Degradation of sodium n-butyl xanthate by vacuum UV-ozone (VUV/O3) in comparison with ozone and VUV photolysis

Fu, Pingfeng; Feng, Jie; Yang, Huifen; Yang, Teng‐Kuei

doi:10.1016/j.psep.2016.02.010

Cited by 52 publications

(24 citation statements)

References 25 publications

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“…To calculate the energy requirements for the ozonation, an average energy consumption of 15 kWh/kg for the O 3 production was assumed [53], and the energy calculations were based on a 90% removal of collectors. EE/O values (kWh/(m 3 •order)) were calculated for batch operations as given by Equation (12). EE/O = P × 1000 V × 60 × ln 10 k collector (12) where P was the electric power (kWh) required for producing dosed O 3 , V was the volume (L) of test collector solution, and k collector was the pseudo-first-order constant (min −1 ).…”

Section: Analysis Of Energy Consumption Efficiencymentioning

confidence: 99%

“…EE/O values (kWh/(m 3 •order)) were calculated for batch operations as given by Equation (12). EE/O = P × 1000 V × 60 × ln 10 k collector (12) where P was the electric power (kWh) required for producing dosed O 3 , V was the volume (L) of test collector solution, and k collector was the pseudo-first-order constant (min −1 ).…”

Section: Analysis Of Energy Consumption Efficiencymentioning

confidence: 99%

“…In the past decades, numerous methods have been developed to remove organic reagents from flotation effluents, such as coagulation and precipitation [7], adsorption [8], chemical oxidation [9], advanced oxidation [10][11][12], and biodegradation [13,14]. Adsorption is an efficient and simple technique in removing flotation reagents, but further treatment of sludge with toxic reagents and high water content becomes very difficult.…”

Section: Introductionmentioning

confidence: 99%

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Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Lin

et al. 2018

Minerals

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Ozonation at a high O3 dosage can achieve high efficiencies in removing flotation reagents but it has a low ozone-utilization rate. The ozonation of potentially toxic thiol collectors (potassium ethyl xanthate (EX), sodium diethyl dithiocarbamate (SN-9), O-isopropyl-N-ethyl thionocarbamate (Z-200) and dianilino dithiophoshoric acid (DDA)) was investigated in an ozone-bubbled reactor at a low O3 dosage of 1.125 mg/(min·L). The degradation kinetics, mineralization, ozone utilization, changes of biodegradability, and water quality parameters were studied, and the degradation behaviors of four collectors were compared. Thiol collectors could be effectively degraded with a removal ratio of >90% and a mineralization ratio of 10‒27%, at a low O3 dosage. The ozonation of thiol collectors followed the pseudo first-order kinetics, and rate constants had the order of kSN-9 > kEX > kZ-200 > kDDA. The Z-200 and DDA were the refractory flotation reagents treated in the ozonation process. After ozonation, the biodegradability of EX, SN-9, and DDA solutions was remarkably raised, but the biodegradability of Z-200 only increased from 0.088 to 0.15, indicating that the Z-200 and its intermediates were biologically persistent organics. After ozonation, the solution pH decreased from 10.0 to 8.0‒9.0, and both the conductivity and oxidation-reduction potential increased. The ozone utilization ratio in decomposing thiol collectors was above 98.41%, revealing almost complete usage of input O3. The results revealed that thiol collectors could be effectively degraded by O3, even at a low dosage, but their degradation behaviors were quite different, due to intrinsic molecular properties.

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Section: Analysis Of Energy Consumption Efficiencymentioning

confidence: 99%

Section: Analysis Of Energy Consumption Efficiencymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Lin

et al. 2018

Minerals

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“…As shown in figure 4, the concentration of SO 4 2− ions increased up to 90.36 mg l −1 for PEX, 64.79 mg l −1 for SDD, 26.90 mg l −1 for IET and 11.48 mg l −1 for DDA, respectively, under UV 185+254 nm irradiation for 120 min. The SO 4 2− ions were the final sulfur product in the oxidation of organic sulfur in thiol collectors [11,12,24]. The occurrence of SO 4 2− ions with increased concentrations well demonstrated that organic sulfur of collectors could be completely mineralized [24].…”

Section: Resultsmentioning

confidence: 99%

UV _{185+254 nm} photolysis of typical thiol collectors: decomposition efficiency, mineralization and formation of sulfur byproducts

et al. 2019

R. Soc. open sci.

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The decomposition of toxic flotation reagents upon UV 185+254 nm irradiation was attractive due to operational simplicity and no dosage of oxidants. In this work, the degradation of typical thiol collectors (potassium ethyl xanthate (PEX), sodium diethyl dithiocarbamate (SDD), O -isopropyl- N -ethyl thionocarbamate (IET) and dianilino dithiophoshoric acid (DDA)) was investigated by UV 185+254 nm photolysis. The degradation efficiencies and mineralization extents of collectors were assessed. The formation of CS 2 and H 2 S byproducts was studied, and the mechanisms of collector degradation were proposed under UV 185+254 nm irradiation. The PEX, SDD and IET were decomposed with nearly 100% removal upon 75 min of UV 185+254 nm irradiation. The decomposition rate constants decreased in the order SDD > PEX > IET ≫ DDA, and the DDA was the refractory collector. After 120 min of UV 185+254 nm irradiation, 15−45% of carbon and 25−75% of sulfur of collectors were completely mineralized, and the mineralization extent decreased in the order PEX > SDD > IET > DDA. The percentage of gaseous sulfur (CS 2 and H 2 S) ranged from 0.48 to 4.85% for four collectors, showing the fraction of emitted sulfur byproducts was small. The aqueous CS 2 concentration increased in the first 10−20 min, and was decreased to a low level of 0.05–0.1 mg l −1 at 120 min. Two mechanisms, i.e. direct UV 254 nm photolysis and indirect oxidation with free radicals, were responsible for collector decomposition in the UV 185+254 nm photolysis.

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“…It has been well documented that sulfur byproducts, such as carbon disulde (CS 2 ), carbonyl sulde (COS), hydrogen sulde ), are generated during the degradation of xanthate collectors by the AOPs. 26,33,35,36 In this case, the DDC collector had same functional -CSS À group as the xanthates. Thus, above-mentioned sulfur byproducts might be also generated while the DDC was degraded.…”

Section: Generation Of Cs 2 and H 2 S Byproductsmentioning

confidence: 99%

Ozone and ozone/vacuum-UV degradation of diethyl dithiocarbamate collector: kinetics, mineralization, byproducts and pathways

Yang

et al. 2019

RSC Adv.

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Degradation of sodium n-butyl xanthate by vacuum UV-ozone (VUV/O3) in comparison with ozone and VUV photolysis

Cited by 52 publications

References 25 publications

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

UV _{185+254 nm} photolysis of typical thiol collectors: decomposition efficiency, mineralization and formation of sulfur byproducts

Ozone and ozone/vacuum-UV degradation of diethyl dithiocarbamate collector: kinetics, mineralization, byproducts and pathways

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Degradation of sodium n-butyl xanthate by vacuum UV-ozone (VUV/O3) in comparison with ozone and VUV photolysis

Cited by 52 publications

References 25 publications

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

UV 185+254 nm photolysis of typical thiol collectors: decomposition efficiency, mineralization and formation of sulfur byproducts

Ozone and ozone/vacuum-UV degradation of diethyl dithiocarbamate collector: kinetics, mineralization, byproducts and pathways

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UV _{185+254 nm} photolysis of typical thiol collectors: decomposition efficiency, mineralization and formation of sulfur byproducts