A Laboratory Column Investigation for the Treatment of Cr(VI) with Zero-Valent Iron

Date

2009-02-01

Author

Uyusur, Burcu
Ünlü, Kahraman

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

234
views

0
downloads

Permeable reactive barrier (PRB) technology is commonly placed in the list of options for groundwater remediation at hazardous waste sites, where Cr(VI) treatment in groundwater has been a concern more than any other inorganic contaminants. The objective of this study was to investigate the effectiveness and longevity of Cr(VI) removal with zero-valent iron based PRBs. The main focus was on two parameters affecting the performance of Cr(VI) removal with PRBs: (1) amount of reactive media and (2) groundwater flux. Laboratory scale columns packed with different amounts of iron powder and quartz sand mixture were fed with an aqueous solution containing 20 mg/L chromium under different groundwater fluxes. When chromium treatment efficiencies of the columns were compared with respect to iron powder/quartz sand ratio, the amount of iron powder was found to be an important parameter for treatment efficiency of PRBs. When the same experiments were conducted at higher fluxes, an increase was observed in the treatment efficiency in the column containing 50% iron. This suggested that the precipitates may not be accumulating at higher fluxes, which in turn, create available surface area for reduction. Extraction experiments were also performed to determine the fraction of chromium that sorbed onto iron hydroxides or iron oxyhydroxides. Analyses showed that chromium was not removed by sorption and that reduction is the only removal mechanism in the laboratory experiments. Cr(VI) removal rate constant and complete removal efficiency values were determined for each reactive mixture. These values are considered to be important design parameters for the field scale permeable reactive barrier applications.

Subject Keywords

Waste Management and Disposal, Pollution, Environmental Chemistry

URI

https://hdl.handle.net/11511/40587

Journal

ENVIRONMENTAL ENGINEERING SCIENCE

DOI

https://doi.org/10.1089/ees.2007.0089

Collections

Department of Environmental Engineering, Article

Suggestions

OpenMETU
Core

Assessment of PCB contamination, the potential for in situ microbial dechlorination and natural attenuation in an urban watershed at the East Coast of the United States Kaya, Devrim; Sowers, Kevin R.; Demirtepe, Hale; Stiell, Brian; Baker, Joel E.; İmamoğlu, İpek; Kjellerup, Birthe (Elsevier BV, 2019-09-15) Sediment contamination is a major environmental issue in many urban watersheds and coastal areas due to the potential toxic effects of contaminants on biota and human health. Characterizing and delineating areas of sediment contamination and toxicity are important goals of coastal resource management in terms of ecological and economical perspectives. Core and surficial sediment samples were collected from an industrialized urban watershed at the East Coast of the United Stated and analyzed to evaluate the ...
The effects of aquifer heterogeneity on the natural attenuation rates of chlorinated solvents Önkal, Başak; Ünlü, Kahraman; Department of Environmental Engineering (2005) Monitored natural attenuation has been particularly used at sites where petroleum hydrocarbons and chlorinated solvents have contaminated soil and groundwater. One of the important aspects of the methodology that has been recognized recently is that the mass removal rates, the most important parameter to determine effectiveness of the methodology, is controlled by the groundwater flow regime and the aquifer heterogeneity. Considering this recognition, the primary objective of this study is to quantitatively...
Modeling natural attenuation of petroleum hydrocarbons (btex) in heterogeneous aquifers Uçankuş, Tuğba; Ünlü, Kahraman; Department of Environmental Engineering (2005) Natural Attenuation can be an effective cleanup option for remediation of Groundwater contamination by BTEX. One of the important aspects of the methodology that has been recognized recently is that mass removal rates, the most important parameters used to determine effectiveness of the methodology, is controlled by groundwater flow regime, which to a large extent controlled by aquifer heterogeneity. Considering this recognition, the primary objective of this research is to quantitatively describe the relat...
Control of trichloroethylene emissions from sparging systems by horizontal bio- and chemo-barriers Tezel, U; Demirer, Göksel Niyazi; Uludag-Demirer, S (Informa UK Limited, 2005-02-01) The scope of this study was to develop a continuous system to clean-up a trichloroethylene (TCE) contaminated gas stream, where biotic and abiotic removal mechanisms are undertaken sequentially simulating the horizontal bio- and chemo-barriers proposed for the in-situ remediation of the contaminated sites. The bio- and chemo-barriers were simulated by using glass columns packed with granular anaerobic mixed culture and Fe(0) filings, respectively. The effect of gas residence time, which is adjusted by the g...
Use of rubber and bentonite added fly ash as a liner material Çokça, Erdal (Elsevier BV, 2004-01-01) In many countries regulations require all hazardous waste disposal facilities to be lined with suitable impermeable barriers to protect against contamination. In this study, a series of laboratory tests on rubber and bentonite added fly ash were conducted. The aim of the tests was to evaluate the feasibility of utilizing fly ash, rubber and bentonite as a low hydraulic conductivity liner material. Type C fly ash was obtained from Soma thermal power plant in Turkey; rubber in pulverized form was waste from t...

Citation Formats

B. Uyusur and K. Ünlü, “A Laboratory Column Investigation for the Treatment of Cr(VI) with Zero-Valent Iron,” ENVIRONMENTAL ENGINEERING SCIENCE, pp. 385–395, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40587.