| In recent years,the development of China's light and heavy industries has gone hand in hand,and the water demand has increased sharply every year.The problem of groundwater pollution has been found with the extraction and use of groundwater becoming normal.The purpose of my article is to explore a technology which could remediate the pollutants of groundwater.The advanced oxidation served as background technology and environmental friendliness was the subject in my article With the condition of above,this article carried out research on degradation of phenol pollution in groundwater.Fenton technology is a type of advanced oxidation technology.Fenton,the scientist from French discovered “Fenton Technology” which has been used in organic pollutants degradation in a wide range since 1894.Biochar is a carbon-based material obtained by pyrolysis of biomass under hypoxic conditions.It has the characteristics of low price and environmental protection.It has a good adsorption effect on heavy metals,organics,inorganic ions and so on because of its abundant functional groups on the surface.So it has a wide range of applications.In this article,I took the advanced oxidation technology as the technical background and proposed phenol as the target pollutant,using corn stalk biochar as the basic material,activated by hydrochloric acid as the system activator,and carried out two oxidants of hydrogen peroxide and sodium persulfate using ferric iron and biochar as the activator.Compared with the activation effect,a green,efficient and environmentally friendly technical method for remediation of groundwater organic pollution is proposed.The specific research results are as follows:(1)In the system of the ferrous chloride,the optimal molar ratio of oxidant to activator is 1:2,the molar ratio of oxidant to pollutant is 40:1,and the optimal initial pH of the system is 4.15.There was little effect of internal temperature on the system in a certain range(10?-30?).The removal rate of phenol in 120 min was 84.74% under the condition of the initial concentration of phenol was 50.00mg/L;(2)In the system of the biochar,firstly,the roasting temperature of biochar was optimized,and it was determined that the roasting rate was the highest when the heating rate was 5.0?/min.In the condition of a nitrogen atmosphere,the optimum roasting temperature was 900?,the roasting time was 180 min,and the natural cooling was performed to room temperature.It was soaked in 10% dilute hydrochloric acid for 12 h and rinsed with ultrapure water and ethanol 3 times alternately,then dried at 110? for 12 h before using it.In this system,the dosage of biochar was 0.50 g / L,the molar ratio of persulfate to phenol was 5: 1,the optimal pH was 6.45(initial pH),and the normal temperature condition were the best experimental conditions.When the temperature of the system was reduced to 10?,the degradation effect of phenol on the system did not decrease significantly.Under the optimal experimental conditions,the degradation efficiency of phenol solution with an initial concentration of 50mg/L was 85.64% within 120 min.When the biochar was continuously reused 4 times,the degradation efficiency of phenol was still 80.50% within 120 min.When the experiment was carried out for 300 min,the mineralization rate of phenol reached 85.94%;(3)This article conducted a simple analysis of the dominant free radicals for phenol degradation.In the condition of ferrous chloride as the activator,it was determined that the sulfate radical was the dominant free radical.Under the condition of high temperature biochar as the activator,the hydroxyl radical was determined.As the dominant free radical,the sulfate radical was the auxiliary free radical,and determined the degradation process of phenol.At the end of this article,the main experimental parameters and characteristics of the two systems were selected for comparison and analysis.According to the proposed environmental parameters of groundwater in the contaminated site(average pH value 6.80,water temperature range is 8?-13?)and high-temperature biochar activated sodium persulfate system had a pharmaceutical investment.There were a variety of advantages of low dosage,simple experimental conditions,and no secondary pollutants.So this system was recommended for groundwater pollution remediation. |
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