Sludge pre-treatment with pulsed electric fields

2004 ◽  
Vol 49 (10) ◽  
pp. 123-129 ◽  
Author(s):  
O. Kopplow ◽  
M. Barjenbruch ◽  
V. Heinz
Keyword(s):  
Electric Fields ◽  
Anaerobic Degradation ◽  
Energy Input ◽  
Degradation Rate ◽  
Pulsed Electric Fields ◽  
Cell Content ◽  
Specific Energy Input ◽  
Sludge Treatment ◽  
Pre Treatment ◽  
Micro Organisms

The anaerobic stabilization process depends - among other things - on the bio-availability of organic carbon. Through pre-treatment of the sludge which leads to the destruction of micro-organisms and to the setting-free of cell content substances (disintegration), the carbon can be microbially converted better and faster. Moreover, effects on the digestion are likely. However, only little experience is available in sludge treatment with pulsed electric fields. Laboratory-scale digestion tests have been run to analyse the influence of pulsed electric fields on the properties of sludge, anaerobic degradation, sludge water reload and foaming of digesters. The results will be compared with those of other disintegration methods (high pressure homogeniser, thermal treatment). The effect of pre-treatment on the sludge is shown by the COD release. Degrees of disintegration have been achieved up to 20%. The specific energy input was high. The energy consumption has been decreased by initial improvements (pre-heating to 55¡C). The filament bacteria were partially destroyed. The foam reduction in the digesters was marginal. The anaerobic degradation performance has been improved in every case. The degradation rate of organic matter increased about 9%. Due to the increase of degradation, there is a higher reload of the sludge-water with COD and nitrogen compounds.

Pulsed electric fields pre-treatment of carrot purees to enhance their polyacetylene and sugar contents

2014 ◽  
Vol 23 ◽  
pp. 79-86 ◽  
Author(s):  
I. Aguiló-Aguayo ◽  
M.B. Hossain ◽  
N. Brunton ◽  
J. Lyng ◽  
J. Valverde ◽  
...  
Keyword(s):  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Pre Treatment

scholarly journals Use of pulsed electric fields to induce breakage of glandular trichome cells in leaves of fresh patchouli (Pogostemon cablin Benth.): Specific energy input consumption

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sukardi Sukardi ◽  
Sudjito Soeparman ◽  
Bambang Dwi Argo ◽  
Yudy Surya Irawan
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Specific Energy ◽  
Energy Input ◽  
Glandular Trichome ◽  
Specific Energy Input ◽  
Variable Electric Field ◽  
Pogostemon Cablin ◽  
Cell Changes ◽  
Electric Field Treatment

Research has been performed using a pulsed electric field (PEF) to damage plant cells to obtain bioactive compounds before extraction. However, research into the use of PEF to break down the glandular trichome (GT) cells of patchouli for essential oil extraction is still limited. The purpose of this study was to determine the specific energy input needed to break patchouli leaf GT cells by PEF treatment. Patchouli leaves were harvested at 7 months of age, then treated with PEF. GT cell changes were analyzed using scanning electron microscopy. The results show that treatment with variable frequencies caused GT cell wrinkling and treatments with a variable electric field caused GT cell rupture. Electric field treatment at E=133.33 V/cm and a PEF exposure time of 2 seconds or E=116.66 V/cm and 3 seconds of PEF exposure resulted in consistent rupture of GT cells. Energy consumption of 0.049 kJ/cm3 promoted GT cell wall shrinkage and consumption of 0.59 kJ/cm3 broke GT cell walls.

Landfill leachate treatment by a photoassisted fenton reaction

1997 ◽  
Vol 35 (4) ◽  
pp. 239-248 ◽  
Author(s):  
Soo-M. Kim ◽  
Sven-U. Geissen ◽  
Alfons Vogelpohl
Keyword(s):  
Landfill Leachate ◽  
Radiation Intensity ◽  
Fenton Reaction ◽  
Energy Input ◽  
Degradation Rate ◽  
Ph Value ◽  
Uv Light ◽  
Molar Ratio ◽  
Leachate Treatment ◽  
Specific Energy Input

A combination of the classical Fenton reaction (Fe(II)+H2O2) with UV light, the photoassisted Fenton reaction, has been investigated for the treatment of landfill leachate. The investigation has been carried out with an experimental set-up to establish the optimal treatment conditions. The degradation rate of organic pollutants is strongly promoted by the photoassisted Fenton reaction. The degradation rate depends on the amount of H2O2 and Fe(II) added, pH value, and radiation intensity. At a specific energy input of 80 kW m−3 the oxidation rate was increased to six times the rate without radiation (0 kW m−3). At the higher radiation intensity of 160 kW m−3 the degradation rate was about two times faster than at that of 80 kW m−3. Due to the regeneration of the consumed Fe(II) ions through the irradiation, the amount of ferrous salt to be added can be remarkably reduced. The optimum conditions were obtained with 1.0 × 10−3 mol 1−1 Fe(II) added, a pH value of 3, and a molar ratio of COD: H2O2 = 1:1. At a COD volume loading of less than 0.6 kg m−3 h−1, a COD degradation of more than 70% could be obtained with an energy input of 80 kW m−3.

scholarly journals Pulsed Electric Fields (PEF) as pre-treatment for freeze-drying of plant tissues

2018 ◽  
Author(s):  
Virginie Boy ◽  
Lubana Al-Sayed ◽  
Emmanuel Madieta ◽  
Emira Mehinagic ◽  
Jean-Louis Lanoisellé
Keyword(s):  
Electric Fields ◽  
Freeze Drying ◽  
Pulsed Electric Fields ◽  
Textural Properties ◽  
Plant Tissues ◽  
Drying Time ◽  
Pre Treatment

The influence of pulsed electric fields (PEF) treatment on freeze-drying for potato and strawberry tissues was investigated. Samples were pre-treated by PEF (  400 V cm-1) for different treatment times. Freeze-drying was carried out at -17°C and 18.4 Pa or 30 Pa for potato and strawberry tissues, respectively. The effects of PEF pre-treatment was compared with intact samples. The drying time was reduced by 35% for potato and 30% for strawberry. The sample rehydration capacity and the electrolytes released during the rehydration were higher for pre-treated samples. Strawberries texture was characterized by the hardness, the cohesiveness and the springiness.Keywords: Pulsed Electric fields; Freeze-drying; Potato; Strawberry; Textural Properties.   

scholarly journals Extraction of Antioxidant Compounds and Pigments from Spirulina (Arthrospira platensis) Assisted by Pulsed Electric Fields and the Binary Mixture of Organic Solvents and Water

2021 ◽  
Vol 11 (16) ◽  
pp. 7629
Author(s):  
Francisco J. Martí-Quijal ◽  
Francesc Ramon-Mascarell ◽  
Noelia Pallarés ◽  
Emilia Ferrer ◽  
Houda Berrada ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Binary Mixture ◽  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Extraction Yield ◽  
Total Phenolic ◽  
Antioxidant Compounds ◽  
Total Phenolic Compounds ◽  
Extraction Technology ◽  
Pre Treatment

The application of pulsed electric fields (PEF) is an innovative extraction technology promoting cell membrane electroporation, thus allowing for an efficient recovery, from an energy point of view, of antioxidant compounds (chlorophylls, carotenoids, total phenolic compounds, etc.) from microalgae. Due to its selectivity and high extraction yield, the effects of PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction at different times (5–180 min) and with different solvents (ethanol (EtOH)/H2O, 50:50, v/v; dimethyl sulfoxide (DMSO)/H2O, 50:50, v/v) were evaluated in order to obtain the optimal conditions for the extraction of different antioxidant compounds and pigments. In addition, the results obtained were compared with those of a conventional treatment (without PEF pre-treatment but with constant shaking). After carrying out the different experiments, the best extraction conditions to recover the different compounds were obtained after applying PEF pre-treatment combined with the binary mixture EtOH/H2O, 50:50, v/v, for 60–120 min. PEF extraction was more efficient throughout the study, especially at short extraction times (5–15 min). In this sense, recovery of 55–60%, 85–90%, and 60–70% was obtained for chlorophylls, carotenoids, and total phenolic compounds, respectively, compared to the maximum total extracted amount. These results show that PEF improves the extraction yield of antioxidant bioactive compounds from microalgae and is a promising technology due to its profitability and environmental sustainability.

scholarly journals Effect of pulsed electric fields pre-treatment on mass transport during the osmotic dehydration of organic kiwifruit

2016 ◽  
Vol 38 ◽  
pp. 243-251 ◽  
Author(s):  
M.V. Traffano-Schiffo ◽  
U. Tylewicz ◽  
M. Castro-Giraldez ◽  
P.J. Fito ◽  
L. Ragni ◽  
...  
Keyword(s):  
Mass Transport ◽  
Electric Fields ◽  
Osmotic Dehydration ◽  
Pulsed Electric Fields ◽  
Pre Treatment
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