- Technical note
- Open Access
Fixed-bed column recirculation system for investigation of sorption and biodegradation of organic pollutants in saturated sediment: a detailed design and development
© The Author(s) 2016
- Received: 7 January 2016
- Accepted: 13 October 2016
- Published: 21 October 2016
Sorption and biodegradation are the primary processes of organic pollution remediation in aquatic and soil/sediment environments. While researchers have substantially reported their findings regarding these processes, little attention has been given to description of experimental apparatus. This technical paper aims to present the development and detailed design of a fixed-bed column recirculation (FBCR) system which has been widely applied to investigate sorption and biodegradation of organic pollutants in aquatic and/or sediment environments.
The FBCR system was developed and tested by three experiments investigating sorption and biodegradation of two herbicides (isoproturon and mecoprop) in different saturated materials (hydrofilt and river sediment). Efficiency of the FBCR system was assessed according to criteria i.e. reliability, leaking inhibition, reproducibility, practical of use and cost. The results indicated that the latest version (Version 4) of the FBCR system has been significantly improved and ready to extend to similar studies.
This system is therefore recommended to researchers who intend to investigate the remediation of organic pollutants in aquatic, soil and sediment environments.
- Fixed-bed column recirculation
- Organic pollutant
In Version 1 (Fig. 3a), the body and the two end-caps were connected together by eight sets of plastic bolts and nuts (four at each end). The column was packed with Hydrofilt material (see the Additional file 1). The system worked properly without leakage at low internal pressure (due to large particle sizes of Hydrofilt, from 0.8 to 1.5 mm). However, once river sediment was packed in the column, internal pressure increased considerably due to fine particle size of the sediment (23 % silt and 76 % sand, Additional file 1: Table S2). This resulted in leakage and, in several cases once the plastic bolts were tightened, fracture was observed. Leakage was often found at the connection between the body and the end-cap. In addition, the cap and the body were easily broken once the plastic bolts were tightened in connecting these parts together.
Version 2 (Fig. 3b) was created to improve the shortcomings of Version 1. Two stainless steel clamps were made to house the body and the two end-caps by using four stainless steel studdings and wing nuts holding the clamps. This design improved the leakage problem and minimized incidences of breakage. However, this design was inconvenient for packing sediment material because the lower end-cap and the body were not fixed together once the upper end-cap was taken off for packing. Furthermore, manufacturing of the stainless steel clamps was costly.
In Version 3 (Fig. 3c), a number of improvements were applied. Two conical connections at the two ends of the column were designed to replace the clamp-connections used in Version 2. The two caps and body of the column were connected by the two conical joints (vaseline should be used at the connect contact in order to facilitate the disassembling step). The connection was strengthened by stainless steel springs (or rubber bands) and hooks surrounding four sides of the column. This design also improved the manipulation of packing material in the column, making it quicker and easier to use. The leakage problem was mostly prevented by the conical joint. After several tests, the advantages of this version were compared to the previous versions and noted in terms of its faster manufacture, easier manipulating and packing, and lower production cost. Experiencing the trials, however, it was observed that the lower conical cap was not really necessary and, as a consequence, further refinements were made resulting in the final version (Version 4).
River water and river sediment were collected at River Thames (Gatehampton, Reading, UK). Hydrofilt, a porous material used in water treatment, was purchased from Akdolit® Company. Herbicides isoproturon (IPU) (3-(4-isopropylphenyl)-1,1-dimethyl urea) and mecoprop (MCPP) (2-(4-chloro-o-tolyloxy) propaonic acid) were purchased from Sigma Aldrich, UK. Further information of these materials, their characteristics, and analytical procedure are presented in Additional file 1: Tables S1 and S2.
Three experiments were established to test the FBCR system.
Experiment 1: Testing IPU attenuation in Hydrofilt material with Version 1
Experiment 2: Testing IPU attenuation in river sediment with Version 3
River sediment (150 g) was packed in the columns. River water (1.5 L) was transferred to the reservoir of Version 3. The IPU stock solution was spiked in the reservoir to achieve final concentration of about 1050 μg L−1. The contaminated solution was recirculated through the column for 14 days. Aqueous samples were collected from the reservoir at every intervals. The samples were then analysed by the HPLC system to determine IPU concentration.
Experiment 3: Testing MCPP attenuation in river sediment with Version 4
River sediment (150 g) was packed in the columns. River water (1.5 L) was transferred to the reservoirs of Version 4 system. Two treatments (n = 3) were established: Treatment 1 with both sterilised river water and river sediment (autoclaved at 121 °C for 30 min); and Treatment 2 with both non-sterile river water and river sediment (the natural materials). The MCPP stock solution was spiked in the reservoirs to achieve the final concentration of about 100 μg L−1. The contaminated solution in the reservoir was recirculated through the column for 18 days. Aqueous samples were collected at every intervals. The samples were also analysed by HPLC to determine MCPP concentration.
Sorption of IPU on Hydrofilt material (Experiment 1)
IPU concentration in the controlled treatment (without packing material) did not significantly decrease (p > 0.05) over 128 h of recirculation (Fig. 5). This indicated that IPU was not significantly lost by sorption to the wall of the apparatus or by evaporation. IPU concentrations in both Treatments 1 and 2 were observed as a biphasic model: (1) the rapid sorption phase occurred over the initial one-third day; and (2) the stable phase occurred over the remaining of 5 days. Over the rapid sorption phase, IPU concentration significantly decreased (15 %) in both Treatments 1 and 2. Stable phase indicated that the equilibrium state of IPU between the solid and liquid phases could be reached. Several isotherm sorption parameters of IPU on Hydrofilt were estimated i.e. the maximum sorption capacity of Hydrofilt to IPU (CS,max) to be 614 ± 71 µg kg−1 and the solid-water distribution coefficient (K d ) to be 6.28 ± 0.70 L kg−1.
Sorption and biodegradation of IPU in river water–river sediment system (Experiment 2)
Sorption and biodegradation of MCPP in river water–river sediment system (Experiment 3)
Observations from the three experiments indicated that the FBCR system is reliable and useful for investigation of sorption and biodegradation of organic pollutants in saturated sediment. This system was found to be efficient, reproducible, practical in terms of packing materials and leaking control, low cost and quick to assemble. In addition, unnecessary mistakes presented in this paper could be also helpful in terms of saving time and cost to reproduce this system. It is therefore recommended to researchers who intend to investigate sorption and biodegradation processes of organic pollutants in aquatic, soil and sediment environments.
The outcomes of this paper are a part of BST Ph.D. research. The research was implemented at the University of East Anglia, Norwich, UK under the supervision of Professor KH and Dr BR. All authors read and approved the final manuscript.
The authors would like to acknowledge the People’s Committee of Ho Chi Minh city (project CT300), Vietnam for funding this research with a PhD fellowship to Bao Son Trinh. Special thanks to Dr Michael Jones and his colleagues at Thames Water Utilities who helped with access to field sites to collect river water and sediment samples.
The authors declare that they have no competing interests.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
- Albrechtsen HJ, Mills MS, Aamand J, Bjerg PL (2001) Degradation of herbicides in shallow Danish aquifers: an integrated laboratory and field study. Pest Manag Sci 57(4):341–350View ArticlePubMedGoogle Scholar
- Alexander M (1999) Biodegradation and bioremediation. Academic Press, New YorkGoogle Scholar
- Bending GD, Lincoln SD, Edmondson RN (2006) Spatial variation in the degradation rate of the pesticides isoproturon, azoxystrobin and diflufenican in soil and its relationship with chemical and microbial properties. Environ Pollut 139(2):279–287View ArticlePubMedGoogle Scholar
- Bornick H (1998) Aromatic amines in the Elbe River development of analytical methods and investigation into the behaviour during drinking water treatment. Ph.D. thesis, Dresden University of TechnologyGoogle Scholar
- Bornick H, Eppinger P, Grischek T, Worch E (2001) Simulation of biological degradation of aromatic amines in river bed sediments. Water Res 35(3):619–624View ArticlePubMedGoogle Scholar
- Cornelissen G, Gustafsson Ö, Bucheli TD, Jonker MTO, Koelmans AA, van Noort PCM (2005) Extensive sorption of organic compounds to black carbon, coal, and kerogen in sediments and soils: mechanisms and consequences for distribution, bioaccumulation, and biodegradation. Environ Sci Technol 39(18):6881–6895ADSView ArticlePubMedGoogle Scholar
- Hiscock KM, Grischek T (2002) Attenuation of groundwater pollution by bank filtration. J Hydrol 266(3–4):139–144View ArticleGoogle Scholar
- Hoppe-Jones C, Oldham G, Drewes JE (2010) Attenuation of total organic carbon and unregulated trace organic chemicals in U.S. riverbank filtration systems. Water Res 44(15):4643–4659View ArticlePubMedGoogle Scholar
- Karickhoff SW (1984) Organic pollutant sorption in aquatic systems. J Hydraul Eng ASCE 110(6):707–735View ArticleGoogle Scholar
- Karickhoff SW, Brown DS, Scott TA (1979) Sorption of hydrophobic pollutants on natural sediments. Water Res 13(3):241–248View ArticleGoogle Scholar
- Katagi T (2006) Behavior of pesticides in water-sediment systems. Rev Environ Contam Toxicol 187:133–251PubMedGoogle Scholar
- Knepper TP, Sacher F, Lange FT, Brauch HJ, Karrenbrock F, Roerden O, Lindner K (1999) Detection of polar organic substances relevant for drinking water. Waste Manag 19(2):77–99View ArticleGoogle Scholar
- Lappin HM, Greaves MP, Slater JH (1985) Degradation of the herbicide mecoprop [2-(2-methyl-4-chlorophenoxy)propionic acid] by a synergistic microbial community. Appl Environ Microbiol 49(2):429–433PubMedPubMed CentralGoogle Scholar
- Sontheimer H (1988) Das Testfilterkonzept, eine Methode zur Beurteulung von Wassern (the test filter concept - a method for the charaterisation of water). DVGW-Schriftenreihe Wasser 60:27–50Google Scholar
- Trinh BS, Hiscock KM, Reid BJ (2012) Mechanistic insights into the role of river sediment in the attenuation of the herbicide isoproturon. Environ Pollut 170:95–101View ArticlePubMedGoogle Scholar
- Walker A, Jurado-Exposito M, Bending GD, Smith VJR (2001) Spatial variability in the degradation rate of isoproturon in soil. Environ Pollut 111(3):407–415View ArticlePubMedGoogle Scholar