Experiment Research On Pretreating The Debiodegradation Industry Wastewater By The Microelectrolysis-Fenton Process

The characters of industry wastewater were summarized in the paper, such as largeflow quantity, high concentration organic, color, toxic, debiodegradation, and so on.Discharged straightly without being treated, these wastewaters would pollute environment.The treated wastewater met the requirements of the discharge standard by the usual presenttreatment process, but many entrepreneurs can't afford the high investment and runningcost. Then, these entrepreneurs often discharge wastewater slinkingly, and it will give riseto pollute environment seriously, and harm people's health finally.The pretreatment process of micro-electrolysis and Fenton had many advantages,suchas less investment , low running cost , small occupation of land, simple process operation,and high efficiency etc. it can especially be applied to pretreat the debiodegradation,highconcentration organic,toxic industry wastewater such as printing-dye wastewater,paper–making wastewater,medical wastewater,electroplating wastewater, coking wastewater,Hacid wastewater ect. Exprimental results showed clearly that it can reduce the pollutantconcentration and enhance the biodegradation of the wastewater, and it made contributionsto treatment and it had the advantage of using the waste circularly.The mechanism of the process: In the reactor, the packing consisted of the mixture ofthe granular scrap iron and active carbon. The micro-electrolysis technology is anelectrochemical technology, which treats the industry wastewater by forming lots ofmicro-batteries in the wastewater. The technology used the difference of the electricpotential between the metal and carbon to form lots of micro-batteries in the waste-waterand make the waste-water purified through the reactions such as oxygen-reduction reaction,coagulation, sediment and so on, and there was no extra electricity needed.The purpose of research: study the mechanism, pretreatment effect and the influencingfactors of the microelectrolysis-Fenton process in the debiodegradatal and toxic industrywastewater treatment. The result of experiments showed the optimal parameter that wouldbe provided to the engineer the design and running operation.The content of research: experiments of pretreating printing-dye wastewater, caffeinewastewater, landfill leachate and chemicalsynthetic dyes wastewater by the process werestudied .On the basis of the optimal parameter which came from static experiments, thedynamic experiments can run. Then, the effects and influencing factors of the dynamicexperiments are studied .The effects of the biodegradation treatment of the pretreatedchemicasynthetic dyes wastewater can be tested by the ABR-IRTPFB process.The conclusions of research: (1) It was practicable to pretreat printing-dye wastewater,caffeine wastewater, landfill leachate, chemicalsynthetic dyes wastewater by themicro-electrolysis and Fenton process. The good effect was tested, the removal rate ofCOD is above 50%, and the biodegradation was rising by 100% -500%, so that the effluentcan be treated by microbiological wastewater treatment process.(2)The results of experiments showed that influent wastewater pH, ratio of scrap ironto carbon,padding granularity, the reaction time of micro-electrolysis , the sedimentationpH, the quantity of PAM ,the reaction time of Fenton, the quantity of H2O2 were the mainlyinfluencing factors of the pretreatment process.(3)The results of synthetical analysis showed that there were more aromaticcompounds, less organic compounds of straight chain in the raw chemicalsynthetic dyeswastewater. There were opposite organic components after pretreatment, the aromaticcompounds were disassembled into organic compounds of long straight chain, H2O andCO2 in the pretreatment process. While there were only organic compounds of shortstraight chain in the effluent of ABR process and the biodegradation was raised too. Theresults of running showed that the biodegradation of the effluent of ABR was enhanced by0.35-0.40. During the stable period of running in IRTPFB, the concentration of COD in thedischarge water was under 95mg/L and met the discharge standard.(4)Each padding had different usable period. During the continuous stable running ofthe treatment process, the usable period of the padding was tested by the removal of CODand the variation of pH in the discharge water. Padding consisted of scrap iron and carbon,or scrap iron and coking ash or scrap iron and fly ash in coal-fired. The usable period ofpadding as 2-4 days was tested in the micro-electrolysis reaction process.There were manyadvantages in the micro-electrolysis pretreatment process which by replacing the carbonwith fly ash in coal-fired or coking ash, such as good effect ,low running cost and reducingthe waste. But the whole padding of fly ash in coal-fired or coking ash must be replacedcompletely after 3-5 circulations, otherwise, the accumulation of impurity in the paddingaffected the effect of the micro-electrolysis pretreatment. However, in padding whichconsisted of carbon and scrap iron in micro-electrolysis process, scrap iron was onlysupplemented in the end of every period, and the padding wasn't replaced completely. Sothe fist investment of padding was high, but there were low running cost and simpleoperation in the latter pretreatment.(5) The structure of reactor was one of the main reasons that the pretreatmentprocess wasn't applied widely. The unreasonable structure of reactor would lead thatpadding was agglomerated and it was difficult to replace the padding in the end of everyperiod. At present, a lot of reactor used in the micro-electrolysis was the structure of upflow pillar. The running experiment showed that the reactor structure of up flow pillar ledto the padding agglomerated and the difficulty of replacing the padding. So the researchexploitation direction heads towards not only padding, but also the reactor structure in the...