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Study On Phenol Removal Of Wastewater By Non-equation Plasma

Posted on:2007-12-04Degree:MasterType:Thesis
Country:ChinaCandidate:H J LiFull Text:PDF
GTID:2121360182492523Subject:Environmental Engineering
Abstract/Summary:PDF Full Text Request
As we know, plasma is "the fourth state" substance, except the other essential theree states of sbustance including solid state, liquid state and gas state. Compared with other three states, plasma has different characters, and has chemisty reactivity. Litmusless substance would be decomposed to electrons, ions and free-particles if been buought to bear high temperature or energy by acceleratting electrons or ions. We call it palsma when substance in a state that is composed by particles with different polarity, and we can get it by keep applying energy on the substance.Using plasma to control pollution, is a new direction of pollution contrlling technology. It is a kind of technique between phisical technique and chemical technique. Plasma pollution control process can not only remove those chemical-waste and biological-waste from gas state but also can remove those chemical waste and radwaste from liquid state or solid state. It can decompose both high concentration and low concentration oganic waste even in a large flux. So, it is a kind of technology which can predigest the pollution control processes that we using now.In this research, we get non-equation plasma by impulse discharge at ordinary air pressure. We take phenol as the represent substance of oganic waste to simulate industrial hard decomposed oganic wastewater. Then, afer a series of experiments, we scrabble and sum-up the commonly rules of the technology that using plasma decomposeing phenol wastewater has.In our research, we get plasma by two methods, which are glow discharge and impulse discharge, and reviewed the effects separately. After compaired the effects, we found that the effects of impulse discharge plasma is better than that of glow discharge plasma produced. When impulse discharge plasma disposal pHenol, the reduction of phenol and solution's COD is a synchronous process, but when glow-discharge plasma disposal phenol, as the concentration of phnol dropped, its solution's COD raise up. This fact show that the using efficiency is higher when using impulse discharge to produce plasma than glow-discharge.There are 6 factors that can influnce the effect that plasma pollution control process disposal phenol. They are: the amount of discharge, polarity of electrodes, electric field'sintension, pH of solution, phenol's concentration and the concentration of Fe2+.(1) the amount of discharge. Increase the amount of discharge can improve the effect of experiment. After 4 times of discharge, the disposal efficiency of phenol is 30%.(2) It can get better effect when the electrode is negative.(3) The disposal efficiency rising up along with the increase of electric field's intension.(4) It is better in acidity condition than in alkalescence condition when the plasma decomposes phenol solution. pH=2 is the best when the plasma can decomposes more than 90% phenol, and more than 37% COD of the solution could be removed.(5) The disposal efficiency rising up along with the the increase of the initial concentration of phenol.(6) Fe2+ can catalyze the chemolysis of phenol and other oganic substances exsit in the solution. But the disposal efficiency will drop down when the concentration of Fe2+ in solution is more than 150mg/L.(7) The research found out how significant all of these 6 factors could be to the experiment by using uniform design. The regress model shows that electric field's intension is the most important factor.(8) Afer been disposaled by non-equation plasma, the phenol wastewater can be decomposed more easier by microorganism. The ratio of BOD/COD raised from 0.26 to 0.36.
Keywords/Search Tags:non-equation plasma, phenol wastewater, glow discharge, high-voltage pulse discharge
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