Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic ecosystems.Planting submerged vegetation in shallow waters was a...Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic ecosystems.Planting submerged vegetation in shallow waters was also expected to achieve this purpose.However,the magnitude and mechanism of carbon dioxide(CO_(2))emission affected by submerged vegetation is not clear enough in complex aquatic ecosystems.This study investigated the influences of submerged plants on CO_(2)emission,ecosystem metabolism features,and microbial community traits based on observations in river networks on the Changjiang River Delta.The results showed that CO_(2)emission from planted waters accounted for 73%of unplanted waters.Meanwhile,planted waters had higher dissolved organic carbon removal capacity in overlying water and higher potential of carbon sequestration in sediment at the same time.These distinctions between the two habitats were attributed to(1)improved CO_(2)and bicarbonate consumption in water columns via enhancing photosynthesis and(2)inhibited CO_(2)production by reconstructing the benthic microbial community.Additional eco-advantages were found in planted sediments,such as a high potential of methane oxidation and xenobiotics biodegradation and a low risk of becoming black and odorous.In brief,submerged vegetation is beneficial in promoting pollution removal and carbon retention synchronously.This study advances our understanding of the feedback between aquatic metabolism and CO_(2)emission.展开更多
Sulfamethazine(SMZ) is an important sulfonamide antibiotic.Although the concentration in the environment is small,it is harmful.The drug residues can be transferred,transformed or accumulated,affecting the growth of a...Sulfamethazine(SMZ) is an important sulfonamide antibiotic.Although the concentration in the environment is small,it is harmful.The drug residues can be transferred,transformed or accumulated,affecting the growth of animals and plants.In this study,the integrated fixed-film activated sludge membrane bioreactor(IFAS-MB R) were constructed to investigate the performance and degradation mechanism of SMZ.The addition of SMZ had a significant impact on the removal of the chemical oxygen demand(COD) and ammonia nitrogen(NH_4^+-N).The optimal operating conditions were hydraulic retention time(HRT) at 10 h and solid retention time(SRT) at 80 d,respectively.On this basis,the effects of different SMZ concentrations on nutrient removal,degradation,and sludge characteristics were compared.The removal efficiency of SMZ increased with the increase of SMZ concentration.The maximum removal rate was as high as 87%.The SMZ dosage also had an obvious effect on sludge characteristics.As the SMZ concentration increased,the extracellular polymer substances(EPS) concentration and the membrane resistance both decreased,which were beneficial for the reduction of membrane fouling.Finally,seven kinds of SMZ biodegradation intermediates were identified,and the possible degradation pathways were speculated.The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent.The relative abundance of Bacteroidetes,Actinobacteria,Saccharibacteria and Nitro spirae increased at the phylum level.Sphingobacteria and Betaproteobacteria became dominant species at the class level.The relative abundance of norankp-Saccharibacteria and Nitrospirae increased significantly,and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.展开更多
This study aims to provide a quantitative basis for the precision emission reduction of land-based total nitrogen(TN)pollutants in Laizhou Bay(LZB),China.The total maximum allocated load(TMAL)of TN pollutants within j...This study aims to provide a quantitative basis for the precision emission reduction of land-based total nitrogen(TN)pollutants in Laizhou Bay(LZB),China.The total maximum allocated load(TMAL)of TN pollutants within jurisdictions around LZB was calculated using the stepwise simulation-optimization model after the division of source units,simulation of the concentration response matrix,setting of the additional constraint conditions for stepwise source units,and calculation of TMAL.The load reduction allocation system for jurisdictions can be constructed on the basis of the TMAL and the load monitored or statistics.The index system for TN emission reduction included indices for two groups:a fixed index of marine emission reduction rate for jurisdictions,which was 11.93%on average;and threshold indices of pollution prevention rate at sources,the increment rate of pollution removal by municipal sewage treatment systems,and watershed retention of jurisdictions,which were 7.43%,1.58%,and 1.09%on average,respectively.Efficiency of pollutant reduction can be evaluated using a 3D hydrodynamic-water quality model.Simulation results showed that the precise reduction indicators achieved the seawater quality improvement target of LZB 5 years earlier than the equal proportion reduction indicators currently used in LZB Basin.展开更多
There is a lack of understanding about the bacterial,fungal and archaeal communities’composition of solid-phase denitrification(SPD)systems.We investigated four SPD systems with different carbon sources by analyzing ...There is a lack of understanding about the bacterial,fungal and archaeal communities’composition of solid-phase denitrification(SPD)systems.We investigated four SPD systems with different carbon sources by analyzing microbial gene sequences based on operational taxonomic unit(OTU)and amplicon sequence variant(ASV).The results showed that the corncob-polyvinyl alcohol sodium alginate-polycaprolactone(CPSP,0.86±0.04 mg NO_(3)^(−)-N/(g·day))and corncob(0.85±0.06 mg NO_(3)^(−)-N/(g·day))had better denitrification efficiency than polycaprolactone(PCL,0.29±0.11 mg NO_(3)^(−)-N/(g·day))and polyvinyl alcoholsodium alginate(PVA-SA,0.24±0.07 mg NO_(3)^(−)-N/(g·day)).The bacterial,fungal and archaeal microbial composition was significantly different among carbon source types such as Proteobacteria in PCL(OTU:83.72%,ASV:82.49%)and Rozellomycota in PVA-SA(OTU:71.99%,ASV:81.30%).ASV methods can read more microbial units than that of OTU and exhibit higher alpha diversity and classify some species that had not been identified by OTU such as Nanoarchaeota phylum,unclassified_f_Xanthobacteraceae genus,etc.,indicating ASV may be more conducive to understand SPD microbial communities.The co-occurring network showed some correlation between the bacteria fungi and archaea species,indicating different species may collaborate in SPD systems.Similar KEGG function prediction results were obtained in two bioinformatic methods generally and some fungi and archaea functions should not be ignored in SPD systems.These results may be beneficial for understanding microbial communities in SPD systems.展开更多
Sulfated rhamnose polysaccharide(SRP)derived from Enteromorpha prolifera is a metal-ion chelating agent that could potentially be used to treat diabetes.The aim of our study was to determine the effect of a variant of...Sulfated rhamnose polysaccharide(SRP)derived from Enteromorpha prolifera is a metal-ion chelating agent that could potentially be used to treat diabetes.The aim of our study was to determine the effect of a variant of SRP on DIABETES.First,we synthesized and characterized SRPE-3 chromium(III)[SRPE-3-Cr(III)]complex using an enzymatic method.The maximum chelation rate was 18.2%under optimal chelating conditions of pH 6.0,time 4 h,and temperature 60°C.Fourier transform infrared spectroscopy results showed important sites for Cr(III)-binding were O–H and C=O groups.We then studied the hypolipidemic effects of SRPE-3-Cr(III)on type 2 diabetes mellitus(T2DM)induced by a high-fat,high-sucrose diet(HFSD).Decreased blood glucose content,body fat ratio,serum TG,TC,LDL-C,and increased serum HDL-C were observed after treatment with SRPE-3-Cr(III).In addition,SRPE-3-Cr(III)significantly reduced leptin,resistin,and TNF-αlevels,and increased adiponectin contents relative to T2DM.Histopathology results also showed that SRPE-3-Cr(III)could alleviate the HFSD-lesioned tissues.SRPE-3-Cr(III)also improved lipid metabolism via a reduction in aspartate aminotransferase,alanine aminotransferase,fatty acid synthase,and acetyl-CoA carboxylase activities in the liver.SRPE-3-Cr(III)at low doses exhibited better lipid-lowering activities,hence,could be considered to be a novel compound to treat hyperlipidemia and also act as an anti-diabetic agent.展开更多
Although G-coordinate is one of the most popular methods used in marine and estuarine modeling, it has long suffered from the so-called ＂steep boundary problem＂, namely, the PGF problem. In this paper, a new method ...Although G-coordinate is one of the most popular methods used in marine and estuarine modeling, it has long suffered from the so-called ＂steep boundary problem＂, namely, the PGF problem. In this paper, a new method called the ＂σ-sharpen immersed boundary method＂ （σ-SIBM） is put forward. In this method, the virtual flat bottom boundary is creatively introduced in regions with the steep boundary and is taken as the boundary of numerical domain. By this, OH/Ox of numerical domain changes to be a controllable value and the steep bottom problem is then transformed to the non-conforming boundary problem, which is, in turn, solved by the SIBM. The accuracy and efficiency of the σ-sharpen immersed boundary method （σ-SIBM） has been showed by both comparative theoretical analysis and classical numerical tests. First, it is shown that the σ-SIBM is more effective than the z-level method, in that σ-SIBM needs special treatment only in the steep section, but the z-level method needs the special treatment in each grid note. Second, it is superior to the p-method in that it is not restricted by the density distribution. This paper revisits the classical seamount numerical test used in numerous studies to prove the sigma errors of the pressure gradient force （PGFE） and their long-term effects on circulation. It can be seen that, as for the maximum erroneous velocity and kinetic energy, the value of σ-SIBM is much less than that of the z-level method and the traditional σ-method.展开更多
基金supported by the Youth Exploration Foundation of Chinese Research Academy of Environmental Sciences(No.2022YSKY-55).
文摘Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic ecosystems.Planting submerged vegetation in shallow waters was also expected to achieve this purpose.However,the magnitude and mechanism of carbon dioxide(CO_(2))emission affected by submerged vegetation is not clear enough in complex aquatic ecosystems.This study investigated the influences of submerged plants on CO_(2)emission,ecosystem metabolism features,and microbial community traits based on observations in river networks on the Changjiang River Delta.The results showed that CO_(2)emission from planted waters accounted for 73%of unplanted waters.Meanwhile,planted waters had higher dissolved organic carbon removal capacity in overlying water and higher potential of carbon sequestration in sediment at the same time.These distinctions between the two habitats were attributed to(1)improved CO_(2)and bicarbonate consumption in water columns via enhancing photosynthesis and(2)inhibited CO_(2)production by reconstructing the benthic microbial community.Additional eco-advantages were found in planted sediments,such as a high potential of methane oxidation and xenobiotics biodegradation and a low risk of becoming black and odorous.In brief,submerged vegetation is beneficial in promoting pollution removal and carbon retention synchronously.This study advances our understanding of the feedback between aquatic metabolism and CO_(2)emission.
基金financially supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2018ZX07601-003)the Fundamental Research Funds for Central Public Research Institutes of China(No.2019-YSKY-009)。
文摘Sulfamethazine(SMZ) is an important sulfonamide antibiotic.Although the concentration in the environment is small,it is harmful.The drug residues can be transferred,transformed or accumulated,affecting the growth of animals and plants.In this study,the integrated fixed-film activated sludge membrane bioreactor(IFAS-MB R) were constructed to investigate the performance and degradation mechanism of SMZ.The addition of SMZ had a significant impact on the removal of the chemical oxygen demand(COD) and ammonia nitrogen(NH_4^+-N).The optimal operating conditions were hydraulic retention time(HRT) at 10 h and solid retention time(SRT) at 80 d,respectively.On this basis,the effects of different SMZ concentrations on nutrient removal,degradation,and sludge characteristics were compared.The removal efficiency of SMZ increased with the increase of SMZ concentration.The maximum removal rate was as high as 87%.The SMZ dosage also had an obvious effect on sludge characteristics.As the SMZ concentration increased,the extracellular polymer substances(EPS) concentration and the membrane resistance both decreased,which were beneficial for the reduction of membrane fouling.Finally,seven kinds of SMZ biodegradation intermediates were identified,and the possible degradation pathways were speculated.The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent.The relative abundance of Bacteroidetes,Actinobacteria,Saccharibacteria and Nitro spirae increased at the phylum level.Sphingobacteria and Betaproteobacteria became dominant species at the class level.The relative abundance of norankp-Saccharibacteria and Nitrospirae increased significantly,and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.
基金the fund provided by the Basic Scientific Research Funds of Dalian University of Technology(No.DUT21RC(3)035)the Open Funds of Key Laboratory of Estuarine and Coastal Environment(No.HKHA2022001)。
文摘This study aims to provide a quantitative basis for the precision emission reduction of land-based total nitrogen(TN)pollutants in Laizhou Bay(LZB),China.The total maximum allocated load(TMAL)of TN pollutants within jurisdictions around LZB was calculated using the stepwise simulation-optimization model after the division of source units,simulation of the concentration response matrix,setting of the additional constraint conditions for stepwise source units,and calculation of TMAL.The load reduction allocation system for jurisdictions can be constructed on the basis of the TMAL and the load monitored or statistics.The index system for TN emission reduction included indices for two groups:a fixed index of marine emission reduction rate for jurisdictions,which was 11.93%on average;and threshold indices of pollution prevention rate at sources,the increment rate of pollution removal by municipal sewage treatment systems,and watershed retention of jurisdictions,which were 7.43%,1.58%,and 1.09%on average,respectively.Efficiency of pollutant reduction can be evaluated using a 3D hydrodynamic-water quality model.Simulation results showed that the precise reduction indicators achieved the seawater quality improvement target of LZB 5 years earlier than the equal proportion reduction indicators currently used in LZB Basin.
基金Thisworkwas supported by the National Key R&D Program of China(No.2019YFC0408602).
文摘There is a lack of understanding about the bacterial,fungal and archaeal communities’composition of solid-phase denitrification(SPD)systems.We investigated four SPD systems with different carbon sources by analyzing microbial gene sequences based on operational taxonomic unit(OTU)and amplicon sequence variant(ASV).The results showed that the corncob-polyvinyl alcohol sodium alginate-polycaprolactone(CPSP,0.86±0.04 mg NO_(3)^(−)-N/(g·day))and corncob(0.85±0.06 mg NO_(3)^(−)-N/(g·day))had better denitrification efficiency than polycaprolactone(PCL,0.29±0.11 mg NO_(3)^(−)-N/(g·day))and polyvinyl alcoholsodium alginate(PVA-SA,0.24±0.07 mg NO_(3)^(−)-N/(g·day)).The bacterial,fungal and archaeal microbial composition was significantly different among carbon source types such as Proteobacteria in PCL(OTU:83.72%,ASV:82.49%)and Rozellomycota in PVA-SA(OTU:71.99%,ASV:81.30%).ASV methods can read more microbial units than that of OTU and exhibit higher alpha diversity and classify some species that had not been identified by OTU such as Nanoarchaeota phylum,unclassified_f_Xanthobacteraceae genus,etc.,indicating ASV may be more conducive to understand SPD microbial communities.The co-occurring network showed some correlation between the bacteria fungi and archaea species,indicating different species may collaborate in SPD systems.Similar KEGG function prediction results were obtained in two bioinformatic methods generally and some fungi and archaea functions should not be ignored in SPD systems.These results may be beneficial for understanding microbial communities in SPD systems.
基金funded by the Innovation Capability Improvement Project of Shandong(2021TSGC1298)the Qingdao Science and Technology Project(2022).
文摘Sulfated rhamnose polysaccharide(SRP)derived from Enteromorpha prolifera is a metal-ion chelating agent that could potentially be used to treat diabetes.The aim of our study was to determine the effect of a variant of SRP on DIABETES.First,we synthesized and characterized SRPE-3 chromium(III)[SRPE-3-Cr(III)]complex using an enzymatic method.The maximum chelation rate was 18.2%under optimal chelating conditions of pH 6.0,time 4 h,and temperature 60°C.Fourier transform infrared spectroscopy results showed important sites for Cr(III)-binding were O–H and C=O groups.We then studied the hypolipidemic effects of SRPE-3-Cr(III)on type 2 diabetes mellitus(T2DM)induced by a high-fat,high-sucrose diet(HFSD).Decreased blood glucose content,body fat ratio,serum TG,TC,LDL-C,and increased serum HDL-C were observed after treatment with SRPE-3-Cr(III).In addition,SRPE-3-Cr(III)significantly reduced leptin,resistin,and TNF-αlevels,and increased adiponectin contents relative to T2DM.Histopathology results also showed that SRPE-3-Cr(III)could alleviate the HFSD-lesioned tissues.SRPE-3-Cr(III)also improved lipid metabolism via a reduction in aspartate aminotransferase,alanine aminotransferase,fatty acid synthase,and acetyl-CoA carboxylase activities in the liver.SRPE-3-Cr(III)at low doses exhibited better lipid-lowering activities,hence,could be considered to be a novel compound to treat hyperlipidemia and also act as an anti-diabetic agent.
基金supported by the National Natural Science Foundation of China(Grant Nos.51209239,51109194)"985 Project"of Minzu Univer-sity of China(Grant No.MUC98507-08)
文摘Although G-coordinate is one of the most popular methods used in marine and estuarine modeling, it has long suffered from the so-called ＂steep boundary problem＂, namely, the PGF problem. In this paper, a new method called the ＂σ-sharpen immersed boundary method＂ （σ-SIBM） is put forward. In this method, the virtual flat bottom boundary is creatively introduced in regions with the steep boundary and is taken as the boundary of numerical domain. By this, OH/Ox of numerical domain changes to be a controllable value and the steep bottom problem is then transformed to the non-conforming boundary problem, which is, in turn, solved by the SIBM. The accuracy and efficiency of the σ-sharpen immersed boundary method （σ-SIBM） has been showed by both comparative theoretical analysis and classical numerical tests. First, it is shown that the σ-SIBM is more effective than the z-level method, in that σ-SIBM needs special treatment only in the steep section, but the z-level method needs the special treatment in each grid note. Second, it is superior to the p-method in that it is not restricted by the density distribution. This paper revisits the classical seamount numerical test used in numerous studies to prove the sigma errors of the pressure gradient force （PGFE） and their long-term effects on circulation. It can be seen that, as for the maximum erroneous velocity and kinetic energy, the value of σ-SIBM is much less than that of the z-level method and the traditional σ-method.
