The Study Of Ultrasonic Extraction Combine With Fenton Oxidation To Dispose The Phenol-Contaminated Soil

Phenol is the simplest phenolic organic, and belongs to aromatic compounds. As it has great toxicity and can cause cancer, it was listed in the prior control pollutants blacklist of water by the government. Phenol widely exists in oil and gas production and coking industry waste water, and goes into groundwater, surface water and soil through various ways. At the same time, as the rapid development of China's industry, there are more and more phenol demanded as industrial chemicals. During the producing and consuming process, the phenol pollution would be much more serious, and the phenol pollution soil range would be more extensive. How to dispose the polluted soil will be an important and meaningful task.The technology of phenol-contaminated soil treatment contains physical technology, chemical technology, biological technology and various technical's combination, but none of us can completely meet the principle that neither destroying the soil fertility and the function of ecological environment nor cause secondary pollution. In this case, I raise the ultrasonic extraction combined with Fenton oxidation treatment technology, which extracted phenol from contaminate soil by ultrasonic, and then, move the disposed soil into landfill after drying. And deal with the leach liquor by Fenton oxidation in order to remove the phenol, the processed wastewater must meet emission standard before they discharged.In order to describe the effect of treatment accurately, it is necessary to find a testing method which is stable and accurate to quantitative analysis of phenol. The methods which used to test phenol are enforced by HPLC and GC, but both of them have shortcomings. This research describes a high performance capillary electrophoresis-diode array detector used for the analysis of phenol in soil. After the research, I get the best condition to test the phenol in soil which column temperature is 25℃,30mmol/LK2HPO4+0.5 mmol/L TTAB (pH= 10) running buffer solution, 206nm detected wavelength,20kV operating voltage, load voltage mode,0.5 psi pressure and injection at 10s. Phenol peak appears during 4.200 to 4.400min, the relative standard deviations of migration times and peak areas were 0.11% and 0.28%. the detection limits (3Sb/Sx) were 0.01mg/L, which means 0.25mg/kg in soil.This method can be used for test the phenol in soil. The RSD is 1.72% and the recovery rate is 98.4% during the test.In the research of extracting the phenol from soil under enhance of ultrasonic, the main object of study is inspect the influence factor and each factors level, find out best level through the experiment. In order to get the optimal conditions scientifically, I choose uniform design,which is different from traditional single factor experiment that it considers the interaction between each factor. By referring to a great deal of reports. I choose the proportion of liquid and solid, ultrasonic temperature, ultrasonic time, ultrasonic power as four factors in the experiment. I did pre-experiments using single factor variable method and experiments under uniform design to find out the best factor level. After the regression analysis, I get the best factors level, each of them are the proportion of liquid and solid is 9:1, ultrasonic temperature is 30℃, ultrasonic time is 4min, ultrasonic power is 500W, under this condition, the phenol's extraction ratio is 91.25%, accord with the result of forecast. After disposing by the ultrasonic, the residual rate of phenol and volatile phenol is 7.74% and 8.83%.The research of desorption dynamics model of phenol in soil under the optimal condition of ultrasonic extraction, after fitting the data with Freundlich dynamics model, level 1 dynamic model and Elovich model, I find that level 1 dynamic model is the fittest model. The level 1 dynamic model is suitable for the dynamic process of diffusion, and the main mechanism is single, energy's change is tiny, so I can make sure that the process of phenol's desorption is phenol diffuse from soil to liquid phase, and ultrasonic promoted in this process.In the research of dispose leach liquor, because of the main ingredient in the leach liquor is phenol and the technology of using Fenton oxidation to dispose the wastewater of hydroxybenzene is quite maturity, I don't need to optimizing the parameters of Fenton oxidation when dealing with the leach liquor. I can quote the research result. Take 500mL of the leach liquor which comes from the ultrasonic processing, and use this leach liquor conduct the Fenton oxidation experiment. In the experiment, after regulate the leach liquor's pH=3 by 1+1's HCl, I add 60mg FeSO4·7H2O and 0.4mL H2O2 which concentration is 30% to 500mL of the leach liquor, after mixing 60min, I get the strainaway rate of phenol and volatile phenol, each of them is 99.61% and 98.94%. After dispose, the water quality fit the third effluent standard of Integrated wastewater discharge standard, and are allowed to discharge into urban drainage system for further dispose.The application research of ultrasonic extraction combine with Fenton oxidation to dispose the phenol-contaminant soil, I need to enlarge the experiment scale in laboratory in order to prepare for production. This design mainly involves the design of ultrasound equipment, the choice of ultrasonic transducer, and the design of Fenton oxidation equipment. By checking relevant literature, consulting relevant experts and considering the actual situation of this experiment, I design the effective volume of ultrasonic equipment is 46L, and the parameters are about 3.14×2202×300(π×(underside radius)2×height(unit:mm)).The total volume of liquid slot wrapped out the effective one is 100L. and the parameters are about 500×500×400(length×wide×height(unit:mm)). At the same time, in the bottom of the effective slot. I design a 100 mesh size sieve which is made of stainless steel and mud discharge bucket, in order to improve ultrasound effect and discharge mud. Choose the ultrasonic transducer which has a ultrasonic frequency of 25KHz, a power of 60W, I need 30 ultrasonic transducers like mentioned above, and the total power is 1800W. The designed volume of Fenton oxidation equipment is 44L. and the parameters are about 3.14×2002×350(π(underside radius)2×height(unit:mm)). At last.I made a Project Budget for the whole technology, the total cost is about 18265 yuan, and dispose 1 tonne polluted soil costs 508 yuan in business.