The gasification wastewater is a kind of typical organic industrial wastewater with high chemical oxygen demand (COD) and ammonia nitrogen, which could not be completely degraded by the traditional physical, chemical ...The gasification wastewater is a kind of typical organic industrial wastewater with high chemical oxygen demand (COD) and ammonia nitrogen, which could not be completely degraded by the traditional physical, chemical and biological method. So it is very important to find an effective treatment process. A combination process of catalytic oxidation with noble metal catalysts and aerobic biological fluid-bed packed with the new ultrastructure biological carriers, which was developed by ourselves, was investigated to treat the gasification wastewater. The pilot scale test with 0.5 m3/h influent flow was carried out to investigate the performance of this new combination process. The results showed that the effluent COD was 84.02 mg/L, ammonia nitrogen was 14.15 mg/L, and total phenol was 0.20 mg/L, which could completely meet the Grade Ⅰof Wastewater Discharge Standard (GB8978-1996), when the influent average COD was 5564 mg/L, ammonia nitrogen was 237 mg/L, and total phenol was 1100 mg/L. The two catalytic reactors could evidently improve the wastewater biodegradability, and the value of BOD5/COD (B/C) increased from 0.23 to 0.413 in the one-stage catalytic reactor and from 0.273 to 0.421 in two-stage catalytic reactor. The further experiment results showed that the effluent quality of this new combination process could still meet the discharge standard, when the COD loading was 8.65 kg / (m3·d). Most of aromatic and heterocyclic compounds were degraded effectively in this combination process.展开更多
This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemica...This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemical,and biological methods to ascertain their effectiveness in formaldehyde mitigation.Physical methods,including air circulation and adsorption,particularly with activated carbon and molecular sieves,are assessed for their efficiency in various concentration scenarios.Chemical methods,such as photocatalytic oxidation using titanium dioxide and plasma technology,are analyzed for their ability to decompose formaldehyde into non-toxic substances.Additionally,biological methods involving plant purification and microbial transformation are explored for their eco-friendly and sustainable removal capabilities.The paper concludes that while each method has its merits,a combined approach may offer the most effective solution for reducing indoor formaldehyde levels.The study underscores the need for further research to integrate these methods in a practical,cost-effective,and environmentally sustainable manner,highlighting their potential to improve indoor air quality significantly.展开更多
Compared to conventional oxidation ditches, an integrated oxidation ditch with vertical circle (IODVC) has the characters of concise configuration, simple operation and maintenance, land saving and automatical sludg...Compared to conventional oxidation ditches, an integrated oxidation ditch with vertical circle (IODVC) has the characters of concise configuration, simple operation and maintenance, land saving and automatical sludge returning. By the utilization of vertical circulation, an aerobic zone and an anoxic zone can be unaffectedly formed in the IODVC. Therefore, COD and nitrogen can be efficiently removed. However, the removal efficiency of phosphorus was low in the IODVC. In the experiment described, a laboratory scale system to add an anaerobic column to the IODVC has been tested to investigate the removal of phosphorus from wastewater. The experimental results showed that the removal efficiency of TP with the anaerobic column was increased to 54.0% from 22.3% without the anaerobic column. After the acetic sodium was added into the influent as carbon sources, the mean TP removal efficency of 77. 5 % was obtained. At the same time, the mean removal efficiencies of COD, TN and NH3-N were 92.2%, 81.6% and 98.1%, respectively, at 12 h of HRT and 21-25 d of SRT. The optimal operational conditions in this study were as follows: recycle rate = 1.5-2.0, COD/TN 〉 6, COD/TP 〉 40, COD loading rate = 0.26-0.32 kgCOD/(kgSS· d), TN loading rate = 0. 028-0. 034 kgTN/( kgSS·d) and TP loading rate = 0.003-0.005 kgTP/(kgSS· d), respectively.展开更多
Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater ...Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.展开更多
Cerium oxide nanoparticles(CNPs)possess a great potential as therapeutic agents due to their ability to self-regenerate by reversibly switching between two valences+3 and+4.This article reviews recent articles dealing...Cerium oxide nanoparticles(CNPs)possess a great potential as therapeutic agents due to their ability to self-regenerate by reversibly switching between two valences+3 and+4.This article reviews recent articles dealing with in vivo studies of CNPs towards Alzheimer’s disease,obesity,liver inflammation,cancer,sepsis,amyotrophic lateral sclerosis,acute kidney injury,radiation-induced tissue damage,hepatic ischemia reperfusion injury,retinal diseases and constipation.In vivo anti-cancer studies revealed the effectiveness of CNPs to reduce tumor growth and angiogenesis in melanoma,ovarian,breast and retinoblastoma cancer cell-induced mice,with their conjugation with folic acid,doxorubicin,CPM,or CXC receptor-4 antagonist ligand eliciting higher efficiency.After conjugation with triphenylphosphonium or magnetite nanoparticles,CNPs were shown to combat Alzheimer’s disease by reducing amyloid-β,glial fibrillary acidic protein,inflammatory and oxidative stress markers in mice.By improving muscle function and longevity,the citrate/EDTA-stabilized CNPs could ameliorate amyotrophic lateral sclerosis.Also,they could effectively reduce obesity in mice by scavenging ROS and reducing adipogenesis,triglyceride synthesis,GAPDH enzyme activity,leptin and insulin levels.In CCl4-induced rats,stress signaling pathways due to inflammatory cytokines,liver enzymes,oxidative and endoplasmic reticulum messengers could be attenuated by CNPs.Commercial CNPs showed protective effects on rats with hepatic ischemia reperfusion and peritonitis-induced hepatic/cardiac injuries by decreasing oxidative stress and hepatic/cardiac inflammation.The same CNPs could improve kidney function by diminishing renal superoxide,hyperglycemia and tubular damage in peritonitis-induced acute kidney injury in rats.Radiation-induced lung and testicular tissue damage could be alleviated in mice,with the former showing improvement in pulmonary distress and bronchoconstriction and the latter exhibiting restoration in spermatogenesis rate and spermatid/spermatocyte number.Through enhancement of gastrointestinal motility,the CNPs could alleviate constipation in both young and old rats.They could also protect rat from light-induced retinal damage by slowing down neurodegenerative process and microglial activation.展开更多
Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing...Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing free radicals, the stability of catalysts is often insufficient, which has become a bottleneck in the application of CWAO. In this paper, a copper-based catalyst with excellent hydrothermal stability was designed and prepared. TiO_(2) with excellent stability was used as the carrier to ensure the longterm anchoring of copper and reduce the leaching of the catalyst. The one pot sol–gel method was used to ensure the super dispersion and uniform distribution of copper nanoparticles on the carrier, so as to ensure that more active centers could be retained in a longer period. Experiments show that the catalyst prepared by this method has good stability and catalytic activity, and the catalytic effect is not significantly reduced after 10 cycles of use. The oxidation degradation experiment of m-cresol with the strongest biological toxicity and the most difficult to degrade in coal chemical wastewater was carried out with this catalyst. The results showed that under the conditions of 140℃, 2 MPa and 2 h, m-cresol with a concentration of up to 1000 mg·L^(-1) could be completely degraded, and the COD removal rate could reach 79.15%. The biological toxicity of wastewater was significantly reduced. The development of the catalyst system has greatly improved the feasibility of CWAO in the treatment of refractory wastewater such as coal chemical wastewater.展开更多
The superior drainage was pre-treated by biologic contact oxidation on BOD5 load of 0.72 kg/(m3·d),and then post-treated by constructed wetland. The results about the effect on the constructed wetland post-treatm...The superior drainage was pre-treated by biologic contact oxidation on BOD5 load of 0.72 kg/(m3·d),and then post-treated by constructed wetland. The results about the effect on the constructed wetland post-treatment show that the total nitrogen (TN) is the restrictive index of the combinational technique treatment effect. To meet the reclaimed water quality standard and reuse for waterscape,the peak hydraulic load of constructed wetland is 0.50 m/d in summer (30-36 ℃) and 0.33 m/d in winter (8-12℃),and the load ratio of the peak hydraulic under the two temperature conditions is 3-2. The results are combined of reclaimed water quantity requirements in different seasons of green building. Reasonable scale of the reclaimed water treatment systems can be determined. The treatment efficacy can be well predicted,and both the design and operations can be effectively guided,by which the reclaimed water treatment systems regard superior drainage as the source and are purified by combinational technique of contact oxidation and artificial wetland.展开更多
BACKGROUND Premature ovarian insufficiency(POI)is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage.Early follicular depletion results in intractable infertility,thereby cons...BACKGROUND Premature ovarian insufficiency(POI)is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage.Early follicular depletion results in intractable infertility,thereby considerably reducing the quality of life of females.Given the continuum in weakened ovarian function,progressing from incipient ovarian failure(IOF)to transitional ovarian failure and further to POI,it is necessary to develop biomarkers for predicting POI.The oxidative stress states in IOF and POI were comprehensively evaluated via oxidative stress[diacron-reactive oxygen metabolites(d-ROMs)]test and anti-oxidant capacity[biological antioxidant potential(BAP)].METHODS Females presenting with secondary amenorrhea over 4 mo and a follicle stimulating hormone level of>40 mIU/mL were categorized into the POI group.Females presenting with a normal menstrual cycle and a follicle stimulating hormone level of>10.2 mIU/mL were categorized into the IOF group.Healthy females without ovarian hypofunction were categorized into the control group.Among females aged<40 years who visited our hospital from January 2021 to June 2022,we recruited 11 patients into both POI and IOF groups.For the potential antioxidant capacity,the relative oxidative stress index(BAP/d-ROMs×100)was calculated,and the oxidative stress defense system was comprehensively evaluated.RESULTS d-ROMs were significantly higher in the POI and IOF groups than in the control group,(478.2±58.7 U.CARR,434.5±60.6 U.CARR,and 341.1±35.1 U.CARR,respectively)(U.CARR is equivalent to 0.08 mg/dL of hydrogen peroxide).However,no significant difference was found between the POI and IOF groups.Regarding BAP,no significant difference was found between the control,IOF,and POI groups(2078.5±157.4μmol/L,2116.2±240.2μmol/L,and 2029.0±186.4μmol/L,respectively).The oxidative stress index was significantly higher in the POI and IOF groups than in the control group(23.7±3.3,20.7±3.6,and 16.5±2.1,respectively).However,no significant difference was found between the POI and IOF groups.CONCLUSION High levels of oxidative stress suggest that evaluating the oxidative stress state may be a useful indicator for the early detection of POI.展开更多
Metagenomic studies have demonstrated the existence of ammonia-oxidizing archaea(AOA) and revealed they are responsible for ammoxidation in some extreme environments. However, the changes in compositional structure an...Metagenomic studies have demonstrated the existence of ammonia-oxidizing archaea(AOA) and revealed they are responsible for ammoxidation in some extreme environments. However, the changes in compositional structure and ammonia-oxidation capacity of AOA communities in biological soil crusts(BSCs) of desert ecosystems remain poorly understood.Here, we utilized Illumina MiSeq sequencing and microbial functional gene array(GeoChip 5.0) to assess the above changes along a 51-year revegetation chronosequence in the Tengger Desert, China. The results showed a significant difference in AOA-community richness between 5-year-old BSCs and older ones. The most dominant phylum during BSC development was Crenarchaeota, and the corresponding species were ammonia-oxidizing_Crenarchaeote and environmental_samples_Crenarchaeota. Network analysis revealed that the positive correlations among dominant taxa increased, and their cooperation was reinforced in AOA communities during BSC succession. Redundancy analysis showed that the dominant factor influencing the change in AOA-community structure was soil texture. GeoChip 5.0 indicated that the amoA gene abundances of AOA and ammonia-oxidizing bacteria(AOB) were basically the same, demonstrating that AOA and AOB played an equally important role during BSCs development. Our study of the long-term succession of BSC demonstrated a persistent response of AOA communities to revegetation development in desert ecosystems.展开更多
To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was...To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch (OD), where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification (SND) rate (rSND) was put forward to quantify SND. The results indicate that: (1) high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen (TN) and total phosphate (TP) removal rates were 80% and 85%, respectively; (2) when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; (3) the natural logarithm of the ratio of NOx to NH4^+ in the effluent had a linear correlation to oxidation-reduction potential (ORP); (4) when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; (5) denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.展开更多
The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors(ASBRs) (0^#-6^#) which had been run under stable anaerobic ammonium oxidation (Anammox). By mean...The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors(ASBRs) (0^#-6^#) which had been run under stable anaerobic ammonium oxidation (Anammox). By means of monitoring and data analysis of COD, NH4^#-N, NO2^--N, NO3^--N and pH, and of microbial test, the results revealed that the optimal Anammox performance was achieved from 2^# reactor in which COD/NH4^+ -N was 1.65, Anammox bacteria and denitrification bacteria could coexist, and Anammox reaction and denitrification reaction could occur simultaneously in the reactors. The ratio of NH4^+-N consumed : NO2^- -N consumed : NO3^- -N produced was 1:1.38:0.19 in 0^# reactor which was not added glucose in the wastewater. When different ratio of COD and NH4^+-N was fed for the reactors, the ratio of NO2^- -N consumed: NH4^+-N consumed was in the range of 1.51-2.29 and the ratio of NO;-N produced: NH4^+ -N consumed in the range of 0 -0.05.展开更多
Magnesium(Mg)and its alloys have become a hot research topic in various industries owing to the specific physical and chemical properties.However,high corrosion rate is considered the key lifetime-limiting.Plasma elec...Magnesium(Mg)and its alloys have become a hot research topic in various industries owing to the specific physical and chemical properties.However,high corrosion rate is considered the key lifetime-limiting.Plasma electrolytic oxidation(PEO)method is a simple strategy to deposit an oxide layer on the surface of light metals such as magnesium alloys,to control corrosion rate and promote some other properties,depending on their performances.Nevertheless,their features including their micropore size,distribution,and interconnectivity,and microcracks have not been improved to an acceptable level to support long-term performances of the magnesium-based substrates.Studies have introduced micro/nano-enabled approaches to enhance various properties of PEO coatings such as corrosion resistance,tribological properties,self-healing ability,bioactivity,biocompatibility,antibacterial properties,or catalytic performances.These strategies consist of incorporating of micro and nanoparticles into the PEO layers to produce multi-functional surfaces or the formation of multi-layered coatings to cover the defects of PEO coatings.In this perspective,the present paper aims to overview various nano/micro-enabled strategies to promote the properties of PEO coatings on magnesium alloys.The main focus is given to the functional changes that occurred in response to the incorporation of various types of nano/micro-structures into the PEO coatings on magnesium alloys.展开更多
The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments...The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor(SBR) activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride(NaCI) to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.展开更多
The characteristic of groundwater belongs to low iron but high manganese in Shenyang Hunnan New Developed Area.The first stage engineering of The WTP of Shenyang Hunnan industry Area were designed according the techno...The characteristic of groundwater belongs to low iron but high manganese in Shenyang Hunnan New Developed Area.The first stage engineering of The WTP of Shenyang Hunnan industry Area were designed according the technology of aerated-contact oxidation,and the water quality couldn’t reach to the standard after the WTP putted into production,1996.展开更多
One of the methods used in practice for the purification of wastewater from vegetable-processing enterprises is biological method of aerobic purification. With the aim to increase air-tank capacity used in traditional...One of the methods used in practice for the purification of wastewater from vegetable-processing enterprises is biological method of aerobic purification. With the aim to increase air-tank capacity used in traditional systems of biochemical purification of wastewater, different ways effecting to the process of vital activity of microorganisms of active sludge are applied. On the one hand, using the compositions of different salts and complex organic biogenous supplements prevents from the accumulation of some anions in the amounts exceeding the limited concentration, on the other hand- allows different groups of microorganisms to choose biogenous elements, which they assimilate easily and fully. It is known, that compounds of silicon and germanium can cause stimulating effects [1] to the organisms of active sludge. The goal of present studies is the intensification of biological processes of oxidation of organic contamination in wastewater by new bio-degradable chemical compounds or compositions on their basis, and by bio-sorbents.展开更多
Solid phases of visible fuorescence substance(VFS)of biological fuids(blood,urine,hemodia-lysate)which was proposed earlier as a morbidity and mortality marker by renal failure and diabetes were investigated in-depth ...Solid phases of visible fuorescence substance(VFS)of biological fuids(blood,urine,hemodia-lysate)which was proposed earlier as a morbidity and mortality marker by renal failure and diabetes were investigated in-depth by the methods of electron and confocal microscopy,optical spectroscopy and matrix assisted laser desorption-ionization(MALDI)mass spectroscopy.It is shown that dry VFS exists predominantly in the form of carbon-oxygen-nitrogen(N≈8.7 wt.%)nanoparticles(NPs)(5≤d≤100nm).For the first time the existence of the threshold energy E_(g)≈2.15eV for excitation of VFS was observed experimentally and confirmed by semi empirical calculations of the bathochromic shift.A good accordance with the earlier autonomous theo-retical calculations was achieved.Thus,the long wavelength limit(575 nm)of the spectral range where the VFS can be used as a fluorescent marker was reliably determined.A pilot MALDI comparative study of graphene oxide(GO)and urine VFS was carried out.Six kinds of nitrogen-free particles(412≤M≤456 Da)were observed in each substance and possible computer models of those have been composed.It is established that along with nitrogen-containing advanced glycation end products(AGEs)also nitrogen-fee carbon-oxygen-lhydrogen particles(probably toxic)with the composition and structure related to GO can exist in biofuids.Both types of particles should be taken into account in search for the reasons of high mortality among end stage renal disease patients.展开更多
Three beakers for removing Fe (II) in reconstituted water (doped with FeSO<sub>4</sub>) were built and tested. Given the set operating conditions ([O<sub>2</sub>] > 4 mg·L<sup>...Three beakers for removing Fe (II) in reconstituted water (doped with FeSO<sub>4</sub>) were built and tested. Given the set operating conditions ([O<sub>2</sub>] > 4 mg·L<sup>-1</sup>, P<sub>atm</sub> = 1.013 bar, T = 25°C ± 1°C and [Fe<sup>2+</sup>]<sub>0</sub> = 0.5 to 2 mg·L<sup>-1</sup>), removal of iron was caused by biological and possibly physical and chemical oxidation because there is a quantity of free oxygen in the medium. The extent of each type of oxidation has not been evaluated as it specifically studies the biological degradation of iron in these beaker tests by setting the operating conditions (pH > 6.5, dissolved oxygen from 0 to 8 mg·L<sup>-1</sup>, Redox Potential from 100 to 400 mV). The experimental studies focused particularly on the measurements of maximum wavelength, conversion efficiencies from Fe (II) to Fe (III), the effect of the Fe (II) concentration, the influence of pH, the action of the temperature of the prepared solutions and the effect of O<sub>2</sub> concentration under specified operating conditions. It noticed precipitated amounts of iron deposited at the bottom of the beakers. Thus, the low concentrations of Fe (II) detected in the influent after the biological oxidation operation could be attributed to microorganisms that consume iron as a substrate.展开更多
基金the Key Project in Science and Technology of Heilongjiang Province , China (No. GB06C20401)
文摘The gasification wastewater is a kind of typical organic industrial wastewater with high chemical oxygen demand (COD) and ammonia nitrogen, which could not be completely degraded by the traditional physical, chemical and biological method. So it is very important to find an effective treatment process. A combination process of catalytic oxidation with noble metal catalysts and aerobic biological fluid-bed packed with the new ultrastructure biological carriers, which was developed by ourselves, was investigated to treat the gasification wastewater. The pilot scale test with 0.5 m3/h influent flow was carried out to investigate the performance of this new combination process. The results showed that the effluent COD was 84.02 mg/L, ammonia nitrogen was 14.15 mg/L, and total phenol was 0.20 mg/L, which could completely meet the Grade Ⅰof Wastewater Discharge Standard (GB8978-1996), when the influent average COD was 5564 mg/L, ammonia nitrogen was 237 mg/L, and total phenol was 1100 mg/L. The two catalytic reactors could evidently improve the wastewater biodegradability, and the value of BOD5/COD (B/C) increased from 0.23 to 0.413 in the one-stage catalytic reactor and from 0.273 to 0.421 in two-stage catalytic reactor. The further experiment results showed that the effluent quality of this new combination process could still meet the discharge standard, when the COD loading was 8.65 kg / (m3·d). Most of aromatic and heterocyclic compounds were degraded effectively in this combination process.
文摘This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemical,and biological methods to ascertain their effectiveness in formaldehyde mitigation.Physical methods,including air circulation and adsorption,particularly with activated carbon and molecular sieves,are assessed for their efficiency in various concentration scenarios.Chemical methods,such as photocatalytic oxidation using titanium dioxide and plasma technology,are analyzed for their ability to decompose formaldehyde into non-toxic substances.Additionally,biological methods involving plant purification and microbial transformation are explored for their eco-friendly and sustainable removal capabilities.The paper concludes that while each method has its merits,a combined approach may offer the most effective solution for reducing indoor formaldehyde levels.The study underscores the need for further research to integrate these methods in a practical,cost-effective,and environmentally sustainable manner,highlighting their potential to improve indoor air quality significantly.
文摘Compared to conventional oxidation ditches, an integrated oxidation ditch with vertical circle (IODVC) has the characters of concise configuration, simple operation and maintenance, land saving and automatical sludge returning. By the utilization of vertical circulation, an aerobic zone and an anoxic zone can be unaffectedly formed in the IODVC. Therefore, COD and nitrogen can be efficiently removed. However, the removal efficiency of phosphorus was low in the IODVC. In the experiment described, a laboratory scale system to add an anaerobic column to the IODVC has been tested to investigate the removal of phosphorus from wastewater. The experimental results showed that the removal efficiency of TP with the anaerobic column was increased to 54.0% from 22.3% without the anaerobic column. After the acetic sodium was added into the influent as carbon sources, the mean TP removal efficency of 77. 5 % was obtained. At the same time, the mean removal efficiencies of COD, TN and NH3-N were 92.2%, 81.6% and 98.1%, respectively, at 12 h of HRT and 21-25 d of SRT. The optimal operational conditions in this study were as follows: recycle rate = 1.5-2.0, COD/TN 〉 6, COD/TP 〉 40, COD loading rate = 0.26-0.32 kgCOD/(kgSS· d), TN loading rate = 0. 028-0. 034 kgTN/( kgSS·d) and TP loading rate = 0.003-0.005 kgTP/(kgSS· d), respectively.
文摘Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.
文摘Cerium oxide nanoparticles(CNPs)possess a great potential as therapeutic agents due to their ability to self-regenerate by reversibly switching between two valences+3 and+4.This article reviews recent articles dealing with in vivo studies of CNPs towards Alzheimer’s disease,obesity,liver inflammation,cancer,sepsis,amyotrophic lateral sclerosis,acute kidney injury,radiation-induced tissue damage,hepatic ischemia reperfusion injury,retinal diseases and constipation.In vivo anti-cancer studies revealed the effectiveness of CNPs to reduce tumor growth and angiogenesis in melanoma,ovarian,breast and retinoblastoma cancer cell-induced mice,with their conjugation with folic acid,doxorubicin,CPM,or CXC receptor-4 antagonist ligand eliciting higher efficiency.After conjugation with triphenylphosphonium or magnetite nanoparticles,CNPs were shown to combat Alzheimer’s disease by reducing amyloid-β,glial fibrillary acidic protein,inflammatory and oxidative stress markers in mice.By improving muscle function and longevity,the citrate/EDTA-stabilized CNPs could ameliorate amyotrophic lateral sclerosis.Also,they could effectively reduce obesity in mice by scavenging ROS and reducing adipogenesis,triglyceride synthesis,GAPDH enzyme activity,leptin and insulin levels.In CCl4-induced rats,stress signaling pathways due to inflammatory cytokines,liver enzymes,oxidative and endoplasmic reticulum messengers could be attenuated by CNPs.Commercial CNPs showed protective effects on rats with hepatic ischemia reperfusion and peritonitis-induced hepatic/cardiac injuries by decreasing oxidative stress and hepatic/cardiac inflammation.The same CNPs could improve kidney function by diminishing renal superoxide,hyperglycemia and tubular damage in peritonitis-induced acute kidney injury in rats.Radiation-induced lung and testicular tissue damage could be alleviated in mice,with the former showing improvement in pulmonary distress and bronchoconstriction and the latter exhibiting restoration in spermatogenesis rate and spermatid/spermatocyte number.Through enhancement of gastrointestinal motility,the CNPs could alleviate constipation in both young and old rats.They could also protect rat from light-induced retinal damage by slowing down neurodegenerative process and microglial activation.
基金support provided by the National Natural Science Foundation of China (21978143 and 21878164)。
文摘Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing free radicals, the stability of catalysts is often insufficient, which has become a bottleneck in the application of CWAO. In this paper, a copper-based catalyst with excellent hydrothermal stability was designed and prepared. TiO_(2) with excellent stability was used as the carrier to ensure the longterm anchoring of copper and reduce the leaching of the catalyst. The one pot sol–gel method was used to ensure the super dispersion and uniform distribution of copper nanoparticles on the carrier, so as to ensure that more active centers could be retained in a longer period. Experiments show that the catalyst prepared by this method has good stability and catalytic activity, and the catalytic effect is not significantly reduced after 10 cycles of use. The oxidation degradation experiment of m-cresol with the strongest biological toxicity and the most difficult to degrade in coal chemical wastewater was carried out with this catalyst. The results showed that under the conditions of 140℃, 2 MPa and 2 h, m-cresol with a concentration of up to 1000 mg·L^(-1) could be completely degraded, and the COD removal rate could reach 79.15%. The biological toxicity of wastewater was significantly reduced. The development of the catalyst system has greatly improved the feasibility of CWAO in the treatment of refractory wastewater such as coal chemical wastewater.
基金Project(SWITCH018530) supported by the EU Sixth Framework Program-Sustainable Water management Improves Tomorrow’s CitiesProject(2008DFA91770) supported by the International Cooperation Items of the Ministry of Science and Technology,China
文摘The superior drainage was pre-treated by biologic contact oxidation on BOD5 load of 0.72 kg/(m3·d),and then post-treated by constructed wetland. The results about the effect on the constructed wetland post-treatment show that the total nitrogen (TN) is the restrictive index of the combinational technique treatment effect. To meet the reclaimed water quality standard and reuse for waterscape,the peak hydraulic load of constructed wetland is 0.50 m/d in summer (30-36 ℃) and 0.33 m/d in winter (8-12℃),and the load ratio of the peak hydraulic under the two temperature conditions is 3-2. The results are combined of reclaimed water quantity requirements in different seasons of green building. Reasonable scale of the reclaimed water treatment systems can be determined. The treatment efficacy can be well predicted,and both the design and operations can be effectively guided,by which the reclaimed water treatment systems regard superior drainage as the source and are purified by combinational technique of contact oxidation and artificial wetland.
文摘BACKGROUND Premature ovarian insufficiency(POI)is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage.Early follicular depletion results in intractable infertility,thereby considerably reducing the quality of life of females.Given the continuum in weakened ovarian function,progressing from incipient ovarian failure(IOF)to transitional ovarian failure and further to POI,it is necessary to develop biomarkers for predicting POI.The oxidative stress states in IOF and POI were comprehensively evaluated via oxidative stress[diacron-reactive oxygen metabolites(d-ROMs)]test and anti-oxidant capacity[biological antioxidant potential(BAP)].METHODS Females presenting with secondary amenorrhea over 4 mo and a follicle stimulating hormone level of>40 mIU/mL were categorized into the POI group.Females presenting with a normal menstrual cycle and a follicle stimulating hormone level of>10.2 mIU/mL were categorized into the IOF group.Healthy females without ovarian hypofunction were categorized into the control group.Among females aged<40 years who visited our hospital from January 2021 to June 2022,we recruited 11 patients into both POI and IOF groups.For the potential antioxidant capacity,the relative oxidative stress index(BAP/d-ROMs×100)was calculated,and the oxidative stress defense system was comprehensively evaluated.RESULTS d-ROMs were significantly higher in the POI and IOF groups than in the control group,(478.2±58.7 U.CARR,434.5±60.6 U.CARR,and 341.1±35.1 U.CARR,respectively)(U.CARR is equivalent to 0.08 mg/dL of hydrogen peroxide).However,no significant difference was found between the POI and IOF groups.Regarding BAP,no significant difference was found between the control,IOF,and POI groups(2078.5±157.4μmol/L,2116.2±240.2μmol/L,and 2029.0±186.4μmol/L,respectively).The oxidative stress index was significantly higher in the POI and IOF groups than in the control group(23.7±3.3,20.7±3.6,and 16.5±2.1,respectively).However,no significant difference was found between the POI and IOF groups.CONCLUSION High levels of oxidative stress suggest that evaluating the oxidative stress state may be a useful indicator for the early detection of POI.
基金supported financially by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA2003010301)the National Natural Science Foundation of China (Grant No. 41621001)
文摘Metagenomic studies have demonstrated the existence of ammonia-oxidizing archaea(AOA) and revealed they are responsible for ammoxidation in some extreme environments. However, the changes in compositional structure and ammonia-oxidation capacity of AOA communities in biological soil crusts(BSCs) of desert ecosystems remain poorly understood.Here, we utilized Illumina MiSeq sequencing and microbial functional gene array(GeoChip 5.0) to assess the above changes along a 51-year revegetation chronosequence in the Tengger Desert, China. The results showed a significant difference in AOA-community richness between 5-year-old BSCs and older ones. The most dominant phylum during BSC development was Crenarchaeota, and the corresponding species were ammonia-oxidizing_Crenarchaeote and environmental_samples_Crenarchaeota. Network analysis revealed that the positive correlations among dominant taxa increased, and their cooperation was reinforced in AOA communities during BSC succession. Redundancy analysis showed that the dominant factor influencing the change in AOA-community structure was soil texture. GeoChip 5.0 indicated that the amoA gene abundances of AOA and ammonia-oxidizing bacteria(AOB) were basically the same, demonstrating that AOA and AOB played an equally important role during BSCs development. Our study of the long-term succession of BSC demonstrated a persistent response of AOA communities to revegetation development in desert ecosystems.
文摘To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch (OD), where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification (SND) rate (rSND) was put forward to quantify SND. The results indicate that: (1) high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen (TN) and total phosphate (TP) removal rates were 80% and 85%, respectively; (2) when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; (3) the natural logarithm of the ratio of NOx to NH4^+ in the effluent had a linear correlation to oxidation-reduction potential (ORP); (4) when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; (5) denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.
文摘The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors(ASBRs) (0^#-6^#) which had been run under stable anaerobic ammonium oxidation (Anammox). By means of monitoring and data analysis of COD, NH4^#-N, NO2^--N, NO3^--N and pH, and of microbial test, the results revealed that the optimal Anammox performance was achieved from 2^# reactor in which COD/NH4^+ -N was 1.65, Anammox bacteria and denitrification bacteria could coexist, and Anammox reaction and denitrification reaction could occur simultaneously in the reactors. The ratio of NH4^+-N consumed : NO2^- -N consumed : NO3^- -N produced was 1:1.38:0.19 in 0^# reactor which was not added glucose in the wastewater. When different ratio of COD and NH4^+-N was fed for the reactors, the ratio of NO2^- -N consumed: NH4^+-N consumed was in the range of 1.51-2.29 and the ratio of NO;-N produced: NH4^+ -N consumed in the range of 0 -0.05.
文摘Magnesium(Mg)and its alloys have become a hot research topic in various industries owing to the specific physical and chemical properties.However,high corrosion rate is considered the key lifetime-limiting.Plasma electrolytic oxidation(PEO)method is a simple strategy to deposit an oxide layer on the surface of light metals such as magnesium alloys,to control corrosion rate and promote some other properties,depending on their performances.Nevertheless,their features including their micropore size,distribution,and interconnectivity,and microcracks have not been improved to an acceptable level to support long-term performances of the magnesium-based substrates.Studies have introduced micro/nano-enabled approaches to enhance various properties of PEO coatings such as corrosion resistance,tribological properties,self-healing ability,bioactivity,biocompatibility,antibacterial properties,or catalytic performances.These strategies consist of incorporating of micro and nanoparticles into the PEO layers to produce multi-functional surfaces or the formation of multi-layered coatings to cover the defects of PEO coatings.In this perspective,the present paper aims to overview various nano/micro-enabled strategies to promote the properties of PEO coatings on magnesium alloys.The main focus is given to the functional changes that occurred in response to the incorporation of various types of nano/micro-structures into the PEO coatings on magnesium alloys.
基金The Hi_Tech Research and Development Program(863) of China(2004AA601020) the National Natural Science Foundation of China(No.50478047)andthe Open Grant of Beijing Key Laboratory
文摘The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor(SBR) activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride(NaCI) to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.
文摘The characteristic of groundwater belongs to low iron but high manganese in Shenyang Hunnan New Developed Area.The first stage engineering of The WTP of Shenyang Hunnan industry Area were designed according the technology of aerated-contact oxidation,and the water quality couldn’t reach to the standard after the WTP putted into production,1996.
文摘One of the methods used in practice for the purification of wastewater from vegetable-processing enterprises is biological method of aerobic purification. With the aim to increase air-tank capacity used in traditional systems of biochemical purification of wastewater, different ways effecting to the process of vital activity of microorganisms of active sludge are applied. On the one hand, using the compositions of different salts and complex organic biogenous supplements prevents from the accumulation of some anions in the amounts exceeding the limited concentration, on the other hand- allows different groups of microorganisms to choose biogenous elements, which they assimilate easily and fully. It is known, that compounds of silicon and germanium can cause stimulating effects [1] to the organisms of active sludge. The goal of present studies is the intensification of biological processes of oxidation of organic contamination in wastewater by new bio-degradable chemical compounds or compositions on their basis, and by bio-sorbents.
基金support for this work by the Archimedes project 3.2.1101.12-0011supported in part by the institutional research funding IUT (IUT 2-26)of the Estonian Ministry of Education and Research.
文摘Solid phases of visible fuorescence substance(VFS)of biological fuids(blood,urine,hemodia-lysate)which was proposed earlier as a morbidity and mortality marker by renal failure and diabetes were investigated in-depth by the methods of electron and confocal microscopy,optical spectroscopy and matrix assisted laser desorption-ionization(MALDI)mass spectroscopy.It is shown that dry VFS exists predominantly in the form of carbon-oxygen-nitrogen(N≈8.7 wt.%)nanoparticles(NPs)(5≤d≤100nm).For the first time the existence of the threshold energy E_(g)≈2.15eV for excitation of VFS was observed experimentally and confirmed by semi empirical calculations of the bathochromic shift.A good accordance with the earlier autonomous theo-retical calculations was achieved.Thus,the long wavelength limit(575 nm)of the spectral range where the VFS can be used as a fluorescent marker was reliably determined.A pilot MALDI comparative study of graphene oxide(GO)and urine VFS was carried out.Six kinds of nitrogen-free particles(412≤M≤456 Da)were observed in each substance and possible computer models of those have been composed.It is established that along with nitrogen-containing advanced glycation end products(AGEs)also nitrogen-fee carbon-oxygen-lhydrogen particles(probably toxic)with the composition and structure related to GO can exist in biofuids.Both types of particles should be taken into account in search for the reasons of high mortality among end stage renal disease patients.
文摘Three beakers for removing Fe (II) in reconstituted water (doped with FeSO<sub>4</sub>) were built and tested. Given the set operating conditions ([O<sub>2</sub>] > 4 mg·L<sup>-1</sup>, P<sub>atm</sub> = 1.013 bar, T = 25°C ± 1°C and [Fe<sup>2+</sup>]<sub>0</sub> = 0.5 to 2 mg·L<sup>-1</sup>), removal of iron was caused by biological and possibly physical and chemical oxidation because there is a quantity of free oxygen in the medium. The extent of each type of oxidation has not been evaluated as it specifically studies the biological degradation of iron in these beaker tests by setting the operating conditions (pH > 6.5, dissolved oxygen from 0 to 8 mg·L<sup>-1</sup>, Redox Potential from 100 to 400 mV). The experimental studies focused particularly on the measurements of maximum wavelength, conversion efficiencies from Fe (II) to Fe (III), the effect of the Fe (II) concentration, the influence of pH, the action of the temperature of the prepared solutions and the effect of O<sub>2</sub> concentration under specified operating conditions. It noticed precipitated amounts of iron deposited at the bottom of the beakers. Thus, the low concentrations of Fe (II) detected in the influent after the biological oxidation operation could be attributed to microorganisms that consume iron as a substrate.