A Study On Removing Salt And Organic Compounds Such As Phenol From Supercritical Saline Wastewater

Super Critical Water Oxidation(SCWO)is a promising technique for the treatment of wastes,which uses supercritical water as the reaction medium supercritical water,and makes use of oxidizing agent(such as,air,oxygen,etc)to eliminate the organic matter in wastewater.In the condition of supercritical water,the oxidizing agent and organic matters are soluble in water.The oxidation reaction is extremely fast and the organic matter degrades completely.So it is an efficient way with wild range of application.In consideration of the special superiority of SCWO,the paper chooses the organic wastewater with phenol,aniline,n-caprylic alcohol and saline organic wastewater as the research object,uses oxygen as the oxidizing agent,and researches the oxydative disintegration behavior of these organic matters in the super critical water,which has received good effect.And the paper will provide a new way to treat saline organic wastewater,which has an important application prospect.Degrading the aline organic wastewater in the self-designed super critical water reactor,I observed the impact of wastewater COD degradation rate,the organics concentration rate,the wastewater hardness,the Carbonate precipitation Quality on wastewater degradating effect under different temperature and oxygen pressure,the processing conditions were optimized obtained.The main research work is as follows:1?Due to the limitations of the equipment,I optimize the reactor to reach the maximum reaction pressure.The maximum volume of distilled water is 70 ml at this time;2?Simulating phenol organic wastewater(COD is 11590.7mg/L),aniline organic wastewater(COD is 51352.0mg/L),octanol organic wastewater(COD is 6542.4mg/L)respectively,I get the optimum conditions,which are as follows: the oxygen pressure is 4,2,4MPa;the temperature is 420 ?;the residence time is 60s;The presses are 29.8,24.5 and 29.8 MPa respectively;The results show that the CODs are 0.88,6.19 and 0.13 g / l;the degradation rates are 92.86%,87.94%,97.96%;the decomposition rates were 96.52%,99.95%,99.25%.3?Mixing the two organic matters of organic wastewater together(total COD is 39555.0mg/L)and simulating phenol and aniline organic wastewater(total COD is 15456.0mg/L),phenol and octanol organic wastewater(total COD is 33712 mg/L),aniline and octanol organic wastewater,I get the optimum conditions,which are as follows: the oxygen pressure is 3,3,4MPa;the temperature is 420 ?;the residence time is 60s;The presses are 27.7,27.8,29.7MPa respectively;The results show that the CODs are 1.33?2.78?0.74g/L;the degradation rates are 96.63%?91.74%?95.18%;the decomposition rates were 97.21%,98.41%,97.06%,96.95%,98.07%,98.71%.4?Mixing the three organic matters of organic wastewater together and simulating phenol,aniline,octanol organic wastewater(total COD is 45908.2mg/L mg/L),I get the optimum conditions,which are as follows: the oxygen pressure is 4MPa;the temperature is 420 ?;the residence time is 60s;The press is 29.8 MPa;The results show that the CODs is 3.52g/L;the degradation rate is 92.32%;the decomposition rates were 98.18%,97.9%,98.31%.5?Adding equimolar CaCl2 and NaOH under the optimum conditions of the degradation of organic wastewater from phenol organic wastewater(COD is 11590.7mg/L),aniline organic wastewater(COD is 51352.0mg/L),octanol organic wastewater(COD is 6542.4mg/L)and three organic compounds(total COD is 45908.2mg/L).Adding equimolar MgCl2 and NaOH under the optimum conditions of the degradation of organic wastewater from three organic compounds(total COD is 45908.2mg/L).Adding CaCl2,MgCl2,NaCl and NaOH under the optimum conditions of the degradation of organic wastewater from three organic compounds(total COD is 45908.2mg/L).Under the optimized conditions for Calcium salt,Magnesium salt,Sodium salt and organic matter in waste removal experiments at the same time.I get the following results.The CODs are 0.66g/L,5.10g/L,0.12g/L,3.06g/L,2.94g/L,2.86g/L;the degradation rates are 94.3%,90.1%,98.2%,93.2%,93.6%,93.8%;the decomposition rates are 96.6%,99.9%,99.3%,(98.2%,97.9% and 98.4%),(98.5%,98.1% and 98.6%),(98.6%,98.3% and 98.9%);hardness are 22.45mmol/l,46.46mmol/l,20.30mmol/l,87.45mmol/l,86.8mmol/l,76.4mmol/l;pH =7.Recovery of carbonate precipitation 1.73 g,3.45 g,0.39 g,5.22 g,5.7g,5.7g respectively.6?In order to study the oxidation process of phenol,aniline and n-octanol in supercritical water,I analyze the intermediates with GC-MS,and research the intermediates and the reaction process.And through the whole process,we get that there are three types of reactions occurring between phenol and aniline.1?directly oxidized to CO2;2?aromatic ring ring opening,fault reaction,generate small molecule organic matter;3?Organic small molecule intermediates mutual reaction,generate more complex products.Octanol mainly generates small molecules aldehydes,alcohols,acids through chain scission oxidation reaction.