Antizar-Ladislao Blanca, Galil Noah I
Imperial College London, Wye campus, Wye, Ashford, Kent TN25 5AH, UK.
Chemosphere. 2006 Jun;64(3):339-49. doi: 10.1016/j.chemosphere.2005.12.047. Epub 2006 Feb 15.
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).
本研究的目的是调查暴露于2,4,6-三氯苯酚（TCP）的砂床柱中长期水力传导率的变化。在20±1℃下，使用砂床柱（内径15 cm；长度200 cm）进行了为期365天的连续流动实验室研究。研究了（i）2,4,6-TCP的初始负荷（15、30、45和60 mg kg-1的2,4,6-TCP），以及（ii）循环水速度（0.09、0.56和1.18 cm min-1）对砂床柱中2,4,6-TCP生物降解和水力传导率变化的影响。实验结果表明，2,4,6-TCP的生物降解在k(1)=0.01-1.64 d-1范围内遵循准一级动力学，并且受初始负荷（p<0.01）和循环水速度（p<0.01）的影响。在2,4,6-TCP生物降解过程中，原生微生物生物量的生长和变化导致砂床柱中的水力传导率在空间（180 cm）和时间（365天）上降低了多达两个数量级。在连续处理365天后，在循环水速度最高和2,4,6-TCP累积负荷最高的砂床柱中观察到最快的水力传导率降低（p<0.05）。
