Method for degrading polycyclic aromatic hydrocarbon in soil using ultraviolet light

Abstract

The invention relates to photodegradation for polycyclic aromatic hydrocarbon contaminated soil, in particular to a method for degrading polycyclic aromatic hydrocarbon in soil by ultraviolet illumination. A humic acid is taken as a sensitizing agent, a mixture of contaminated soil and the humic acid is paved in a vessel and is placed into an ultraviolet illumination box for illumination gradation, the thickness of a soil layer is between 0.15 and 0.5 mm, and the adding amount of the humic acid is between 3 and 45 mg / kg soil; and illumination conditions in the illumination box are as follows: the wavelength of the ultraviolet illumination is between 210 and 365 nm, a sample is 5 to 20 cm away from a light source, the illumination intensity is between 500 and 10, 000 mu m w / cm<2>, the temperature is between 20 and 38 DEG C, the relative humidity in a ventilation control box is between 30 and 50 percent, and the illumination time is between 2 and 18 days. The method has the advantages of quick speed, high efficiency, easy operation, and no generation of secondary pollution.

Description

technical field

[0001] The invention relates to the photodegradation of polycyclic aromatic hydrocarbons polluted soil, in particular to a method for degrading polycyclic aromatic hydrocarbons in soil by ultraviolet light using humic acid as a sensitizer Background technique

[0002] Polycyclic aromatic hydrocarbons (PAHs) are a class of organic pollutants ubiquitous in the environment. There are two aspects to its source: natural source and man-made source. Natural sources are mainly forest and grassland fires, volcanic eruptions, synthesis of plants and microorganisms, among which synthesis of higher plants and microorganisms, and volcanic activity are the main factors that produce the background value of PAHs; artificial sources come from industrial production and processing (such as coke, carbon production of black and coal tar, refining and fractionation of crude oil and its derivatives, etc.), and incomplete combustion of organic matter. Among anthropogenic sources, ...