Characteristics and inhibition of mercury re-emission from desulfurization slurry by Fenton reagent

Hao, W.; Chen, Hen; Wang, Qianwen; Yang, Hongmin

doi:10.1016/j.fuproc.2019.02.006

Cited by 16 publications

(9 citation statements)

References 42 publications

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“…Besides, reaction temperature plays a significant role in the gaseous diffusion of Hg 0 and the collision opportunity between Hg 2+ and S(IV) species. Increasing slurry temperature was revealed to remarkably promote Hg 2+ reducing to Hg 0 . , A decline of pH values can also enhance Hg 0 re-emission, where the mercury proportions in solid and liquid phases were found to decrease simultaneously. , Moreover, the flue gas components or the ions coexisted in desulfurization liquid also have some impacts on mercury re-emission and migration. ,− Under a typical air atmosphere, O 2 was confirmed to inhibit Hg 0 re-emission and promote the stabilization of mercury in the liquid phase. ,, The results of the study by Liu et al and Wo et al indicated that NO 3 – has neglected impact on Hg 0 re-emission. More mercury would be retained in the liquid phase in the presence of Cl – or excess NO 2 – due to the complexation with Hg 2+ .…”

Section: Introductionmentioning

confidence: 96%

“…14,15 A decline of pH values can also enhance Hg 0 re-emission, where the mercury proportions in solid and liquid phases were found to decrease simultaneously. 13,16 Moreover, the flue gas components or the ions coexisted in desulfurization liquid also have some impacts on mercury re-emission and migration. 15,17−21 Under a typical air atmosphere, O 2 was confirmed to inhibit Hg 0 reemission and promote the stabilization of mercury in the liquid phase.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, Hg 0 re-emission is undesired, especially in oxy-fuel combustion. To avoid the above problems caused by Hg 0 re-emission, a lot of work has been carried out to investigate the characteristics of mercury re-emission and migration in WFGD systems. − The sulfur species (SO 3 2– and HSO 3 – ) in desulfurization liquid are identified as the main reason for Hg 0 re-emission. The reactions occurred under a N 2 atmosphere are summarized as follows − …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characteristics of Mercury Re-emission and Migration in a Lab-Scale Wet Flue Gas Desulfurization Scrubber under Simulated Air and Oxy-Fuel Combustion Atmospheres

Bao

Liu

et al. 2020

Energy Fuels

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Based on a lab-scale wet flue gas desulfurization scrubber, mercury re-emission and migration during the desulfurization process were experimentally investigated under simulated air and oxy-fuel combustion atmospheres. The effects of O 2 , CO 2 , and metal ions were especially studied. The results show that adding O 2 to a pure N 2 atmosphere can remarkably enhance Hg 0 re-emission because of an obvious decline of pH values, while the introduction of 75% CO 2 to N 2 atmosphere results in a limited Hg 0 re-emission because of a lower pH drop. The re-emission of Hg 0 is found to be slightly suppressed with increasing O 2 concentration from 3 to 9% under air atmosphere and from 3 to 6% under oxy-fuel combustion atmosphere. Moreover, a further increase of O 2 concentration to 12% has no significant impact on Hg 0 re-emission under these two atmospheres. At a higher CO 2 concentration, less mercury is re-emitted to the gas phase and more mercury is maintained in the solid phase. Under N 2 atmosphere, metal ions such as Fe 2+ , Mn 2+ , and Ni 2+ can intensify Hg 0 re-emission in the order of Fe 2+ > Ni 2+ > Mn 2+ . However, the reduction of mercury is inhibited by metal ions under air and oxy-fuel combustion atmospheres. The inhibitory effect of Fe 2+ is intensified with increasing CO 2 concentration. It can be concluded that the existence of Fe 2+ is more conducive to mercury control under oxy-fuel combustion atmosphere than that under air atmosphere.

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Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characteristics of Mercury Re-emission and Migration in a Lab-Scale Wet Flue Gas Desulfurization Scrubber under Simulated Air and Oxy-Fuel Combustion Atmospheres

Bao

Liu

et al. 2020

Energy Fuels

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“…In recent years, a series of additives, such as Fenton reagent, ethylenediaminetetraacetic acid (EDTA), sodium sulfide (Na 2 S), sodium hydrosulfide (NaHS), hydrogen iodide (HI), 2,4,6-trimercaptotiazine, trisodium salt nonahydrate (TMT), and sodium dithiocarbamate (DTCR), have been investigated to determine the precipitation properties of Hg 2+ . ,− Xu et al explored five addition agents to inhibit mercury re-emission and improve gaseous mercury removal, and the results showed that Fenton reagent and EDTA exhibited better performance on the inhibition of mercury re-emission. Ochoa-González et al found that Fenton reagent can prevent the reduction of Hg 2+ as H 2 O 2 was the precursor used to convert sulfite ions into sulfate or to oxidize Hg 0 , while TMT and NaHS in low doses also can prevent the reduction of Hg 2+ as insoluble HgS and Hg 3 (TMT) precipitate onto the gypsum slurry.…”

Section: Introductionmentioning

confidence: 99%

“…Researches have found that the accumulated Hg 2+ , which absorbed from the upstream flue gas, in the desulfurization slurry is unstable, and it may release from the slurry into the gas flow, causing a reduction in the overall mercury removal efficiency. 22 Moreover, the mercury concen- tration in the discharged gas flue can be even higher than that in the WFGD inlet flue gas in some cases. 23 This phenomenon is also known as mercury re-emission from the desulfurization slurry.…”

Section: Introductionmentioning

confidence: 99%

Characteristics and Kinetics Study of Mercury Re-emission Inhibited by DTCR in Simulated Desulfurization Slurry

2020

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The mercury re-emission characteristics and inhibition effect of sodium dithiocarbamate (DTCR) on mercury re-emission in a simulated desulfurization slurry were investigated. The effects of the desulfurization slurry parameters (including slurry temperature, initial pH value, O2 concentration, and Cl– concentration) on mercury re-emission with and without DTCR were explored. Moreover, the kinetic parameters (reaction order, reaction rate constant, and apparent activation energy) of mercury re-emission and inhibition were calculated by the experimental data. The results showed that addition of DTCR could effectively reduce the mercury re-emission from the desulfurization slurry. The mercury re-emission was enhanced with increases of the slurry temperature and initial pH, while O2 and Cl– in the slurry could inhibit the mercury re-emission. Further study shows that the mercury re-emission reaction processes in the desulfurization slurry with and without DTCR are both consistent with the pseudo-first-order kinetics. In the absence of DTCR, the reaction rate constant of mercury re-emission is 0.01888 min–1, and the apparent activation energy is 44.59 kJ/mol. In the presence of 0.002% DTCR, the reaction rate constant of mercury re-emission is 0.01126 min–1 and the apparent activation energy is 49.08 kJ/mol. Moreover, the effects of slurry parameters on the reaction rate constant were also explored. The present findings are valuable for coal-fired power plants to control mercury re-emission from a desulfurization slurry.

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Removal of Hg2+ from desulfurization wastewater by tannin-immobilized graphene oxide

Chen

Feng-jun

Cai

et al. 2021

Environ Sci Pollut Res

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A novel adsorbent by immobilizing tannic acid (TA) on graphene oxide (GO) was proposed and used to remove Hg 2+ from desulfurization wastewater. The morphology and physic-chemical property of tanninimmobilized graphene oxide (TAIGO) was characterized by Scanning electron microscopy (SEM), Atomic Force Microscope (AFM), and Fourier transform infrared spectroscopy (FTIR). The characterization results showed that the TA was immobilized on the GO successfully, and new functional groups were introduced on TAIGO. The effect of contact time, adsorbent dose, pH, and ion components on removal e ciency were evaluated. It was found that the adsorption process would complete within 15 min, and a higher removal e ciency could be obtained on the increased adsorbent dosage. The pH value would affect the protonation process of TAIGO and the form of Hg 2+ in the wastewater. The high-concertation Cland SO 3 2would hinder the absorption performance, while SO 4 2and cations had a negligible impact.Besides, an excellent economic bene t of TAIGO was achieved in the regeneration performance evaluation experiment, and removal e ciency of was 88% remained after three recycles. Most importantly, the TAIGO exhibited a better adsorption performance and economic bene t than GO and TA.The adsorption process was tted with the pseudo-second-order kinetic model(R=0.9995), and the adsorption of TAIGO for Hg 2+ was mainly relies on the functional groups on GO and the chelation reaction between TA and Hg 2+ . These facts indicated that the TAIGO was a low-cost and high removal ofHg 2+ e ciency adsorbent, which could be further used in the practical desulfurization wastewater.

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Characteristics and inhibition of mercury re-emission from desulfurization slurry by Fenton reagent

Cited by 16 publications

References 42 publications

Characteristics of Mercury Re-emission and Migration in a Lab-Scale Wet Flue Gas Desulfurization Scrubber under Simulated Air and Oxy-Fuel Combustion Atmospheres

Characteristics of Mercury Re-emission and Migration in a Lab-Scale Wet Flue Gas Desulfurization Scrubber under Simulated Air and Oxy-Fuel Combustion Atmospheres

Characteristics and Kinetics Study of Mercury Re-emission Inhibited by DTCR in Simulated Desulfurization Slurry

Removal of Hg2+ from desulfurization wastewater by tannin-immobilized graphene oxide

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