After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds （VOSCs）： methanethiol （MESH）, dimethyl sulfide （DMS）, dime^yl disulfide （DMDS）, d...After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds （VOSCs）： methanethiol （MESH）, dimethyl sulfide （DMS）, dime^yl disulfide （DMDS）, dimethyl trisulfide （DMTS） and dimethyl tetrasulfide （DMTeS）. Even in the untreated control without a methionine addition, methionine and its catabolites （VOSCs, mainly DMDS） were found in considerable amounts that were high enough to account for the water＇s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine＋glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.展开更多
Simultaneous removal of hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) in off-gas mixture from a wastewater treatment plant (WWTP) is difficult due to the occasional inhibitory effects of H2S on ...Simultaneous removal of hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) in off-gas mixture from a wastewater treatment plant (WWTP) is difficult due to the occasional inhibitory effects of H2S on VOSC degradation. In this study, a two-stage bio-trickling filter (BTF) system was developed to treat off-gas mixture from a real WWTP facility. At an empty bed retention time of 40 s, removal efficiencies of H2S, methanethiol, dimethyl sulfide, and dimethyl disulfide were 90.1, 88.4, 85.8 and 61.8%, respectively. Furthermore, the effect of lifting load shock on system performance was investigated and results indicated that removal of both H2S and VOSCs was slightly affected. Illumina Miseq sequencing revealed that the microbial community of first-stage BTF contained high abundance of H2S-affinity genera including Acidithiobacillus (51.43%), Metallibacterium (25.35%), and Thionomas (8.08%). Analysis of mechanism demonstrated that first stage of BTF removed 86.1% of H2S, mitigating the suppression on VOSC degradation in second stage of BTF. Overall, the twostage BTF system, an innovative bioprocess, can simultaneously remove H2S and VOSC.展开更多
Hydrogen fuel cells are among the promising energy sources worldwide,which could accomplish cyclic production of energy and avoid the emission of green-house or contaminative byproducts.However,sulfur compounds(SCs)ev...Hydrogen fuel cells are among the promising energy sources worldwide,which could accomplish cyclic production of energy and avoid the emission of green-house or contaminative byproducts.However,sulfur compounds(SCs)even at trace level(nmol/mol)are usually involved in cell construction and further H_(2)production,which would cause degradation of the catalysts and shorten the lifetime of the fuel cells.Moreover,the highly reactive SCs could cause varied species and concentrations of them in complex matrices,so online rather than offline analysis of SCs in H_(2)would be preferred.In this context,we developed a new system combining online cryogenic preconcentration of nine SCs and subsequent determination by GC-SCD(sulfur chemiluminescent detector),with the correlation coefficients of the calibration curves higher than 0.999,calculated limits of detection no higher than 0.050 nmol/mol,analytical time around 30 min per sample,and satisfactory precision and accuracy(RSD<5%and SD<15%).The analytical performance was much better than or at least comparable to the previously reported and the developed system was successfully applied for real sample analysis.展开更多
采用气相色谱-离子迁移谱技术,建立了检测畜禽有机废物堆肥中挥发性硫化合物-甲硫醚、乙硫醚、二甲基二硫醚和二硫化碳的方法。样品经除氨后用采气袋收集,经MXT-1气相色谱填充柱分离,采用正、负两种模式,在优化的载气流量和系统温度条...采用气相色谱-离子迁移谱技术,建立了检测畜禽有机废物堆肥中挥发性硫化合物-甲硫醚、乙硫醚、二甲基二硫醚和二硫化碳的方法。样品经除氨后用采气袋收集,经MXT-1气相色谱填充柱分离,采用正、负两种模式,在优化的载气流量和系统温度条件下进行检测。结果表明,4种挥发性硫化合物在各自线性范围内均表现出良好的线性关系(R^(2)>0.99);检出限为0.008~0.097 mg/m^(3),回收率为85%~116%,相对标准偏差(Relative Standard Deviation,RSD)为1.13%~8.42%。该方法无需浓缩富集等预处理,仅采用气袋就可完成堆肥恶臭气体的收集,检测灵敏、响应快速,可用于堆肥气体中挥发性硫化合物的现场监测。展开更多
The PdPtVO_(x)/CeO_(2)-ZrO_(2)(PdPtVO_(x)/CZO)catalysts were obtained by using different approaches,and their physical and chemical properties were determined by various techniques.Catalytic activities of these materi...The PdPtVO_(x)/CeO_(2)-ZrO_(2)(PdPtVO_(x)/CZO)catalysts were obtained by using different approaches,and their physical and chemical properties were determined by various techniques.Catalytic activities of these materials in the presence of H_(2)O or SO_(2)were evaluated for the oxidation of ethylbenzene(EB).The PdPtVO_(x)/CZO sample exhibited high catalytic activity,good hydrothermal stability,and reversible sulfur dioxide-poisoning performance,over which the specific reaction rate at 160℃,turnover frequency at 160℃(TOF_(Pd or Pt)),and apparent activation energy were 72.6 mmol/(g_(Pt)·sec)or 124.2 mmol/(g_(Pd)·sec),14.2 sec^(-1)(TOF_(Pt))or 13.1 sec^(-1)(TOF_(Pd)),and 58 k J/mol,respectively.The large EB adsorption capacity,good reducibility,and strong acidity contributed to the good catalytic performance of PdPtVO_(x)/CZO.Catalytic activity of PdPtVO_(x)/CZO decreased when 50 ppm SO_(2)or(1.0 vol.%H_(2)O+50 ppm SO_(2))was added to the feedstock,but was gradually restored to its initial level after the SO_(2)was cut off.The good reversible sulfur dioxide-resistant performance of PdPtVO_(x)/CZO was associated with the facts:(i)the introduction of SO_(2)leads to an increase in surface acidity;(ii)V can adsorb and activate SO_(2),thus accelerating formation of the SO_(x)^(2-)(x=3 or 4)species at the V and CZO sites,weakening the adsorption of sulfur species at the PdPt active sites,and hence protecting the PdPt active sites to be not poisoned by SO_(2).EB oxidation over PdPtVO_(x)/CZO might take place via the route of EB→styrene→phenyl methyl ketone→benzaldehyde→benzoic acid→maleic anhydride→CO_(2)and H_(2)O.展开更多
Methane dominated gas is one of the cleanest energy resources;however, there is no direct method to determine its source rock. Natural gases produced from the eastern Sichuan Basin together with seismic data were stud...Methane dominated gas is one of the cleanest energy resources;however, there is no direct method to determine its source rock. Natural gases produced from the eastern Sichuan Basin together with seismic data were studied for their sources and secondary alteration by thermochemical sulfate reduction(TSR). Our results demonstrate that Upper Permian to Lower Triassic(P_(3)ch-T_(1)f) gases in the surrounding of the Kaijiang-Liangping area show volatile organic sulfur compounds(VOSCs) δ^(34)S values close to those of the associated H_(2)S, and may have been altered by methane-dominated TSR, resulting in positive shift in methane δ^(13)C_(1)values with increasing TSR extents. Other(or group 2) gases produced from the P_(3)ch-T_(1)f reservoirs from the southern area and the Upper Carboniferous to Middle Permian(C_(2)h-P_(2)q) from the eastern Sichuan Basin are not significantly changed by TSR, show similar δ^(34)S values between the kerogens and some VOSCs, and may have been derived from the Lower Silurian and Middle Permian source rocks. This study demonstrates a case for the first time showing the δ^(34)S values of VOSCs can be used as a tool for direct correlation between non-TSR altered gas and source rocks. Methane-dominated gas pools can be found using gas and source rock geochemistry combined with seismic data.展开更多
基金supported by the National Natural Science Foundation of China (No. 50979102, 40730528,40901252, 20907057)
文摘After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds （VOSCs）： methanethiol （MESH）, dimethyl sulfide （DMS）, dime^yl disulfide （DMDS）, dimethyl trisulfide （DMTS） and dimethyl tetrasulfide （DMTeS）. Even in the untreated control without a methionine addition, methionine and its catabolites （VOSCs, mainly DMDS） were found in considerable amounts that were high enough to account for the water＇s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine＋glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.
文摘Simultaneous removal of hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) in off-gas mixture from a wastewater treatment plant (WWTP) is difficult due to the occasional inhibitory effects of H2S on VOSC degradation. In this study, a two-stage bio-trickling filter (BTF) system was developed to treat off-gas mixture from a real WWTP facility. At an empty bed retention time of 40 s, removal efficiencies of H2S, methanethiol, dimethyl sulfide, and dimethyl disulfide were 90.1, 88.4, 85.8 and 61.8%, respectively. Furthermore, the effect of lifting load shock on system performance was investigated and results indicated that removal of both H2S and VOSCs was slightly affected. Illumina Miseq sequencing revealed that the microbial community of first-stage BTF contained high abundance of H2S-affinity genera including Acidithiobacillus (51.43%), Metallibacterium (25.35%), and Thionomas (8.08%). Analysis of mechanism demonstrated that first stage of BTF removed 86.1% of H2S, mitigating the suppression on VOSC degradation in second stage of BTF. Overall, the twostage BTF system, an innovative bioprocess, can simultaneously remove H2S and VOSC.
基金the financial support to this work by Sichuan Science and Technology,China(Nos.2019ZDZX0035&2018TZDZX0008)the Ministry of Education through the 111 Project(No.B17030).
文摘Hydrogen fuel cells are among the promising energy sources worldwide,which could accomplish cyclic production of energy and avoid the emission of green-house or contaminative byproducts.However,sulfur compounds(SCs)even at trace level(nmol/mol)are usually involved in cell construction and further H_(2)production,which would cause degradation of the catalysts and shorten the lifetime of the fuel cells.Moreover,the highly reactive SCs could cause varied species and concentrations of them in complex matrices,so online rather than offline analysis of SCs in H_(2)would be preferred.In this context,we developed a new system combining online cryogenic preconcentration of nine SCs and subsequent determination by GC-SCD(sulfur chemiluminescent detector),with the correlation coefficients of the calibration curves higher than 0.999,calculated limits of detection no higher than 0.050 nmol/mol,analytical time around 30 min per sample,and satisfactory precision and accuracy(RSD<5%and SD<15%).The analytical performance was much better than or at least comparable to the previously reported and the developed system was successfully applied for real sample analysis.
文摘采用气相色谱-离子迁移谱技术,建立了检测畜禽有机废物堆肥中挥发性硫化合物-甲硫醚、乙硫醚、二甲基二硫醚和二硫化碳的方法。样品经除氨后用采气袋收集,经MXT-1气相色谱填充柱分离,采用正、负两种模式,在优化的载气流量和系统温度条件下进行检测。结果表明,4种挥发性硫化合物在各自线性范围内均表现出良好的线性关系(R^(2)>0.99);检出限为0.008~0.097 mg/m^(3),回收率为85%~116%,相对标准偏差(Relative Standard Deviation,RSD)为1.13%~8.42%。该方法无需浓缩富集等预处理,仅采用气袋就可完成堆肥恶臭气体的收集,检测灵敏、响应快速,可用于堆肥气体中挥发性硫化合物的现场监测。
基金supported by the National Natural Science Foundation Committee of China-Liaoning Provincial People’s Government Joint Fund(No.U1908204)the National Natural Science Foundation of China(21976009)+2 种基金the National Key R&D Program of China(Nos.2022YFB3506200 and 2022YFB3504100)the Beijing Natural Science Foundation(J210006)the R&D Program of Beijing Municipal Education Commisson(No.KZ202210005011)。
文摘The PdPtVO_(x)/CeO_(2)-ZrO_(2)(PdPtVO_(x)/CZO)catalysts were obtained by using different approaches,and their physical and chemical properties were determined by various techniques.Catalytic activities of these materials in the presence of H_(2)O or SO_(2)were evaluated for the oxidation of ethylbenzene(EB).The PdPtVO_(x)/CZO sample exhibited high catalytic activity,good hydrothermal stability,and reversible sulfur dioxide-poisoning performance,over which the specific reaction rate at 160℃,turnover frequency at 160℃(TOF_(Pd or Pt)),and apparent activation energy were 72.6 mmol/(g_(Pt)·sec)or 124.2 mmol/(g_(Pd)·sec),14.2 sec^(-1)(TOF_(Pt))or 13.1 sec^(-1)(TOF_(Pd)),and 58 k J/mol,respectively.The large EB adsorption capacity,good reducibility,and strong acidity contributed to the good catalytic performance of PdPtVO_(x)/CZO.Catalytic activity of PdPtVO_(x)/CZO decreased when 50 ppm SO_(2)or(1.0 vol.%H_(2)O+50 ppm SO_(2))was added to the feedstock,but was gradually restored to its initial level after the SO_(2)was cut off.The good reversible sulfur dioxide-resistant performance of PdPtVO_(x)/CZO was associated with the facts:(i)the introduction of SO_(2)leads to an increase in surface acidity;(ii)V can adsorb and activate SO_(2),thus accelerating formation of the SO_(x)^(2-)(x=3 or 4)species at the V and CZO sites,weakening the adsorption of sulfur species at the PdPt active sites,and hence protecting the PdPt active sites to be not poisoned by SO_(2).EB oxidation over PdPtVO_(x)/CZO might take place via the route of EB→styrene→phenyl methyl ketone→benzaldehyde→benzoic acid→maleic anhydride→CO_(2)and H_(2)O.
基金financially supported by the National Natural Science Foundation of China (Grant No.41961144023)the Israeli Science Foundation (Grant No.3195/19)。
文摘Methane dominated gas is one of the cleanest energy resources;however, there is no direct method to determine its source rock. Natural gases produced from the eastern Sichuan Basin together with seismic data were studied for their sources and secondary alteration by thermochemical sulfate reduction(TSR). Our results demonstrate that Upper Permian to Lower Triassic(P_(3)ch-T_(1)f) gases in the surrounding of the Kaijiang-Liangping area show volatile organic sulfur compounds(VOSCs) δ^(34)S values close to those of the associated H_(2)S, and may have been altered by methane-dominated TSR, resulting in positive shift in methane δ^(13)C_(1)values with increasing TSR extents. Other(or group 2) gases produced from the P_(3)ch-T_(1)f reservoirs from the southern area and the Upper Carboniferous to Middle Permian(C_(2)h-P_(2)q) from the eastern Sichuan Basin are not significantly changed by TSR, show similar δ^(34)S values between the kerogens and some VOSCs, and may have been derived from the Lower Silurian and Middle Permian source rocks. This study demonstrates a case for the first time showing the δ^(34)S values of VOSCs can be used as a tool for direct correlation between non-TSR altered gas and source rocks. Methane-dominated gas pools can be found using gas and source rock geochemistry combined with seismic data.
