Research On Pretreatment Of Phenolic Wasterwater With The Integrated Hydrolysis Acidification -iron-carbon Microelectrolysis Reactor

Phenolic wastewater is a common industrial wastewater, which has strong toxicity, does great harm to the environment and becomes a serious problem in environmental protection. It is one of the hazardous wastewater, which needs be solved specially. Phenol is a sort of representative organic pollutants which are difficult to be degraded. The numerous amount of phenol is causing great harm to the environment and can be widely found in industrial waste water. The disposal methods of phenolic wastewater include physical chemistry technology, biology and advanced oxidation technology, etc.However,these methods all have some shortcomings, for instance, treatment is not thorough or the cost is too high.The hydrolysis acidification-iron-carbon micro-electrolysis integrated reaction is applied to treat phenolic wastewater in the light of the characteristics of its wastewater quality, which is hard to biodegrade because of the phenol, and hard to disposal due to it contains high concentration of COD. The filler of reactor was the mixture of ferric filings and carbon granules. The reactor is designed according to the theoretic calculation. In this reactor, it put the bio-treatment and the ferric-carbon micro-electrolysis process together, so as to make the organic carbohydrate contamination and phenol of the phenolic wastewater remove effectively. The test proved that the reactor has a good treatment effect.Firstly, the separated hydrolysis acidification reactor is tested by stable running test under the condition that the HRT is controlled at 5h, the COD and phenol at a certain concentration, the value of pH and temperature at normal level. The results show that the value of pH of the effluent is 5.0～5.2, which can provide a great condition for the follow-up iron-carbon micro-electrolysis processes.Secondly, take the effluent of the hydrolysis acidification reactor as the inflow of the separated iron-carbon micro-electrolysis, through experiment of single factor analysis, we can get the best craft conditions: retention time: 3h, iron carbon volume ratio: 1:1, ferric carbon mass ratio: 100:500.Thirdly, based on the conclusions of the single factor test, the scrap iron and the shell activated carbon is put on the upper of the integrated reactor, in order to compose the integrated reaction. And then it is examined by the stable operation test. The test results show that the reactor has an excellent running characteristics and also has better treatment efficiency on the phenolic wastewater. The reactor could remove about 54%～58% of COD and 45%～50% of phenol. What's more, the value of BOD5/COD can increase to 0.82. The effluent pH can reach to 6.6, which can provide a great condition for the follow-up biochemical processes.The paper put forward innovatively to using the hydrolysis acidification-iron-carbon micro-electrolysis integrated reactor to improve the biodegradability of phenolic wastewater. While the hydrolysis acidification process can provide the acidic environment for the iron-carbon micro-electrolysis, the latter reactor also can degrade phenol, which the former reactor can not degrade completely. Under the synergistic effect, both phenol and high concentrations of COD are removed to a certain extent. The materials used in the test are the waste of industrial production, such as scrap iron and shell activated carbon, which is easily accessed and very cheap. So the process is a typical example, which is called"treat the waste by waste". The research method and conclusion have reference value for the further research and practice.