Search results for "Water science"
showing 10 items of 1545 documents
Understanding water energy nexus in drinking water provision: an eco-efficiency assessment of water companies
2022
Producción Científica
Online mass flow prediction in CFB boilers with explicit detection of sudden concept drift
2010
Fuel feeding and inhomogeneity of fuel typically cause fluctuations in the circulating fluidized bed (CFB) process. If control systems fail to compensate the fluctuations, the whole plant will suffer from dynamics that is reinforced by the closed-loop controls. This phenomenon causes reducing efficiency and the lifetime of process components. In this paper we address the problem of online mass flow prediction, which is a part of control. Particularly, we consider the problem of learning an accurate predictor with explicit detection of abrupt concept drift and noise handling mechanisms. We emphasize the importance of having domain knowledge concerning the considered case and constructing the…
Discussion of “Soil Water Retention Characteristics of Vertisols and Pedotransfer Functions Based on Nearest Neighbor and Neural Networks Approaches …
2013
The concentration and non-carcinogenic risk assessment of aluminium in fruits, soil, and water collected from Iran
2020
The current study was conducted to investigate the concentration of bio-available aluminium (Al) in totally 90 samples of five types of fruits (grape, apple, nectarine, plum, and peach), the water ...
Characterization of Chlorolignins in Bleached Kraft Pulp Mill Effluents Using Elemental Analysis and Fingerprinting by CuO Oxidation And Hplc
1994
Abstract Elemental analyses and chemical degradation techniques were applied to characterize lignin compounds in different stages of the chlorine bleaching process and in total mill effluent. Ultrafiltration was used for separation of chlorolignins into three nominal molecular weight fractions. Alkaline CuO oxidation products were analyzed by HPLC with diode array detection. Major compounds were identified by reference to authentic compounds. For comparison, native lignins (MWL), kraft lignins, and humic substances were studied as well. The oxygen, carbon and organic chlorine contents were closely similar in the various mill samples and their fractions. In all mill samples, vanillin and 6-c…
HPLC-SEC: a new approach to characterise complex wastewater effluents
2016
ABSTRACTThis work investigates the use of HPLC-SEC to characterise dissolved organic matter (DOM) of complex wastewater effluents. A silica-based column, sodium acetate eluent and multiple detections were employed: UV-254 absorbance for humictype, and tryptophan-like (Ex/Em = 270/355) and tyrosine-like (Ex/Em = 270/310) fluorescence for protein type compounds. Effects of eluent pH, eluent ionic strength and injection volume on separation efficiency were tested. Humic-type and protein-type fractions were clearly differentiated and eluted within and out of calibration range. Eluent ionic strength had the greatest influence on global resolution; the lowest eluent concentration of 0.01 M produc…
Beerkan Estimation of Soil Transfer parameters (BEST) across soils and scales
2019
Abstract Theories and models used in soil hydrological sciences rely on the knowledge of the spatially and temporally variable soil hydraulic properties, i.e. the water retention and hydraulic conductivity curves. Obtaining reliable experimental information on these curves for an area of interest is not easy and it still remains a challenge for soil scientists. In 2006, a simple and physically based methodology was proposed to completely characterize the soil using a single ring infiltration experiment in the field and determination of soil particle size distribution, initial and final soil water content and dry soil bulk density. This methodology, named BEST – Beerkan Estimation of Soil Tr…
Public choice of urban water service management: a multi-criteria approach
2013
Local policy makers in developed countries have to make decisions in increasingly complex scenarios. Consequently, they should use all the tools available when deciding which management option is the most suitable for urban water service, given how important that service is and the variety of criteria involved in making such a decision. This article employs ‘analytic hierarchy process’ techniques to perform an ex post analysis of the decision to transfer the management of the urban water service in Granada (in southern Spain) to a public-private partnership. The main conclusion is that the decision was rational, in that it was the best possible alternative considering the hierarchy of prefe…
Evaluation of activated sludge model no.2 at high phosphorus concentrations
2001
This paper presents laboratory scale experimentation carried out to study enhanced biological phosphorus removal at high phosphorus concentrations in a sequencing batch reactor. Four series of data obtained in a sequencing batch reactor are examined in light of the Activated Sludge Model No. 2. This model was calibrated using data from the first and second series working at low phosphorus concentrations. The Activated Sludge Model No. 2 successfully characterised the enhanced biological phosphorus removal performance of the sequencing batch reactor at low phosphorus concentrations. The calibrated model was then used to adjust experimental results of the other series working at high phosphor…
Wide-scope screening of pharmaceuticals, illicit drugs and their metabolites in the Amazon River.
2021
Only a limited number of households in the Amazon are served by sewage collection or treatment facili- ties, suggesting that there might be a significant emission of pharmaceuticals and other wastewater contaminants into freshwater ecosystems. In this work, we performed a wide-scope screening to assess the occurrence of pharmaceuticals, illicit drugs and their metabolites in freshwater ecosystems of the Brazilian Amazon. Our study included 40 samples taken along the Amazon River, in three of its major tributaries, and in small tributaries crossing four important urban areas (Manaus, Santarém, Macapá, Belém). More than 900 compounds were investigated making use of target and suspect screenin…