New mathematical procedure for the automatic estimation of influent characteristics in WWTPs

2007 ◽  
Vol 56 (8) ◽  
pp. 95-106 ◽  
Author(s):  
P. Grau ◽  
S. Beltrán ◽  
M. de Gracia ◽  
E. Ayesa

This paper proposes a new methodology for the automatic characterization of the influent wastewater in WWTP. With this methodology, model components are automatically estimated by means of optimization algorithms combining a-priori knowledge of the expected wastewater composition with experimental information from the available measurement data. The characterization is carried out based on an extended model components list in which components are described by means their elemental mass fractions. This allows an easy establishment of relationships between model components with experimental data and also, to obtain a general methodology applicable to any model used for wastewater biological treatments. The characterization of the wastewater influent of Galindo-Bilbao according this methodology has demonstrated its validity and the easy application to the ASM1 model influent characterization.

2006 ◽  
Vol 53 (1) ◽  
pp. 225-240 ◽  
Author(s):  
M. de Gracia ◽  
L. Sancho ◽  
J.L. García-Heras ◽  
P. Vanrolleghem ◽  
E. Ayesa

This paper proposes a systematic methodology for the analysis of the mass and charge balances in dynamic models expressed using the Petersen matrix notation. This methodology is based on the definition of the model components via elemental mass fractions and in the estimation of the COD as a function of the redox equations associated with these elements. This approach makes the automatic calculation of all the stoichiometric coefficients under different measuring units and the study of COD, charge or mass fluxes easier. As an example of its application this methodology was applied to the ADM1 in order to illustrate its usefulness for the analysis of organic matter characterisation, nitrogen release or biogas composition in anaerobic digestion. The application of the methodology for a rigorous integration of different IWA models is proposed for further study.


2006 ◽  
Vol 54 (4) ◽  
pp. 157-166 ◽  
Author(s):  
E. Huete ◽  
M. de Gracia ◽  
E. Ayesa ◽  
J.L. Garcia-Heras

This paper presents a systematic methodology to characterise the influent sludge in terms of the ADM1 components from the experimental measurements traditionally used in wastewater engineering. For this purpose, a complete characterisation of the model components in their elemental mass fractions and charge has been used, making a rigorous mass balance for all the process transformations and enabling the future connection with other unit-process models. It also makes possible the application of mathematical algorithms for the optimal characterisation of several components poorly defined in the ADM1 report. Additionally, decay and disintegration have been necessarily uncoupled so that the decay proceeds directly to hydrolysis instead of producing intermediate composites. The proposed methodology has been applied to the particular experimental work of a pilot-scale CSTR treating real sewage sludge, a mixture of primary and secondary sludge. The results obtained have shown a good characterisation of the influent reflected in good model predictions. However, its limitations for an appropriate prediction of alkalinity and carbon percentages in biogas suggest the convenience of including the elemental characterisation of the process in terms of carbon in the analytical program.


1994 ◽  
Vol 29 (7) ◽  
pp. 229-237 ◽  
Author(s):  
J. Kruit ◽  
F. Boley ◽  
L. J. A. M. Jacobs ◽  
T. W. M. Wouda

Influent characterization and biosorption experiments were carried out with settled influent of seven wastewater treatment plants to study the influence of O2 in the selector in relation to the success of developing good settling properties of the sludge. In previous years working selectors were installed and/or pilot plant research was carried out at these wastewater treatment plants. Characterization of the influent was done with help of standard COD and BOD measurements with help of a coarse filter. The research has elucidated that the presence of O2 in the selector, at initial sludge loadings of 3.5-6.5 kg BOD/kg MLSS.d, is important for producing good settling properties of the sludge when the sum of readily biodegradable COD and rapidly hydrolysable COD is greater than 40%. When the sum of sludge COD and slow hydrolysable COD is greater than 50% an unaerated selector can be used.


Paleobiology ◽  
2016 ◽  
Vol 43 (1) ◽  
pp. 68-84 ◽  
Author(s):  
Bradley Deline ◽  
William I. Ausich

AbstractA priori choices in the detail and breadth of a study are important in addressing scientific hypotheses. In particular, choices in the number and type of characters can greatly influence the results in studies of morphological diversity. A new character suite was constructed to examine trends in the disparity of early Paleozoic crinoids. Character-based rarefaction analysis indicated that a small subset of these characters (~20% of the complete data set) could be used to capture most of the properties of the entire data set in analyses of crinoids as a whole, noncamerate crinoids, and to a lesser extent camerate crinoids. This pattern may be the result of the covariance between characters and the characterization of rare morphologies that are not represented in the primary axes in morphospace. Shifting emphasis on different body regions (oral system, calyx, periproct system, and pelma) also influenced estimates of relative disparity between subclasses of crinoids. Given these results, morphological studies should include a pilot analysis to better examine the amount and type of data needed to address specific scientific hypotheses.


2014 ◽  
Vol 14 (1) ◽  
pp. 283-299 ◽  
Author(s):  
V. F. Sofieva ◽  
J. Tamminen ◽  
E. Kyrölä ◽  
T. Mielonen ◽  
P. Veefkind ◽  
...  

Abstract. A new ozone climatology, based on ozonesonde and satellite measurements, spanning the altitude region between the earth's surface and ~60 km is presented (TpO3 climatology). This climatology is novel in that the ozone profiles are categorized according to calendar month, latitude and local tropopause heights. Compared to the standard latitude–month categorization, this presentation improves the representativeness of the ozone climatology in the upper troposphere and the lower stratosphere (UTLS). The probability distribution of tropopause heights in each latitude–month bin provides additional climatological information and allows transforming/comparing the TpO3 climatology to a standard climatology of zonal mean ozone profiles. The TpO3 climatology is based on high-vertical-resolution measurements of ozone from the satellite-based Stratospheric Aerosol and Gas Experiment II (in 1984 to 2005) and from balloon-borne ozonesondes from 1980 to 2006. The main benefits of the TpO3 climatology are reduced standard deviations on climatological ozone profiles in the UTLS, partial characterization of longitudinal variability, and characterization of ozone profiles in the presence of double tropopauses. The first successful application of the TpO3 climatology as a priori in ozone profile retrievals from Ozone Monitoring Instrument on board the Earth Observing System (EOS) Aura satellite shows an improvement of ozone precision in UTLS of up to 10% compared with the use of conventional climatologies. In addition to being advantageous for use as a priori in satellite retrieval algorithms, the TpO3 climatology might be also useful for validating the representation of ozone in climate model simulations.


2002 ◽  
Vol 124 (4) ◽  
pp. 791-799 ◽  
Author(s):  
Achintya Mukhopadhyay ◽  
Xiao Qin ◽  
Suresh K. Aggarwal ◽  
Ishwar K. Puri

A new formulation for extending the concept of heatlines and masslines to reacting flows through use of conserved scalars has been proposed. The formulation takes into account the distinct diffusion coefficients of different species. Results have been obtained for a number of two-dimensional nonreacting and reacting free shear flows under normal and zero gravity. For nonreacting flows, total enthalpy and elemental mass fractions have been used as the transported conserved scalars. For reacting flows, mixture fractions, defined as normalized elemental mass fractions and enthalpy, have been employed. The results show this concept to be a useful tool for obtaining better insights into the global qualitative picture of scalar transport for both nonreacting and reacting flows.


2011 ◽  
Vol 396-398 ◽  
pp. 1180-1183
Author(s):  
He Ping Li ◽  
Hu Qiang Lv ◽  
Yao Zhang ◽  
Yong Zhe Yang

In the normal pressure and presence of catalyst, a novel composite modified starch or functional surfactant was synthesized by using the cassava starch as the main feedstock through the alkalization, etherification and oxidation etc.. The degree of substitution was up to 1.21. Based on the orthogonal experiment and computer-aid methods, the optimum conditions were resulted as follows: the mass fractions(vs. dry starch) of chloroacetic acid, catalyst and oxidant were 32%, 0.01% and 1.14% respectively, and the reaction temperature of etherification was at 50°C for 4.1h. The structural characterization of the composite modified starch was determined by IR and X-ray diffraction.


Author(s):  
Yu. I. Buryak ◽  
A. A. Skrynnikov

The article is devoted to the substantiation of the procedure for testing complex technical systems to assess the probability of performing the task, taking into account a priori data obtained from the results of modeling, field tests of components and prototypes, operation of analogues, etc. The conditions for the formation of a combined sample consisting of field experiments and experiments counted on the results of modeling are justified. Data uniformity is checked using the Student's criterion. The minimum volume of full-scale tests is determined by the requirement of equality of the amount of Fischer information about the estimated parameter obtained during full-scale tests and at the expense of a priori data A strategy for conducting field experiments is proposed, in which the required quality of evaluating the probability of completing the task is achieved with the minimum possible number of field experiments. At the first stage, a series of experiments with a volume equal to half of the required sample size is performed. At the second stage, the experiments are conducted sequentially with an assessment after each experiment of the requirements for the amount of information about the evaluated parameter and for the uniformity of data. Experiments are terminated when the specified requirements are met, and then a combined sample is formed, which is used to evaluate the probability of the system performing the task. A model example is considered. The estimation of the gain in the number of experiments performed at different probability values was carried out.


Author(s):  
С.Н. Волков ◽  
А.И. Житенев ◽  
О.Н. Рублевская ◽  
Ю.А. Курганов ◽  
И.Г. Костенко ◽  
...  

Анализ официальных источников информации показывает, что распределение экстремальных дождей по территории происходит с учетом микроклиматических особенностей ее местности. Для оценки степени достоверности таких закономерностей в пределах мегаполисов проведены экспериментальные исследования, в которых в качестве экспериментальной базы принята система водоотведения Санкт-Петербурга, в качестве средств измерения – сеть из 34 автоматических осадкомеров, осуществляющих записи с интервалом 5 минут, в качестве экспериментальной информации – база данных результатов измерений в течение шести лет. В результате исследований установлено, что в городской среде формируется микроклимат, отличающийся от климата за ее пределами. Кроме того, в масштабах мегаполисов имеются микроклиматические зоны, в которых зависимости интенсивностей осадков от их повторяемости могут существенно отличаться. При этом отличия начинают проявляться при периодах р однократного превышения расчетной интенсивности дождей от 1,5–2 лет, а при их меньших значениях отличия не выявлены. Полученный результат согласуется с данными исследований других авторов, экспериментально установивших, что количество экстремальных дождей увеличивается в тех районах мегаполисов, как правило, исторических,в которых меньше зеленых насаждений и, соответственно, более высокая степень перегрева поверхности в летнее время. The analysis of official data resources shows that the distribution of extreme rainfall over the territory is carried out with account of the microclimatic features of the area. To estimate the degree of reliability of such patterns within megalopolises, experimental studies were carried out, where the wastewater disposal system of St. Petersburg was assumed as an experimental base; a network of 34 automatic rain gauges recording with an interval of 5 minutes was assumed as a measuring instrument, and a base was used as experimental information, i. e., a measurement data base for six years. As a result of the research, it has been established that a microclimate is formed in the urban environment that differs from the climate outside it. Besides, on a megacity scale, there are microclimatic zones where the dependences of precipitation intensities on their frequency can differ significantly. In this case, the differences begin to manifest at periods p of one-time excess of the calculated rainfall intensity from 1.5–2 years, whereas at lower values, no differences have been found. The result obtained is consistent with the research data obtained by other authors, who experimentally established that the amount of extreme rainfall increased in those areas of megacities, as a rule, historical ones, where fewer green spaces are located, and, accordingly, a higher degree of surface overheating in summer is recorded.


2021 ◽  
Author(s):  
Rafael Pimentel ◽  
Pedro Torralbo ◽  
Javier Aparicio ◽  
María José Pérez-Palazón ◽  
Ana Andreu ◽  
...  

<p>Mediterranean mountain areas are especially vulnerable to changes. Climatic trends observed in the last decades point out to an increasing number of extreme events (i.e., number of heat waves and droughts) and consequently, a direct alteration of the hydrological states of their associated ecosystems. The savanna type ecosystem called <em>dehesa</em> is one of them. This system is the result of a long-term co-evolution of indigenous ecosystems and human settlement in a sustainable balance, with high relevance from both the environmental (biodiversity) and socioeconomic (livestock farming, including Iberian pork food industry) point of view. <em>Dehesa </em>systems have a complex vegetation cover structure, where isolated trees, mainly holm oak, cork oak and oak, Mediterranean shrubs, and pastures coexist. Different problems have arisen in <em>dehesa</em> during last years, an example of them are seca episodes, a disease of oak trees that results in drying and final death. This condition is caused by a fungus, but very likely triggered by external hydrological related conditions like air temperature and soil water content.  Remote sensing techniques have been widely used as the best alternative to monitor vegetation patterns over these areas. However, the presence of clouds and the fixed spatiotemporal resolution of these sensors constitute a limitation in more local studies.</p><p>This work proposes the combined use of remote sensing by both terrestrial photography and satelital sensors, and hydrometeorological information as data sources for improving the hydrological characterization of vegetation in <em>dehesa</em> areas. The study was carried out in the Santa Clotilde experimental area, within the Cardeña-Montoro Natural Park (southern Spain). Three years of local sub-daily terrestrial photography and hydrometeorological information allowed us to define different hydrometeorological/ecohydrological indicators that are representative of key vegetation states. This local information is linked with vegetation indexes derived from high spatial resolution satellite information (i.e., Landsat TM, ETM+ and OLI (30 m x 30 m) and Sentinel-2 (10 m x 10 m) and distributed meteorological variables to extend the results from the local to the watershed scale. The promising results will be used in a short future as the basis of an advanced monitoring service where meteorological seasonal forecast information could be used to derive key indicators and help in a priori diagnosis of the system facilitating decisions making.</p><p>This work has been funded by project SIERRA Seguimiento hIdrológico de la vEgetación en montaña mediteRránea mediante fusión de sensores Remotos en Andalucía), with the economic collaboration of the European Funding for Rural Development (FEDER) and the Office for Economy, Knowledge, Enterprises and University of the Andalusian Regional Government.</p>


Sign in / Sign up

Export Citation Format

Share Document