Final Degradation Products Research Articles

Self-floating graphitic carbon nitride/zinc phthalocyanine nanofibers for photocatalytic degradation of contaminants

The effective elimination of micropollutants by an environmentally friendly method has received extensive attention recently. In this study, a photocatalyst based on polyacrylonitrile (PAN)-supported graphitic carbon nitride coupled with zinc phthalocyanine nanofibers (g-C3N4/ZnTcPc/PAN nanofibers) was successfully prepared, where g-C3N4/ZnTcPc was introduced as the catalytic entity and the PAN nanofibers were employed as support to overcome the defects of easy aggregation and difficult recycling. Herein, rhodamine B (RhB), 4-chlorophenol and carbamazepine (CBZ) were selected as the model pollutants. Compared with the typical hydroxyl radical-dominated catalytic system, g-C3N4/ZnTcPc/PAN nanofibers displayed the targeted adsorption and degradation of contaminants under visible light or solar irradiation in the presence of high additive concentrations. According to the results of the radical scavenging techniques and the electron paramagnetic resonance technology, the degradation of target substrates was achieved by the attack of active species, including photogenerated hole, singlet oxygen, superoxide radicals and hydroxyl radicals. Based on the results of ultra-performance liquid chromatography and mass spectrometry, the role of free radicals on the photocatalytic degradation intermediates was identified and the final photocatalytic degradation products of both RhB and CBZ were some biodegradable small molecules.

Schiff base triphenylphosphine palladium (II) complexes: Synthesis, structural elucidation, electrochemical and biological evaluation

The complexes N-(2-oxidophenyl)salicylideneiminatotriphenylphosphine palladium(II) (1) and N-(2-sulfidophenyl)salicylideneiminato triphenylphosphine palladium(II) (2) of tridentate Schiff bases derived from salicylaldehyde and an amino- or thiophenol, have been synthesized and characterized by various spectroscopic, analytical and electro-analytical techniques. X-ray single crystal analysis of complex 1 has revealed its square planar geometry. The thermal analysis has shown the absence of coordinated water and final degradation product is PdO. The alkaline phosphatase studies have indicated that enzymatic activity is concentration dependent which is inversely proportional to the concentration of the compounds. The biological assays (brine shrimp cytotoxicity, DPPH) have reflected their biologically active and mild antioxidant nature. However, results of DNA protection assay have shown that they possess moderate protective activity against hydroxyl free radicals (OH). The voltammetric studies ascertain two-electron reduction of the compounds through purely diffusion controlled process and reveal intercalative mode of drug DNA interactions.

A Kinetic Degradation Study of Curcumin in Its Free Form and Loaded in Polymeric Micelles.

Curcumin, a phenolic compound, possesses many pharmacological activities and is under clinical evaluation to treat different diseases. However, conflicting data about its stability have been reported. In this study, the kinetic degradation of curcumin from a natural curcuminoid mixture under various conditions (pH, temperature, and dielectric constant of the medium) was investigated. Moreover, the degradation of pure curcumin at some selected conditions was also determined. To fully solubilize curcumin and to prevent precipitation of curcumin that occurs when low concentrations of co-solvent are present, a 50:50 (v/v) aqueous buffer/methanol mixture was used as standard medium to study its degradation kinetics. The results showed that degradation of curcumin both as pure compound and present in the curcuminoid mixture followed first order kinetic reaction. It was further shown that an increasing pH, temperature, and dielectric constant of the medium resulted in an increase in the degradation rate. Curcumin showed rapid degradation due to autoxidation in aqueous buffer pH = 8.0 with a rate constant of 280 × 10(-3)h(-1), corresponding with a half-life (t1/2) of 2.5h. Dioxygenated bicyclopentadione was identified as the final degradation product. Importantly, curcumin loaded as curcuminoid mixture in ω-methoxy poly (ethylene glycol)-b-(N-(2-benzoyloxypropyl) methacrylamide) (mPEG-HPMA-Bz) polymeric micelles and in Triton X-100 micelles was about 300-500 times more stable than in aqueous buffer. Therefore, loading of curcumin into polymeric micelles is a promising approach to stabilize this compound and develop formulations suitable for further pharmaceutical and clinical studies.

Analysis of l-DOPA-derived melanin and a novel degradation product formed under alkaline conditions

When the therapeutic drug l-DOPA, which is used to treat Parkinson’s disease, is combined with magnesium oxide (MgO), a formulation change produces a dark substance. Infrared spectroscopy reveals that this substance is melanin. After allowing the l-DOPA and MgO mixture to stand, the l-DOPA content decreases significantly, and a new degradation product (the final degradation product of l-DOPA, FDP-D) is generated. Formation of this product requires a solution with a pH of >10, and the presence of MgO is not necessary. FDP-D is not produced by tyrosinase decomposition of l-DOPA and is therefore not a melanin-related compound. Pure FDP-D is isolated by adjusting the l-DOPA solution to pH 10 with ammonium hydroxide, allowing it to stand for 3 days at room temperature, adding trifluoroacetic acid (TFA), filtering the precipitate, and separating the supernatant with high-performance liquid chromatography (HPLC). Mass spectrometry indicates that the isolated FDP-D has a molecular formula of C9H9NO7. On the basis of NMR analysis (1H NMR, 13C NMR, DEPT, H-H COSY, HMQC, and HMBC), FDP-D appears to be a substance with the novel structure 7a-hydroxy-5-oxo-1,2,3,5,7,7a-hexahydropyrano [3,4-b]pyrrole-2,7-dicarboxylic acid.

The alginate lyases FlAlyA, FlAlyB, FlAlyC, and FlAlex from Flavobacterium sp. UMI-01 have distinct roles in the complete degradation of alginate

We recently reported the isolation of Flavobacterium sp. UMI-01 as a novel alginate-assimilating bacterium from decayed brown algae. In our previous study, FlAlyA was purified and characterized as an endolytic alginate lyase, producing alginate oligosaccharides (AOSs) from its polymer. Additionally, crude extracts from strain UMI-01 were found to be capable of producing of 4-deoxy-l-erythro-5-hexoseulose uronic acids (DEHs) through degradation of AOSs. Here, we report the enzymatic characteristics of four alginate lyases, i.e., FlAlyA, FlAlyB, FlAlyC, and FlAlex, found in the genomic sequence of UMI-01 using recombinant proteins. Our results demonstrated that the distinct roles of these enzymes facilitated complete degradation of alginate to DEH in strain UMI-01. First, FlAlyA attacked the alginate polymer in an endolytic manner, producing AOS. Recombinant FlAlyA could completely degraded alginate into AOS in vitro, and its activity was 20–52-fold higher than those of commercially available enzymes. Next, DEH was generated as a final degradation product through the functions of FlAlyB, FlAlyC, and FlAlex, which exhibited distinct substrate preferences; FlAlyB, FlAlyC, and FlAlex were identified as polyM-, polyMG-, and polyG-specific enzymes, respectively. Thus, our results confirmed that the combination of these four enzymes resulted in the most efficient degradation of alginate to DEH in vitro.

Method for the Accelerated Testing of the Durability of a Construction Binder using the Arrhenius Approach

Abstract The single most reliable indicator of a material’s durability is its performance in long-term tests, which cannot always be carried out due to a limited time budget. The second option is to perform some kind of accelerated durability tests. The aim of the work described in this article was to develop a method for the accelerated durability testing of binders. It was decided that the Arrhenius equation approach and the theory of chemical reaction kinetics would be applied in this case. The degradation process has been simplified to a single quantifiable parameter, which became compressive strength. A model hydraulic binder based on fluidised bed combustion ash (FBC ash) was chosen as the test subject for the development of the method. The model binder and its hydration products were tested by high-temperature X-ray diffraction analysis. The main hydration product of this binder was ettringite. Due to the thermodynamic instability of this mineral, it was possible to verify the proposed method via long term testing. In order to accelerate the chemical reactions in the binder, four combinations of two temperatures (65 and 85°C) and two different relative humidities (14 and 100%) were used. The upper temperature limit was chosen because of the results of the high-temperature x-ray testing of the ettringite’s decomposition. The calculation formulae for the accelerated durability tests were derived on the basis of data regarding the decrease in compressive strength under the conditions imposed by the four above-mentioned combinations. The mineralogical composition of the binder after degradation was also described. The final degradation product was gypsum under dry conditions and monosulphate under wet conditions. The validity of the method and formula was subsequently verified by means of long-term testing. A very good correspondence between the calculated and real values was achieved. The deviation of these values did not exceed 5 %. The designed and verified method does not also consider the influence of other effects, for instance, chemical corrosion or corrosion caused by frost-thaw cycles. However, this method could be a supplementary tool applicable to the study of degradation processes and the estimation of a binder´s durability as well.

Efficient nitrate removal using micro‐electrolysis with zero valent iron/activated carbon nanocomposite

ABSTRACTBACKGROUNDIncreasing nitrate concentration in ground water resources due to increased municipal and industrial contaminations is posing a great threat to human health worldwide. Therefore, an efficient technique to remove nitrate from ground water is in high demand.RESULTIn this study, nanoscale zero valent iron (NZVI)/activated carbon (AC) nanocomposite material was successfully synthesized to form a highly efficient micro‐galvanic cell to be used in the chemical reduction of nitrate. Analysis of NZVI‐AC composites were conducted by BET, XRD, SEM, TEM and XPS, while utilizing sodium borohydride as a reducing agent in liquid phase reaction for the reduction of ferrous ions. Several factors during the preparation process were investigated for their effect on the performance of the material when used for the reduction of nitrate in aqueous media. Experiment results demonstrated that the material prepared under optimized preparation conditions can remove up to 94.3% of nitrates with composites at 2.1 g L−1. The final degradation products are mainly N2 and .CONCLUSIONThe composites were found to behave more efficiently for nitrate removal when compared with NZVI. In addition, the production of these new composite materials can be economically scaled up as with NZVI, which is necessary for practical environmental remediation. © 2016 Society of Chemical Industry

Enhanced UV–visible response of bismuth subcarbonate nanowires for degradation of xanthate and photocatalytic reaction mechanism

(BiO)2CO3 nanowires were prepared by simple hydrothermal treatment of commercial Bi2O3 powders and characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of (BiO)2CO3 nanowires was studied through degradation of sodium isopropyl xanthate. Photocatalytic experimental results indicated that the as-prepared (BiO)2CO3 nanowires show high photocatalytic efficiency. Photocatalytic activity increased after two cycles. Time-dependent UV–vis spectra demonstrated that the final degradation products included isopropyl alcohol and carbon disulfide. UV–vis diffuse reflection spectra showed that the band gap of the as-prepared (BiO)2CO3 nanowires and recycled (BiO)2CO3 nanowires were 2.75 eV and 1.15 eV, respectively. XPS results indicated that formation of Bi2S3@(BiO)2CO3 core–shell nanowires occurred after recycled photodegradation of isopropyl xanthate owing to existence of two types of Bi configurations in the recycled (BiO)2CO3 nanowires. A probable degradation mechanism of isopropyl xanthate was also proposed.

Toxicity assessment of perfluorooctane sulfonate using acute and subchronic male C57BL/6J mouse models

Perfluorooctane sulfonate (PFOS) is a principal representative and the final degradation product of several commercially produced perfluorinated compounds. However, PFOS has a high bioaccumulation potential and therefore can exert toxicity on aquatic organisms, animals, and cells. Considering the widespread concern this phenomenon has attracted, we examined the acute and subchronic toxic effects of varying doses of PFOS on adult male C57BL/6 mice. The acute oral LD50 value of PFOS in male C57BL/6J mice was 0.579 g/kg body weight (BW). Exposure to the subchronic oral toxicity of PFOS at 2.5, 5, and 10 mg PFOS/kg BW/day for 30 days disrupted the homeostasis of antioxidative systems, induced hepatocellular apoptosis (as revealed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay), triggered liver injury (as evidenced by the increased serum levels of aspartate aminotransferase, alanine amino transferase, alkaline phosphatase, and gamma-glutamyl transpeptidase and by the altered histology), and ultimately increased the liver size and relative weight of the mice. PFOS treatment caused liver damage but only slightly affected the kidneys and spleen of the mice. This study provided insights into the toxicological effects of PFOS.

Degradation of Triton X‐100 in Water Falling Film Dielectric Barrier Discharge Reactor

The aim of this study was to investigate the degradation of the non‐ionic surfactant Triton X‐100 (TX‐100) by using an advanced oxidation process in a non‐thermal plasma reactor based on water falling film dielectric barrier discharge (DBD). The effects of two catalytic plasma systems, Fe2+/DBD and H2O2/DBD, were tested to improve the degradation of TX‐100 and the mineralization efficiency in the DBD reactor. Both catalytic systems exhibited significant improvements in degradation efficiency, especially in the beginning of the treatment: the efficiency increased from 23 to 88 and 50%, for 5 mg L−1 Fe2+/DBD and 10 mmol L−1 H2O2/DBD, respectively. The mineralization efficiency of TX‐100 in the non‐catalytic DBD treatment was very low (1%), but with addition of catalysts, the mineralization efficiency was drastically improved, with H2O2/DBD at 4–34% (depending on the H2O2 concentration) and Fe2+/DBD at 2–21% (depending on the Fe2+ concentration). Degradation products of TX‐100 in non‐catalytic and two catalytic systems were identified using UHPLC‐Orbitrap‐MS. Based on the degradation products that were identified, a simple mechanistic scheme was proposed. MS analysis revealed that degradation of TX‐100 in the DBD reactor occurred by shortening the ethoxy chain. In the presence of catalysts, there are additional reactions of cleavage of the alkyl chain followed by formation of polyethoxylated phenol (H2O2/DBD) and addition of OH• radicals onto the aromatic ring (Fe2+/DBD). The final degradation products did not cause any significant toxic effects to Vibrio fischeri or Artemia salina.

The contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using diamond anodes

In this work, the contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using boron-doped diamond (BDD) anodes was investigated in different electrolytes. A complete mineralization of cyanuric acid was obtained in NaCl; however lower degrees of mineralization of 70% and 40% were obtained in Na2SO4 and NaClO4, respectively. This can be explained by the nature of the oxidants electrogenerated in each electrolyte. It is clear that the contribution of active chlorine (Cl2, HClO, ClO−) electrogenerated from oxidation of chlorides on BDD is much more important in the electrolytic degradation of cyanuric acid than the persulfate and hydroxyl radicals produced by electro-oxidation of sulfate and water on BDD anodes. This could be explained by the high affinity of active chlorine towards nitrogen compounds. No organic intermediates were detected during the electrolytic degradation of cyanuric acid in any the electrolytes, which can be explained by their immediate depletion by hydroxyl radicals produced on the BDD surface. Nitrates and ammonium were the final products of electrolytic degradation of cyanuric acid on BDD anodes in all electrolytes. In addition, small amounts of chloramines were formed in the chloride medium. Low current density (≤10mA/cm2) and neutral medium (pH in the range 6–9) should be used for high efficiency electrolytic degradation and negligible formation of hazardous chlorate and perchlorate.

The function and development of standards for a newly commercialized technology � absorbable metallic implants

The function and development of standards for a newly commercialized technology � absorbable metallic implants

The effect of PLGA-PEG-PLGA modification on the sol-gel transition and degradation properties

This paper deals with the influence of an incubation medium pH on the hydrolytic degradation of a novel thermosensitive biodegradable triblock copolymer based on hydrophilic poly(ethylene glycol) and hydrophobic copolymer poly(lactic acid-co-glycolic acid) (PLGA-PEG-PLGA), consequently modified at ,#-ends with itaconic acid (ITA) resulting in ,#-itaconyl(PLGA-PEG-PLGA). Itaconic acid, obtained from renewable resources, delivers a reactive double bond and carboxylic functional group to the end of PLGA-PEG-PLGA copolymer: this is important for a reaction with biologically active substances. The suitability of the sample degradation was assessed depending on whether the copolymer formed a gel at 37°C. Two reversible physical sol-gel-sol transitions from a sol (liquid phase) to a gel (solid phase) and back to a sol (suspension) were verified using the tube inverting method. The hydrolytical degradation was evaluated at a physiological temperature (37°C) in the presence of phosphate solutions, at a pH of either 4.2 or 7.4 by monitoring the decrease of the number average molecular weight of copolymers by GPC. Moreover, the degradation kinetics was confirmed by the HPLC/DAD method, where the increasing amount of final degradation products (lactic and glycolic acids) was detected. The study demonstrated that the carboxylic groups modified copolymer (ITA/PLGA–PEG– PLGA/ITA) is more susceptible to hydrolytical degradation than the unmodified copolymer within first days of degradation at pH 7.4.

Debromination of 1,2,4,5-Tetrabrominated Benzene in Alcohol Solution with Nanoscale Pd/C Particles: Factors, Pathways, and Mechanism

In this study, the catalytic debromination of 1,2,4,5-tetrabrominated benzene (1245TBB) was performed in a solution of NaOH in alcohol (Visopropanol:Vmethanol = 99:1) in the presence of a nanoscale catalyst Pd/C at a temperature of 50°C. The final degradation product of 1,2,4,5-tetrabrominated benzene is benzene. The debromination efficiency of 1245TBB and its degraded intermediate products (1,2,4-tribromobenzene, 1,2,-dibromobenzene, and bromobenzene) were highly dependent on the Pd/C loading and NaOH concentration. The catalyst life was evaluated, which showed that the deactivated catalyst could be reactivated about 30% after washing with 100 mmol L-1 NaOH solution in isopropanol. The possible 1245TBB debromination mechanism and pathways are also proposed and discussed in this study.

A 2-Hydroxypyridine Catabolism Pathway in Rhodococcus rhodochrous Strain PY11.

Rhodococcus rhodochrous PY11 (DSM 101666) is able to use 2-hydroxypyridine as a sole source of carbon and energy. By investigating a gene cluster (hpo) from this bacterium, we were able to reconstruct the catabolic pathway of 2-hydroxypyridine degradation. Here, we report that in Rhodococcus rhodochrous PY11, the initial hydroxylation of 2-hydroxypyridine is catalyzed by a four-component dioxygenase (HpoBCDF). A product of the dioxygenase reaction (3,6-dihydroxy-1,2,3,6-tetrahydropyridin-2-one) is further oxidized by HpoE to 2,3,6-trihydroxypyridine, which spontaneously forms a blue pigment. In addition, we show that the subsequent 2,3,6-trihydroxypyridine ring opening is catalyzed by the hypothetical cyclase HpoH. The final products of 2-hydroxypyridine degradation in Rhodococcus rhodochrous PY11 are ammonium ion and α-ketoglutarate.

Mobility and degradation of disulfoton in coffee culture soil

Abstract Mobility and degradation of the insecticide disulfoton (DST) in the soil were studied in this work, through leaching columns spiked with the analytical standard solution and the commercial product Baysiston ® . In both experiments, the DST presented low mobility, keeping the upper layer of the soil, while its degradation products, mainly the disulfoton sulfone (DSA) and oxygen analogue of disulfoton sulfone (OADSA) percolated into deeper soil layers. Such behavior confirms its potential for contamination of soil and groundwater. It has also been proposed a new DST degradation route wherein oxygen analogue of disulfoton (AODST) can be oxidized to the final degradation product (AODSA) by direct and/or indirect conversion.

Photocatalytic Degradation of Gaseous Formaldehyde by Modified Hierarchical TiO2 Nanotubes at Room Temperature

As a major indoor air pollutant, formaldehyde released from building and furnishing materials is one of the main volatile organic compounds (VOCs). Hierarchical TiO2 nanotube arrays (TiO2 NTs) prepared via a facile two-step anodization showed excellent photocatalytic (PC) degradation of formaldehyde at room temperature. Modification with noble metal nanoparticles (NMNs) could further improve the PC activity of TiO2 NTs. The final products of formaldehyde degradation were detected to be CO2 and H2O, which indicated that the mineralization of formaldehyde was the major process in this PC reaction. The reaction rate constants (k) determined for the three catalysts were in the order kTiO2 NTs < kAu/TiO2 NTs < kPt/TiO2 NTs (Pt/TiO2 NTs had the highest PC ability). The significant enhancement of PC performance can be ascribed to the formation of a Schottky junction between the NMNs and TiO2 NTs.

Effect of time and temperature on the sensitivity of C3d complement detection with HLA single antigen beads

The C3d Detection assay, consisting of PE-labeled anti-human C3d antibody, Complement Serum and a Positive Control for C3d, is a reagent set used for the qualitative detection of complement C3d bound to antibodies/antigen complex. These reagents used in conjunction with a solid phase assays, such as Immucor’s HLA recombinant single antigen beads, have the ability to detect donor specific HLA antibodies (DSA) and may help identify C3d+DSA+ patients with higher risk of organ rejection (Sicard A et al. J Am Soc Nephrol. 2015 26: 457–67). C3d is one of the final degradation product of C3, it binds to antigen and interacts with CR2 on B-cells stimulating there proliferation. C3 is a key protein in the complement system, since it is the most abundant protein and has the ability to activate itself which greatly magnifies the response and C3d production. The other major end product of C3 are the components of the membrane attack complex (MAC) that form the basis of the complement dependent cytotoxicity (CDC) assay. The objective of this study was to examine the correlation of the C3d/HLA single antigen assay with CDC and at parameters that may increase C3d production thus increasing sensitivity of C3d Detection in serum with low titer HLA antibody. In vitro studies have shown that the formation of the final components of the complement cascade are temperature and time dependent. Our results with the Luminex-based C3d Detection assay confirmed that observation and showed that incubation with Complement Serum at increasing temperatures (from 20 °C to 27 °C) and/or longer times (from 30 to 120 minutes) will result in several fold increase of the C3d specific MFI values of low titer serum. This results in increased sensitivity, easier interpretation of the results and significant increase in the correlation of C3d with the CDC assay. In conclusion, the ability to vary the sensitivity of the C3d assay may increase its utility in analyzing patient samples and potentially complement (no pun intended) the standard CDC assay. D. Dalfo: Employee; Company/Organization; Immucor. N. Jiang: Employee; Company/Organization; Immucor. A. Contreras: Employee; Company/Organization; Immucor. I. Balazs: Employee; Company/Organization; Immucor.

Recombinant Trichoderma harzianum endoglucanase I (Cel7B) is a highly acidic and promiscuous carbohydrate-active enzyme.

Trichoderma filamentous fungi have been investigated due to their ability to secrete cellulases which find various biotechnological applications such as biomass hydrolysis and cellulosic ethanol production. Previous studies demonstrated that Trichoderma harzianum IOC-3844 has a high degree of cellulolytic activity and potential for biomass hydrolysis. However, enzymatic, biochemical, and structural studies of cellulases from T. harzianum are scarce. This work reports biochemical characterization of the recombinant endoglucanase I from T. harzianum, ThCel7B, and its catalytic core domain. The constructs display optimum activity at 55 °C and a surprisingly acidic pH optimum of 3.0. The full-length enzyme is able to hydrolyze a variety of substrates, with high specific activity: 75 U/mg for β-glucan, 46 U/mg toward xyloglucan, 39 U/mg for lichenan, 26 U/mg for carboxymethyl cellulose, 18 U/mg for 4-nitrophenyl β-D-cellobioside, 16 U/mg for rye arabinoxylan, and 12 U/mg toward xylan. The enzyme also hydrolyzed filter paper, phosphoric acid swollen cellulose, Sigmacell 20, Avicel PH-101, and cellulose, albeit with lower efficiency. The ThCel7B catalytic domain displays similar substrate diversity. Fluorescence-based thermal shift assays showed that thermal stability is highest at pH 5.0. We determined kinetic parameters and analyzed a pattern of oligosaccharide substrates hydrolysis, revealing cellobiose as a final product of C6 degradation. Finally, we visualized effects of ThCel7B on oat spelt using scanning electron microscopy, demonstrating the morphological changes of the substrate during the hydrolysis. The acidic behavior of ThCel7B and its considerable thermostability hold a promise of its industrial applications and other biotechnological uses under extremely acidic conditions.

Mechanochemical degradation of hexachlorobenzene using Mg/Al2O3 as additive

In the present work, we investigate the destruction efficiency of hexachlorobenzene (HCB) by milling with various reagents in a planetary ball mill under different milling conditions. Under the same conditions of mill rotary rate and charge ratio, the mixture of magnesium powder and aluminum oxide (Mg/Al2O3) was found best in promoting the destruction of HCB, which can be completed destroyed after 90 min grinding at a charge ratio of 20:1 (reagent/HCB, m/m), a ball mass/reagent mass ration of 30:1 and a mill rotation speed of 550 rpm. The ground samples were characterized and analyzed by X-ray fluorescence, gas chromatography (GC), X-ray diffraction and ion chromatography. The intermediate products, such as pentachlorobenzene, tetrachlorobenzene, trichlorobenzene isomers, dichlorobenzene and monochlorobenzene were detected by GC. Then the main dechlorination path way for HCB was proposed. With a series of verification experiments, the final degradation products of HCB were amorphous carbon and inorganic chlorine. Based on this study, Mg/Al2O3 has the potential to complete the innocuous treatment of chlorinated compounds.