Coke plant effluents with high contents of organic compounds are mainly treated by biological aerobic fermentation after physical pre-treatment. In this study, a brown coal condensate wastewater from a low temperature...Coke plant effluents with high contents of organic compounds are mainly treated by biological aerobic fermentation after physical pre-treatment. In this study, a brown coal condensate wastewater from a low temperature coking process was fermented under methanogenic conditions in discontinuous experiments. By this fermentation, acetate, propionate, and the main polyphenolic compounds （catechol, resorcinol and hydroquinone） were degraded to a level below the detection limit. The COD was reduced by 72% with a residual concentration of 2.1 g/L. This anaerobic fermented wastewater had a residual BOD5 of 0.66 g/L and 2.2 L CH4 were formed per litre of wastewater. An abiotic pre-treatment for this wastewater with air had a negative effect on the COD reduction and decrease of colour on the methanogenic fermentation due to the autoxidation of polyphenolic compounds to humic-like compounds. This study showed that methanogenic fermentations in the treatment sequence of brown coal coking wastewaters could reduce energy consumption for aeration in further treatment processes and had the potential for a better effluent quality due to a less formation of recalcitrant humic-like compounds.展开更多
To investigate the influence of haze on the chemical composition and formation processes of ambient aerosol particles,PM_（2.5） and size-segregated aerosol particles were collected daily during fall at an urban site ...To investigate the influence of haze on the chemical composition and formation processes of ambient aerosol particles,PM_（2.5） and size-segregated aerosol particles were collected daily during fall at an urban site of Gwangju,Korea.During the study period,the total concentration of secondary ionic species（SIS） contributed an average of 43.9% to the PM_（2.5） ,whereas the contribution of SIS to the PM_（2.5） during the haze period was 62.3%.The NO_3 and SO^（2-）_4 concentrations in PM_（2.5） during the haze period were highly elevated,being 13.4 and 5.0 times higher than those during non-haze period,respectively.The PM,NO^-_3,SO^（2-）_4,oxalate,water-soluble organic carbon（WSOC）,and humic-like substances（HULIS） had tri-modal size distributions peaks at 0.32,1.0,and 5.2 μm during the non-haze and haze periods.However,during the non-haze period they exhibited dominant size distributions at the condensation mode peaking at 0.32 μm,while on October 21 when the heaviest haze event occurred,they had predominant droplet mode size distributions peaking at 1.00 μm.Moreover,strong correlations of WSOC and HULIS with SO^（2-）_4,oxalate,and K＋at particle sizes of 〈 1.8 μm indicate that secondary processes and emissions from biomass burning could be responsible for WSOC and HULIS formations.It was found that the factors affecting haze formation could be the local stable synoptic conditions,including the weak surface winds and high surface pressures,the long-range transportation of haze from eastern China and upwind regions of the Korean peninsula,as well as the locally emitted and produced aerosol particles.展开更多
Humic-like substances(HULIS)are a major component of brown carbon and consequently play a major role in climate change.In this study,70 PM_(2.5) samples were collected from Xi'an in winter 2019 and summer 2020.Neu...Humic-like substances(HULIS)are a major component of brown carbon and consequently play a major role in climate change.In this study,70 PM_(2.5) samples were collected from Xi'an in winter 2019 and summer 2020.Neutral HULIS(HULIS-n),acidic HULIS(HULIS-a),and high-polarity water-soluble organic compounds(HP-WSOC)were analyzed to determine their carbon concentrations and measure their ultraviolet-visible absorption and infrared spectra.Of the three components,HULIS-n had the highest carbon content in both winter(3.29±1.45μg m^(-3))and in summer(1.38±1.10μg m^(-3)).The semi-quantitative results for the functional groups revealed that HP-WSOC was rich in carboxylic acids and had high aromaticity in winter,whereas HULIS-n was rich in carboxylic acids in summer.Moreover,HULJS-a was richer in nitrate esters and saturated aliphatic hydrocarbons in summer than in winter.The results for specific ultraviolet absorbance(SUVA)and E_(250)/E_(365) revealed that HULIS had higher molecular weight and aromaticity in winter than in summer.HULIS-n dominated in the total light absorption of HULIS+HP-WSOC in both winter(73.08%)and summer(48.57%).Overall,the results on the carbon content,optical properties,and functional groups of WSOCs with differing polarity can improve un-derstanding of environmental and climatic effects.展开更多
Humification plays a critical role in the environmental fate of organic wastes, and MnO_2 holds great promise for enhancing this reaction. However, the effects of MnO_2 on the enhancement of the humification reaction ...Humification plays a critical role in the environmental fate of organic wastes, and MnO_2 holds great promise for enhancing this reaction. However, the effects of MnO_2 on the enhancement of the humification reaction remain ambiguous. To better reveal the mechanism by which MnO_2 enhances the reaction and investigate the fate of the humification products, abiotic humification experiments were performed using increasing concentrations of dissolved organic matter(DOM) to a fixed amount of MnO_2. DOM was represented by model humic precursors consisting of catechol, glucose and glycine. The results indicate that the reduction of MnO_2 played a dominant role in the formation of fulvic-like acids(FLAs), and the subsequent reduction products, MnOOH and Mn(II), acted as catalysts in the formation of humic-like acids(HLAs). Moreover, CO_2 release occurred during the formation of FLAs, and a strong linear correlation between CO_2 release and the formation of FLAs was observed(p < 0.01), where 0.73–1.87 mg of CO_2 was released per mg dissolved organic carbon(DOC)FLAs. Furthermore, the concentration of MnO_2 had a pronounced influence on the product behavior, where a lower MnO_2 concentration decreased the quantity of FLAs produced.展开更多
The application of organic amendments on soils poor in organic matter(OM) can improve long-term soil fertility, but may also enhance the mineralization of native soil organic matter. Three organic amendments, compost,...The application of organic amendments on soils poor in organic matter(OM) can improve long-term soil fertility, but may also enhance the mineralization of native soil organic matter. Three organic amendments, compost, sewage sludge and horse manure, used by urban market gardeners in Dakar, Senegal were analyzed for their OM maturity. Their fate was evaluated in a 45-d agronomic trial in a sandy Arenosol with lettuce. In each case, water-extractable organic matter(WEOM) and humic-like substances(HLS)were isolated from raw amendments and amended soils, and characterized using ultraviolet-visible(UV/Vis) spectroscopy. Results highlighted the general more aromatic character of HLS and WEOM fractions extracted from compost compared to the other two amendments. When applied to soils, however, these differences were not clearly observed. The aromaticity and humification degree of the labile fraction(WEOM) increased with depth in the first 30 cm for all amendments. This indicated the high lixiviation rates that fresh OM underwent in the studied sandy soil. Finally, a statistical analysis of the results was able to discriminate between surface and deeper horizons and between amended- and non-amended soil samples. Spectroscopic indices showed indeed strong increase/decrease with depth linked with the mineralization/humification processes that the fresh OM from amendments underwent during the 45 d of the agronomic trial. This study highlights the potential of spectroscopic techniques to study agricultural amendment organic matter fractions and their fate in soils.展开更多
The formation of humic-like acids(HLAs)is an essential process for converting liquid digestate into organic soil amendments to enhance agricultural sustainability.The aim of this study was to investigate the impact of...The formation of humic-like acids(HLAs)is an essential process for converting liquid digestate into organic soil amendments to enhance agricultural sustainability.The aim of this study was to investigate the impact of oxygen and/or MnO_(2)on the production of HLAs.Herein,abiotic humification performance of the digestate dissolved organic matter(DOM)is investigated with fluxes of air and N2 in the absence and presence of MnO_(2).Our results demonstrated that the fate of digestate DOM greatly depends on the oxidizing environment,the MnO_(2)enhanced nitrogen involved in the formation of HLAs.The synergistic effects of MnO_(2)and oxygen effectively improved the production of HLAs,and the corresponding component evolution was analyzed using spectroscopic evidence.The twodimensional correlation spectroscopy results demonstrated that the reaction sequence of digestate DOM followed the order of protein-like substances,substances with an absorbance at 325 nm,substances with UV absorbance at 254 nm and HLAs.Additionally,excitation emission matrix fluorescence combined with parallel factor analysis(EEM-PARAFAC)showed that tryptophan-like C3 was more prone to transformation than tyrosine-like C2 and was responsible for the humification process.The substance with an absorbance at 325 nm was a reaction intermediate in the transformation process of protein-like substances to HLAs.The above findings can be used to promote the production of liquid fertilizer associated with carbon sequestration as well as the sustainable development of biogas production.展开更多
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0853)
文摘Coke plant effluents with high contents of organic compounds are mainly treated by biological aerobic fermentation after physical pre-treatment. In this study, a brown coal condensate wastewater from a low temperature coking process was fermented under methanogenic conditions in discontinuous experiments. By this fermentation, acetate, propionate, and the main polyphenolic compounds （catechol, resorcinol and hydroquinone） were degraded to a level below the detection limit. The COD was reduced by 72% with a residual concentration of 2.1 g/L. This anaerobic fermented wastewater had a residual BOD5 of 0.66 g/L and 2.2 L CH4 were formed per litre of wastewater. An abiotic pre-treatment for this wastewater with air had a negative effect on the COD reduction and decrease of colour on the methanogenic fermentation due to the autoxidation of polyphenolic compounds to humic-like compounds. This study showed that methanogenic fermentations in the treatment sequence of brown coal coking wastewaters could reduce energy consumption for aeration in further treatment processes and had the potential for a better effluent quality due to a less formation of recalcitrant humic-like compounds.
基金supported by the Basic Science Research Programs through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(NRF2014R1A1A4A01003896)the support from the BK21 Plus program through the NRF funded by the MOE
文摘To investigate the influence of haze on the chemical composition and formation processes of ambient aerosol particles,PM_（2.5） and size-segregated aerosol particles were collected daily during fall at an urban site of Gwangju,Korea.During the study period,the total concentration of secondary ionic species（SIS） contributed an average of 43.9% to the PM_（2.5） ,whereas the contribution of SIS to the PM_（2.5） during the haze period was 62.3%.The NO_3 and SO^（2-）_4 concentrations in PM_（2.5） during the haze period were highly elevated,being 13.4 and 5.0 times higher than those during non-haze period,respectively.The PM,NO^-_3,SO^（2-）_4,oxalate,water-soluble organic carbon（WSOC）,and humic-like substances（HULIS） had tri-modal size distributions peaks at 0.32,1.0,and 5.2 μm during the non-haze and haze periods.However,during the non-haze period they exhibited dominant size distributions at the condensation mode peaking at 0.32 μm,while on October 21 when the heaviest haze event occurred,they had predominant droplet mode size distributions peaking at 1.00 μm.Moreover,strong correlations of WSOC and HULIS with SO^（2-）_4,oxalate,and K＋at particle sizes of 〈 1.8 μm indicate that secondary processes and emissions from biomass burning could be responsible for WSOC and HULIS formations.It was found that the factors affecting haze formation could be the local stable synoptic conditions,including the weak surface winds and high surface pressures,the long-range transportation of haze from eastern China and upwind regions of the Korean peninsula,as well as the locally emitted and produced aerosol particles.
基金supported by the Key R&D project of Shaanxi Province(grant No.2022zDLSF06-07)Chinese Academy of Sciences(CAS)“Light of West China”Program(grant No.XAB2021YN06)the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAs(grant No.SKLLQG2103,SKLLQG2110)was also thanked.
文摘Humic-like substances(HULIS)are a major component of brown carbon and consequently play a major role in climate change.In this study,70 PM_(2.5) samples were collected from Xi'an in winter 2019 and summer 2020.Neutral HULIS(HULIS-n),acidic HULIS(HULIS-a),and high-polarity water-soluble organic compounds(HP-WSOC)were analyzed to determine their carbon concentrations and measure their ultraviolet-visible absorption and infrared spectra.Of the three components,HULIS-n had the highest carbon content in both winter(3.29±1.45μg m^(-3))and in summer(1.38±1.10μg m^(-3)).The semi-quantitative results for the functional groups revealed that HP-WSOC was rich in carboxylic acids and had high aromaticity in winter,whereas HULIS-n was rich in carboxylic acids in summer.Moreover,HULJS-a was richer in nitrate esters and saturated aliphatic hydrocarbons in summer than in winter.The results for specific ultraviolet absorbance(SUVA)and E_(250)/E_(365) revealed that HULIS had higher molecular weight and aromaticity in winter than in summer.HULIS-n dominated in the total light absorption of HULIS+HP-WSOC in both winter(73.08%)and summer(48.57%).Overall,the results on the carbon content,optical properties,and functional groups of WSOCs with differing polarity can improve un-derstanding of environmental and climatic effects.
基金the financial support from the National Key Technology R&D Programs(No.2014BAC02B02)
文摘Humification plays a critical role in the environmental fate of organic wastes, and MnO_2 holds great promise for enhancing this reaction. However, the effects of MnO_2 on the enhancement of the humification reaction remain ambiguous. To better reveal the mechanism by which MnO_2 enhances the reaction and investigate the fate of the humification products, abiotic humification experiments were performed using increasing concentrations of dissolved organic matter(DOM) to a fixed amount of MnO_2. DOM was represented by model humic precursors consisting of catechol, glucose and glycine. The results indicate that the reduction of MnO_2 played a dominant role in the formation of fulvic-like acids(FLAs), and the subsequent reduction products, MnOOH and Mn(II), acted as catalysts in the formation of humic-like acids(HLAs). Moreover, CO_2 release occurred during the formation of FLAs, and a strong linear correlation between CO_2 release and the formation of FLAs was observed(p < 0.01), where 0.73–1.87 mg of CO_2 was released per mg dissolved organic carbon(DOC)FLAs. Furthermore, the concentration of MnO_2 had a pronounced influence on the product behavior, where a lower MnO_2 concentration decreased the quantity of FLAs produced.
基金supported by the Swiss National Science Foundation (No. 207021-109689/1)
文摘The application of organic amendments on soils poor in organic matter(OM) can improve long-term soil fertility, but may also enhance the mineralization of native soil organic matter. Three organic amendments, compost, sewage sludge and horse manure, used by urban market gardeners in Dakar, Senegal were analyzed for their OM maturity. Their fate was evaluated in a 45-d agronomic trial in a sandy Arenosol with lettuce. In each case, water-extractable organic matter(WEOM) and humic-like substances(HLS)were isolated from raw amendments and amended soils, and characterized using ultraviolet-visible(UV/Vis) spectroscopy. Results highlighted the general more aromatic character of HLS and WEOM fractions extracted from compost compared to the other two amendments. When applied to soils, however, these differences were not clearly observed. The aromaticity and humification degree of the labile fraction(WEOM) increased with depth in the first 30 cm for all amendments. This indicated the high lixiviation rates that fresh OM underwent in the studied sandy soil. Finally, a statistical analysis of the results was able to discriminate between surface and deeper horizons and between amended- and non-amended soil samples. Spectroscopic indices showed indeed strong increase/decrease with depth linked with the mineralization/humification processes that the fresh OM from amendments underwent during the 45 d of the agronomic trial. This study highlights the potential of spectroscopic techniques to study agricultural amendment organic matter fractions and their fate in soils.
基金The authors are grateful for the financial support from the National Key Technology Research and Development Programs,China(No.2018YFC1901405)the National Natural Science Foundation of China(Grant No.52100167)+3 种基金the Natural Science Foundation of Hebei Province,China(No.B2020203024)the Key Research and Development Plan of Hebei Province,China(No.21327312D)the Young and Middle-Aged Science and Technology Innovation Leadership Talents Project of Xinjiang Production and Construction Corps,China(No.2019CB028)the Science and Technology Public Relations Projects in Key Fields of Xinjiang Production and Construction Corps,China(No.2019AB028).
文摘The formation of humic-like acids(HLAs)is an essential process for converting liquid digestate into organic soil amendments to enhance agricultural sustainability.The aim of this study was to investigate the impact of oxygen and/or MnO_(2)on the production of HLAs.Herein,abiotic humification performance of the digestate dissolved organic matter(DOM)is investigated with fluxes of air and N2 in the absence and presence of MnO_(2).Our results demonstrated that the fate of digestate DOM greatly depends on the oxidizing environment,the MnO_(2)enhanced nitrogen involved in the formation of HLAs.The synergistic effects of MnO_(2)and oxygen effectively improved the production of HLAs,and the corresponding component evolution was analyzed using spectroscopic evidence.The twodimensional correlation spectroscopy results demonstrated that the reaction sequence of digestate DOM followed the order of protein-like substances,substances with an absorbance at 325 nm,substances with UV absorbance at 254 nm and HLAs.Additionally,excitation emission matrix fluorescence combined with parallel factor analysis(EEM-PARAFAC)showed that tryptophan-like C3 was more prone to transformation than tyrosine-like C2 and was responsible for the humification process.The substance with an absorbance at 325 nm was a reaction intermediate in the transformation process of protein-like substances to HLAs.The above findings can be used to promote the production of liquid fertilizer associated with carbon sequestration as well as the sustainable development of biogas production.
