This review starts with the description of the quantitative significance of dissolved organic material in general and dissolved humic substances (HS) in particular in various ecosystems. Despite their high quantities,...This review starts with the description of the quantitative significance of dissolved organic material in general and dissolved humic substances (HS) in particular in various ecosystems. Despite their high quantities, the knowledge about the role of HS is still very low and full of old, but still recycled paradigms. HS are thought to be inert or at least refractory and too large to be taken up by aquatic organisms. Instead, I present evidence that dissolved HS that mainly derives from the terrestrial environment, are taken up and directly and/or indirectly interfere with freshwater organisms and, thus, structure biocenoses. Relatively well known is in the meantime the fuelling function of allochthonous HS, which, upon irradiation, release fatty acids, which serve as substrates for microbial growth. This is an indirect effect of HS. Microbes, in turn, are food for mixotrophic algae and (heterotrophic) zooplankton. Thus, non-eutrophicated freshwaters are net-heterotrophic, meaning that respiration exceeds primary production. Furthermore, model calculations exemplify that only a very small portion of the terrestrial production is sufficient to cause net-heterotrophy in these freshwater bodies. But, recent papers show also that due to different stoichiometries the maximal plankton biomass production with algae or mixotrophs is higher than with bacteria. Very recently, several direct effects of HS have been elucidated. Among them are:induction of chaperons (stress shock proteins), induction and modulation of biotransformation enzymes, modulation (mainly inhibition) of photosynthetic oxygen release of aquatic plants, production of an internal oxidative stress, modulation of the offspring numbers in the nematode Caenorhabditis elegans[WTBZ], feminization of fish and amphibs, interference within the thyroid system, and action as chemical attractant to C. elegans. We are still in the phase of identifying the various physiological, biochemical, and molecular-biological effects. Hence, the ecological and ecophysiological significance of these HS-mediated effects still remain somewhat obscure. Nevertheless, HS appear generally to have an impact on the individual as well as on the community and even ecosystem level comparable to that of, for instance, nutrients.展开更多
Based on the characteristics of the lignite sample, effects of assistant anthraquinone （AQ） on extraction yield of humic substances （HS） and the action mechanisms of AQ in alkaline condition were studied by Fouvie...Based on the characteristics of the lignite sample, effects of assistant anthraquinone （AQ） on extraction yield of humic substances （HS） and the action mechanisms of AQ in alkaline condition were studied by Fouvier transform infrared （FT-IR） spectroscopy. The results indicate that assistant AQ can not only increase the extraction yield of HS but also reduce the alkali dosage （NaOH） as well as the extraction temperature and extraction time. Under the optimal conditions of alkali dosage of 9%, AQ dosage of 0.75%, extraction temperature of 80 ℃, extraction time of 30 min, stirring speed of 600 r/min and solid-to-liquid ratio of 1：3, the extraction yield of HS reaches 80.08%, which is increased by more than 20% compared with the conventional extraction. FT-IR spectra show that AQ is able to prevent dissolved HS from being destroyed into undissolved substance by alkali and 1-IS obtained in the presence of AQ possesses more groups of COOR and --COOH than that obtained without AQ.展开更多
Modified humic acid (MHA) binder based on lignite humic substances is a novel sort of promising organic binder for iron ore pellets.Humic acid (HA) is one of the main ingredients of MHA binder.Pure HA was firstly isol...Modified humic acid (MHA) binder based on lignite humic substances is a novel sort of promising organic binder for iron ore pellets.Humic acid (HA) is one of the main ingredients of MHA binder.Pure HA was firstly isolated from lignite and then adsorption of HA onto magnetite particle surface was investigated.The final results indicate that the adsorption of HA onto magnetite surface accords with Langmuir model well,and it is evidently influenced by the initial HA concentration and solution pH value.Adsorption depends on chemical interaction at pH values above the PZC (the pH where the Zeta potentials of minerals are zero) of magnetite,while electrostatic attraction and chemical interaction both contribute to the adsorption at pH values below the PZC.展开更多
The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting, and its effect on the fluorescence spectroscopy characteristics of humic a...The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting, and its effect on the fluorescence spectroscopy characteristics of humic acid (HA) was studied. The results show that the emission spectra have a sharp peak at 400 nm and a broad shoulder with the maximum centered at 460 nm. The excitation spectra have two peaks and exhibit red shift (shift to longer wavelengths) at 470 nm. The synchronous scan spectra present a number of peaks and shoulders, and the peaks at shorter wavelengths disappear gradually and form a shoulder. At the final stage of composting, the fluorescence spectra have similar shapes, but the fluorescence intensities decrease. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase. Compared with the fluorescence spectroscopy characteristics of HA from soil, the structure of HA from compost is simpler and the activity is higher.展开更多
A modified humic acid(MHA) binder was tested as a substitute for bentonite to prepare qualified specularite pellets. The results show that there is stronger chemisorption between organic functional groups in MHA binde...A modified humic acid(MHA) binder was tested as a substitute for bentonite to prepare qualified specularite pellets. The results show that there is stronger chemisorption between organic functional groups in MHA binder molecular and specularite particles, improving the green pellet strength. MHA binder has obvious effect on the strength and microstructure of preheated pellets due to the thermal decomposition of organic matters in MHA binder. Appropriately increasing preheating temperature or time can eliminate the adverse impact of organic matters on the preheated pellet strength. Compared with the bentonite pellets, the roasted pellets with MHA binder have a more compact microstructure, and the recrystallization of the Fe2O3 crystal grains is better.Consequently, under optimal conditions, 0.75%(mass fraction) MHA binder pellets have equal or better pellet strengths and contain1.06% more total iron than 2 % bentonite pellets. The testing results indicate that MHA binder is a promising and effective alternative to bentonite for the specularite pellets.展开更多
Humic substances (especially fulvic acid (FA)) are the major components of natural organic matter (NOM) that widely exist in drinking water source. Due to their potential effects on public health,the removal of FA was...Humic substances (especially fulvic acid (FA)) are the major components of natural organic matter (NOM) that widely exist in drinking water source. Due to their potential effects on public health,the removal of FA was one of the main concerns during the water treatment. Therefore,the contact filtration of FA by using aluminum sulfate as coagulant on the basis of jar tests was carried out. The effects of pH and coagulant dosage on the FA removal and the development of head loss were investigated. The results show that the range of pH value during the FA contact filtration can be effectively influenced by the dosage of aluminum sulfate,and the high aluminum sulfate dosage is an important factor that can result in early filter breakthrough. The FA filtration by deep-bed filtration or by membrane filtration is sometimes disparate under the same coagulation conditions. The choice of aluminum sulfate dosage by the method of membrane filtration,i.e. the "true color measurement",may result in inappropriate filter run,whereas it can be determined with simple jar tests by observing the formation of micro flocs. Considering the effects of pH on aluminum sulfate dosage and FA removal,the optimal pH range of 5.5?6.0 is suggested.展开更多
The structure characteristics and adhesive property of humic substance(HS) extracted with different methods were mainly studied by terms of elementary analysis,visible spectrum,FT-IR spectroscopy,viscosity,adsorption ...The structure characteristics and adhesive property of humic substance(HS) extracted with different methods were mainly studied by terms of elementary analysis,visible spectrum,FT-IR spectroscopy,viscosity,adsorption and pelletizing experiments.The results show that HSs extracted with new method(HS-a) own higher degree of aromatization and polymerization,larger relative molecular mass and more polar functional groups than HS extracted with usual method(HS-b).The viscosity of HS-b is about 30-40 mPa·s lower than that of HS-a.The maximum adsorption amounts of HS-a and HS-b onto iron concentrates are 9.11 mg/g and 8.08 mg/g,respectively.Meanwhile,HS-a has a better performance than HS-b in the practical application for pelletizing of iron concentrates.The difference in agglomeration behaviors with iron concentrates lies in the differences of the structure characteristics of HSs.With higher content of polar functional groups,larger relative molecular mass and viscosity of HSs,the agglomeration behavior is improved.展开更多
Humic acids can promote the germination of many vegetable seeds,but the key active components remain unclear.This study utilized nutrient content,cross polarization magic angle spin ^(13)C solid magnetic resonance(CPM...Humic acids can promote the germination of many vegetable seeds,but the key active components remain unclear.This study utilized nutrient content,cross polarization magic angle spin ^(13)C solid magnetic resonance(CPMAS-^(13)C-NMR)and ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)to characterize the chemical components of humic acids.Tomato seed germination index(GI)was determined with the goal of screening the key active components of humic acids.Humic acids had a significantly higher nutrient content,except for the total nitrogen(TN)and the total phosphorus(TP)contents.Humic acids had a higher content of O-CH_(3)/NCH,aromatic C-O and carbonyl C compared to weathered coal,with significantly lower anomeric C,aromatic C and O-alkyl C/alkyl C.There were 611 different compounds identified among the test materials using UHPLC-MS.Humic acids also had a significantly higher GI(158.0%and 153.1%)than weathered coal(85.5%).The organic matter(OM),TP and available potassium(AK)contents in humic acids were significantly positively correlated with GI,and available phosphorus(AP)was significantly negatively correlated.Among the carbon components,O-CH3/NCH,aromatic C-O and O-alkyl C/alkyl C were significantly positively correlated with GI,while anomeric C was significantly negatively correlated.Furthermore,among the top 10 positive and five negative correlation compounds,lipids and lipid-like molecules[armexifolin,boviquinone 4,3-methyladipic acid,lxocarpalactone A,monic acid,DG(20:1(11Z)/18:4(6Z,9Z,12Z,15Z)/0:0),and brassinolide]and organic acids and derivatives(N-acetylglutamic acid,8-hydroxy-5,6-octadienoic acid,acetyl-L-tyrosine,and hydroxyprolyl-methionine)in humic acids might be crucial active components for improving tomato seed germination.The results provided direct evidence for the identification of bioactive molecules of humic acids,and a scientific basis for the precise utilization of bioactive molecular components of humic acids in sustainable agricultural development.展开更多
P-arsanilic acid(p-ASA),as a kind of organoarsenic feed additive,has been widely used in poultry and swine breeding.However,it has caused the arsenic pollution around the farm.Currently data shows humic acid(HA)is clo...P-arsanilic acid(p-ASA),as a kind of organoarsenic feed additive,has been widely used in poultry and swine breeding.However,it has caused the arsenic pollution around the farm.Currently data shows humic acid(HA)is closely to the migration and transformation of p-ASA.Therefore,the interaction between p-ASA and HA was investigated by using the method of fluorescence quenching titration.The association constant changed from2.74 to 4.88 L·mol-1at a p H varying from 5 to 9 and reached the maximum at p H 7.In addition,log K varied from4.15 to 5.02 L·mol-1when the temperature increased from 15℃to 35℃.The log K increased with an increase in the concentration of HA.The dominant mechanism between p-ASA and HA is static quenching.The primary interaction force was likely the hydrogen bond,and the binding behavior occurred on the As-O stretch of p-ASA and the carboxylic acid C=O stretch of HA.The results showed that dissolved organic matters could affect the fate and biogeochemical cycling of organoarsenic pharmaceuticals in aquatic ecosystems.展开更多
文摘This review starts with the description of the quantitative significance of dissolved organic material in general and dissolved humic substances (HS) in particular in various ecosystems. Despite their high quantities, the knowledge about the role of HS is still very low and full of old, but still recycled paradigms. HS are thought to be inert or at least refractory and too large to be taken up by aquatic organisms. Instead, I present evidence that dissolved HS that mainly derives from the terrestrial environment, are taken up and directly and/or indirectly interfere with freshwater organisms and, thus, structure biocenoses. Relatively well known is in the meantime the fuelling function of allochthonous HS, which, upon irradiation, release fatty acids, which serve as substrates for microbial growth. This is an indirect effect of HS. Microbes, in turn, are food for mixotrophic algae and (heterotrophic) zooplankton. Thus, non-eutrophicated freshwaters are net-heterotrophic, meaning that respiration exceeds primary production. Furthermore, model calculations exemplify that only a very small portion of the terrestrial production is sufficient to cause net-heterotrophy in these freshwater bodies. But, recent papers show also that due to different stoichiometries the maximal plankton biomass production with algae or mixotrophs is higher than with bacteria. Very recently, several direct effects of HS have been elucidated. Among them are:induction of chaperons (stress shock proteins), induction and modulation of biotransformation enzymes, modulation (mainly inhibition) of photosynthetic oxygen release of aquatic plants, production of an internal oxidative stress, modulation of the offspring numbers in the nematode Caenorhabditis elegans[WTBZ], feminization of fish and amphibs, interference within the thyroid system, and action as chemical attractant to C. elegans. We are still in the phase of identifying the various physiological, biochemical, and molecular-biological effects. Hence, the ecological and ecophysiological significance of these HS-mediated effects still remain somewhat obscure. Nevertheless, HS appear generally to have an impact on the individual as well as on the community and even ecosystem level comparable to that of, for instance, nutrients.
基金Project(50725416) supported by the National Science Fund for Distinguished Young Scholars in ChinaProject(50804059) supported by the National Natural Science Foundation of China+1 种基金Project(2008BAB32B06) supported by the Key Program in National Science and Technology Pillar Program during the 11th Five-year Plan Period of ChinaProject(200805331080) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘Based on the characteristics of the lignite sample, effects of assistant anthraquinone （AQ） on extraction yield of humic substances （HS） and the action mechanisms of AQ in alkaline condition were studied by Fouvier transform infrared （FT-IR） spectroscopy. The results indicate that assistant AQ can not only increase the extraction yield of HS but also reduce the alkali dosage （NaOH） as well as the extraction temperature and extraction time. Under the optimal conditions of alkali dosage of 9%, AQ dosage of 0.75%, extraction temperature of 80 ℃, extraction time of 30 min, stirring speed of 600 r/min and solid-to-liquid ratio of 1：3, the extraction yield of HS reaches 80.08%, which is increased by more than 20% compared with the conventional extraction. FT-IR spectra show that AQ is able to prevent dissolved HS from being destroyed into undissolved substance by alkali and 1-IS obtained in the presence of AQ possesses more groups of COOR and --COOH than that obtained without AQ.
基金Project(50804059) supported by the National Natural Science Foundation of ChinaProject(50725416) supported by the National Natural Science Funds for Distinguished Young Scholars of China
文摘Modified humic acid (MHA) binder based on lignite humic substances is a novel sort of promising organic binder for iron ore pellets.Humic acid (HA) is one of the main ingredients of MHA binder.Pure HA was firstly isolated from lignite and then adsorption of HA onto magnetite particle surface was investigated.The final results indicate that the adsorption of HA onto magnetite surface accords with Langmuir model well,and it is evidently influenced by the initial HA concentration and solution pH value.Adsorption depends on chemical interaction at pH values above the PZC (the pH where the Zeta potentials of minerals are zero) of magnetite,while electrostatic attraction and chemical interaction both contribute to the adsorption at pH values below the PZC.
基金Project(2005CB724203) supported by the Major State Basic Research and Development Program of ChinaProject(IRT0719) supported by the Program for Changjiang Scholars and Innovative Research Team in University of China+1 种基金Projects(50608029,50808073) supported by the National Natural Science Foundation of ChinaProject(2007185) supported by the Environmental Protection Technology Research Program of Hunan Province,China
文摘The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting, and its effect on the fluorescence spectroscopy characteristics of humic acid (HA) was studied. The results show that the emission spectra have a sharp peak at 400 nm and a broad shoulder with the maximum centered at 460 nm. The excitation spectra have two peaks and exhibit red shift (shift to longer wavelengths) at 470 nm. The synchronous scan spectra present a number of peaks and shoulders, and the peaks at shorter wavelengths disappear gradually and form a shoulder. At the final stage of composting, the fluorescence spectra have similar shapes, but the fluorescence intensities decrease. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase. Compared with the fluorescence spectroscopy characteristics of HA from soil, the structure of HA from compost is simpler and the activity is higher.
基金Project(50804059)supported by the National Natural Science Foundation of ChinaProject(CX2012B121)supported by the Innovation Research Program for Graduate Student of Hunan Province,China
文摘A modified humic acid(MHA) binder was tested as a substitute for bentonite to prepare qualified specularite pellets. The results show that there is stronger chemisorption between organic functional groups in MHA binder molecular and specularite particles, improving the green pellet strength. MHA binder has obvious effect on the strength and microstructure of preheated pellets due to the thermal decomposition of organic matters in MHA binder. Appropriately increasing preheating temperature or time can eliminate the adverse impact of organic matters on the preheated pellet strength. Compared with the bentonite pellets, the roasted pellets with MHA binder have a more compact microstructure, and the recrystallization of the Fe2O3 crystal grains is better.Consequently, under optimal conditions, 0.75%(mass fraction) MHA binder pellets have equal or better pellet strengths and contain1.06% more total iron than 2 % bentonite pellets. The testing results indicate that MHA binder is a promising and effective alternative to bentonite for the specularite pellets.
基金Project(2009ZX07424-004) supported by the Water Special Program of China
文摘Humic substances (especially fulvic acid (FA)) are the major components of natural organic matter (NOM) that widely exist in drinking water source. Due to their potential effects on public health,the removal of FA was one of the main concerns during the water treatment. Therefore,the contact filtration of FA by using aluminum sulfate as coagulant on the basis of jar tests was carried out. The effects of pH and coagulant dosage on the FA removal and the development of head loss were investigated. The results show that the range of pH value during the FA contact filtration can be effectively influenced by the dosage of aluminum sulfate,and the high aluminum sulfate dosage is an important factor that can result in early filter breakthrough. The FA filtration by deep-bed filtration or by membrane filtration is sometimes disparate under the same coagulation conditions. The choice of aluminum sulfate dosage by the method of membrane filtration,i.e. the "true color measurement",may result in inappropriate filter run,whereas it can be determined with simple jar tests by observing the formation of micro flocs. Considering the effects of pH on aluminum sulfate dosage and FA removal,the optimal pH range of 5.5?6.0 is suggested.
基金Project(50725416) supported by the National Science Fund for Distinguished Young Scholars of ChinaProject(50804059) supported by the National Natural Science Foundation of China+1 种基金Project(200805331080) supported by Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject supported by the Graduate Degree Thesis Innovation Foundation of Central South University,China
文摘The structure characteristics and adhesive property of humic substance(HS) extracted with different methods were mainly studied by terms of elementary analysis,visible spectrum,FT-IR spectroscopy,viscosity,adsorption and pelletizing experiments.The results show that HSs extracted with new method(HS-a) own higher degree of aromatization and polymerization,larger relative molecular mass and more polar functional groups than HS extracted with usual method(HS-b).The viscosity of HS-b is about 30-40 mPa·s lower than that of HS-a.The maximum adsorption amounts of HS-a and HS-b onto iron concentrates are 9.11 mg/g and 8.08 mg/g,respectively.Meanwhile,HS-a has a better performance than HS-b in the practical application for pelletizing of iron concentrates.The difference in agglomeration behaviors with iron concentrates lies in the differences of the structure characteristics of HSs.With higher content of polar functional groups,larger relative molecular mass and viscosity of HSs,the agglomeration behavior is improved.
基金Supported by the National Natural Science Foundation of China(42207371)the Technological Project of Jiangsu Vocational College of Agriculture and Forestry(2021kj17)+1 种基金Yafu Technology Innovation and Service Major Project of Jiangsu Vocational College of Agriculture and Forestry(2024kj01)Key Research Projects of Jiangsu Vocational College of Agriculture and Forestry(2023kj14)。
文摘Humic acids can promote the germination of many vegetable seeds,but the key active components remain unclear.This study utilized nutrient content,cross polarization magic angle spin ^(13)C solid magnetic resonance(CPMAS-^(13)C-NMR)and ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)to characterize the chemical components of humic acids.Tomato seed germination index(GI)was determined with the goal of screening the key active components of humic acids.Humic acids had a significantly higher nutrient content,except for the total nitrogen(TN)and the total phosphorus(TP)contents.Humic acids had a higher content of O-CH_(3)/NCH,aromatic C-O and carbonyl C compared to weathered coal,with significantly lower anomeric C,aromatic C and O-alkyl C/alkyl C.There were 611 different compounds identified among the test materials using UHPLC-MS.Humic acids also had a significantly higher GI(158.0%and 153.1%)than weathered coal(85.5%).The organic matter(OM),TP and available potassium(AK)contents in humic acids were significantly positively correlated with GI,and available phosphorus(AP)was significantly negatively correlated.Among the carbon components,O-CH3/NCH,aromatic C-O and O-alkyl C/alkyl C were significantly positively correlated with GI,while anomeric C was significantly negatively correlated.Furthermore,among the top 10 positive and five negative correlation compounds,lipids and lipid-like molecules[armexifolin,boviquinone 4,3-methyladipic acid,lxocarpalactone A,monic acid,DG(20:1(11Z)/18:4(6Z,9Z,12Z,15Z)/0:0),and brassinolide]and organic acids and derivatives(N-acetylglutamic acid,8-hydroxy-5,6-octadienoic acid,acetyl-L-tyrosine,and hydroxyprolyl-methionine)in humic acids might be crucial active components for improving tomato seed germination.The results provided direct evidence for the identification of bioactive molecules of humic acids,and a scientific basis for the precise utilization of bioactive molecular components of humic acids in sustainable agricultural development.
基金National Natural Science Foundation of China(41373111)
文摘P-arsanilic acid(p-ASA),as a kind of organoarsenic feed additive,has been widely used in poultry and swine breeding.However,it has caused the arsenic pollution around the farm.Currently data shows humic acid(HA)is closely to the migration and transformation of p-ASA.Therefore,the interaction between p-ASA and HA was investigated by using the method of fluorescence quenching titration.The association constant changed from2.74 to 4.88 L·mol-1at a p H varying from 5 to 9 and reached the maximum at p H 7.In addition,log K varied from4.15 to 5.02 L·mol-1when the temperature increased from 15℃to 35℃.The log K increased with an increase in the concentration of HA.The dominant mechanism between p-ASA and HA is static quenching.The primary interaction force was likely the hydrogen bond,and the binding behavior occurred on the As-O stretch of p-ASA and the carboxylic acid C=O stretch of HA.The results showed that dissolved organic matters could affect the fate and biogeochemical cycling of organoarsenic pharmaceuticals in aquatic ecosystems.
