Experimental Study On The Treatment Of Tetrahydrofuran Wastewater With Blow Off-UV/Fenton Combined Method

Tetrahydrofuran (THF) is a ring-structured organic compound which cannot be decomposed by the activated sludge, and its molecular formula is C4H8O. Tetrahydrofuran is characterized as high polarity, low boiling point, colorless and transparent, volatile liquid, and miscibility with water, which makes it a good organic solvent. THF is toxic and threatens the stability of the water. This thesis studies the effects of different treating methods:UV/Fenton method, air stripping method and air stripping-UV/Fenton combined method, then obtains the variation rule of treating effect of the THF wastewater of different factors, and obtains the optimum technological parameters.This thesis mainly studies the air stripping method, UV/Fenton method, and air stripping-UV/Fenton combined method to treat THF wastewater in a self-made equipment. Test device includes O25 ceramic Pall rings, air-stripping tower whose diameter is 65 mm, and the tower packing whose height is 1m. When studying air stripping method, four factors, which are temperature, hydraulic load, wastewater concentration and gas liquid ratio, are researched to get the optimal parameters at ambient temperature:when the hydraulic loading is 15L/h, and gas liquid ratio 5624, the removal rate of the THF is more than 90%. When studying UV/Fenton oxidation method, factors, such as wastewater concentration, reaction time, pH, Fe2+ concentration, H2O2:Fe2+ mole ratio and light intensity, are studied. When the THF concentration in wastewater is 500mL/L, reaction time 2.5h, pH 3, Fe2+ concentration 20mmol/L, H2O2:Fe2+ mole ratio 4:1 and light intensity 40w, the optimal parameters can be obtained. Test using air stripping-UV/Fenton combined method suggests that after the treatment, the high concentration THF wastewater can reach the discharge standard. Air stripping-UV/Fenton combined method is advantageous due to the relatively low cost, reduced oxidant dosage, and lesser secondary pollution.Tests results show that air stripping method, UV/Fenton method, and air stripping-UV/Fenton combined method all prove to be effective. The order is displayed from high cost to low:air stripping method. UV/Fenton method, and then air stripping-UV/Fenton combined method. After air stripping-UV/Fenton combined treatment, the tetrahydrofuran wastewater can meet the discharge standard. This study can provide theoretical basis and design reference for the THF wastewater treatment, and possess favorable practical value.