Biodegradation of 2,4,6-trichlorophenol and associated hydraulic conductivity reduction in sand-bed columns.
The aim of this research was to investigate the long-term hydraulic conductivity changes in sand-bed columns exposed to 2,4,6-trichlorophenol (TCP). Continuous flow laboratory studies were conducted using sand-bed columns (15 cm i.d.; 200 cm length) at 20+/-1 degrees C during 365 d. The influence of (i) initial loads of 2,4,6-TCP (15, 30, 45 and 60 mg kg(-1) of 2,4,6-TCP), and (ii) recirculating water velocity (0.09, 0.56 and 1.18 cm min(-1)) on the biodegradation of 2,4,6-TCP and hydraulic conductivity changes in the sand-bed columns were investigated. The experimental results indicated that biodegradation of 2,4,6-TCP followed pseudo-first-order kinetics in the range of k(1)=0.01-1.64 d(-1), and it was influenced by initial load (p<0.01) and recirculating water velocity (p<0.01). Indigenous microbial biomass growth and changes resulted in a spatial (180 cm) and temporal (365 d) reduction of hydraulic conductivity in the sand-bed columns by up to two orders of magnitude during biodegradation of 2,4,6-TCP. The fastest hydraulic conductivity reductions were observed in the sand-bed column operated at the highest recirculating water velocity and highest cumulative load of 2,4,6-TCP following 365 d of continuous treatment (p<0.05).
Imperial College London, Wye campus, Wye, Ashford, Kent TN25 5AH, UK. b.antizar@imperial.ac.uk
Blanca
B
Antizar-Ladislao
Noah I
NI
Galil
D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development; D018533:Biomass; D002733:Chlorophenols / Q000032:analysis*; D004553:Electric Conductivity; D005410:Flame Ionization; D008956:Models, Chemical; D016062:Porosity; D012822:Silicon Dioxide; D014874:Water Pollutants, Chemical / Q000032:analysis*
D002733:Chlorophenols; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; C024564:2,4,6-trichlorophenol