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Sludge composition and characteristics shaped microbial community and further determined process performance: A study on full-scale thermal hydrolysis-anaerobic digestion processes

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Journal of environmental sciences 2024年第3期137卷 96-107页

作者： wei Liu Chenxiang Sun wei Li Tianle Li Zhan Chen Jiawei wang Zhengran Ren xianghua wen School of Environment Tsinghua UniversityBeijing 100084China Jinneng Holding Group DatongShanxi 037000China Research and Development Center Beijing Drainage Group Co.Ltd.Beijing 100124China beij.ng Dabeinong science and Technology Group Co. Ltd.Beijing 100080China

Anaerobic digestion (AD) with thermal hydrolysis (TH) pretreatment is a promising process for excess sludge treatment,while there lacks of the knowledge from full-scale process about the impact of sludge composition and characteristics on microbial community and *** sludge physiochemical indices,microbial community and performance data of four full-scale TH-AD plants were characterized,and their relationships was *** four plants were operated under almost similar total organic loading rate (OLR)but their methanogenesis performance differentiate into two groups,namely superior group(SupG) and the inferior group (Inf G).In both groups,TH effectively solubilized particulate organic compounds,meanwhile raised the ammonia nitrogen (NH_(4)^(+)-N) and volatile fatty acid (VFA) *** with the Sup G,thermal hydrolyzed sludge of Inf G had higher level of VFAs,NH_(4)^(+)-N and total chemical oxygen demand (t COD),which showed higher inhibition effect on microbes,leading to a community with lower diversity,lower abundance of carbohydrate degrading functional guild,higher protein degrading one,and methanogens that adapted to limited substrates,and further declined the methane production ***,it was recommended that OLR alone was not sufficient for controlling the system in design and operation,the concentration of VFAs,NH_(4)^(+)-N and t COD should be equally *** higher concentration,together with the higher abundance of Defluviitoga and Proteiniphilum were recommended as indicators for inferior running *** results proposed that microbial communities played a role of bridge between environmental factors and performance,provided implications for engineering ecology and operational regulation for full-scale sludge TH-AD process.

关键词： Thermal hydrolysis Anaerobic digestion Microbial community Full-scale

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Expression of lignin peroxidase H2 from Phanerochaete chrysosporium by multi-copy recombinant Pichia strain

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Journal of environmental sciences 2009年第2期21卷 218-222页

作者： wang wei,wen xianghua department of environmental science and engineering,tsinghua university,beij.ng 100084,china. department of environmental science and engineering Tsinghua University Beijing 100084 China

The lipH2 gene, encoding the expression of lignin peroxidase, was cloned from Phanerochaete chrysosporium BKM-F-1767 and expressed in Pichia pastoris X-33, a yeast. The cDNA of LiPH2 was generated from total RNA extracted from P chrysosporium by PCR with primers that do not contain a P. chrysosporium lignin peroxidase secretion signal. The gene was then successfully inserted into the expression vector pPICZα, and resulted in the recombinant vector pPICZα-lipH2. The transformation was conducted in two ways. One was using the wild Pichia pastoris as the recipients, which results in the recombinant P. pastoris with single or low lipH2 gene copy. The second was using P. pastoris and single or low lipH2 gene copy as the recipients, which results in the recombinant P. pastoris with multi-copies of lipH2 genes. This study firstly expressed the gene lipH2 in P. pastoris and achieved the successful expression of the lipH2 depending upon the generation of a recombinant strain that contained multiple copies. The lignin peroxidase activity reached a maximum of 15 U/L after 12 h induction.

关键词： heterologous expression lignin peroxidase Pichia pastoris

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Design of policy mechanism to promote cleaner production in china

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Journal of environmental sciences 2001年第3期13卷 346-350页

作者： ZHAng Tian zhu(department of environmental science and engineering, tsinghua university, beij.ng 100084, china. department of environmental science and engineering Tsinghua University Beijing 100084 China. zhangtz@***

In order to promote cleaner production in china. a package of policy options was presented based on the identification of the barriers encountered in the CP demonstration project and the effectiveness and feasibility of policy options for the CP implementation were analyzed. Furthermore, the policy mechanism framework was given, which composes of compulsory, economic incentive, social pressure and supportive function. Finally, the implementation strategy of the policy mechanism, in which the emphasis will be changed from compulsory policy options towards economic and social pressure policy options, was proposed.

关键词： cleaner production barrier identification policy mechanism china

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To enhance the reproduction of Phanerochaete chrysosporium by adding natural lixiviums in liquid medium

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Journal of environmental sciences 2003年第6期15卷 808-814页

作者： LIN Gang, wen Xiang-hua, QIAN Yi (department of environmental science and engineering, tsinghua university, beij.ng 100084, china. department of environmental science and engineering Tsinghua University Beijing 100084 Chin

Great promotion to the reproduction of white rot fungus Phanerochaete chrysosporium by adding natural lixiviums such as from wood, maize core and potato in liquid medium was found in this research. Incubated in the liquid medium contained 10 mg/L glucose as carbon source with natural lixiviums for three days, the production of mycelium pellet reaches more than 80 g/L, which is 5 times more than that of without natural lixiviums. Incubated in the liquid medium contained 5 mg/L glucose as carbon source with natural lixiviums for three days, the production of mycelium pellet can reach 69.5 g/L, while the production in the medium without natural lixiviums is very low. When the liquid medium contained 1—20 g/L glucose as carbon source, the production of mycelium pellet in 3 d can only reach 12.5 g/L to 14.5 g/L. The fungus in the medium with potato lixiviums are easily contaminated by other microorganisms and in the medium with maize core lixiviums are easily bulking, while in the medium with wood lixiviums are neither easily contaminated nor bulking. Medium with wood lixiviums can produce more pellet than other medium, endure contamination and keep better sedimentation capacity. So that, wood lixivium is better additive to the culture of white rot fungi in liquid medium. Addition of the mixture of wood, maize core and potato lixiviums is of advantage to the production of mycelium pellet. The difference of the production in the medium with different amount of wood lixiviums showed little in the first 3 d, while it expanded after 3 d. Wood lixiviums stimulate the growth of P. chrysosporium instead of supply organics which fungi need.

关键词： white rot fungi medium additive

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Estimating health damage cost from secondary sulfate particles—a case study of Hunan Province,china

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Journal of environmental sciences 2003年第5期15卷 611-617页

作者： HAO Ji ming, LI Ji, YE Xue mei, ZHU Tian le (department of environmental science and engineering, tsinghua university, beij.ng 100084, china. ) department of environmental science and engineering Tsinghua University Beijing 100084 China

china.s coal dominated energy pattern has resulted in large amount of SO 2 emissions. Estimate of the sulfur related health damage cost is necessary to help perform systematic cost benefit analysis and set national energy and emissions control priorities. Current researches were confined to gaseous SO 2 in urban areas; however, secondary sulfate (SO 2- 4) particles can exert serious impact in a wider region. Based on the concept of “intake fraction', CALPUFF long range dispersion model and 180 sample emission sources, multiple regression equation was obtained with good correlation( r =0 85), which illustrates that populations were key parameters to determine intake fraction but source characteristics were insignificant. Based on the formula and the population distribution data, county level intake fractions were mapped for Hunan Province(range: 1 1×10 -6 -3 2×10 -6 ) of china. A combination of county level SO 2 emissions with the intake fractions yields a total 1 98 tons of sulfate(SO 2- 4) inhalation, and resulting total health damage cost to be 0 76(willingness to pay approach, WTP) or 0 16(human capital approach, HC) billion USD in 1997, about 2.1% or 0 45% of GDP in Hunan in 1997. Average health damage cost per ton of SO 2 emission is 930(WTP) or 200 USD(HC). The results demonstrated that more stringent regulation should be forced.

关键词： intake fraction health impact Hunan Province sulfate regression analysis

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An ecosystem-based understanding and analysis for SENCE toward sustainable development

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Journal of environmental sciences 2001年第3期13卷 328-332页

作者： CHEng Sheng\|tong, HOU Ji\|xiong , JIA Hai\|feng (department of environmental science and engineering, tsinghua university, beij.ng 100084, china. department of environmental science and engineering Tsinghua University Beijing 100084 China.

There is a need to find a comprehensive approach focusing on the conflicts between economical growth and environmental protection. Chinese scholars advocate a comprehensive ecosystem viewpoint named social-economic-natural complex ecosystem(SENCE). The kernel of the concept lies in the hierarchical structure of SENCE, through which methods from ecological network can be useful to the compound system. The author gives a schema depicting its structure, following a made analysis to help understand the reliance of economy on ecosystem. It is obvious that more actions should be done to strive for sustainable development.

关键词： social-economic-natural complex ecosystem (SENCE) ecosystem model sustainable development

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Effect of carbon source on the denitrification in constructed wetlands

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Journal of environmental sciences 2009年第8期21卷 1036-1043页

作者： LU Songliu, HU Hongying, SUN Yingxue, YAng Jia ESPC State Key Joint Laboratory, department of environmental science and engineering, tsinghua university, beij.ng 100084, china. [a]ESPC State Key Joint Laboratory Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

The ability of constructed wetlands with different plants in nitrate removal were investigated. The factors promoting the rates of denitrification including organic carbon, nitrate load, plants in wetlands, pH and water temperature in field were systematically investigated. The results showed that the additional carbon source （glucose） can remarkably improve the nitrate removal ability of the constructed wetland. It demonstrated that the nitrate removal rate can increase from 20% to more than 50% in summer and from 10% to 30% in winter, when the nitrate concentration was 30-40 rag/L, the retention time was 24 h and 25 mg/L dissolved organic carbon （DOC） was ploughed into the constructed wetland. However, the nitrite in the constructed wetland accumulated a little with the supply of the additional carbon source in summer and winter, and it increased from 0.15 to 2 mg/L in the effluent. It was also found that the abilities of plant in adjusting pH and temperature can result in an increase of denitrification in wetlands. The seasonal change may also impact the denitrification.

关键词： constructed wetland carbon source denitrification nitrate nitrite

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Prediction of soot–water partition coefficients for selected persistent organic pollutants from theoretical molecular descriptors

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Progress in Natural science:Materials International 2008年第7期18卷 867-872页

作者： Qing Zhang, Jun Huang, Gang Yu * POPs Research Centre, department of environmental science and engineering, tsinghua university, beij.ng 100084, china POPs Research Centre Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

Quantitative structure–property relationship (QSPR) models were developed for soot–water partition coefficient (KSC) values of selected persistent organic pollutants (POPs), i.e. 10 polychlorinated dibenzo-p-dioxins and dibenzofurans, nine polychlorinated biphe- nyls, four polycyclic aromatic hydrocarbons and two polybrominated diphenyl ethers, using partial least squares (PLS) regression. Quan- tum chemical descriptors computed by parameterized model revision 3 Hamiltonian method were used as predictor variables. The cross- validated Q2cum value for the optimal QSPR model is 0.844, indicating a good predictive capability for the logKSC values of these chem- icals. The QSPR results showed that average molecular polarizability (a), standard heat of formation (DHf) and energy of the lowest unoccupied molecular orbital (ELUMO) have dominant effects on KSC of POPs. The results suggested that logKSC values of POPs increase with the increase of a. Contrarily, logKSC values decrease with the increase of ELUMO and DHf of POPs.

关键词： Quantitative structure–property relationships Black carbon Persistent organic pollutants Quantum chemical descriptors Partial least squares

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Relationship of Retinal Nerve Fiber Layer Thickness and Retinal Vessel Calibers with Cognitive Impairment in the Asymptomatic Polyvascular Abnormalities Population

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Biomedical and environmental sciences 2024年第2期37卷 196-203页

作者： wang Dan Dan wang An Xin ZHAng Xiao Li wei wen Bin WU Shou Ling ZHAO Xing Quan department of Neurology Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China china.National Clinical Research Center for Neurological Diseases Beijing 100070China beij.ng Tongren Eye Center Beijing Key Laboratory of Ophthalmology and Visual ScienceBeijing Tongren HospitalCapital Medical UniversityBeijing 100005China department of Cardiology Kailuan HospitalTangshan 063001HebeiChina

Objective Cognitive impairment(CI)in older individuals has a high morbidity rate worldwide,with poor diagnostic methods and susceptible population *** study aimed to investigate the relationship between different retinal metrics and CI in a particular population,emphasizing polyvascular *** We collected information from the Asymptomatic Polyvascular Abnormalities Community Study on retinal vessel calibers,retinal nerve fiber layer(RNFL)thickness,and cognitive function of 3,785participants,aged 40 years or *** regression was used to analyze the relationship between retinal metrics and cognitive *** stratified by different vascular statuses were also *** RNFL thickness was significantly thinner in the CI group(odds ratio:0.973,95%confidence interval:0.953–0.994).In the subgroup analysis,the difference still existed in the non-intracranial arterial stenosis,non-extracranial carotid arterial stenosis,and peripheral arterial disease subgroups(Png small vessel change in RNFL and CI should be investigated in the future.

关键词： Retinal nerve fiber layer Cognitive impairment Polyvascular abnormality

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Al_(1-x)Sc_(x)Sb_(y)N_(1-y):An opportunity for ferroelectric semiconductor field effect transistor

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science china.Physics,Mechanics & Astronomy) 2024年第11期67卷 133-140页

作者： Shujin Guo xianghua Kong Hong Guo College of Physics and Electronic engineering Center for Computational SciencesSichuan Normal UniversityChengdu 610068China College of Physics and Optoelectronic engineering Shenzhen UniversityShenzhen 518060China department of Physics McGill UniversityMontreal H3A 2T8Canada

For the in-memory computation architecture,a ferroelectric semiconductor field-effect transistor(FeSFET)incorporates ferroelectric material into the FET channel to realize logic and memory in a single *** emerging groupⅢnitride material Al_(1-x)Sc_(x)N provides an excellent platform to explore FeSFET,as this material has significant electric polarization,ferroelectric switching,and high carrier ***,steps need to be taken to reduce the large band gap of~5 eV of Al_(1-x)Sc_(x)N to improve its transport property for in-memory logic *** state-of-the-art first principles analysis,here we predict that alloying a relatively small amount(less than~5%)of Sb impurities into Al_(1-x)Sc_(x)N very effectively reduces the band gap while maintaining excellent *** show that the co-doped Sb and Sc act cooperatively to give a significant band bowing leading to a small band gap of~1.76 eV and a large polarization parameter~0.87 C/m^(2),in the quaternary Al_(1-x)Sc_(x)Sb_(y)N_(1-y)*** Sb impurity states become more continuous as a result of interactions with Sc and can be used for impurity-mediated *** on the Landau-Khalatnikov model,the Landau parameters and the corresponding ferroelectric hysteresis loops are obtained for the quaternary *** findings indicate that Al_(1-x)Sc_(x)Sb_(y)N_(1-y)is an excellent candidate as the channel material of FeSFET.

关键词： ferroelectricity Al_(1-x)Sc_(x)N FeSFET

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