difference was observed in ethanol yield and productivity, the flocculation of the bacterial species enabled biomass recovery by cost-effective sedimentation, instead of centrifugation with intensive capital investment and energy consumption. In addition, tolerance to inhibitory byproducts released during biomass pretreatment, particularly acetic acid and vanillin, was improved. These experimental results indicate that Z. mobilis, particularly its flocculating strain, is superior to S. cerevisiae as a host to be engineered for fuel ethanol production from lignocellulosic biomass. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Molecular comparison of bacterial communities within iron-containing flocculent mats associated with submarine volcanoes along the Kermadec Arc.

    Science.gov (United States)

    Hodges, Tyler W; Olson, Julie B

    2009-03-01

    Iron oxide sheaths and filaments are commonly found in hydrothermal environments and have been shown to have a biogenic origin. These structures were seen in the flocculent material associated with two submarine volcanoes along the Kermadec Arc north of New Zealand. Molecular characterization of the bacterial communities associated with the flocculent samples indicated that no known Fe-oxidizing bacteria dominated the recovered clone libraries. However, clones related to the recently described Fe-oxidizing bacterium Mariprofundus ferrooxydans were obtained from both the iron-containing flocculent (Fe-floc) and sediment samples, and peaks corresponding to Mariprofundus ferrooxydans, as well as the related clones, were observed in several of our terminal restriction fragment length polymorphism profiles. A large group of epsilonproteobacterial sequences, for which there is no cultured representative, dominated clones from the Fe-floc libraries and were less prevalent in the sediment sample. Phylogenetic analyses indicated that several operational taxonomic units appeared to be site specific, and statistical analyses of the clone libraries found that all samples were significantly different from each other. Thus, the bacterial communities in the Fe-floc samples were not more closely related to each other than to the sediment communities.

  3. Treatment of landfill leachate by a combined process: Iron electrodissolution, iron oxidation by H2O2 and chemical flocculation

    Directory of Open Access Journals (Sweden)

    Dayana Donneys-Victoria

    2018-01-01

    Full Text Available The efficiency of iron electrodissolution and the flocculation processes with Fe2+ and Fe3+ for removing color, turbidity, chloride and chemical oxygen demand (COD were studied by treating a landfill leachate effluent from “El Carrasco” (Bucaramanga, Colombia. The pH and current density for the electrodissolution treatment were determined from potentiodynamic polarization studies. The electrodissolution process was performed under galvanostatic conditions at 24 A m−2 with changing polarity of the electrodes. Hydrogen peroxide was used for the oxidation of Fe2+ to Fe3+ while Ca(OH2 was used for the flocculation as the pH modifier and coagulant adjuvant agent along with an anionic polyacrylamide. The results showed that higher removal efficiencies of the COD, color and turbidity were obtained (85, 96 and 76%, respectively using 0.225 g L−1 of hydrogen peroxide at pH about 8.5 after 150 min; requiring 0.6 kWh m−3 and a total treatment cost of 2.24 USD m−3. Keywords: Leachate, Iron electrodissolution, Potentiodynamic polarization, Flocculation

  4. Coagulation, flocculation, dissolved air flotation and filtration in the removal of Giardia spp. and Cryptosporidium spp. from water supply.

    Science.gov (United States)

    Andreoli, Fernando César; Sabogal-Paz, Lyda Patricia

    2017-11-15

    Removing protozoa from a water supply using coagulation, flocculation, dissolved air flotation (DAF) and filtration on a bench scale was evaluated. Calcium carbonate flocculation with and without immunomagnetic separation (IMS) was chosen to detect Giardia spp. cysts and Cryptosporidium spp. oocysts in the studied samples. The results indicated that DAF removed between 1.31 log and 1.79 log of cysts and between 1.08 log and 1.42 log of oocysts. The performance was lower in filtration, with the removal of 1.07 log-1.44 log for cysts and 0.82 log-0.98 log for oocysts. The coagulation, flocculation, DAF and filtration steps removed more than 2.2 log of cysts and oocysts from the water studied. However, protozoa were detected in the filtered water, even with turbidity values of 0.2 NTU. The recovery of the detection method met the international criteria and was higher when there was no IMS. Including the third acid dissociation in the IMS was critical to improve the performance of the protocol tested. However, there was an increase in the technical and analytical complexity and costs. It was also observed that the efficiency of the treatment was linked to the performance of the selected method of detecting protozoa.

  5. RENEWABLE ENERGY IN TOURISM

    Directory of Open Access Journals (Sweden)

    MĂDĂLINA MIHĂILĂ

    2012-06-01

    Full Text Available Recent reports published by the International Energy Agency and U.S. Department of Energy, regarding the global energy outlook for the first three decades of the XXI century, warns of global trends on energy demand, increasing dependence on energy imports, coal use and volume emissions of greenhouse gases, torism industry being one of the biggest energy consumption industry. Uncertainties on different models of regional development and access of the world to traditional energy resources require a change of orientation towards long-term scenarios for assessing energy domain, increasing the share of energy from renewable resources beeing one of the solutions. Intourism the renewable energy is a solution for a positive impact on enviroment , reduced operational costs and even won an extra-profit.

  6. Renewables in Electricity Markets

    DEFF Research Database (Denmark)

    Ordoudis, Christos; Papakonstantinou, Athanasios; Pinson, Pierre

    2014-01-01

    Electricity is nowadays commonly exchanged through electricity markets, designed in a context where dispatchable generators, with non-negligible marginal costs, were dominating. By depending primarily on conventional (fossil, hydro and nuclear) power generation based on marginal pricing...... not designed to take into account the uncertainty brought by the substantial variability and limited predictability associated with stochastic sources, most notably wind power and solar energy. Due to these developments, the need for decision making models able to account for the uncertainty introduced by high...... from renewables, and on the adaption of electricity market designs and power system operations to the aforementioned characteristics of renewables. Additionally, the aim of the research group is supplemented by providing the appropriate frameworks for secure future investments in the field...

  7. Renewable Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Mathiesen, Brian Vad; Connolly, David

    2014-01-01

    on the electricity sector, smart energy systems include the entire energy system in its approach to identifying suitable energy infrastructure designs and operation strategies. The typical smart grid sole focus on the electricity sector often leads to the conclusion that transmission lines, flexible electricity......This paper presents the learning of a series of studies that analyse the problems and perspectives of converting the present energy system into a 100 % renewable energy system using a smart energy systems approach. As opposed to, for instance, the smart grid concept, which takes a sole focus...... are to be found when the electricity sector is combined with the heating and cooling sectors and/or the transportation sector. Moreover, the combination of electricity and gas infrastructures may play an important role in the design of future renewable energy systems. The paper illustrates why electricity smart...

  8. Bolivia renewable energy development

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.

    1997-12-01

    The author summarizes changes which have occurred in Bolivia in the past year which have had an impact on renewable energy source development. Political changes have included the privatization of power generation and power distribution, and resulted in a new role for state level government and participation by the individual. A National Rural Electrification Plan was adopted in 1996, which stresses the use of GIS analysis and emphasizes factors such as off grid, economic index, population density, maintenance risk, and local organizational structure. The USAID program has chosen to stress economic development, environmental programs, and health over village power programs. The national renewables program has adopted a new development direction, with state projects, geothermal projects, and private sector involvement stressed.

  9. Renewable Energy Symposium

    International Nuclear Information System (INIS)

    2016-01-01

    Representatives of state universities, public institutions and Costa Rican private sector, and American experts have exposed projects or experiences about the use and generation of renewable energy in different fields. The thematics presented have been about: development of smart grids and design of electrical energy production systems that allow money saving and reducing emissions to the environment; studies on the use of non-traditional plants and agricultural waste; sustainable energy model in the process of coffee production; experiments from biomass for the fabrication of biodiesel, biogas production and storage; and the use of non-conventional energy. Researches were presented at the Renewable Energy Symposium, organized by the Centro de Investigacion en Estructuras Microscopicas and support of the Vicerrectoria de Investigacion, both from the Universidad de Costa Rica [es

  10. Renewable energy systems advanced conversion technologies and applications

    CERN Document Server

    Luo, Fang Lin

    2012-01-01

    Energy conversion techniques are key in power electronics and even more so in renewable energy source systems, which require a large number of converters. Renewable Energy Systems: Advanced Conversion Technologies and Applications describes advanced conversion technologies and provides design examples of converters and inverters for renewable energy systems-including wind turbine and solar panel energy systems. Learn Cutting-Edge Techniques for Converters and Inverters Setting the scene, the book begins with a review of the basics of astronomy and Earth physics. It then systematically introduc

  11. Renewable energy project development

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, J.

    1996-12-31

    The author presents this paper with three main thrusts. The first is to discuss the implementation of renewable energy options in China, the second is to identify the key project development steps necessary to implement such programs, and finally is to develop recommendations in the form of key issues which must be addressed in developing such a program, and key technical assistance needs which must be addressed to make such a program practical.

  12. Renewing Samsø

    DEFF Research Database (Denmark)

    Papazu, Irina

    2017-01-01

    and globally, I ask: if indeed such a process of renewal must be understood as a political process and the island’s energy transition as an inherently political event, what can Samsø teach us about the workings of politics and local democracy as enacted in practice? This is politics not as election result...... or ideological struggle over values, ideals and the distribution of goods, but as the down-to-earth but significant activity of creating something new together....

  13. Renewable Energy in Latvia

    Energy Technology Data Exchange (ETDEWEB)

    Shipkovs, P.; Kashkarova, G. [Latvian Energy Agency, Riga (Latvia); Shipkovs, M. [Energy-R Ltd., Riga (Latvia)

    1997-12-31

    Latvia is among those countries that do not have gas, coal and, for the time being, also oil resources of its own. The amount of power produced in Latvia does not meet the demand, consequently a part of the power has to be purchased from neighbouring countries. Firewood, peat and hydro resources are the only significant domestic energy resources. Massive decrease of energy consumption has been observed since Latvia regained independence. Domestic and renewable energy resources have been examined and estimated. There are already 13 modern boiler houses operating in Latvia with total installed capacity 45 MW that are fired with wood chips. Latvian companies are involved in the production of equipment. 7 small HPPs have been renewed with the installed capacity 1.85 MW. Wind plant in Ainazi has started its operation, where two modern wind turbines with the capacity of 0.6 MW each have been installed. Mechanism of tariff setting is aligned. Favourable power energy purchasing prices are set for renewable energy sources and small cogeneration plants

  14. Market analysis. Renewable fuels

    International Nuclear Information System (INIS)

    2014-01-01

    The Agency for Renewable Resources (FNR) had on behalf of the Federal Ministry of Food and Agriculture created a study on the market development of renewable resources in Germany and published this in the year of 2006. The aim of that study was to identify of actual status and market performance of the individual market segments of the material and energetic use as a basis for policy recommendations for accelerated and long term successful market launch and market share expansion of renewable raw materials. On behalf of the FNR, a market analysis of mid-2011 was carried out until the beginning of 2013, the results of which are hereby resubmitted. This market analysis covers all markets of material and energetic use in the global context, taking account of possible competing uses. A market segmentation, which was based on the product classification of the Federal Statistical Office, formed the basis of the analysis. A total of ten markets have been defined, seven material and three energetic use. [de

  15. Renewable Energy in Latvia

    Energy Technology Data Exchange (ETDEWEB)

    Shipkovs, P; Kashkarova, G [Latvian Energy Agency, Riga (Latvia); Shipkovs, M [Energy-R Ltd., Riga (Latvia)

    1998-12-31

    Latvia is among those countries that do not have gas, coal and, for the time being, also oil resources of its own. The amount of power produced in Latvia does not meet the demand, consequently a part of the power has to be purchased from neighbouring countries. Firewood, peat and hydro resources are the only significant domestic energy resources. Massive decrease of energy consumption has been observed since Latvia regained independence. Domestic and renewable energy resources have been examined and estimated. There are already 13 modern boiler houses operating in Latvia with total installed capacity 45 MW that are fired with wood chips. Latvian companies are involved in the production of equipment. 7 small HPPs have been renewed with the installed capacity 1.85 MW. Wind plant in Ainazi has started its operation, where two modern wind turbines with the capacity of 0.6 MW each have been installed. Mechanism of tariff setting is aligned. Favourable power energy purchasing prices are set for renewable energy sources and small cogeneration plants

  16. Renewable Energy Systems: Technology Overview and Perspectives

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ionel, Dan M.; Yang, Yongheng

    2017-01-01

    In this chapter, essential statistics demonstrating the increasing role of renewable energy generation are first discussed. A state-of-the-art review section covers the fundamentals of wind turbine and photovoltaic (PV) systems. Schematic diagrams illustrating the main components and system topol......, including PV and concentrating solar power; wave energy; fuel cells; and storage with batteries and hydrogen, respectively. Recommended further readings on topics of electric power engineering for renewable energy are included in the final section.......In this chapter, essential statistics demonstrating the increasing role of renewable energy generation are first discussed. A state-of-the-art review section covers the fundamentals of wind turbine and photovoltaic (PV) systems. Schematic diagrams illustrating the main components and system...... topologies are included. Also, the increasing role of power electronics is explained as an enabler for renewable energy integration and for future power systems and smart grids. Recent examples of research and development, including new devices and system installations for utility power plants...

  17. What drives renewable energy development?

    International Nuclear Information System (INIS)

    Alagappan, L.; Orans, R.; Woo, C.K.

    2011-01-01

    This viewpoint reviews renewable energy development in 14 markets that differ in market structure (restructured vs. not restructured), use of feed-in-tariff (FIT) (yes vs. no), transmission planning (anticipatory vs. reactive), and transmission interconnection cost allocated to a renewable generator (high vs. low). We find that market restructuring is not a primary driver of renewable energy development. Renewable generation has the highest percent of total installed capacity in markets that use a FIT, employ anticipatory transmission planning, and have loads or end-users paying for most, if not all, of the transmission interconnection costs. In contrast, renewable developers have been less successful in markets that do not use a FIT, employ reactive transmission planning, and have generators paying for most, if not all, of the transmission interconnection costs. While these policies can lead to higher penetration of renewable energy in the short run, their high cost to ratepayers can threaten the economic sustainability of renewable energy in the long-run. - Highlights: → Market structure seems to have little effect on renewable energy development. → Renewable energy development is more successful in markets that use a FIT. → Anticipatory transmission planning aids renewable energy development. → Low interconnection costs for developers also aids renewable energy development.

  18. Renewable energy education in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Acikgoz, Caglayan [Department of Chemical and Process Engineering, Faculty of Engineering, Bilecik University, P.O.11030, Bilecik (Turkey)

    2011-02-15

    Utilization of renewable energy sources and the application of environmentally sound energy technologies are essential to sustainable development and will help to secure the quality of living and the well-being of the future generations. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, wind, solar, geothermal, and biomass. The use of renewable energy as a topic to study energy and its forms permits a novel way to motivate students, particularly those who energy topics taking conscience with the environment. This paper presents the analysis and classification of renewable energy sources and how to find out their origin and a way to motivate students in energy topics related to renewable sources and also, the development of didactic competencies in special blended learning arrangements for educationalists, trainers and lecturers in adult education in the field of renewable energies in Turkey. (author)

  19. Ethanol production from kitchen waste using the flocculating yeast Saccharomyces cerevisiae strain KF-7

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yue-Qin; Liu, Kai; An, Ming-Zhe; Morimura, Shigeru; Kida, Kenji [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Koike, Yoji [Tokyo Gas Co., Ltd., 1-7-7 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa 230-0045 (Japan); Wu, Xiao-Lei [Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2008-11-15

    A process for producing ethanol from kitchen waste was developed in this study. The process consists of freshness preservation of the waste, saccharification of the sugars in the waste, continuous ethanol fermentation of the saccharified liquid, and anaerobic treatment of the saccharification residue and the stillage. Spraying lactic acid bacteria (LCB) on the kitchen waste kept the waste fresh for over 1 week. High glucose recovery (85.5%) from LCB-sprayed waste was achieved after saccharification using Nagase N-40 glucoamylase. The resulting saccharified liquid was used directly for ethanol fermentation, without the addition of any nutrients. High ethanol productivity (24.0 g l{sup -1} h{sup -1}) was obtained when the flocculating yeast strain KF-7 was used in a continuous ethanol fermentation process at a dilution rate of 0.8 h{sup -1}. The saccharification residue was mixed with stillage and treated in a thermophilic anaerobic continuous stirred tank reactor (CSTR); a VTS loading rate of 6 g l{sup -1} d{sup -1} with 72% VTS digestion efficiency was achieved. Using this process, 30.9 g ethanol, and 65.2 l biogas with 50% methane, was produced from 1 kg of kitchen waste containing 118.0 g total sugar. Thus, energy in kitchen waste can be converted to ethanol and methane, which can then be used as fuels, while simultaneously treating kitchen waste. (author)

  20. Performance of a continuously operated flocculent sludge UASB reactor with slaughterhouse wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, S.; Zeeuw, W. de

    1988-01-01

    This investigation was carried out to assess the performance of a continuously operated, one-stage, flocculent sludge upflow anaerobic sludge blanket (UASB) reactor treating slaughterhouse wastewater at a process temperature of 30/sup 0/C. The results indicate that the type of substrate ingredients, coarse suspended solids, colloidal and soluble compounds in the wastewater, affect the performance of the reactor because of different mechanisms involved in their removal and their subsequent conversion into methane. Two different mechanisms are distinguished. An entrapment mechanism prevails for the elimination of coarse suspended solids while an adsorption mechanism is involved in the removal of the colloidal and soluble fractions of the wastewater. The results obtained lead to the conclusion that the system can satisfactorily handle organic space loads up to 5 kg COD m/sup -3/ day/sup -1/ at 30/sup 0/C. The data indicate, however, that continuing heavy accumulation of substrate components in the reactor is detrimental to the stability of the anaerobic treatment process as the accumulation can lead to sludge flotation and consequently to a complete loss of the active biomass from the reactor.

  1. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    Directory of Open Access Journals (Sweden)

    L. D. Sánchez

    2012-12-01

    Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

  2. Simulations of the flocculent spiral M33: what drives the spiral structure?

    Science.gov (United States)

    Dobbs, C. L.; Pettitt, A. R.; Corbelli, E.; Pringle, J. E.

    2018-05-01

    We perform simulations of isolated galaxies in order to investigate the likely origin of the spiral structure in M33. In our models, we find that gravitational instabilities in the stars and gas are able to reproduce the observed spiral pattern and velocity field of M33, as seen in HI, and no interaction is required. We also find that the optimum models have high levels of stellar feedback which create large holes similar to those observed in M33, whilst lower levels of feedback tend to produce a large amount of small scale structure, and undisturbed long filaments of high surface density gas, hardly detected in the M33 disc. The gas component appears to have a significant role in producing the structure, so if there is little feedback, both the gas and stars organise into clear spiral arms, likely due to a lower combined Q (using gas and stars), and the ready ability of cold gas to undergo spiral shocks. By contrast models with higher feedback have weaker spiral structure, especially in the stellar component, compared to grand design galaxies. We did not see a large difference in the behaviour of Qstars with most of these models, however, because Qstars stayed relatively constant unless the disc was more strongly unstable. Our models suggest that although the stars produce some underlying spiral structure, this is relatively weak, and the gas physics has a considerable role in producing the large scale structure of the ISM in flocculent spirals.

  3. A Study of Parameters Affecting the Solvent Extraction-Flocculation Process of Used Lubricating Oil

    Directory of Open Access Journals (Sweden)

    Hussein Qasim Hussein

    2017-06-01

    Full Text Available The aim of this study was to investigate the effect of operating variables on, the percentage of removed sludge (PSR obtained during re-refining of 15W-40 Al-Durra spent lubricant by solvent extraction-flocculation treatment method. Binary solvents were used such as, Heavy Naphtha (H.N.: MEK (N:MEK, H.N. : n-Butanol (N:n-But, and H.N. : Iso-Butanol (N:Iso:But. The studied variables were mixing speed (300-900, rpm, mixing time (15-60, min, and operating temperature (2540, oC. This study showed that the studied operating variables have effects where, increasing the mixing time up to 45 min for H.N.: MEK, H.N.: n-Butanol and 30 min for H.N.: Iso-Butanol increased the PSR, after that percentage was decreased; increasing the mixing speed for all the studied solvents up to 700 rpm increased the PSR, after that the percentage was decreased, while increasing the operating temperature decreased the PSR for all the solvents. This study has resulted in reasonably accurate multivariate process correlation that relates the removed sludge percentage to the process variables. The determination coefficients (

  4. Removal of Zn-65, Mo-99 and I-125 from effluent by coagulation-flocculation process

    International Nuclear Information System (INIS)

    Syed Hakimi Sakuma Syed Ahmad

    1996-01-01

    The aim of this study is to investigate the efficiency treatment in removing Zn-65, Mo-99 and I-1 25 from an aqueous radioactive effluent. The wastes are currently being produced from hospitals, research institutes, clinics and universities. Effluent was spiked separately with each type of the radioisotope and was treated by the coagulation-flocculation process. By varying the chemical dosages (i.e., alum, soda ash, ferric chloride and coagulant aid) in the treatment, different decontamination factor values were obtained. Optimum dosages and types of chemical used to remove a particular radioisotope was determined. Results indicated that optimum pH value for removing Zn-65 in an effluent was pH 8. The highest decontamination factor value was 61. In removal of 1-125 radioisotope, ferric chloride was suitable as a coagulant that gives the highest decontamination factor value of 5.0. Treatment to remove Mo-99 radioisotopes was conducted in the laboratory and treatment plant scale. For Mo-99 radioisotope treatment by laboratory and Plant scale, the highest decontamination factor obtained was between pH values of 4.0 to 4.5. By extrapolation of both scales, the plant scale treatment does not vary significantly from laboratory scale. This indicated treatment dosages of chemicals for the Low Level Treatment Plant scale be deduced from the laboratory scale

  5. UV disinfection and flocculation-chlorination sachets to reduce hepatitis E virus in drinking water.

    Science.gov (United States)

    Guerrero-Latorre, Laura; Gonzales-Gustavson, Eloy; Hundesa, Ayalkibet; Sommer, Regina; Rosina, Girones

    2016-07-01

    Hepatitis E Virus (HEV) is a major cause of waterborne outbreaks in areas with poor sanitation. As safe water supplies are the keystone for preventing HEV outbreaks, data on the efficacy of disinfection treatments are urgently needed. Here, we evaluated the ability of UV radiation and flocculation-chlorination sachets (FCSs) to reduce HEV in water matrices. The HEV-p6-kernow strain was replicated in the HepG2/C3A cell line, and we quantified genome number using qRT-PCR and infectivity using an immunofluorescence assay (IFA). UV irradiation tests using low-pressure radiation showed inactivation kinetics for HEV of 99.99% with a UV fluence of 232J/m(2) (IC 95%, 195,02-269,18). Moreover, the FCSs preparations significantly reduced viral concentrations in both water matrices, although the inactivation results were under the baseline of reduction (4.5 LRV) proposed by WHO guidelines. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Ethanol production from kitchen waste using the flocculating yeast Saccharomyces cerevisiae strain KF-7

    International Nuclear Information System (INIS)

    Tang, Y.-Q.; Koike, Yoji; Liu Kai; An, M.-Z.; Morimura, Shigeru; Wu Xiaolei; Kida, Kenji

    2008-01-01

    A process for producing ethanol from kitchen waste was developed in this study. The process consists of freshness preservation of the waste, saccharification of the sugars in the waste, continuous ethanol fermentation of the saccharified liquid, and anaerobic treatment of the saccharification residue and the stillage. Spraying lactic acid bacteria (LCB) on the kitchen waste kept the waste fresh for over 1 week. High glucose recovery (85.5%) from LCB-sprayed waste was achieved after saccharification using Nagase N-40 glucoamylase. The resulting saccharified liquid was used directly for ethanol fermentation, without the addition of any nutrients. High ethanol productivity (24.0 g l -1 h -1 ) was obtained when the flocculating yeast strain KF-7 was used in a continuous ethanol fermentation process at a dilution rate of 0.8 h -1 . The saccharification residue was mixed with stillage and treated in a thermophilic anaerobic continuous stirred tank reactor (CSTR); a VTS loading rate of 6 g l -1 d -1 with 72% VTS digestion efficiency was achieved. Using this process, 30.9 g ethanol, and 65.2 l biogas with 50% methane, was produced from 1 kg of kitchen waste containing 118.0 g total sugar. Thus, energy in kitchen waste can be converted to ethanol and methane, which can then be used as fuels, while simultaneously treating kitchen waste

  7. Wastewater Treatment in Dyehouse using Flocculation Method and Water re-use

    Directory of Open Access Journals (Sweden)

    Prelog Karla

    2017-06-01

    Full Text Available The main goal of the research was to determine whether the treatment of dye-house wastewater with fl occulation could be efficient enough for water re-use in further production. A cationic condensation product was chosen for the treatment of industrial mixed wastewater collected in one week in Gorenjska predilnica d. d. Treated water was used for laboratory dyeing of cotton, polyester, polyacrylonitril, polyamide and wool with three different recipes representing light, medium and dark shade. The fabrics were dyed comparatively using technological and treated water under the same conditions. Colourimetric evaluation of dyed samples was done on spectrophotometer DataColour Spectrafl ash SF-600X. Wet fastness and colour fastness to perspiration (acid and alkaline of differently dyed samples were investigated. The results showed a high efficiency of flocculation for dye-house wastewater treatment and reuse of treated water in production. The change of colour was acceptable for all dyed samples except cotton light shade. Wet fastness became worse only on cotton but not more than one grade, when comparing the samples dyed in technological and those dyed in cleaned water. The colour fastness to perspiration did not change for polyester and polyacrylonitril; it was worse only for cotton samples.

  8. In situ determination of flocculated suspended material settling velocities and characteristics using a floc camera

    Science.gov (United States)

    Schoellhamer, David H.; Haught, Dan; Manning, Andrew

    2012-01-01

    Estimates of suspended sediment settling are necessary for numerical sediment models, water quality studies, and rehabilitation of coastal ecosystems. Settling of cohesive sediment, which is common in estuaries, is more difficult to quantify than noncohesive sediment because of flocculation. Flocs are composed of an aggregation of finer silts, clays, and organic material. Floc characteristics, such as the diameter, density, porosity, and water content determine floc settling velocities. A floc camera provides the ability to capture the settling velocities and other desired characteristics of individual flocs in situ. Water samples taken using a Van Dorn sampler are immediately subsampled using a pipette and transferred to the floc camera. The Perspex settling column is outfitted with a LED backlighting to distinguish flocs. The floc camera’s high pixel and temporal resolution allows image analysis software to detect individual flocs and process floc statistics per image. Observed changes in floc location with respect to time presents a way of calculating settling velocities. This work presents results of validation tests with known sediment size distributions and of deployment of the camera during a field study.

  9. Clay-oil flocculation during surf washing at the Sea Empress incident

    International Nuclear Information System (INIS)

    Wood, P.; Lunel, T.; Bailey, N.; Lee, K.

    1997-01-01

    Results of investigations into clay-oil flocculation during surf washing of oiled cobbles at Marros Beach, as a response to oiling during the Sea Empress incident, were summarized. Stranded oil on the cobble storm beach was found to associate with fine minerals and form flocs when introduced into sea water. The emulsions persisted for about 14 days after the oiling, after which it begun to disintegrate. After 50 days the remaining emulsion was found to be unstable and penetrated the beach to depths of up to three meters. Since no evidence of biodegradation was found during this period, oil reduction was attributed to sheening, facilitated by tidal fluctuations. Surf washing operation was undertaken over a seven day period beginning 47 days after the spill. Some 8150 tonnes of oiled cobbles were moved a distance of between 12 and 18 m seaward along a length of 850 m. Analysis of samples after two days following surf washing showed that oil concentration did not exceed 22 ppm, compared to 700 ppm before relocation. The significant reduction was considered to have been the result of enhanced oil dispersion coupled with the effects of the surf washing operations. 10 refs., 7 tabs., 10 figs

  10. Production of a High Efficiency Microbial Flocculant by Proteus mirabilis TJ-1 Using Compound Organic Wastewater

    Science.gov (United States)

    Zhang, Zhiqiang; Xia, Siqing; Zhang, Jiao

    2010-11-01

    The production of a high efficiency microbial flocculant (MBF) by Proteus mirabilis TJ-1 using compound organic wastewater was investigated. To cut down the cost of the MBF production, several nutritive organic wastewaters were selected to replace glucose and peptone as the carbon source and the nitrogen source in the optimized medium of strain TJ-1, respectively. The compound wastewater of the milk candy and the soybean milk was found to be good carbon source and nitrogen source for this strain to produce MBF. The cost-effective culture medium consists of (per liter): 800 mL wastewater of milk candy, 200 mL wastewater of soybean milk, 0.3 g MgSO4ṡ7 H2O, 5 g K2HPO4, 2 g and KH2PO4, pH 7.0. The economic cost for the MBF production can be cut down over a half by using the developed culture medium. Furthermore, the utilization of the two wastewaters in the preparation of culture medium of strain TJ-1 can not only save their big treatment cost, but also realize their resource reuse.

  11. In-situ precipitation and flocculation of iron hydroxides. A novel alternative to gel treatments

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, I.; Lakatos-Szabo, J. [Miskolch Univ. (Hungary). Research Inst. of Applied Chemistry; Kosztin, B.; Palasthy, Gy. [Hungarian Oil and Gas Company, Szolnok (Hungary)

    2002-01-01

    Development of a new well treatment method was stimulated by recognizing that some inorganic compounds, particularly Fe(III) compounds, can be transformed into gel-like precipitate by in-situ hydrolysis which is then immobilized by flocculation or spontaneous aging. These blocking materials have excellent stability under field conditions, but in case of technological failure the gel phase can easily be broken up into mobile sols. Further, the novel method is characterized by outstanding placement selectivity; self-controlling chemical mechanism and injectivity problems may not arise even in low permeable porous systems. During a field tests, extending over four years, 10 oil producing and 7 water injection wells were treated. The well responses were different: ration of the technical success was about 60%, while 40% of treatment was definitely profitable. In special reservoir blocks the injectors were simultaneously treated with the oil producing wells. The primary aim of these projects was to enhance the effect of profile correction around the producers and to improve the frontal displacement mechanism. The novel method proved to be compatible with the reservoir system and technical failure was not encountered during the past five years. The positive results contributed significantly to a recent decision of the operator that, parallel with other profile correction and water shut-off (e.g. polymer/silicate) techniques, application of the novel method will be extended to other reservoirs of the Algyo field, Hungary. (orig.)

  12. Boosting renewable energies

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    Public policy and funding are basically different, but both are needed to develop the renewable energy market. Public policy creates incentives, but also obligations. The setting up of a 'repurchase rate' also called a 'feed-in tariff' or 'clean energy cash back scheme' obliges electric power companies to buy back energy of renewable origin at a fixed, guaranteed rate. The extra-cost generated, although usually low, is passed on to all customers and does not cost the State anything. Funding is characterized by its source, the manner in which it is obtained and who supplies it, whether it be banks, mutual funds, development agencies, electric power companies, local governments or the consumers themselves. Repurchasing yields regular cash flows over a given period at a lower risk and allows banks to provide funding. This is one of the reasons for its success. This solution is also very popular with political leaders because it does not weigh down public funding. Both these reasons explain why repurchasing is so appreciated in Europe and in a growing number of countries, more than seventy having adopted it in 2010. In addition, it is regularly discounted in relation to technological breakthroughs and lower costs. As is the case in Europe, the problem lies in maintaining an acceptable rate while avoiding excessive project profitability. In Europe, for instance, the number of renewable energy projects is such that consumers are starting to complain about seeing their electricity rates rise because of the famous feed-in tariff, even though the cost of renewable energies continues to drop on a regular basis. The United States and a few other countries, including China, prefer the quota system, or RPS (Renewable Portfolio Standards), which requires electric power companies to generate a minimal share of electric power by a renewable energy source. These companies consequently invest in renewable energy projects or purchase this energy from other suppliers. Like the

  13. Renewables 2017 Global Status Report

    International Nuclear Information System (INIS)

    Sawin, Janet L.; Sverrisson, Freyr; Seyboth, Kristin; Adib, Rana; Murdock, Hannah E.; Lins, Christine; Edwards, Isobel; Hullin, Martin; Nguyen, Linh H.; Prillianto, Satrio S.; Satzinger, Katharina; Appavou, Fabiani; Brown, Adam; Chernyakhovskiy, Ilya; Logan, Jeffrey; Milligan, Michael; Zinaman, Owen; Epp, Baerbel; Huber, Lon; Lyons, Lorcan; Nowak, Thomas; Otte, Pia; Skeen, Jonathan; Sovacool, Benjamin; Witkamp, Bert; Musolino, Evan; Brown, Adam; Williamson, Laura E.; Ashworth, Lewis; Mastny, Lisa

    2017-01-01

    Renewable energy technologies increase their hold across developing and emerging economies throughout the year The year 2016 saw several developments and ongoing trends that all have a bearing on renewable energy, including the continuation of comparatively low global fossil fuel prices; dramatic price declines of several renewable energy technologies; and a continued increase in attention to energy storage. For the third consecutive year, global energy-related carbon dioxide emissions from fossil fuels and industry were nearly flat in 2016, due largely to declining coal use worldwide but also due to improvements in energy efficiency and to increasing use of renewable energy. As of 2015, renewable energy provided an estimated 19.3% of global final energy consumption, and growth in capacity and production continued in 2016. The power sector experienced the greatest increases in renewable energy capacity in 2016, whereas the growth of renewables in the heating and cooling and transport sectors was comparatively slow. Most new renewable energy capacity is installed in developing countries, and largely in China, the single largest developer of renewable power and heat over the past eight years. In 2016, renewable energy spread to a growing number of developing and emerging economies, some of which have become important markets. For the more than 1 billion people without access to electricity, distributed renewable energy projects, especially those in rural areas far from the centralised grid, offer important and often cost-effective options to provide such access. The renewable energy sector employed 9.8 million people in 2016, an increase of 1.1% over 2015. By technology, solar PV and biofuels provided the largest numbers of jobs. Employment shifted further towards Asia, which accounted for 62% of all renewable energy jobs (not including large-scale hydropower), led by China. The development of community renewable energy projects continued in 2016, but the pace of

  14. Talking Renewables; A renewable energy primer for everyone

    Science.gov (United States)

    Singh, Anirudh

    2018-03-01

    This book provides a clear and factual picture of the status of renewable energy and its capabilities today. The book covers all areas of renewable energy, starting from biomass energy and hydropower and proceeding to wind, solar and geothermal energy before ending with an overview of ocean energy. The book also explores how the technologies are being implemented today and takes a look at the future of renewable energy.

  15. Regional Renewable Energy Cooperatives

    Science.gov (United States)

    Hazendonk, P.; Brown, M. B.; Byrne, J. M.; Harrison, T.; Mueller, R.; Peacock, K.; Usher, J.; Yalamova, R.; Kroebel, R.; Larsen, J.; McNaughton, R.

    2014-12-01

    We are building a multidisciplinary research program linking researchers in agriculture, business, earth science, engineering, humanities and social science. Our goal is to match renewable energy supply and reformed energy demands. The program will be focused on (i) understanding and modifying energy demand, (ii) design and implementation of diverse renewable energy networks. Geomatics technology will be used to map existing energy and waste flows on a neighbourhood, municipal, and regional level. Optimal sites and combinations of sites for solar and wind electrical generation (ridges, rooftops, valley walls) will be identified. Geomatics based site and grid analyses will identify best locations for energy production based on efficient production and connectivity to regional grids and transportation. Design of networks for utilization of waste streams of heat, water, animal and human waste for energy production will be investigated. Agriculture, cities and industry produce many waste streams that are not well utilized. Therefore, establishing a renewable energy resource mapping and planning program for electrical generation, waste heat and energy recovery, biomass collection, and biochar, biodiesel and syngas production is critical to regional energy optimization. Electrical storage and demand management are two priorities that will be investigated. Regional scale cooperatives may use electric vehicle batteries and innovations such as pump storage and concentrated solar molten salt heat storage for steam turbine electrical generation. Energy demand management is poorly explored in Canada and elsewhere - our homes and businesses operate on an unrestricted demand. Simple monitoring and energy demand-ranking software can easily reduce peaks demands and move lower ranked uses to non-peak periods, thereby reducing the grid size needed to meet peak demands. Peak demand strains the current energy grid capacity and often requires demand balancing projects and

  16. Introduction to renewable energy

    CERN Document Server

    Nelson, Vaughn C

    2011-01-01

    IntroductionEnergy and SocietyTypes of EnergyRenewable EnergyAdvantages/DisadvantagesEconomicsGlobal WarmingOrder of Magnitude EstimatesGrowth (Exponential)SolutionsEnergyIntroductionDefinition of Energy and PowerHeatThermodynamicsEnergy Dilemma in Light of the Laws of ThermodynamicsUse of Fossil FuelsNuclearFinite ResourceSummarySunSolar PowerElectromagnetic SpectrumEnergy Balance of the EarthEarth-Sun MotionInsolationSolar ResourceGreenhouse EffectHeat Transfer and StorageIntroductionConductionConvectionRadiationThermal MassSeasonal Heating or CoolingThermal ComfortSolar Heating and CoolingB

  17. Renewable sources of energy

    International Nuclear Information System (INIS)

    Wojas, K.

    1996-01-01

    The author takes a look at causes of the present interest in the renewable, natural sources of energy. These are: the fuel deposits becoming exhausted, hazard to environment (especially carbon dioxide) and accessibility of these sources for under-developed countries. An interrelation is shown between these sources and the energy circulations connected with atmosphere and ocean systems. The chief ones from among them that are being used now are discussed, i.e. solar radiation, wind, water waves energy, tides, geothermal heat, and the like. Problems of conversion of the forms of these kinds of energy are also given a mention. (author)

  18. Flocculation of organic carbon from headwaters to estuary - the impact of soil erosion, water quality and land use on carbon transformation processes in eight streams draining Exmoor, UK

    Science.gov (United States)

    Snoalv, J.; Groeneveld, M.; Quine, T. A.; Tranvik, L.

    2017-12-01

    Flocculation of dissolved organic carbon (DOC) in streams and rivers is a process that contributes to the pool of particulate organic carbon (POC) in the aquatic system. In low-energy waters the increased sedimentation rates of this higher-density fraction of organic carbon (OC) makes POC important in allocating organic carbon into limnic storage, which subsequently influences emissions of greenhouse gases from the continental environment to the atmosphere. Allochthonous OC, derived from the terrestrial environment by soil erosion and litterfall, import both mineral aggregate-bound and free OC into freshwaters, which comprise carbon species of different quality and recalcitrance than autochthonous in-stream produced OC, such as from biofilms, aquatic plants and algae. Increased soil erosion due to land use change (e.g. agriculture, deforestation etc.) influences the input of allochthonous OC, which can lead to increased POC formation and sedimentation of terrestrial OC at flocculation boundaries in the landscape, i.e. where coagulation and flocculation processes are prone to occur in the water column. This study investigates the seasonal variation in POC content and flocculation capacity with respect to water quality (elemental composition) in eight river systems (four agricultural and four wooded streams) with headwaters in Exmoor, UK, that drain managed and non-managed land into Bristol Channel. Through flocculation experiments the samples were allowed to flocculate by treatments with added clay and salt standards that simulate the flocculation processes by 1) increased input of sediment into streams, and 2) saline mixing at the estuarine boundary, in order to quantify floc production and investigate POC quality by each process respectively. The results show how floc production, carbon quality and incorporation (e.g. complexation) of metals and rare earth elements (REE) in produced POC and remaining DOC in solution vary in water samples over the season and how

  19. Variations of floc morphology and extracellular organic matters (EOM) in relation to floc filterability under algae flocculation harvesting using polymeric titanium coagulants (PTCs).

    Science.gov (United States)

    Zhang, Weijun; Song, Rongna; Cao, Bingdi; Yang, Xiaofang; Wang, Dongsheng; Fu, Xingmin; Song, Yao

    2018-05-01

    The work evaluated the algae cells removal efficiency using titanium salt coagulants with different degree of polymerization (PTCs), and the algae cells aggregates and extracellular organic matter (EOM) under chemical flocculation were investigated. The results indicated that PTCs performed well in algae cells flocculation and separation. The main mechanism using PTCs of low alkalisation degree for algae flocculation was associated with charge neutralization, while adsorption bridging and sweep flocculation was mainly responsible for algae removal by PTCs of high alkalisation degree treatment. In addition, the flocs formed by PTC 1.0 showed the best filtration property, and EOM reached the minimum at this time, indicating the flocs formed by PTC 1.0 were more compact than other PTCs, which can be confirmed by SEM analysis. Three-dimensional excitation emission matrix fluorescence (3D-EEM) and high performance size exclusion chromatography (HPSEC) revealed that the EOMs were removed under PTCs flocculation, which improved floc filterability. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Renewable Energy Country Attractiveness Indices

    International Nuclear Information System (INIS)

    2011-02-01

    Since 2003 Ernst and Young team has been releasing quarterly data that ranks national renewable energy markets, and their suitability for individual technologies. The Country Attractiveness Indices now track the relative attractiveness of 30 countries' renewable energy markets across a selection of technologies each quarter. The Renewable Energy Country Attractiveness Indices publication scores and comments on various technologies, including: on-shore wind, off-shore wind, solar PV, solar CSP, biomass, and geothermal.

  1. Policies for a renewable future

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter identifies changes needed in policies regarding the utilization of renewable energy sources. The topics of the chapter include financial and legal incentives, information needs, long range energy and economic policy, environmental issues as an impetus to commercialization of renewable energy sources, taxing use of fossil fuels, encouraging renewable energy use by electric utilities through least-cost planning, educating the public and providing technical assistance, research and development, and environmental regulation and monitoring

  2. Renewable energy development in China

    Energy Technology Data Exchange (ETDEWEB)

    Junfeng, Li

    1996-12-31

    This paper presents the resources availability, technologies development and their costs of renewable energies in China and introduces the programs of renewable energies technologies development and their adaptation for rural economic development in China. As the conclusion of this paper, renewable energies technologies are suitable for some rural areas, especially in the remote areas for both household energy and business activities energy demand. The paper looks at issues involving hydropower, wind energy, biomass combustion, geothermal energy, and solar energy.

  3. Visions of regulatory renewal

    International Nuclear Information System (INIS)

    Edgeworth, A.

    1998-01-01

    The economic contribution of the CEPA (Canadian Energy Pipeline Association) member companies to Canada's trade balance was discussed. CEPA member companies transport 95 per cent of the crude oil and natural gas produced in Canada to domestic and export markets. This represents a total of 5.6 Tcf of gas annually. Half of Canada's natural gas and oil production is exported to U.S. markets. All of these exports are transported by pipeline. CEPA member companies operate 90,000 km of pipeline from British Columbia to Quebec. Expansions are needed as a result of a significant increase in demand for natural gas and crude oil since 1990. Several issues exist for regulatory renewal. They include the need to create a level playing field, the overseeing of tolls and contract renewal terms, changing risk/reward trade-offs, the right to confidentiality of information and price discovery mechanism. The drivers for regulatory reform at Westcoast Energy are the need for pricing flexibility, customers desire for toll certainty, decontracting and opposition to rolled-in expansions for gathering and processing. An overview of Westcoast Energy's negotiated toll settlement, its implications, and the components of Westcoast Energy's 'light handed regulation' (LHR) was presented

  4. Renewable Energy Marketplace

    Science.gov (United States)

    Ghadimian, Vachik

    The renewable energy sector is evolving, and today, renewable energy has become a viable alternative for many facilities. Because this sector is in its infancy stage, lack of experience has resulted in failing solar projects. This project involves the design and implementation of a functioning web application that streamlines and automates the planning, risk assessment and financing of a solar development project. The three key stakeholders, the host facility, solar installer and financier are seamlessly integrated into a single marketplace. By designing a project development workflow, projects are vetted early on and terminated if deemed infeasible, saving time and resources. By risk assessing the project using the proposed scoring model, one can inherit more confident investors. The project scoring model also serves as a debt rating system, where investors can measure the risk/rewards. The platform will also serve as a communication medium between the three stakeholders. Besides storing documents like engineering drawings, permits, etc., the platform auto-generates all necessary transactional documents, legal documents and agreements among the three stakeholders.

  5. Mexican renewable electricity law

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Mendoza, B.J.; Sheinbaum-Pardo, C. [Institute of Engineering of the National Autonomous University of Mexico, Circuito Exterior s/n, Edificio 12 Bernardo Quintana, Piso 3, Cubiculo 319, Ciudad Universitaria, Delegacion Coyoacan, CP 04510, Mexico D.F. (Mexico)

    2010-03-15

    Two renewable electricity bills have been proposed in Congress since 2005 in Mexico. The first one was rejected by the Senate and the second one was approved by both the House of Representatives and the Senate in October 2008. Our objective is to explain the nature of both bills and to analyze each of them bearing in mind the Mexican electricity sector management scheme. In the Mexican electricity sector single-buyer scheme, the state-owned companies (Comision Federal de Electricidad and Luz y Fuerza del Centro) are responsible of the public services and the private sector generates electricity under six modalities: self-supply, cogeneration, independent production, small production, export, and import, which are not considered a public service. This scheme has caused controversies related to the constitutionality of the 1992 Power Public Services Law that allowed this scheme to be implemented. Both bills, the rejected one and the approved one, were formulated and based on that controversial law and their objectives are linked precisely more to the controversial issues than to the promotion of renewable electricity technologies; consequently, the gap among environmental, economic and social issues related with sustainability notion is wider. (author)

  6. Mexican renewable electricity law

    International Nuclear Information System (INIS)

    Ruiz-Mendoza, B.J.; Sheinbaum-Pardo, C.

    2010-01-01

    Two renewable electricity bills have been proposed in Congress since 2005 in Mexico. The first one was rejected by the Senate and the second one was approved by both the House of Representatives and the Senate in October 2008. Our objective is to explain the nature of both bills and to analyze each of them bearing in mind the Mexican electricity sector management scheme. In the Mexican electricity sector single-buyer scheme, the state-owned companies (Comision Federal de Electricidad and Luz y Fuerza del Centro) are responsible of the public services and the private sector generates electricity under six modalities: self-supply, cogeneration, independent production, small production, export, and import, which are not considered a public service. This scheme has caused controversies related to the constitutionality of the 1992 Power Public Services Law that allowed this scheme to be implemented. Both bills, the rejected one and the approved one, were formulated and based on that controversial law and their objectives are linked precisely more to the controversial issues than to the promotion of renewable electricity technologies; consequently, the gap among environmental, economic and social issues related with sustainability notion is wider. (author)

  7. Landfill Leachate Treatment Using Coupled, Sequential Coagulation-flocculation and Advanced Oxidation Processes

    Directory of Open Access Journals (Sweden)

    José L. Álvarez Cruz

    2017-11-01

    Full Text Available This study evaluated the efficiency of Fenton (Fe/H2O2 and photo-assisted Fenton (Fe2+/H2O2/UV reactions combined with coagulation-flocculation (C-F processes to remove the chemical oxygen demand (COD in a landfill leachate from Mexico at a laboratory scale. The C-F experiments were carried out in jar test equipment using different FeSO4 concentrations (0.0, 0.6, 1.0, 3, and 6 mM at pH = 3.0. The effluent from the C-F processes were then treated using the Fenton reaction. The experiments were carried out in a 500 mL glass reactor fillet with 250 mL of landfill leachate. Different molar ratio concentrations (Fe/H2O2 were tested (e.g., 1.6, 3.3, 30, 40 and 75, and the reaction was followed until COD analysis showed no significant further variation in concentration or until 90 min of reaction time were completed. The photo-assisted Fenton reaction was carried out using a UV lamp (365 nm, 5 mW with the same Fe/H2O2 molar ratio values described above. The results suggested that the photo-assisted Fenton process is the most efficient oxidation method for removing organic matter and color in the leachate. The photo-assisted Fenton process removed 68% of the COD and 90% of the color at pH = 3 over 30 minutes of reaction time using a H2O2/Fe molar ratio equal to 75 only using a third of the reaction time of the previous process.

  8. Alcoholic fermentation with flocculant Saccharomyces cerevisiae in fed-batch process.

    Science.gov (United States)

    Guidini, Carla Zanella; Marquez, Líbia Diniz Santos; de Almeida Silva, Helisângela; de Resende, Miriam Maria; Cardoso, Vicelma Luiz; Ribeiro, Eloízio Júlio

    2014-02-01

    Studies have been conducted on selecting yeast strains for use in fermentation for ethanol production to improve the performance of industrial plants and decrease production costs. In this paper, we study alcoholic fermentation in a fed-batch process using a Saccharomyces cerevisiae yeast strain with flocculant characteristics. Central composite design (CCD) was used to determine the optimal combination of the variables involved, with the sucrose concentration of 170 g/L, a cellular concentration in the inoculum of 40% (v/v), and a filling time of 6 h, which resulted in a 92.20% yield relative to the theoretical maximum yield, a productivity of 6.01 g/L h and a residual sucrose concentration of 44.33 g/L. With some changes in the process such as recirculation of medium during the fermentation process and increase in cellular concentration in the inoculum after use of the CCD was possible to reduce the residual sucrose concentration to 2.8 g/L in 9 h of fermentation and increase yield and productivity for 92.75% and 9.26 g/L h, respectively. A model was developed to describe the inhibition of alcoholic fermentation kinetics by the substrate and the product. The maximum specific growth rate was 0.103 h(-1), with K(I) and K(s) values of 109.86 and 30.24 g/L, respectively. The experimental results from the fed-batch reactor show a good fit with the proposed model, resulting in a maximum growth rate of 0.080 h(-1).

  9. Liquid-liquid and liquid-solid phase separation and flocculation for a charged colloidal dispersion

    International Nuclear Information System (INIS)

    Lai, S.K.; Wu, K.L.

    2002-01-01

    We model the intercolloidal interaction by a hard-sphere Yukawa repulsion to which is added the long-range van der Waals attraction. In comparison with the Derjaguin-Landau-Verwey-Overbeek repulsion, the Yukawa repulsion explicitly incorporates the spatial correlations between colloids and small ions. As a result, the repulsive part can be expressed analytically and has a coupling strength depending on the colloidal volume fraction. By use of this two-body potential of mean force and in conjunction with a second-order thermodynamic perturbation theory, we construct the colloidal Helmholtz free energy and use it to calculate the thermodynamic quantities, pressure and chemical potential, needed in the determination of the liquid-liquid and liquid-solid phase diagrams. We examine, in an aqueous charged colloidal dispersion, the effects of the Hamaker constant and particle size on the conformation of a stable liquid-liquid phase transition calculated with respect to the liquid-solid coexistence phases. We find that there exists a threshold Hamaker constant or particle size whose value demarcates the stable liquid-liquid coexistence phases from their metastable counterparts. Applying the same technique and using the energetic criterion, we extend our calculations to study the flocculation phenomenon in aqueous charged colloids. Here, we pay due attention to determining the loci of a stability curve stipulated for a given temperature T 0 , and obtain the parametric phase diagram of the Hamaker constant vs the coupling strength or, at given surface potential, the particle size. By imposing T 0 to be the critical temperature T c , i.e., setting k B T 0 (=k B T c ) equal to a reasonable potential barrier, we arrive at the stability curve that marks the irreversible reversible phase transition. The interesting result is that there occurs a minimum size for the colloidal particles below (above) which the colloidal dispersion is driven to an irreversible (reversible) phase

  10. A heuristic formula for turbulence-induced flocculation of cohesive sediment

    Science.gov (United States)

    Winterwerp, J. C.; Manning, A. J.; Martens, C.; de Mulder, T.; Vanlede, J.

    2006-06-01

    This paper presents new measurements on the settling velocity of mud flocs in the Lower Sea Scheldt, Belgium, and compares the results with data obtained previously in the Tamar estuary, UK. The data show that the flocs are fairly compact with a fractal dimension of about 2.2, which is indicative for reaction limited aggregation processes, characteristic in dynamic aquatic systems with large tidal flow velocities and high SPM (suspended particulate matter) concentrations. The data also reveal a fairly small dependency of the settling velocity from SPM concentrations, consistently much smaller than earlier data published in literature. Furthermore, a simple explicit formulation is proposed for the settling velocity of cohesive sediment in estuaries and coastal seas. It is derived from an analytical solution of a Lagrangean flocculation model, which accounts for turbulence-induced aggregation and floc break-up. Also the effects of variations in SPM and of a limited residence time of the flocs in the turbulent water column are included. The model has been calibrated against data from settling velocity measurements carried out in the Tamar estuary. Values of the measured settling velocity vary between 0.5 and 5 mm s -1 at SPM-values between 0.05 and 8 g l -1. Using the tuned coefficients, the model describes the observations satisfactory, with an overall relative standard deviation of 30%. Also, the well-known and observed increase in settling velocity with turbulent shear stress at low stresses and the opposite trend at high stresses is described properly. Next, the model is applied to the new data obtained in the Lower Sea Scheldt estuary, again comparing favourably with overall relative standard deviations of 30-50%. It appeared that the coefficients of the model can be determined from independent measurements, but two of them have to be determined by trial and error, for which a simple procedure is proposed.

  11. Renewables 2007 - Global status report

    International Nuclear Information System (INIS)

    Martinot, Eric; Mastny, Lisa; Rosbotham, Lyle; Suding, Paul; Sonntag-O'Brien, Virginia; Lempp, Philippe

    2007-01-01

    In 2007, more than $100 billion was invested in new renewable energy capacity, manufacturing plants, and research and development-a true global milestone. Yet perceptions lag behind the reality of renewable energy because change has been so rapid in recent years. This report captures that reality and provides an overview of the status of renewable energy worldwide in 2007. The report covers trends in markets, investments, industries, policies, and rural (off-grid) renewable energy. (By design, the report does not provide analysis, discuss current issues, or forecast the future.) Many of the trends reflect increasing significance relative to conventional energy

  12. Integrating Renewables in Electricity Markets

    DEFF Research Database (Denmark)

    Morales González, Juan Miguel; Conejo, Antonio J.; Madsen, Henrik

    in the electricity market. • The development of procedures to enable demand response and to facilitate the integration of stochastic renewable units. This book is written in a modular and tutorial manner and includes many illustrative examples to facilitate its comprehension. It is intended for advanced...... such as: • The modeling and forecasting of stochastic renewable power production. • The characterization of the impact of renewable production on market outcomes. • The clearing of electricity markets with high penetration of stochastic renewable units. • The development of mechanisms to counteract...

  13. Economics of nuclear and renewables

    International Nuclear Information System (INIS)

    Khatib, Hisham; Difiglio, Carmine

    2016-01-01

    This paper provides an assessment of the economic challenges faced by both nuclear power and “new” renewable electricity technologies. The assessment reflects the need to incorporate new renewables into power grids and issues faced in dispatching power and their effect on traditional electricity technologies as well as the need for transmission extension and/or grid reinforcement. Wider introduction of smart grids and the likely demise of nuclear in some OECD countries are bound to enhance the future prospects for new renewables. However, their immediate future expansion will depend on continued subsidies, which are becoming difficult to sustain in present economic circumstances. Development of large energy storage facilities and carbon pricing could significantly enhance future renewable energy prospects. Correspondingly, expanding renewable energy, in spite of their popularity with some governments and sections of the public, is likely to face challenges which will slow their present rapid progress. Nuclear is now shied away from in many industrialized countries and having mixed prospects in developing economies. In many instances, it suffers from high initial costs, long lead times and often excessive construction delays. Nuclear power also faces challenging risks – investment as well as regulatory. In contrast to renewables, its share of global energy consumption is declining. - Highlights: •Renewables are increasing their energy share. •Renewables system cost is higher than their production cost. •Nuclear share is not increasing and their costs are not reduced. •Discount rate and subsidies are important in economics of renewables and nuclear.

  14. Regulatory guidance for license renewal

    International Nuclear Information System (INIS)

    Thoma, John A.

    1991-01-01

    The proposed 10 CFR Part 54 rule proceduralizes the process for license renewal by identifying both the administrative and technical requirements for a renewal application. To amplify and support this regulation, written guidance has been provided in the form of a draft Regulatory Guide (DG 1009) and a draft Standard Review Plan for License Renewal (NUREG 1299). This guidance is scheduled to be finalized in 1992. Similar guidance will be provided for the proposed revisions to 10 CFR Part 51 concerning the environmental aspects of license renewal. (author)

  15. Power Converters and Control of Renewable Energy Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Chen, Zhe

    2004-01-01

    The global electrical energy consumption is steadily rising and therefore a continuous demand to increase the power generation capacity. A significant percentage of the required capacity increase can be based on renewable energy sources. Wind turbine technology, as the most cost effective renewable...... energy conversion system, will play an important part in our future energy supply. But other sources like microturbines, photovoltaics and fuel cell systems may also be serious contributor to the power supply. Characteristically, power electronics will be an efficient and important interface to the grid...... for the renewables and this paper will first briefly discuss three different alternative/renewable energy sources. Next, various configurations of small and medium power conversion topologies are presented including their control (mainly for PV-systems). Finally wind turbine configuration and their control...

  16. Preserving Data for Renewable Energy

    Science.gov (United States)

    Macduff, M.; Sivaraman, C.

    2017-12-01

    The EERE Atmosphere to Electrons (A2e) program established the Data Archive and Portal (DAP) to ensure the long-term preservation and access to A2e research data. The DAP has been operated by PNNL for 2 years with data from more than a dozen projects and 1PB of data and hundreds of datasets expected to be stored this year. The data are a diverse mix of model runs, observational data, and dervived products. While most of the data is public, the DAP has securely stored many proprietary data sets provided by energy producers that are critical to the research goals of the A2e program. The DAP uses Amazon Web Services (AWS) and PNNL resources to provide long-term archival and access to the data with appropriate access controls. As a key element of the DAP, metadata are collected for each dataset to assist with data discovery and usefulness of the data. Further, the DAP has begun a process of standardizing observation data into NetCDF, which allows users to focus on the data instead of parsing the many formats. Creating a central repository that is in tune with the unique needs of the A2e research community is helping active tasks today as well as making many future research efforts possible. In this presentation, we provide an overview the DAP capabilities and benefits to the renewable energy community.

  17. Nano- and microparticles and associated pollutants in stormwater runoff: effects of disc filtration with and without flocculant addition

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Mørch-Madsen, Andreas; Mikkelsen, Peter Steen

    2014-01-01

    Danish municipalities work towards separating stormwater and sewage. But stormwater runoff may be heavily polluted and therefore it is needed to find Best Available Technologies (BAT) to source separate and treat stormwater before discharge into surface waters. The aim here was to determine...... for treating stormwater runoff. The micro-sized particles were found to be mainly 2.1-19 μm in diameter and nano-sized particles were also observed (86-228 nm). Although the flocculant increased the observed volume of the micro-sized particles by 46%, the majority of the particles where still

  18. Elimination of man-made radionuclides from natural waters by applying a standard coagulation-flocculation process

    International Nuclear Information System (INIS)

    Baeza, A.; Miro, C.; Salas, A.; Fernandez, M.; Herranz, M.; Legarda, F.

    2004-01-01

    Effectiveness of potable water treatment processes that consist of the stages of coagulation-flocculation-decantation, using iron-based coagulants, in eliminating gamma-emitting man-made radioisotopes of cesium, strontium, and americium from two natural waters with different degrees of mineralization was studied. The resulting decontamination was found to depend on the chemical behavior of each of the radionuclides considered, on the pH at which the process of coagulation is carried out, and on the concentration of the other stable cations present. (author)

  19. EDITORIAL: Renewing energy technology Renewing energy technology

    Science.gov (United States)

    Demming, Anna

    2011-06-01

    Renewable energy is now a mainstream concern among businesses and governments across the world, and could be considered a characteristic preoccupation of our time. It is interesting to note that many of the energy technologies currently being developed date back to very different eras, and even predate the industrial revolution. The fuel cell was first invented as long ago as 1838 by the Swiss--German chemist Christian Friedrich Schönbein [1], and the idea of harnessing solar power dates back to ancient Greece [2]. The enduring fascination with new means of harnessing energy is no doubt linked to man's innate delight in expending it, whether it be to satisfy the drive of curiosity, or from a hunger for entertainment, or to power automated labour-saving devices. But this must be galvanized by the sustained ability to improve device performance, unearthing original science, and asking new questions, for example regarding the durability of photovoltaic devices [3]. As in so many fields, advances in hydrogen storage technology for fuel cells have benefited significantly from nanotechnology. The idea is that the kinetics of hydrogen uptake and release may be reduced by decreasing the particle size. An understanding of how effective this may be has been hampered by limited knowledge of the way the thermodynamics are affected by atom or molecule cluster size. Detailed calculations of individual atoms in clusters are limited by computational resources as to the number of atoms that can studied, and other innovative approaches that deal with force fields derived by extrapolating the difference between the properties of clusters and bulk matter require labour-intensive modifications when extending such studies to new materials. In [4], researchers in the US use an alternative approach, considering the nanoparticle as having the same crystal structure as the bulk but relaxing the few layers of atoms near the surface. The favourable features of nanostructures for catalysis

  20. Renewable Acrylonitrile Production

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Karp, Eric M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eaton, Todd R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sanchez i Nogue, Violeta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vorotnikov, Vassili [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tan, Eric C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brandner, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manker, Lorenz [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bratis, Adam D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Liu, Rongming [University of Colorado; Gill, Ryan T. [University of Colorado; Gilhespy, Michelle [Johnson Matthey Technology Centre; Skoufa, Zinovia [Johnson Matthey Technology Centre; Watson, Michael J. [Johnson Matthey Technology Centre; Fruchey, O. Stanley [MATRIC; Cywar, Robin M. [Formerly NREL

    2017-12-08

    Acrylonitrile (ACN) is a petroleum-derived compound used in resins, polymers, acrylics, and carbon fiber. We present a process for renewable ACN production using 3-hydroxypropionic acid (3-HP), which can be produced microbially from sugars. The process achieves ACN molar yields exceeding 90% from ethyl 3-hydroxypropanoate (ethyl 3-HP) via dehydration and nitrilation with ammonia over an inexpensive titanium dioxide solid acid catalyst. We further describe an integrated process modeled at scale that is based on this chemistry and achieves near-quantitative ACN yields (98 +/- 2%) from ethyl acrylate. This endothermic approach eliminates runaway reaction hazards and achieves higher yields than the standard propylene ammoxidation process. Avoidance of hydrogen cyanide as a by-product also improves process safety and mitigates product handling requirements.

  1. Rewards of renewables

    Science.gov (United States)

    McNamee, Gregory

    2008-09-01

    In 1987 an American-style fridge freezer would use about 950 kWh of electricity and cost about 150 (£80) a year to run. Two decades on, a comparable appliance uses half the electricity and costs less than half as much to run. In 1975 there were about 3780 000 cars on the streets of Los Angeles, whereas today there are more than 5200 000 - yet air-pollution levels have fallen by half and an increasing number of those vehicles are hybrids or rely on renewable fuels like bio-diesel. Last year, half a million homes in Southern California were receiving direct solar power, either from solar electricity plants or from rooftop photovoltaic panels.

  2. Marine Renewable Energy Seascape

    Directory of Open Access Journals (Sweden)

    Alistair G.L. Borthwick

    2016-03-01

    Full Text Available Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation measures. Ocean energy has huge potential, but there are major interdisciplinary problems to be overcome regarding technology, cost reduction, investment, environmental impact, governance, and so forth. This article briefly reviews ocean energy production from offshore wind, tidal stream, ocean current, tidal range, wave, thermal, salinity gradients, and biomass sources. Future areas of research and development are outlined that could make exploitation of the marine renewable energy (MRE seascape a viable proposition; these areas include energy storage, advanced materials, robotics, and informatics. The article concludes with a sustainability perspective on the MRE seascape encompassing ethics, legislation, the regulatory environment, governance and consenting, economic, social, and environmental constraints. A new generation of engineers is needed with the ingenuity and spirit of adventure to meet the global challenge posed by MRE.

  3. Resources: the renewable promises

    International Nuclear Information System (INIS)

    Bellin, I.; Damier, J.; Persiaux, R.

    2010-01-01

    A set of brief articles gives an overview of development perspectives and objectives for renewable energies in France (biomass, hydraulic, wind, geothermal, solar, and sea energies). The influence of public investments and subsidies, and possible technological developments are evoked for solar energy. The advances of various projects and ideas in the field of sea energy are discussed: sea current energy, wave and swell energy, offshore wind generators, ocean thermal energy. The objectives and impacts of the use of biomass and of the development of bio-refineries are discussed, as well as the challenge CO 2 capture and storage. The evolution of electricity networks is outlined in terms of electricity storage, demand management and energy saving

  4. Renewable Energy Certificate Program

    Energy Technology Data Exchange (ETDEWEB)

    Gwendolyn S. Andersen

    2012-07-17

    This project was primarily to develop and implement a curriculum which will train undergraduate and graduate students at the University seeking a degree as well as training for enrollees in a special certification program to prepare individuals to be employed in a broad range of occupations in the field of renewable energy and energy conservation. Curriculum development was by teams of Saint Francis University Faculty in the Business Administration and Science Departments and industry experts. Students seeking undergraduate and graduate degrees are able to enroll in courses offered within these departments which will combine theory and hands-on training in the various elements of wind power development. For example, the business department curriculum areas include economic modeling, finance, contracting, etc. The science areas include meteorology, energy conversion and projection, species identification, habitat protection, field data collection and analysis, etc.

  5. Participatory urban renewal

    Directory of Open Access Journals (Sweden)

    Drago Kos

    2005-01-01

    Full Text Available The article consists of two parts. The first deals with the theoretical framework of urban rehabilitation. Literature provides the basis for a conclusion, which is that the key issue in rehabilitation projects is legitimate negotiation of various interests between participating individuals and institutions. In the second part this presentation and analyses of events that took place at the urban design workshop organised within the framework of the research project Renewal of housing estates in Ljubljana, provide experiential confirmation of the starting thesis. We established that the directly involved residents were willing to actively participate in rehabilitation procedures, however the process is never triggered, because of insufficient capacities in institutional frameworks. In conclusion several real proposals are shown, namely, how to surmount obstacles in urban rehabilitation and especially in larger housing estates built after World War 2.

  6. Renewal of radiological equipment.

    Science.gov (United States)

    2014-10-01

    In this century, medical imaging is at the heart of medical practice. Besides providing fast and accurate diagnosis, advances in radiology equipment offer new and previously non-existing options for treatment guidance with quite low morbidity, resulting in the improvement of health outcomes and quality of life for the patients. Although rapid technological development created new medical imaging modalities and methods, the same progress speed resulted in accelerated technical and functional obsolescence of the same medical imaging equipment, consequently creating a need for renewal. Older equipment has a high risk of failures and breakdowns, which might cause delays in diagnosis and treatment of the patient, and safety problems both for the patient and the medical staff. The European Society of Radiology is promoting the use of up-to-date equipment, especially in the context of the EuroSafe Imaging Campaign, as the use of up-to-date equipment will improve quality and safety in medical imaging. Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or renewal. This plan should look forward a minimum of 5 years, with annual updates. Teaching points • Radiological equipment has a definite life cycle span, resulting in unavoidable breakdown and decrease or loss of image quality which renders equipment useless after a certain time period.• Equipment older than 10 years is no longer state-of-the art equipment and replacement is essential. Operating costs of older equipment will be high when compared with new equipment, and sometimes maintenance will be impossible if no spare parts are available.• Older equipment has a high risk of failure and breakdown, causing delays in diagnosis and treatment of the patient and safety problems both for the patient and the medical staff.• Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or replacement. This plan should look forward a

  7. Renewable Energy in European Regions

    NARCIS (Netherlands)

    Krozer, Yoram

    2012-01-01

    The regional dynamics of energy innovation, in particular the shift from fossil fuels to renewable energy in the EU, is discussed within the framework of neo-Schumpeterian theory. The EU’s 4.2% average annual growth in renewable energy production in the last decade has been accompanied by diverging

  8. Business development in renewable energy

    NARCIS (Netherlands)

    Krozer, Yoram; Visa, Ion

    2014-01-01

    This paper discusses how to foster development of renewable energy business. Factors that impede or enhance renewable energy in the EU 27 member states in the period 1998–2008 are analyzed. Nine factors are considered: population density, production output and energy sector output to indicate market

  9. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    Energy Technology Data Exchange (ETDEWEB)

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  10. Renewal Processes and Repairable Systems

    NARCIS (Netherlands)

    2003-01-01

    In this thesis we discuss the following topics: 1. Renewal reward processes The marginal distributions of renewal reward processes and its version, which we call in this thesis instantaneous reward processes, are derived. Our approach is based on the theory of point processes, especially Poisson

  11. Renewable energies: public policy challenges

    International Nuclear Information System (INIS)

    Grazi, Laure; Souletie, Arthur

    2016-03-01

    Renewable energy sources (RES) are low-carbon energies available right within our borders, and as such can be of great value in addressing the challenges of climate change and energy security. In 2014, renewable energies accounted for 14.6% of France's gross final energy consumption. The French Energy Transition Act for Green Growth sets renewables targets of 23% and 32% as a share of gross final energy consumption by 2020 and 2030, respectively. However, renewable energies are still more costly than conventional energies. A significant share of this additional cost is borne by energy consumers, particularly in the form of energy taxation and biofuels blending obligations. Public aid is also provided to support heat production from renewable energy sources (RES-H). The two most significant aids available today are the Energy Transition Tax Credit (CITE) and the Heat Fund. Comparing the various types of renewable energies shows sharp disparities in terms of the cost of avoiding one tonne of CO 2 , which ranges from euros 59 to more than euros 500 for electricity production it follows that the cost of the energy transition is likely to vary significantly depending on which renewable energy sources are pushed to the fore. The combustion of biomass for heat production appears to offer an economically efficient way to reduce CO 2 emissions. Of the various renewable technologies available for the production of electricity (with the exception of hydropower, which was excluded from the scope of this study), onshore wind power is the least costly

  12. Renewable Energy Education in India

    Science.gov (United States)

    Bajpai, Shrish; Kidwai, Naimur Rahman

    2017-01-01

    The issue of renewable energy sources that have great potential to give solutions to the longstanding energy problems of India has been considered. It has been stated that renewable energy sources are an important part of India's plan to increase energy security and provide new generation with ample job opportunities. India's plans to move towards…

  13. 75 FR 26919 - Charter Renewals

    Science.gov (United States)

    2010-05-13

    ...: Notice of Renewal of the Advisory Committee on Commercial Remote Sensing Charter. SUMMARY: In accordance... Commercial Remote Sensing (ACCRES) is in the public interest in connection with the performance of duties imposed on the Department by law. The ACCRES Charter was renewed on April 1, 2010. SUPPLEMENTARY...

  14. Electrochemical Approaches to Renewable Energy

    Science.gov (United States)

    Lobaccaro, Peter

    Renewable energy is becoming an increasingly important component of the world's energy supply as the threat of global warming continues to rise. There is a need to reduce the cost of this renewable energy and a future challenge to deal with the strain intermittent power sources like renewables place on the power grid. In this dissertation, electrochemistry is harnessed to address possible solutions to both of these issues. First, it is used to develop a low cost alternative photovoltaic material. Then, it is used to investigate the production of chemical fuel stocks which can be used for energy storage. In chapter 2, advances are made in the electrochemical deposition of indium (In) on molybdenum foil which enables the deposition of electronic-grade purity, continuous films with thicknesses in the micron range. As an example application, the electrodeposited In films are phosphorized via the thin-film vapor-liquid-solid growth method. The resulting poly-crystalline InP films display excellent optoelectronic quality, comparable to films grown from more standard vacuum deposition techniques. This demonstrates the versatility of the developed electrochemical deposition procedure. In the remaining chapters, renewable fuel production is investigated. First in chapter 3, molybdenum disulfide (MoS2) is examined as a catalyst for the hydrogen evolution reaction (HER). Typically, high-cost synthesized MoS2 is used as the catalyst because the pristine MoS 2 mineral is known to be a poor catalyst. The fundamental challenge with pristine MoS2 is the inert HER activity of the predominant (0001) basal surface plane. Here, we report a general thermal process in which the basal plane is texturized to increase the density of HER-active edge sites. The process generates high HER catalytic performance in pristine MoS 2 across various morphologies such as the bulk mineral, films composed of micron-scale flakes, and even films of a commercially-available spray of nanoflake MoS2. In

  15. Sedimentation Effects of Adding Flocculants to Leached Slurries at Lab Scale in the “Comandante Ernesto Che Guevara” plant in Cuba

    Directory of Open Access Journals (Sweden)

    Eluberto Espinosa-Espinosa

    2016-10-01

    Full Text Available The objective of this investigation was to evaluate the effects of adding PICIZ 7010, AN 910SH and Quimifloc N-30 flocculants to leached and magnetized slurries at lab scale. The evaluation was completed through the comparative method in accordance to the NRBI-579 Standard: Sedimentation Tests which use Talmage and Fitch method. The addition of Quimifloc N-30 flocculants to 6 g/t of reduced ore increased slurry density by 5,9 %, improved liquor clarification as result of a reduction of up to 75 % in suspended solids and slightly reduced the required unit area.

  16. The nuclear techniques in function of improving the efficiency of the flocculators and floats in the industrial waste treatment station of PETROBRAS

    International Nuclear Information System (INIS)

    Damera Martinez, Arnaldo; Ramos Espinosa, Kenia A.; Pinto, Amenonia Ferreira; Barbalho, Andrea de Magalhaes; Derivet Zarzabal, Milagros

    2001-01-01

    This work was carried out in the Station of Treatment of Industrial Waste (STIW) in PETROBRAS (Brazil). The STIW has the function of receiving, to treat and storage liquid wastes coming from diverse points of the refinery, avoiding the environment contamination. This study consists on the determination of the time of residence inside the flocculators and floats, by means of nuclear technique of radioactive tracer, using Tc-99m. This technique has a great economic and environmental importance because the time of residence obtained experimentally in the flocculators and the floats, can be compared with those obtained theoretically, which allow to influence on the system, optimizing its operation

  17. Power Electronics for Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Blaabjerg, Frede

    2016-01-01

    A microgrid (MG) is a stand-alone or grid-connected hybrid renewable system that uses distributed renewable and nonrenewable energy sources and energy storage systems (ESSs) to supply power to local loads. The system is ordinarily based on power electronics, with interface converters allowing...... a continuous supply of power in the presence of variable RES production. This chapter describes some specific features of DC MGs in terms of power architecture, control, and protection. It also reviews several uncommon power electronic interfaces. Regarding control, operation without critical communication...... are explained in this chapter. The chapter concludes with a review of power electronic intensive protection solutions for DC MGs....

  18. Renewables in Global Energy Supply

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Renewable energies are essential contributors to the energy supply portfolio as they contribute to world energy supply security, reducing dependency on fossil fuel resources, and provide opportunities for mitigating greenhouse gases. Differences in definition and lack of adequate data complicated the discussion between participants on these key issues. The International Energy Agency believes that this fact sheet can be of use to all to facilitate the debate on the past, current and future place and role of renewables in total energy supply. Our goal is to present as objectively as possible the main elements of the current renewables energy situation. The definitions and coverage of national statistics vary between countries and organisations. In this fact sheet, the renewables definition includes combustible renewables and waste (CRW), hydro, geothermal, solar, wind, tide and wave energy.

  19. New renewables - a business challenge

    International Nuclear Information System (INIS)

    Jochum, G.

    2004-01-01

    This article takes a look at the increased use of renewable forms of energy and, in particular, the so-called 'new renewables' that are the subject of discussion in Europe and Switzerland. The wide divergence between the political and economical viewpoints concerning renewables is examined and the question is posed on how political desires and economical sense can be brought closer together. Questions concerning the public acceptance of various forms of energy are looked at and the expectations placed on renewable forms of energy are commented on. Criteria for models of promotion are listed including CO 2 emissions, technology and cost efficiency, marketing aspects and flexibility. Also, aspects concerning plausibility, fairness and responsibility are looked at. A model named 'Swiss Renewables Model' is proposed and its efficiency, functionality and financing are discussed

  20. The potential of renewable energies

    International Nuclear Information System (INIS)

    Glubrecht, H.

    1998-01-01

    If one compares the progress in research and development of renewable energy applications with the finding which has been granted to these activities during the 23 years after the first oil shock, one cannot but be very impressed. It is indicated in this paper hoe comprehensive the potential of renewable energy is. One should take into account that the methods described form a broad interdisciplinary field in contrast to fossil and nuclear technologies. From technical point of view the present and future energy demand can be met by the broad spectrum of renewable energies in combination with energy conservation. Many of these techniques are already economically competitive: solar architecture, wind energy, hydropower, low temperature heat production, photovoltaic for remote areas, various types of biomass application, geothermal energy although not exactly renewable. The future of renewable energies will depend on opening markets for these techniques

  1. Somerset County Renewable Energy Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Katula, Denise [County of Somerset, Somervile, NJ (United States)

    2014-05-07

    The County of Somerset, New Jersey, through the Somerset County Improvement Authority (SCIA), applied Federal funding through the U.S. Department of Energy to will apply project funds to buy-down the capital costs of equipment associated with the installation of solar photovoltaic (PV) systems at two sites owned by the County. This Renewable Energy Initiative allows the County to take advantage of clean renewable energy, without any adverse debt impacts, and at a price that results in operating budget savings beyond what is presently available in the marketplace. This project addressed the objectives of the Office of Energy Efficiency and Renewable Energy by making the acquisition of renewable energy more affordable for the County, thereby, encouraging other counties and local units to develop similar programs and increase the deployment of solar energy technologies. The two sites that were funded by the DOE grant are part of a much larger, ambitious, and unique renewable energy project, described in the next section.

  2. Renewal-anomalous-heterogeneous files

    International Nuclear Information System (INIS)

    Flomenbom, Ophir

    2010-01-01

    Renewal-anomalous-heterogeneous files are solved. A simple file is made of Brownian hard spheres that diffuse stochastically in an effective 1D channel. Generally, Brownian files are heterogeneous: the spheres' diffusion coefficients are distributed and the initial spheres' density is non-uniform. In renewal-anomalous files, the distribution of waiting times for individual jumps is not exponential as in Brownian files, yet obeys: ψ α (t)∼t -1-α , 0 2 >, obeys, 2 >∼ 2 > nrml α , where 2 > nrml is the MSD in the corresponding Brownian file. This scaling is an outcome of an exact relation (derived here) connecting probability density functions of Brownian files and renewal-anomalous files. It is also shown that non-renewal-anomalous files are slower than the corresponding renewal ones.

  3. Modeling renewable energy company risk

    International Nuclear Information System (INIS)

    Sadorsky, Perry

    2012-01-01

    The renewable energy sector is one of the fastest growing components of the energy industry and along with this increased demand for renewable energy there has been an increase in investing and financing activities. The tradeoff between risk and return in the renewable energy sector is, however, precarious. Renewable energy companies are often among the riskiest types of companies to invest in and for this reason it is necessary to have a good understanding of the risk factors. This paper uses a variable beta model to investigate the determinants of renewable energy company risk. The empirical results show that company sales growth has a negative impact on company risk while oil price increases have a positive impact on company risk. When oil price returns are positive and moderate, increases in sales growth can offset the impact of oil price returns and this leads to lower systematic risk.

  4. Renewable energies for power generation

    International Nuclear Information System (INIS)

    Freris, L.; Infield, D.

    2009-01-01

    Power generation from renewable energy sources is different from power generation from classical energies (nuclear, thermal..). Therefore, the integration into the grid of the electricity supplied by renewable sources requires a deep thinking. The reason is that these power sources are controlled by variable elements, like wind, water and sun, which condition production. This book deals with the following aspects in detail: characteristics of classical and intermittent generators; grid balancing between supply and demand; conversion methods of renewable energies into electricity; power systems; privatizing of power generation and birth of new markets, in particular the 'green' power market; development of renewable energies thanks to technical advances. It gives a comprehensive overview of the present day available renewable energy sources for power generation. (J.S.)

  5. [Effect of polymeric aluminum-iron on EPS and bio-flocculation in A2/O system].

    Science.gov (United States)

    Wen, Qin-Xue; Liu, Ai-Cui; Chen, Zhi-Qiang; Shi, Han-Chang; Lü, Bing-Nan

    2012-04-01

    Polymeric aluminum-iron (PAFC) was added at the end of aeration tank to enhance phosphorus removal, so that the phosphorus concentration in the effluent could meet the calss A standard in municipal sewage treatment plant pollutant discharge standard (GB 18918-2002). The characteristics of extracellular polymer substances (EPS) and bio-flocculation for the activated sludge in the A2/O system were analyzed in the experiment. The results showed that, the gross of EPS varied little with the increase in PAFC dosage, while, the ratio of albumen to polysaccharide declined from 3.30 to 2.30. When the PAFC dosage increased, the concentration of Al3+ in EPS increased during the whole anaerobic-anoxic-aerobic cycle. The flocs of activated sludge became larger after PAFC addition, Zeta potential of the effluent dropped significantly from - 15.83 mV to -21.20 mV and sludge yield increased. Therefore, bio-flocculation of the activated sludge in the A2/O system improved when a proper amount of PAFC was added, subsequently improve the water quality of the effluent.

  6. Impact of Coagulant and Flocculant Addition to an Anaerobic Dynamic Membrane Bioreactor (AnDMBR) Treating Waste-Activated Sludge.

    Science.gov (United States)

    Kooijman, Guido; Lopes, Wilton; Zhou, Zhongbo; Guo, Hongxiao; de Kreuk, Merle; Spanjers, Henri; van Lier, Jules

    2017-03-23

    In this work, we investigated the effects of flocculation aid (FA) addition to an anaerobic dynamic membrane bioreactor (AnDMBR) (7 L, 35 °C) treating waste-activated sludge (WAS). The experiment consisted of three distinct periods. In period 1 (day 1-86), the reactor was operated as a conventional anaerobic digester with a solids retention time (SRT) and hydraulic retention time (HRT) of 24 days. In period 2 (day 86-303), the HRT was lowered to 18 days with the application of a dynamic membrane while the SRT was kept the same. In period 3 (day 303-386), a cationic FA in combination with FeCl₃ was added. The additions led to a lower viscosity, which was expected to lead to an increased digestion performance. However, the FAs caused irreversible binding of the substrate, lowering the volatile solids destruction from 32% in period 2 to 24% in period 3. An accumulation of small particulates was observed in the sludge, lowering the average particle size by 50%. These particulates likely caused pore blocking in the cake layer, doubling the trans-membrane pressure. The methanogenic consortia were unaffected. Dosing coagulants and flocculants into an AnDMBR treating sludge leads to a decreased cake layer permeability and decreased sludge degradation.

  7. A novel Fe(III) dependent bioflocculant from Klebsiella oxytoca GS-4-08: culture conditions optimization and flocculation mechanism.

    Science.gov (United States)

    Yu, Lei; Tang, Qing-Wen; Zhang, Yu-Jia; Chen, Rong-Ping; Liu, Xin; Qiao, Wei-Chuan; Li, Wen-Wei; Ruan, Hong-Hua; Song, Xin

    2016-10-07

    In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses. With the aid of Fe 3+ , the FE of kaolin solution by P-GS408 could achieve 99.48% in ten minutes. Functional groups of polysaccharide were involved in the first adsorption step and the zeta potential of kaolin solution changed from -39.0 mV to 43.4 mV in the presence of Fe 3+ and P-GS408. Three-dimensional excitation-emission (EEM) fluorescence spectra demonstrates that the trivalent Fe 3+ and Al 3+ can bind efficiently with P-GS408, while those univalent and divalent cations cannot. With the help of SEM images, FTIR, zeta potential and EEM spectra, we proposed the P-GS408 flocculation mechanism, which consists of coordination bond combination, charge neutrality, adsorption and bridging, and net catching.

  8. Capital renewal as a real option

    NARCIS (Netherlands)

    Reindorp, M.J.; Fu, M.C.

    2011-01-01

    We consider the timing of replacement of obsolete subsystems within an extensive, complex infrastructure. Such replacement action, known as capital renewal, must balance uncertainty about future profitability against uncertainty about future renewal costs. Treating renewal investments as real

  9. Battery storage for supplementing renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    The battery storage for renewable energy systems section of the Renewable Energy Technology Characterizations describes structures and models to support the technical and economic status of emerging renewable energy options for electricity supply.

  10. The randomly renewed general item and the randomly inspected item with exponential life distribution

    International Nuclear Information System (INIS)

    Schneeweiss, W.G.

    1979-01-01

    For a randomly renewed item the probability distributions of the time to failure and of the duration of down time and the expectations of these random variables are determined. Moreover, it is shown that the same theory applies to randomly checked items with exponential probability distribution of life such as electronic items. The case of periodic renewals is treated as an example. (orig.) [de

  11. Building a sustainable market for renewables

    Energy Technology Data Exchange (ETDEWEB)

    Rader, N.

    1996-12-31

    Opinions regarding marketing approaches for electricity generation from renewable resources are presented in the paper. The Renewables Portfolio Standard of the California Public Utilities Commission is described. This system is based on renewable energy credits. Other marketing approaches, including surcharges, auctioned renewables credit, green pricing, and green marketing are also assessed. It is concluded that the Renewables Portfolio Standard creates a stable economic environment for the renewable energy industries.

  12. Renewables 2013. Global Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Sawin, J. L. [and others

    2013-07-01

    Renewable energy markets, industries, and policy frameworks have evolved rapidly in recent years. The Renewables Global Status Report provides a comprehensive and timely overview of renewable energy market, industry, investment, and policy developments worldwide. It relies on the most recent data available, provided by many contributors and researchers from around the world, all of which is brought together by a multi-disciplinary authoring team. The report covers recent developments, current status, and key trends; by design, it does not provide analysis or forecasts. This latest Renewables Global Status Report saw: a shift in investment patterns that led to a global decrease in clean energy investment; continuing growth in installed capacity due to significant technology cost reductions and increased investment in developing countries; renewables progressively supplementing established electricity systems, demonstrating that the implementation of suitable policies can enable the successful integration of higher shares of variable renewables; and the emergence of integrated policy approaches that link energy efficiency measures with the implementation of renewable energy technologies.

  13. Developing Government Renewable Energy Projects

    Energy Technology Data Exchange (ETDEWEB)

    Kurt S. Myers; Thomas L. Baldwin; Jason W. Bush; Jake P. Gentle

    2012-07-01

    The US Army Corps of Engineers has retained Idaho National Laboratory (INL) to conduct a study of past INL experiences and complete a report that identifies the processes that are needed for the development of renewable energy projects on government properties. The INL has always maintained expertise in power systems and applied engineering and INL’s renewable energy experiences date back to the 1980’s when our engineers began performing US Air Force wind energy feasibility studies and development projects. Over the last 20+ years of working with Department of Defense and other government agencies to study, design, and build government renewable projects, INL has experienced the do’s and don’ts for being successful with a project. These compiled guidelines for government renewable energy projects could include wind, hydro, geothermal, solar, biomass, or a variety of hybrid systems; however, for the purpose of narrowing the focus of this report, wind projects are the main topic discussed throughout this report. It is our thought that a lot of what is discussed could be applied, possibly with some modifications, to other areas of renewable energy. It is also important to note that individual projects (regardless the type) vary to some degree depending on location, size, and need but in general these concepts and directions can be carried over to the majority of government renewable energy projects. This report focuses on the initial development that needs to occur for any project to be a successful government renewable energy project.

  14. renewables 2011 - Global status report

    International Nuclear Information System (INIS)

    Sawin, Janet L.; Martinot, Eric; Barnes, Douglas; Martinot, Eric; McCrone, Angus; Roussell, Jodie; Sawin, Janet L.; Sims, Ralph; Sonntag-O'Brien, Virginia; Adib, Rana; Skeen, Jonathan; Musolino, Evan; Riahi, Lily; Mastny, Lisa

    2011-01-01

    Changes in renewable energy markets, investments, industries, and policies have been so rapid in recent years that perceptions of the status of renewable energy can lag years behind the reality. This report captures that reality and provides a unique overview of renewable energy worldwide as of early 2011. The report covers both current status and key trends; by design, it does not provide analysis or forecast the future. Global energy consumption rebounded in 2010 after an overall downturn in 2009. Renewable energy, which experienced no downturn in 2009, continued to grow strongly in all end-use sectors - power, heat and transport - and supplied an estimated 16% of global final energy consumption. Renewable energy accounted for approximately half of the estimated 194 gigawatts (GW) of new electric capacity added globally during the year. Renewables delivered close to 20% of global electricity supply in 2010, and by early 2011 they comprised one quarter of global power capacity from all sources. In several countries, renewables represent a rapidly growing share of total energy supply, including heat and transport

  15. Marine Renewable Energy Center

    Energy Technology Data Exchange (ETDEWEB)

    Vigeant, Paul [Univ. of Massachusetts, Dartmouth, MA (United States); Miller, John [Univ. of Massachusetts, Dartmouth, MA (United States); Howes, Brian [Univ. of Massachusetts, Dartmouth, MA (United States); McGowan, Jon G. [Univ. of Massachusetts, Amherst, MA (United States); Baldwin, Kenneth [Univ. of New Hampshire, Durham, NH (United States); Grilli, Annette [Univ. of Rhode Island, Kingston, RI (United States); Terray, Eugene [Woods Hole Oceanographic Inst., Woods Hole, MA (United States)

    2013-10-08

    Project Goals: The funding provided by this contract supported the following activities: A) Test Site Development; B) Seed Grant Funded Technology Development; C) Stakeholder Activities The first year of funding was dedicated to the formation of the NE MREC University Consortium which was comprised of University of Massachusetts Dartmouth (UMD) and Amherst (UMA), Massachusetts Institute of Technology (MIT), Woods Hole Oceanographic Institution (WHOI), University of New Hampshire (UNH), and the University of Rhode Island (URI). The consortium worked together to encourage research and promote benefits of obtaining energy from ocean wind, waves, tides and currents. In addition, NE MREC’s goal was to fund projects aimed at potential test sites with the first year funding going to studies of the potential for tidal device testing in Muskeget Channel, at the General Sullivan Bridge in New Hampshire, and for wave device testing at the proposed National Offshore Renewable Energy Innovation Zone (NOREIZ) located off the Massachusetts coast. The project spanned 4.5 years and addressed three specific tasks that are interrelated but also served as independent investigations.

  16. Renewables 2005. Global status report

    International Nuclear Information System (INIS)

    2005-01-01

    This report provides an overview of the status of renewable energy worldwide in 2005. It covers markets, investments, industries, policies, and rural (off-grid) renewable energy in developing countries. By design, the report does not provide analysis, recommendations, or conclusions. An extensive research and review process over several months involving more than 100 researchers and contributors has kept inaccuracies to a minimum. REN21 sees this report as the beginning of an active exchange of views and information. This report reveals some surprising facts about renewable energy, many reflecting strong growth trends and increasing significance relative to conventional energy. (au)

  17. Renewables 2005. Global status report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report provides an overview of the status of renewable energy worldwide in 2005. It covers markets, investments, industries, policies, and rural (off-grid) renewable energy in developing countries. By design, the report does not provide analysis, recommendations, or conclusions. An extensive research and review process over several months involving more than 100 researchers and contributors has kept inaccuracies to a minimum. REN21 sees this report as the beginning of an active exchange of views and information. This report reveals some surprising facts about renewable energy, many reflecting strong growth trends and increasing significance relative to conventional energy. (au)

  18. Renewables 2005 - Global status report

    International Nuclear Information System (INIS)

    Martinot, Eric

    2005-01-01

    This report provides an overview of the status of renewable energy worldwide in 2005. It covers markets, investments, industries, policies, and rural (off-grid) renewable energy in developing countries. By design, the report does not provide analysis, recommendations, or conclusions. An extensive research and review process over several months involving more than 100 researchers and contributors has kept inaccuracies to a minimum. REN21 sees this report as the beginning of an active exchange of views and information. This report reveals some surprising facts about renewable energy, many reflecting strong growth trends and increasing significance relative to conventional energy

  19. Renewable, ethical? Assessing the energy justice potential of renewable electricity

    Directory of Open Access Journals (Sweden)

    Aparajita Banerjee

    2017-08-01

    Full Text Available Energy justice is increasingly being used as a framework to conceptualize the impacts of energy decision making in more holistic ways and to consider the social implications in terms of existing ethical values. Similarly, renewable energy technologies are increasingly being promoted for their environmental and social benefits. However, little work has been done to systematically examine the extent to which, in what ways and in what contexts, renewable energy technologies can contribute to achieving energy justice. This paper assesses the potential of renewable electricity technologies to address energy justice in various global contexts via a systematic review of existing studies analyzed in terms of the principles and dimensions of energy justice. Based on publications including peer reviewed academic literature, books, and in some cases reports by government or international organizations, we assess renewable electricity technologies in both grid integrated and off-grid use contexts. We conduct our investigation through the rubric of the affirmative and prohibitive principles of energy justice and in terms of its temporal, geographic, socio-political, economic, and technological dimensions. Renewable electricity technology development has and continue to have different impacts in different social contexts, and by considering the different impacts explicitly across global contexts, including differences between rural and urban contexts, this paper contributes to identifying and understanding how, in what ways, and in what particular conditions and circumstances renewable electricity technologies may correspond with or work to promote energy justice.

  20. Renewables 2010 - Global status report

    International Nuclear Information System (INIS)

    Sawin, Janet L.; Martinot, Eric; Sonntag-O'Brien, Virginia; McCrone, Angus; Roussell, Jodie; Barnes, Douglas; Flavin, Christopher; Mastny, Lisa; Kraft, Diana; Wang, Shannon; Ellenbeck, Saskia; Ilieva, Lili; Griebenow, Christof; Adib, Rana; Lempp, Philippe; Welker, Bettina

    2010-01-01

    Changes in renewable energy markets, investments, industries, and policies have been so rapid in recent years that perceptions of the status of renewable energy can lag years behind the reality. This report captures that reality and provides a unique overview of renewable energy worldwide as of early 2010. The report covers both current status and key trends. By design, the report does not provide analysis, discuss current issues, or forecast the future. Many of the trends reflect the increasing significance of renewable energy relative to conventional energy sources (including coal, gas, oil, and nuclear). By 2010, renewable energy had reached a clear tipping point in the context of global energy supply. Renewables comprised fully one quarter of global power capacity from all sources and delivered 18 percent of global electricity supply in 2009. In a number of countries, renewables represent a rapidly growing share of total energy supply-including heat and transport. The share of households worldwide employing solar hot water heating continues to increase and is now estimated at 70 million households. And investment in new renewable power capacity in both 2008 and 2009 represented over half of total global investment in new power generation. Trends reflect strong growth and investment across all market sectors-power generation, heating and cooling, and transport fuels. Grid-connected solar PV has grown by an average of 60 percent every year for the past decade, increasing 100-fold since 2000. During the past five years from 2005 to 2009, consistent high growth year-after-year marked virtually every other renewable technology. During those five years, wind power capacity grew an average of 27 percent annually, solar hot water by 19 percent annually, and ethanol production by 20 percent annually. Biomass and geothermal for power and heat also grew strongly. Much more active policy development during the past several years culminated in a significant policy milestone

  1. Evaluation of cytotoxicity and inflammatory activity of wastewater collected from a textile factory before and after treatment by coagulation-flocculation methods.

    Science.gov (United States)

    Makene, Vedastus W; Tijani, Jimoh O; Petrik, Leslie F; Pool, Edmund J

    2016-08-01

    Effective treatment of textile effluent prior to discharge is necessary in order to avert the associated adverse health impacts on human and aquatic life. In the present investigation, coagulation/flocculation processes were evaluated for the effectiveness of the individual treatment. Effectiveness of the treatment was evaluated based on the physicochemical characteristics. The quality of the pre-treated and post-flocculation treated effluent was further evaluated by determination of cytotoxicity and inflammatory activity using RAW264.7 cell cultures. Cytotoxicity was determined using WST-1 assay. Nitric oxide (NO) and interleukin 6 (IL-6) were used as biomarkers of inflammation. NO was determined in cell culture supernatant using the Griess reaction assay. The IL-6 secretion was determined using double antibody sandwich enzyme linked immunoassay (DAS ELISA). Cytotoxicity results show that raw effluent reduced the cell viability significantly (P production than the negative control. The inflammatory results further show that the raw effluent induced significantly (P production of IL-6 than the negative control. Among the coagulants/flocculants evaluated Al2(SO4)3.14H2O at a dosage of 1.6 g/L was the most effective to remove both toxic and inflammatory pollutants. In conclusion, the inflammatory responses in RAW264.7 cells can be used as sensitive biomarkers for monitoring the effectiveness of coagulation/flocculation processes used for textile effluent treatment.

  2. TiO2 Photocatalyst Nanoparticle Separation: Flocculation in Different Matrices and Use of Powdered Activated Carbon as a Precoat in Low-Cost Fabric Filtration

    Directory of Open Access Journals (Sweden)

    Carlos F. Liriano-Jorge

    2014-01-01

    Full Text Available Separation of photocatalyst nanoparticles is a problem impeding widespread application of photocatalytic oxidation. As sedimentation of photocatalyst particles is facilitated by their flocculation, the influence of common constituents of biologically pretreated wastewaters (NaCl, NaHCO3, and their combination with humic acid sodium salt on flocculation was tested by the pipet method. Results showed that the impact of these substances on TiO2 nanoparticle flocculation is rather complex and strongly affected by pH. When humic acid was present, TiO2 particles did not show efficient flocculation in the neutral and slightly basic pH range. As an alternative to photocatalyst separation by sedimentation, precoat vacuum filtration with powdered activated carbon (PAC over low-cost spunbond polypropylene fabrics was tested in the presence of two PAC types in aqueous NaCl and NaHCO3 solutions as well as in biologically treated greywater and in secondary municipal effluent. PAC concentrations of ≥2 g/L were required in order to achieve a retention of nearly 95% of the TiO2 nanoparticles on the fabric filter when TiO2 concentration was 1 g/L. Composition of the aqueous matrix and PAC type had a slight impact on precoat filtration. PAC precoat filtration represents a potential pretreatment for photocatalyst removal by micro- or ultrafiltration.

  3. Comparison between coagulation-flocculation and ozone-flotation for Scenedesmus microalgal biomolecule recovery and nutrient removal from wastewater in a high-rate algal pond.

    Science.gov (United States)

    Oliveira, Gislayne Alves; Carissimi, Elvis; Monje-Ramírez, Ignacio; Velasquez-Orta, Sharon B; Rodrigues, Rafael Teixeira; Ledesma, María Teresa Orta

    2018-07-01

    The removal of nutrients by Scenedesmus sp. in a high-rate algal pond, and subsequent algal separation by coagulation-flocculation or flotation with ozone to recover biomolecules, were evaluated. Cultivation of Scenedesmus sp. in wastewater resulted in complete NH 3 -H removal, plus 93% total nitrogen and 61% orthophosphate removals. Ozone-flotation obtained better water quality results than coagulation-flocculation for most parameters (NH 3 -N, NTK, nitrate and nitrite) except orthophosphate. Ozone-flotation, also produced the highest recovery of lipids, carbohydrates and proteins which were 0.32 ± 0.03, 0.33 ± 0.025 and 0.58 ± 0.014 mg/mg of biomass, respectively. In contrast, there was a low lipid extraction of 0.21 mg of lipids/mg of biomass and 0.12-0.23 mg of protein/mg of biomass in the coagulation-flocculation process. In terms of biomolecule recovery and water quality, ozone showed better results than coagulation-flocculation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Ethanol production with a flocculating mutant of Zymomonas mobilis and immobilized glycoside hydrolases. Ethanolgewinnung mit einer flockenden Mutante von Zymomonas mobilis und immobilisierten Glycosidhydrolasen

    Energy Technology Data Exchange (ETDEWEB)

    Tramm-Werner, S.

    1987-05-25

    A method to extend the substrate spectrum of Z. mobilis was developed. Higher ethanol yields were achieved by simultaneous use of hydrolases cross-linked with glutar aldehyde together with the flocculating Zymomonas cells (TW 602). Apart from the high product yields, the method is characterized by low susceptibility to infections.

  5. Effects of evaporation pressure and antifoam concentration and the use of a flocculant and adjuvant on the quality of sugar honey and panela

    Directory of Open Access Journals (Sweden)

    Luz Esperanza Prada Forero

    2014-07-01

    Full Text Available The implementation of multi-effect evaporators on panela (unrefined whole cane sugar production process requires, besides the technological adjustment, to maintain product characteristics; this condition revealed the lack of knowledge of the effect of evaporation pressure on the quality of panela. In order to fill part of this gap, this study sought to determine the effect of both the concentration of antifoam and the use of a flocculant (Heliocarpus popayanensis Kunth and an adjuvant (lime on the quality of sugar honey and panela, when evaporation is performed at different atmospheric pressures. In order to achieve this, the present study worked on two completely randomized experimental designs with four replications, a density of evaporation heat flow of 27.78 kW/m2 and juice from the CC85-46 variety. In the first design, two variables were studied: evaporation pressure and use of flocculant and adjuvant with a 4x2x2 factorial arrangement without antifoam. In the second design, variables evaporation pressure and quantity of antifoam with a 4x3 factorial arrangement without flocculant nor adjuvant were studied. The results show that the quality of the product deteriorates in pressurized systems (glucoside coefficient increases up to 200%, is not affected by the use of 50 μL of antifoam per liter of clarified juice and improved by the use of flocculant (turbidity is reduced by 55%. Solidification and hardness improve with the addition of the adjuvant, but this increased 48% color and 24% turbidity.

  6. Was the extreme and widespread marine oil-snow sedimentation and flocculent accumulation (MOSSFA) event during the Deepwater Horizon blow-out unique?

    NARCIS (Netherlands)

    Vonk, S.M.; Hollander, D.J.; Murk, A.J.

    2015-01-01

    During the Deepwater Horizon blowout, thick layers of oiled material were deposited on the deep seafloor. This large scale benthic concentration of oil is suggested to have occurred via the process of Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA). This meta-analysis investigates

  7. THE EFFECTS OF GRADIENT VELOCITY AND DETENTION TIME TO COAGULATION – FLOCCULATION OF DYES AND ORGANIC COMPOUND IN DEEP WELL WATER

    Directory of Open Access Journals (Sweden)

    Muhamad Lindu

    2010-06-01

    Full Text Available The treatment of deep well water of Trisakti University by coagulation and flocculation using baffle channel system has been conducted. The detention time of hydrolic were varied. The coagulant dose was varied as 50, 100, 150, 200, 300, 350, 400, 450 and 500 ppm. Water of well sampel was added by coagulant with rotation velocity 200 rpm for 1 minute. The optimal coagulant dose was determined by measuring turbidity, colour, total suspended solids and organic compound. The result showed that the organic compound and colour of deep well water of Trisakti University could be reduced by coagulation and flocculation process by hydrolyc system. The optimal dose of the coagulant was 250 ppm. The removal efficiency of colour and organic compound using optimal dose for continuous flow reactor reached after water flow passed the reactor for 3 - 5 times detention time in the reactor. The optimal gradient velocity (G was 30 - 35 sec-1 and collision energy (GT was 65.000 - 79.000 to get optimal flocculation. With this condition, the removal efficiency of turbidity, colour and organic was more than 90%.   Keywords: coagulation, flocculation, colour, organic compound, deep well

  8. Effects of hydrodynamic mixing intensity coupled with ionic strength on the initial stage dynamics of bridging flocculation of polystyrene latex particles with polyelectrolyte

    NARCIS (Netherlands)

    Adachi, Y.; Matsumoto, T.; Cohen Stuart, M.A.

    2002-01-01

    Effects of hydrodynamic mixing intensity on the initial stage dynamics of bridging flocculation induced by adsorbing polyelectrolyte were analyzed as an extension of previous report on the effect of ionic strength (J. Coll. Int. Sci. 204 (1998) 328). Mixing condition were changed by adopting forked

  9. Financing of Renewable Energy Projects

    International Nuclear Information System (INIS)

    Santizo, Rodolfo; Berganza, Jose

    2000-01-01

    The paper describes the role of the Banco Centroamericano de Integracion Economica in financing renewable energy projects in Central America. Also decribes the different financing modes to the goverment and private sectors

  10. Nuclear energy and renewable energies

    International Nuclear Information System (INIS)

    1994-01-01

    The nuclear energy and the renewable energies namely: solar energy, wind energy, geothermal energy and biomass are complementary. They are not polluting and they are expected to develop in the future to replace the fossil fuels

  11. VT Renewable Energy Sites - Hydroelectric

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  12. VT Renewable Energy Sites - Geothermal

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  13. VT Renewable Energy Sites - Landfills

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  14. VT Renewable Energy Sites - Wind

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  15. Renewable energies in United Kingdom

    International Nuclear Information System (INIS)

    Baize, T.

    1993-01-01

    An evaluation of research and development policy in United Kingdom on renewable energy sources is presented with economical studies (short or long term profitability), engaged programs and electric production. (A.B.). refs. tabs

  16. Which leadership for renewable energies?

    International Nuclear Information System (INIS)

    Chaumien, Marielle

    2016-02-01

    This publication first outlines that France is late in deploying renewable energies by 2020. It comments the application of the Energy multi-year plan (PPE), evokes the content of a report by the French Court of Auditors about costs and means of implementation of transition (with notably the issue of maintenance of nuclear plants). It also shows that European Union is not a leader in renewable energies any more, that some European countries are changing sides, that figures and trends must be carefully compared with those in the field of fossil and nuclear energies, that all energies are not all the same, that jobs and system integration are also important, that investments and attractiveness of countries in renewable energies must be assessed, and that a mobilisation on small scale and consumer-based renewable energies is required. Ten recommendations are made for France to support the EU leadership development

  17. VT Renewable Energy Sites - Solar

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  18. Renewable energy in the EU

    International Nuclear Information System (INIS)

    Lambert, Allan; Myers, Stephen; Trow, Stuart

    1998-05-01

    Contains Executive Summary and Chapters on: Overview of European Renewable Energy; Austria; Belgium; Denmark; Finland; France; Germany; Greece; Ireland; Italy; Luxembourg; The Netherlands; Portugal; Spain; Sweden; The United Kingdom. (Author)

  19. Nanostructured Materials for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-11-01

    This factsheet describes a research project whose overall objective is to advance the fundamental understanding of novel photoelectronic organic device structures integrated with inorganic nanostructures, while also expanding the general field of nanomaterials for renewable energy devices and systems.

  20. Renewables Global Futures Report: Great debates towards 100% renewable energy

    International Nuclear Information System (INIS)

    Teske, Sven; Fattal, Alex; Lins, Christine; Hullin, Martin; Williamson, Laura E.

    2017-01-01

    The first version of REN21's Renewables Global Futures Report (GFR) published in January 2013 identified a panorama of likely future debates related to the renewable energy transition. As a reflection of the wide range of contemporary thinking by the many experts interviewed for the report, it did not present just one vision of the future but rather a 'mosaic' of insights. Given the positive feedback in response to the first edition, a new edition has been prepared, continuing where the last one left off. The objective of this report is to gather opinions about the feasibility of a 100% renewable energy future, and the macro-economic impacts it would entail. In so doing, the report reflects on the debates of 2013, and tracks their evolution to the present time. Some remain, some have changed, some have been overtaken by progress, and new ones have arisen. They are summarised here as the Great Debates in renewable energy. The questionnaire for the survey was developed in close cooperation between the REN21 Secretariat, the Institute for Sustainable Future (ISF) of the University of Technology Sydney/Australia (UTS) and the Institute for Advanced Sustainability Studies (IASS) in Potsdam/Germany. It covered the following topics: 1. How much renewables?; 2. Power sector; 3. Heating and cooling; 4. Transport; 5. Storage; 6. Demand-side management and energy efficiency; 7. Integration of sectors; 8. Macro-economic considerations; 9. Technology and costs; 10. Policy; 11. Cities; 12. Distributed renewable energy/energy access; 13. Barriers/challenges/enablers. 114 experts were interviewed in total; the average interview time was approximately one hour. The interviews were conducted between May and October 2016. The questionnaire was also mirrored in an online version and used both by interviewers and interviewees to record the interview process. Interviewees were selected from the following regions: Africa, Australia and Oceania, China, Europe, India, Japan, Latin America