| The harmonizing development among resources, environment, energy and population is the most significant social problem all around the world. Environmental protection and ecological equilibrium are always considered priority to industrial production from the strategy based on the sustainable development. Circular economy is a new practice model which is recommended to promote sustainable development in present international society, which emphasizes utilizing resource and protecting environment most effectively and represents an economic growth mode of "ResourceProduct-Renewable resources", and realizes "Lowest pollution, Harmlessly disposal Reuse as resource", and obtains the highest economic profit and environmental benefit in exchange of the lowest cost.During the producing process of gallic acid by acid catalysis, the waste liquid which was generated accompanying with gallic acid production has high colourity (dark brown), high acidity (pH value around 1.0), high CODcr concentration (around 54000mg/L),BOD5 concentration(around 2000mg/L), and low biochemical degradability, so it is very difficult to treat and reach the discharging standard if only using single or simple way, meanwhile a lot of waste residue whose main component is waste activated carbon was generated during the refining process of gallic acid, and a little gallic acid is contained in the wasted residue, so if the waste liquid discharges without being treated effectively before and the waste residue piles up at random, the water and nearby environment will be polluted seriously. This thesis mainly focuses on the treatment of wasted liquid and reuse of waste carbon residue generated during the production of gallic acid. The combining way of Fenton's reagent catalysis and oxidation, neutralization and biological treatment was used to treat waste liquid from gallic acid production, and hot water was used to wash the wasted residue and reclaim the gallic acid in it, then the waste residue was treated by thermal regeneration and activation with KOH respectively.(1) The better technology conditions which Fenton reagent was used to catalyze and oxidize the waste liquid from gallic acid production were as follows: n(H2O2)/n(Fe2+)=10:1, the amount of 30% H2O2 is 80ml per 1L waste liquid, the reaction time is 30min, the initial pH value is around 2.0, and the reaction temperature is room temperature.(2) The waste liquid was neutralized and precipitated by CaO after being catalyzed and oxidized by Fenton's reagent. The CODcr of the waste liquid decreased from 54000mg/L to 34000mg/L when it was catalyzed and oxidized by Fenton's reagent, then the CODcr decreased to 16900mg/L when it was neutralized and precipitated by CaO, the total removal rate was 68.7%. If the waste water was neutralized and precipitated directly by CaO without Fenton's reagent catalysis and oxidation before, the CODcr only decreased from 54000mg/L to 37700 mg/L, and the removal rate is 30.2%.(3) The waste liquid was treated by biological method after being neutralized and precipitated by CaO and being catalyzed and oxidized by Fenton's reagent, the result indicated that the CODcr removal rate decreased with the increasing of CODcr concentration, higher the CODcr concentration was, longer the living time of microorganism was, longer the needed time up to high CODcr removal rate was.The waste liquid is treated by the Fenton reagent whose CODcr removal rate is higher than isn't done(4) The excellent technology conditions to wash waste residue and reclaim gallic acid in it by hot water was as below:the ratio of solid weight(g) to liquid volume(ml) was about 0.151, the washing time was about 60min, and the temperature was about 60℃,and the reclaim rate of gallic acid was 51.84mg/g.(5) The excellent technology conditions of thermal regeneration to reuse waste carbon residue was as below:carbonization temperature was 500℃, carbonization time was 120 min, the absorption rate of methylene blue by thermal regenerated carbon was 168.0mg/g, and the average harvesting rate of thermally regenerated carbon was 56.9%.(6) The best conditions by orthogonal test to regenerate waste carbon residue by KOH was as below:concentration of KOH solution was 90g/L, and carbonization time was 1h, and carbonization temperature was 700℃, and the dipping time was 24h.(7) When the activated carbon by KOH generated under the best conditions by orthogonal test was used to adsorb 100ml, 100mg/L phenol solution, its saturated adsorption time is 60min, and its adsorption capability was better than the original activated carbon, and much better than the thermally regenerated carbon.(8) The determination of specific surface area, pore volume and pore diameter of thermally regenerated carbon, activated carbon by KOH and original activated carbon showed as follows:The specific surface area of original activated carbon reaches 1231.5835m2/g, that of activated carbon by KOH is 1005.4394m2/g, and that of thermally regenerated carbon is 343.3104m2/g. The pore volume of original activated carbon is 1.0298cm3/g, and that of activated carbon by KOH is 0.7523cm3/g, and that of thermally regenerated carbon is 0.2354cm3/g. The mean pore diameter of original activated carbon is 32.5753A, mainly micro and moderate pores. The mean pore diameter of activated carbon by KOH is 23.5362 A, mainly micro pore, part moderate pore. The mean pore diameter of thermally regenerated carbon is 10.2348 A, mainly micro pore. The results showed that the adsorption capability of thermally regenerated carbon is much worse than original activated carbon and activated carbon by KOH. The specific surface area, pore volume and pore diameter of activated carbon by KOH are all smaller a little than that of original activated carbon.
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