Abstract
Ultraviolet (UV) photodegradation is increasingly applied to control volatile organic compounds (VOCs) due to its degradation capabilities for recalcitrant compounds. However, sometimes the UV photodegradation products are also toxic and can affect human health. Here, 10 VOCs at 150~200 ppm in air were treated using a laboratory-scale UV reactor with 185/254 nm irradiation, and the biotoxicity of their off-gas was studied by investigating their off-gas absorption solutions. The CO2 increase and VOC decrease were 39~128 ppm and 0~42 ppm, respectively, indicating that the VOCs and their products were mineralized in off-gas absorption solutions. The total organic carbon (TOC) of the absorption solutions are 4~20 mg∙L−1. Luminescent bacteria and Daphnia magna were used to detect the acute toxicity, and an umu assay was used to determine the genotoxic potential. Trichloroethylene showed a highest toxicity to luminescent bacteria, while chlorobenzene had the lowest toxicity. Water-soluble UV photodegradation products for styrene are very toxic to Daphnia magna. In the umu assay, the genotoxicities of off-gas absorption solutions of trichloroethylene, methylbenzene, ethyl acetate, butyl alcohol, and styrene were 51.26, 77.80, 86.89, 97.20, and 273.62 mg (4-NQO)·L−1 respectively. In addition, the analysis of the genotoxicity/TOC and intermediates products indicated that the off-gas absorption solutions of styrene, trichloroethylene, and butyl alcohol contain many highly toxic substances.
Highlights
Volatile organic compounds (VOCs) are one of the major contributors to air pollution.They are often found in industrial waste gas from chemical manufacturing plants, hazardous sites, and groundwater remediation facilities [1]
volatile organic compounds (VOCs) can be removed via thermal oxidation, adsorption, biofiltration, non-thermal plasma, photodegradation, photocatalysis, etc. [4,5,6]
The original total mass of the carbon in VOCs injected into the UV reactor (MC) was estimated to be about 10 to 45 mg
Summary
Volatile organic compounds (VOCs) are one of the major contributors to air pollution They are often found in industrial waste gas from chemical manufacturing plants, hazardous sites, and groundwater remediation facilities [1]. The core component of the photoreactor for VOC removal is a low-pressure mercury UV lamp, producing strong irradiation with 85% output UV light at 254 nm and 15% output at 185 nm [8]. In these processes, strong oxidizing substances such as ozone and hydroxyl radical react with VOCs to create water and
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have