S. Almuzaini et al., REMOVAL OF VOCS FROM REFINERY AND PETROCHEMICAL WASTEWATERS USING DISSOLVED AIR FLOTATION, Water science and technology, 30(3), 1994, pp. 79-90
Citations number
18
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
A field sampling and analysis program was carried out at a refinery an
d petrochemical industrial complex in the Shuaiba Industrial Area to c
haracterize the volatile organic compounds (VOCs) emitted from wastewa
ter and examine their removal by dissolved air notation (DAF) and gran
ular activated carbon (GAG) treatment. Compounds such as benzene, tolu
ene, ethylbenzene, and xylene were identified. The total VOC emission
of these compounds ranged from 0.1 to 3.2 mg/m(3). The VOCs concentrat
ions in wastewater ranged from 34 to 4445 g/l. An actual refinery wast
ewater was fed at a rate of 10 l/min into a pilot scale 592-liter diss
olved air flotation(DAF) unit connected to a granular activated carbon
column. Results indicated that liquid detention time and air/water ra
tio were the main factors affecting VOCs stripping from the DAF basin.
Up to 20% of influent VOCs concentrations were last by volatilization
at an ah-to-water ratio of 0.5. Adsorption by dry granular activated
carbon (GAG) was capable of reducing the VOCs concentration in off-gas
from the DAF unit by more than 99%. It is recommended to couple cover
ed DAF units with dry GAC columns to minimize occupational exposure to
VOC emission.