Application And Preperation Of Iron-carbon Ceramic Micro-electrolysis Packing

Micro-electrolysis technology has the advantages of widely application, good performance and low cost. However, it also has the drawbacks of campaction, passivation and exchanging difficultly. The campaction was the main factor restricting its usage in large scale. The objective of this study was to develop iron-carbon ceramic micro-electrolysis packing. Firstly, the preparation method of the micro-electrolysis packings was optimized. Secondly, the physical and chemical feature was characterized and the treatment effects of several micro-electrolysis packings were compared. Finally, the continuous reactor was operated to investigate the performance of the micro-electrolysis packing.In the experiment, as the basic materials, the scrap iron, powder activated carbon and bentonite were roasted to iron-carbon ceramic with a diameter of 3-5mm in different proportions, temperatures and additions. The beaker experiment and single factor analysis method were used to optimize the preparation methods of the ceramic for the purpose of improving the removal of organic matter, decreacing the biotoxicity and increasing the biodegradability of the wastewater. The results showed that the optimum performance was obtained from the iron-carbon ceramic prepared at the roasting temperature, addition, volume ratio of scrap iron, powder activated carbon and bentonite.The new packing was round, rough and porous in the surface with the diameter of 3-5mm. True density, apparent density and the bulk density were 4.41, 3.52 and 1.26 (103kg/m~3) . In the surface, the main components were iron, carbon, oxygen and silicon, which had the mass fractrion of 56.92%, 12.53%, 18.67% and 7.52%, respectively. The ceramic had enough strength. The BET specific surface area was 16.45m~2/g. The mesoporous was the main hole.To investigate the treatment capability of the iron-carbon ceramic packing to chemical industry wastewater (including two mixing water and one practical wastewater), another two micro-electrolysis packings bought in market and a traditional iron-carbon bulk packing were compared with the ceramic packing. The iron-carbon ceramic packing was much better than the two micro-electrolysis packings bought in market to all the wastewater and mixing water. As the reusage of the different packings, the iron-carbon ceramic packing turned out good treatment performance.Two continuous reactors were employed to compare the treatment performance and campaction of the traditional iron-carbon bulk packing and the new iron-carbon ceramic packing. The result showed that in the initial stage of the reator operation, the traditional carbon-iron packing had a better performance than the new packing, which was mainly because of the absorption effect of activated carbon. After a week, the two packing had the equivalent effect, the COD removal rate was above 40% and the B/C was increased to about 0.3. After 50 days'operation, the iron-carbon ceramic packing was better than carbon-iron packing obviously. The optimum operation condition was pH = 3, HRT = 2h. It also turned out that the reactor packed with iron-carbon ceramic had good campaction resistibility. From the beginning to the end of the reactor operation, the filtration resistance was basically stable. However, the flitration resistance of the traditional iron-carbon packing reactor sharply increased during one month continuous operation and meanwhile the performance decreaced gradually.