Adapting the use of Fe3O4 nanoparticles in large-scale water treatment facilities

2014 ◽  
Vol 1708 ◽  
Author(s):  
K. Simeonidis ◽  
N. Andritsos ◽  
E. Kaprara ◽  
S. Mourdikoudis ◽  
M. Mitrakas
Keyword(s):  
Large Scale ◽  
Flow Reactor ◽  
Solid Phase ◽  
Complete Removal ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Continuous Flow Reactor ◽  
Alkaline Conditions ◽  
Treatment Facilities ◽  
Co Precipitation

ABSTRACTMagnetite nanoparticles were produced by the chemical co-precipitation of iron sulfates at alkaline conditions and were tested as a Cr(VI) adsorbent from water. Batch adsorption experiments showed a high removal efficiency, which is maximized at pH values below 6. This behavior was also verified in a continuous flow reactor, where nanoparticles were in contact with the polluted water. In particular, using a particle concentration of 1 g/L in water containing 100 μg Cr(VI)/L, a contact time of at least 2 h was required to achieve complete removal of Cr(VI). The recovery of nanoparticles after their use was accomplished using their magnetic nature. Application of an external magnetic field at the sides of the tube in which the suspension was flowing was sufficient to completely collect the nanoparticles in the outflow of the contact reactor, thus, providing water free of Cr(VI) and a solid phase.

Continuous-Flow Reactor-Based Enzymatic Synthesis of Phosphorylated Compounds on a Large Scale

2012 ◽  
Vol 18 (21) ◽  
pp. 6604-6609 ◽  
Author(s):  
Lara Babich ◽  
Aloysius F. Hartog ◽  
Michael A. van der Horst ◽  
Ron Wever
Keyword(s):  
Enzymatic Synthesis ◽  
Continuous Flow ◽  
Large Scale ◽  
Flow Reactor ◽  
Continuous Flow Reactor ◽  
Phosphorylated Compounds

scholarly journals An Optimized Cr(VI)-Removal System Using Sn-based Reducing Adsorbents

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2477 ◽  
Author(s):  
George Papadopoulos ◽  
Theopoula Asimakidou ◽  
Dimitrios Karfaridis ◽  
Ioannis Kellartzis ◽  
George Vourlias ◽  
...  
Keyword(s):  
Drinking Water ◽  
High Efficiency ◽  
Flow Reactor ◽  
Synthesis Method ◽  
Free Water ◽  
Complete Removal ◽  
Polluted Water ◽  
Tin Chloride ◽  
Point Of Use ◽  
Test Operation

Despite significant risks to human health due to elevated Cr(VI) concentrations in drinking water, a selective adsorbent capable of purifying water before consumption is still not commercially available. This work introduces an integrated household water filtration setup, for point-of-use applications, loaded with a tin-based Cr(VI)-oriented adsorbent that was tested under various contact times, pH values and Cr(VI) concentrations. The adsorbent comprises a chloride-substituted stannous oxy-hydroxide with a structure resembling that of the mineral abhurite. It demonstrated high reducing capacity that triggered the formation of insoluble Cr(III) hydroxides and the complete removal of Cr(VI) in considerably high volumes of polluted water. Test operation of the filtration system verified its ability to produce Cr(VI)-free water in compliance with the impending drinking water regulation, even for extreme initial concentrations (1000 μg/L). Apart from its high efficiency, the potential of the studied material is enhanced by its minimal-cost synthesis method carried out in a continuous-flow reactor by tin chloride precipitation under acidic conditions.

Large-Scale Production of CdSe Nanocrystal by a Continuous Flow Reactor

2003 ◽  
Vol 5 (1/2) ◽  
pp. 81-85 ◽  
Author(s):  
Manabu Kawa ◽  
Hidekazu Morii ◽  
Atau Ioku ◽  
Soichiro Saita ◽  
Kikuo Okuyama
Keyword(s):  
Continuous Flow ◽  
Large Scale ◽  
Flow Reactor ◽  
Scale Production ◽  
Continuous Flow Reactor ◽  
Large Scale Production

Large-scale synthesis of high quality InP quantum dots in a continuous flow-reactor under supercritical conditions

2015 ◽  
Vol 26 (8) ◽  
pp. 085604 ◽  
Author(s):  
Christian Ippen ◽  
Benjamin Schneider ◽  
Christopher Pries ◽  
Stefan Kröpke ◽  
Tonino Greco ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Continuous Flow ◽  
Large Scale ◽  
Flow Reactor ◽  
High Quality ◽  
Supercritical Conditions ◽  
Continuous Flow Reactor ◽  
Large Scale Synthesis ◽  
Inp Quantum Dots

Renewable Energy from Agricultural Waste

2018 ◽  
Vol 69 (6) ◽  
pp. 1363-1366 ◽  
Author(s):  
Stefania Daniela Bran ◽  
Petre Chipurici ◽  
Mariana Bran ◽  
Alexandru Vlaicu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gas Chromatography ◽  
Continuous Flow ◽  
Laboratory Experiments ◽  
Fermentation Process ◽  
Flow Reactor ◽  
Agricultural Waste ◽  
Continuous Flow Reactor ◽  
Natural Support ◽  
Co2 Flow

This paper has aimed at evaluating the concentration of bioethanol obtained using sunflower stem as natural support, molasses as carbon source and Saccharomyces cerevisiae yeast in a continuous flow reactor. The natural support was tested to investigate the immobilization/growth of S. cerevisiae yeast. The concentration of bioethanol produced by fermentation was analyzed by gas chromatography using two methods: aqueous solutions and extraction in organic phase. The CO2 flow obtained during the fermentation process was considered to estimate when the yeast was deactivated. The laboratory experiments have highlighted that the use of plant-based wastes to bioconversion in ethanol could be a non-pollutant and sustainable alternative.

Application of iron-coated sand on the treatment of toxic metals

2004 ◽  
Vol 4 (5-6) ◽  
pp. 335-341 ◽  
Author(s):  
Jae-Kyu Yang ◽  
Yoon-Young Chang ◽  
Sung-Il Lee ◽  
Hyung-Jin Choi ◽  
Seung-Mok Lee
Keyword(s):  
Heavy Metals ◽  
Selective Adsorption ◽  
Complete Removal ◽  
Batch Adsorption ◽  
Column Experiments ◽  
Adsorption Behaviour ◽  
Optimum Amount ◽  
Initial Ph ◽  
New Treatment ◽  
Coated Sand

Iron-coated sand (ICS) prepared by using FeCl3 and Joomoonjin sand widely used in Korea was used in this study. In batch adsorption kinetics, As(V) adsorption onto ICS was completed within 20 minutes, while adsorption of Pb(II), Cd(II), and Cu(II) onto ICS was slower than that of As(V) and strongly depended on initial pH. At pH 3.5, ICS showed a selective adsorption of Pb(II) compared to Cd( II) and Cu(II) . However, above pH 4.5, near complete removal of Pb(II), Cd(II), and Cu(II) was observed through adsorption or precipitation depending on pH. As(V) adsorption onto ICS occurred through an anionic-type and followed a Langmuir-type adsorption behaviour. In column experiments, pH was identified as an important parameter in the breakthrough of As(V). As(V) breakthrough at pH 4.5 was much slower than at pH 9 due to a strong chemical bonding between As(V) and ICS as similar with batch adsorption behaviour. With variation of ICS amounts, the optimum amount of ICS at pH 4.5 was identified as 5.0 grams in this research. At this condition, ICS could be used to treat 200 mg of As(V) with 1 kg of ICS until 50 ppb of As(V) appeared in the effluent. In this research, as a new treatment system, ICS can be potentially used to treat As(V) and cationic heavy metals.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

The Use of Solid Phase Microextraction (SPME) to Monitor for Major Organoleptic Compounds Produced by Chrysophytes in Surface Waters

1999 ◽  
Vol 40 (6) ◽  
pp. 251-256 ◽  
Author(s):  
Susan B. Watson ◽  
Brian Brownlee ◽  
Trevor Satchwill ◽  
E. McCauley
Keyword(s):  
Surface Waters ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Small Sample ◽  
Good Recovery ◽  
Culture Material ◽  
Treatment Facilities ◽  
Efficient Extraction ◽  
Cost Efficient ◽  
Related Compounds

An efficient extraction method is needed to measure trace levels of taste and odour compounds in surface waters. This is usually accomplished by costly and involved analytical procedures. We have developed a simpler alternative, using a commercially available microextraction apparatus (SPME). With this technique we successfully monitored trace levels of some target organoleptics (unsaturated aldehydes e.g. heptadienal, nonadienal, and related compounds) which commonly cause aquatic taste and odour. We identified these compounds in culture material, and analyzed for them during the development of odourous chrysophyte blooms in two ponds. Preliminary work has also found a good recovery of some important off-flavour terpenoids (e.g. geosmin and MIB). SPME is labour and cost efficient, and therefore appealing to water treatment facilities for detection and monitoring. In addition, SPME requires only small sample volumes, and is therefore suitable for culture work.

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