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).
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.chemosphere.2005.12.047 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Impacts of autochthonous particulate organic matter on redox-conditions and elimination of trace organic chemicals in managed aquifer recharge.
Environ Sci Pollut Res Int
March 2023
Technische Universität Berlin, Chair of Water Quality Control, KF4, Straße des 17. Juni 135, 10623, Berlin, Germany.
Autochthonous carbon fixation by algae and subsequent deposition of particulate organic matter can have significant effects on redox conditions and elimination of trace organic chemicals (TOrCs) in managed aquifer recharge (MAR). This study investigated the impacts of different algae loadings (0-160 g/m) and infiltration rates (0.06-0.
View Article and Find Full Text PDFEnhanced retention of bacteria by TiO2 nanoparticles in saturated porous media.
J Contam Hydrol
August 2016
Department of Civil and Environmental Engineering, University of Missouri, Columbia, MO, 65211, USA. Electronic address:
The simultaneous transport of TiO2 nanoparticles and bacteria Pseudomonas aeruginosa in saturated porous media was investigated. Nanoparticle and bacterium size and surface charge were measured as a function of electrolyte concentration. Sand column breakthrough curves were obtained for single and combined suspensions, at four different ionic strengths.
View Article and Find Full Text PDFStorms cause a substantial increase in the fecal indicator bacteria (FIB) concentrations in stream water as a result of FIB-laden runoff and the release of FIB from stream sediments. Previous work has emphasized the association between FIB and bed sediments finer than sand. The objectives of this work were to elucidate the effect of various velocities on the entrainment of bed-dwelling coliforms in sand-bed streams and to refine methodologies for quantifying sandy streambeds as sources of FIB.
View Article and Find Full Text PDFPhosphate removal from aqueous solution using ZVI/sand bed reactor: Behavior and mechanism.
Water Res
August 2016
Groupement de Recherche Eau Sol Environnement - GRESE EA 4330, University of Limoges, 123 Avenue Albert Thomas, Limoges, France.
This research reports on phosphate removal from aqueous solution using ZVI/sand packed columns. The influence of column preconditioning, consisting of ZVI pre-oxidation before feeding the columns with phosphate solution, revealed that a column aged for 1 day was more efficient than un-conditioned column, 5-days and 10-days preconditioned columns. The distribution of phosphate trapped inside the columns was evaluated by measuring phosphate concentration in the solids at different levels (P1, P2 and P3) along the depth of the columns.
View Article and Find Full Text PDFAlthough many studies have measured denitrification in stream sediments, few have utilized these data with local water column and sediment measurements to develop a predictive model for NO uptake. In this study, sediment denitrification was measured from cores in five streams under various land uses in south-central Minnesota using denitrification enzyme activity (DEA) assays and amplification of the gene via real-time, quantitative polymerase chain reaction. Hydraulic and environmental variables were measured in the vicinity of the sediment cores to evaluate the influence of fluid flow and chemical variables on denitrification activity.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!