176 research outputs found
Az alapelektrolit oldat ionjainak szerepe az elektrolitkatódos, atmoszférikus nyomású ködfénykisülésben = The role of ions of basic electrolyte in the ELectrolyte Cathode Atmospheric pressure glow Discharge (ELCAD)
Az intenzitásarányokbĂłl kapott elektron (Cu vonalak) Ă©s gázhĹ‘mĂ©rsĂ©kletek (OH sávfejek) igen jĂłl közelĂtik egymást, maximumuk az elektrĂłdáknál van. Ez megfelel egy atmoszfĂ©rikus kisĂĽlĂ©snek. Ennek megfelelĹ‘en, az atomi fĂ©mvonalak intenzitásmaximuma a negatĂv fĂ©nyben van, ahol a hátttĂ©r intenzitás alacsony. A kapilláris ELCAD katĂłdesĂ©se, áramsűrűsĂ©ge, hĹ‘mĂ©rsĂ©kletei nĹ‘ttek, a sötĂ©ttĂ©r hossza csökkent az áram növelĂ©sekor. A kapilláris ELCAD- ban a töltĂ©ssűrűsĂ©gek jĂłval nagyobbak, az elektronsokszorozĂłdás jĂłval kisebb, mint a normális esetben. Ez arra utal, hogy a jĂłval nagyobb töltĂ©ssűrűsĂ©get a megnövekedett szekunder elektron emissziĂł Ă©s nem a rövidebb sötĂ©ttĂ©rbeli ionizáciĂł hozza lĂ©tre. Az emittált atomi fĂ©mvonalak intenzitása az M-OH kötĂ©stĹ‘l fĂĽgg: ha ez gyenge (ionos) az intenzitás nagy, ha kötĂ©s kovalens, az intenzitás nagy. Egy Ăşj áramlĂł oldatos mintabeinjektálási kĂsĂ©rletet vĂ©geztĂĽnk el, hogy kikerĂĽljĂĽk az alap Ă©s a mintaoldat eltĂ©rĹ‘ pH Ă©rtĂ©kĂ©bĹ‘l eredĹ‘ nehĂ©zsĂ©geket (kisĂĽlĂ©s megszűnĂ©se). EzĂ©rt egy koncentrikusan egymásba illeszkedĹ‘, kettĹ‘s kapilláris rendszert használtunk. A belsĹ‘ben az alapelektrolit, a kĂĽlsĹ‘ben a mintaoldat áramlott. A detektálási határok: Cd:10 ng ; Zn: 30 ng; Cu Ă©s Pb: 50 ng. Az 1993-2006 között az ELCAD tĂ©májában megjelent összes közlemĂ©nyt felhasználva, felkĂ©rĂ©sre megĂrtuk az eddigi ELCAD kutatások áttekintĹ‘, kritikai elemzĂ©sĂ©t. Appl. Spectr.Rev. 42, 573-604 (2007) | The electron and gas temperatures obtained from the intensity ratios (Cu lines, OH bands) approximated each others well, their maximums are at the electrodes corresponding to an atmospheric glow discharge. Hence the intensity maximum of atomic metal lines occurred in the negative glow, where the background intensities are low. In the abnormal ELCAD, the cathode fall, the current density, the temperatures increased, the length of cathode dark space decreased with increasing current. The charge densities are significantly higher, the multiplication of electrons is much lower, than that received for a normal one. The main reason of this is the enhanced rate of the secondary electron emission and not an increased ionization in a shorter cathode dark space. The intensity of atomic metal lines depends on the bond character of the M-OH leaving the cathode. If this bond is weak (ionic), the intensity is low. If this bond is strong (covalent) the intensity is high. Flow injection experiments were carried out with a concentric double capillary system. The basic solution was flowed in the inner, the sample was flowed in the outer one. The plasma operation became independent from the ionic conductivity of the sample solution. The reached detection limits are: Cd:10 ng;Zn:30 ng; Cu and Pb:50 ng. For an invitation, we wrote a critical review of the ELCAD reserches taking into account all papers published in this field in 1993-2006. Appl.Spectr.Rev. 42, 573-604 (2007)
Electrocoagulation: an electrochemical process for water clarification
Electrocoagulation is a group of various procedures used for removing contaminants from water by electrochemically dissolving aluminum or iron. The contaminants of the solution may be incorporated in the in situ forming metal hydroxide flocs, which can be filtered as a precipitate or skimmed as a float. The main features of the procedure are highlighted on the example of cleaning of an oily waste-water. Design parameters of a 1 m3/h waste-water cleaning system are calculated from the results of small-scale experiments
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