Abstract

The influence of nonionic surfactant Brij 30 on toluene dissolved in the water phase and biodegradation kinetic behaviors of toluene in a polyvinyl alcohol (PVA)/peat/KNO₃/ (granular activated carbon) GAC composite bead biofilter were investigated. The toluene dissolved in the water phase was enhanced by the addition of surfactant into the aqueous solution and the maximum amount of toluene dissolved in the water phase occurred at the surfactant concentration of 34.92 mgl^-1. Zero-order kinetics with diffusion limitation was regarded as the most adequate biochemical reaction kinetic model. The microbial growth rate and biochemical reaction rate were inhibited at higher surfactant content and toluene inlet concentration. The degree of inhibitive effect was more pronounced at lower toluene inlet concentration. The maximum elimination capacity decreased with increasing surfactant content. The addition of nonionic surfactant Brij 30 into filter material was unfavorable for toluene degraded by the microbial.

Key words: Nonionic surfactant Brij30, toluene, dissolution capacity, biodegradation, composite bead biofilter.

Abbreviation

GAC, Granular activated carbon; VOCs, volatile organic compounds; PVA, polyvinyl alcohol; PCP, pentachlorophenol; SDS, sodium dodecyl sulfate; CMC, critical micelle concentration; EBRT, empty bed residence time; GC,gas chromatography.