Hydrodechlorination/detoxification of PCDDs, PCDFs, and co-PCBs in fly ash by using calcium polysulfide

Tabata, Masaaki; Ghaffar, Abdul; Shono, Akifumi; Notomi, Keiichi

doi:10.1016/j.wasman.2012.10.019

Cited by 14 publications

(4 citation statements)

References 22 publications

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“…Despite strong reducing media, the existence of chlorobenzene in reaction media suggests the stability of this compound. The removal of chloride atom from chlorobenzene to produce benzene is always a difficult task because of the C-Cl bond which is persistent in nature as suggested by other researchers [16][17][18].…”

Section: Resultsmentioning

confidence: 99%

Two-Phase Dechlorination/Detoxification of Lindane (Hexachlorocyclohexane)

Ghaffar

Tabata

Mashiatullah

2014

Advances in Environmental Chemistry

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Dechlorination of lindane was carried out in a two-phase reaction. In first phase Devarda's alloy and sodium borohydride were used in aqueous/ethanol reaction media. The reaction duration and temperature were optimized. In first phase higher dechlorination (78%) was achieved at 80 ∘ C with 40-minute reaction time and the products were chlorobenzene, dichlorobenzene, and chlorocyclohexane. In second phase, Ca(OH) 2 and sulfur were added in reaction media. The reactions conditions like temperature and reaction time were optimized. After 30 minutes, dechlorination was enhanced from 78% to 94% and the final products were benzene, phenol, catechol, benzenethiol, cyclohexane, cyclohexanol, and cyclohexanethiol. The results suggested that dechlorination of lindane in first and second phase was carried out through hydrodechlorination and substitution reactions, respectively. The developed method was applied for lindane containing real wastewater and higher dechlorination (91%) was achieved under optimized reaction conditions.

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Section: Resultsmentioning

confidence: 99%

Two-Phase Dechlorination/Detoxification of Lindane (Hexachlorocyclohexane)

Ghaffar

Tabata

Mashiatullah

2014

Advances in Environmental Chemistry

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“…Typically, the decrease in Cl 2 will significantly impede the de novo synthesis. Furthermore, active radicals such as hydrogen radicals (H•) via thermal ionization in the presence of moisture might impede the formation of dioxins or attack the C-l bonds to form aromatic compounds [43,44], as shown in Figure 6. The C-Cl bond is easy to attack by active radicals because too many chlorine atoms would weaken the binding force of C and Cl [45,46] The results also prove that the chlorine atoms on the longitudinal (1,4,6,9) positions are preferentially removed compared to the chlorine atoms on lateral (2,3,7,8) positions [47].…”

Section: Inhibition Mechanismsmentioning

confidence: 99%

The Effect of Adjusting Sinter Raw Mix on Dioxins from Iron Ore Co-Sintering with Municipal Solid Waste Incineration Fly Ash

Guo

Peng

et al. 2022

Energies

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The inhibition effect of calcined lime (CaO) and limestone (CaCO3) on the formation of dioxins during iron ore co-sintering with fly ash was investigated in a sinter pot in the present work. Experimental results indicated that international total toxicity equivalent concentration of dioxins decreased from 1.4335 to 0.2922, 0.1048, 0.4562, and 0.3098 ng I-TEQ Nm−3 under four different experimental conditions. It can be concluded that 5 wt.% calcined lime with 3 wt.% limestone is the optimal addition to reduce the concentration of dioxins in flue gas, with 92.70% inhibition efficiency. Effects on dioxin distribution was also analyzed. The distribution proportion of low-chlorinated dioxins was found to increase, while that of high-chlorinated dioxins decreased, except for octachlorianted dibenzo-p-dioxins (OCDD). The reason is that the consumption of HCl not only inhibits the de novo synthesis, but also dramatically promotes the condensation and dechlorination to produce more tetrachlorianted dibenzo-p-dioxins and octachlorianted dibenzo-p-dioxins through precursors. Finally, condensation, dichlorination, and inhibition mechanisms of dioxins during co-sintering with municipal solid waste incineration (MSWI) fly ash are proposed.

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“…[3,4] The catalytic hydro-dehalogenation is the best technique to treat industrial waste in a cost-effective way. [5,6] These kinds of reactions are eco-friendly and environmentally sustainable process. [7][8][9] M. Yus et al reviewed various types of metal-mediated hydro-dehalogenation systems in detail.…”

Section: Introductionmentioning

confidence: 99%

“…to treat their waste that contains halogens. [6,[18][19][20] There are several catalytic systems reported for the hydrodehalogenation process and some of them use transition metal catalysts. The major catalytic methods used for this reaction in the past few decades are Pd, [21][22][23] Ru, [24] Rh, [25,26] Ni, [27,28] Fe, [29] Cu, [30] and etc.…”

Section: Introductionmentioning

confidence: 99%

Advantage of Using NaH₂PO₂ over Alkali Metal Formates as a Hydrogen Source for Pd‐gC₃N₄ Catalyzed Hydro‐Dehalogenation of Aryl Halides

2021

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Halogenated and polyhalogenated aromatic compounds are known for their toxicity and effect on human health and the environment. These aromatic hydrocarbons have been widely used in pesticides, flame retardants, pharmaceuticals, and other industrial chemicals. The substitution of halogen atoms of aromatic halides by hydrogen atoms in the presence of a metal catalyst is an important organic transformation and is known as a catalytic hydro-dehalogenation reaction. It is an important technique used for the treatment of halogenated industrial waste. Herein, we investigated the comparative hydro-dehalogenation of aryl halides in the presence of Pd-gC 3 N 4 catalyst using various hydrogen transfer sources in an eco-friendly manner. We also investigated the advantage of using sodium hypophosphite (NaH 2 PO 2 ) as a hydrogen source for hydrodehalogenation in comparison to alkali metal formates. For hydro-dehalogenation of 1 mmol of aryl halide, 2 equivalents of NaH 2 PO 2 are used while 4 equivalents of KHCO 2 are required in the presence of 3.8 wt % of Pd metal catalyst. The Pd-GCN catalyst was characterized by various microscopic and spectral techniques such as PXRD, FTIR, SEM, TEM, XPS, and TGA, etc. A gram scale reaction was performed to analyze the industrial potential of the proposed catalytic system. Finally, the recyclability of Pd-GCN was found excellent and the catalyst could run multiple cycles with sustained activity.

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Hydrodechlorination/detoxification of PCDDs, PCDFs, and co-PCBs in fly ash by using calcium polysulfide

Cited by 14 publications

References 22 publications

Two-Phase Dechlorination/Detoxification of Lindane (Hexachlorocyclohexane)

Two-Phase Dechlorination/Detoxification of Lindane (Hexachlorocyclohexane)

The Effect of Adjusting Sinter Raw Mix on Dioxins from Iron Ore Co-Sintering with Municipal Solid Waste Incineration Fly Ash

Advantage of Using NaH₂PO₂ over Alkali Metal Formates as a Hydrogen Source for Pd‐gC₃N₄ Catalyzed Hydro‐Dehalogenation of Aryl Halides

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Hydrodechlorination/detoxification of PCDDs, PCDFs, and co-PCBs in fly ash by using calcium polysulfide

Cited by 14 publications

References 22 publications

Two-Phase Dechlorination/Detoxification of Lindane (Hexachlorocyclohexane)

Two-Phase Dechlorination/Detoxification of Lindane (Hexachlorocyclohexane)

The Effect of Adjusting Sinter Raw Mix on Dioxins from Iron Ore Co-Sintering with Municipal Solid Waste Incineration Fly Ash

Advantage of Using NaH2PO2 over Alkali Metal Formates as a Hydrogen Source for Pd‐gC3N4 Catalyzed Hydro‐Dehalogenation of Aryl Halides

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Advantage of Using NaH₂PO₂ over Alkali Metal Formates as a Hydrogen Source for Pd‐gC₃N₄ Catalyzed Hydro‐Dehalogenation of Aryl Halides