Pd/Fe3O4 nano-catalysts for selective dehalogenation in wastewater treatment processes—Influence of water constituents

Abstract Palladium catalysts can be used for the selective removal of halogenated organic compounds from aqueous waste via hydrodehalogenation reactions in the presence of other omnipresent constituents of industrial wastewaters. This detoxification of the water and drastic lowering of the AOX value (adsorbable organically bound halogens) can prevent the need for further cost-intensive treatment or discharge into waste incineration plants. Often, the water can then be released to municipal sewage plants. The present paper deals with a highly active, magnetically re-extractable nanoscale Pd-on-magnetite catalyst (Pd/Fe 3 O 4 ) which has been developed for application in wastewater treatment processes. The study provides insight into the performance of this catalyst and gives information about its general applicability under wastewater conditions and its sensitivity towards constituents of a wastewater matrix. The catalyst can tolerate various inorganic and organic substances in relevant concentrations. Wastewaters containing a high background concentration of organic solvents can also be cleaned from halogenated pollutants. However, waters which contain heavy metals such as lead or mercury or reduced sulphur species such as sulphides need specific pre-treatments prior to Pd-catalysed hydrodehalogenation.

[1]  C. Werth,et al.  Effects of natural water ions and humic acid on catalytic nitrate reduction kinetics using an alumina supported Pd-Cu catalyst. , 2006, Environmental science & technology.

[2]  F. Kopinke,et al.  Hydrodehalogenation of halogenated hydrocarbons in water with Pd catalysts: Reaction rates and surface competition , 2006 .

[3]  G. Graham,et al.  Characterization of model automotive exhaust catalysts: Pd on ceria and ceria–zirconia supports , 1999 .

[4]  T. Lim,et al.  Effects of anions on the kinetics and reactivity of nanoscale Pd/Fe in trichlorobenzene dechlorination. , 2008, Chemosphere.

[5]  T. Okamoto,et al.  Self-regeneration of a Pd-perovskite catalyst for automotive emissions control , 2002, Nature.

[6]  J. Durand,et al.  An Overview of Palladium Nanocatalysts: Surface and Molecular Reactivity , 2008 .

[7]  M. Aramendía,et al.  Selective Liquid-Phase Hydrogenation of Citral over Supported Palladium , 1997 .

[8]  Jeffrey A Cunningham,et al.  Palladium-catalyzed hydrodehalogenation of 1,2,4,5-tetrachlorobenzene in water-ethanol mixtures. , 2008, Journal of hazardous materials.

[9]  M. Reinhard,et al.  Pd-Catalyzed TCE Dechlorination in Groundwater: Solute Effects, Biological Control, and Oxidative Catalyst Regeneration , 2000 .

[10]  S. Ordóñez,et al.  Deactivation of a Pd/Al2O3 catalyst used in hydrodechlorination reactions: Influence of the nature of organochlorinated compound and hydrogen chloride , 2006 .

[11]  M. Reinhard,et al.  Pd-catalyzed TCE dechlorination in water: effect of [H2](aq) and H2-utilizing competitive solutes on the TCE dechlorination rate and product distribution. , 2001, Environmental science & technology.

[12]  A. Lecloux.  Chemical, biological and physical constrains in catalytic reduction processes for purification of drinking water , 1999 .

[13]  T. Lim,et al.  Catalytic reduction of chlorobenzenes with Pd/Fe nanoparticles: reactive sites, catalyst stability, particle aging, and regeneration. , 2007, Environmental science & technology.

[14]  C. Schüth,et al.  Field application of a tailored catalyst for hydrodechlorinating chlorinated hydrocarbon contaminants in groundwater , 2004 .

[15]  F. Kopinke,et al.  Permanganate oxidation of sulfur compounds to prevent poisoning of Pd catalysts in water treatment processes. , 2008, Environmental science & technology.

[16]  M. Reinhard,et al.  Hydrodehalogenation of 1- to 3-Carbon Halogenated Organic Compounds in Water Using a Palladium Catalyst and Hydrogen Gas , 1999 .

[17]  T. Strathmann,et al.  Rapid metal-catalyzed hydrodehalogenation of Iodinated x-ray contrast media. , 2008, Environmental science & technology.

[18]  R. M. Schlosser,et al.  Field application of palladized iron for the dechlorination of trichloroethene , 2000 .

[19]  M. Reinhard,et al.  Tailoring catalysts for hydrodechlorinating chlorinated hydrocarbon contaminants in groundwater , 2000 .

[20]  M. Aramendía,et al.  Influence of the Reaction Conditions and Catalytic Properties on the Liquid-Phase Hydrodechlorination of Chlorobenzene over Palladium-Supported Catalysts: Activity and Deactivation , 1999 .

[21]  R. Köhler,et al.  Catalytic hydrodechlorination of groundwater contaminants in water and in the gas phase using Pd/γ-Al2O3 , 2003 .

[22]  K. Strenge.  Grenzflächen- und Kolloidchemie , 1995 .

[23]  Stewart F. Parker,et al.  Poisoning and deactivation of palladium catalysts , 2001 .

[24]  M. Keane,et al.  Catalyst deactivation during the liquid phase hydrodechlorination of 2,4-dichlorophenol over supported Pd: influence of the support , 2003 .

[25]  M. Reinhard,et al.  In-situ destruction of chlorinated hydrocarbons in groundwater using catalytic reductive dehalogenation in a reactive well: testing and operational experiences , 2000 .

[26]  M. Reinhard,et al.  Catalytic hydrodehalogenation of chlorinated ethylenes using palladium and hydrogen for the treatment of contaminated water , 1995 .

[27]  M. Aramendía,et al.  Liquid-phase hydrodechlorination of chlorobenzene over palladium-supported catalysts: Influence of HCl formation and NaOH addition , 2002 .

[28]  C. Lund,et al.  The effect of a membrane reactor upon catalyst deactivation during hydrodechlorination of dichloroethane , 1999 .

[29]  F. Kopinke,et al.  Alternative sources of hydrogen for hydrodechlorination of chlorinated organic compounds in water on Pd catalysts , 2004 .

[30]  M. Moeder,et al.  Trace analysis of technical nonylphenol, bisphenol A and 17alpha-ethinylestradiol in wastewater using solid-phase microextraction and gas chromatography-mass spectrometry. , 2003, Journal of chromatography. A.

[31]  F. Kopinke,et al.  Highly active Pd-on-magnetite nanocatalysts for aqueous phase hydrodechlorination reactions. , 2009, Environmental science & technology.

[32]  D. Fritsch,et al.  Hydrodechlorination of chloroorganic compounds in ground water by palladium catalysts: Part 1. Development of polymer-based catalysts and membrane reactor tests , 2003 .

[33]  A. Schnyder,et al.  Supported palladium catalysts for fine chemicals synthesis , 2001 .

[34]  M. Franzreb,et al.  A novel repulsive-mode high gradient magnetic separator. Part I. Design and experimental results , 2004, IEEE Transactions on Magnetics.