scholarly journals Análisis de la capacidad necesaria en los procesos de tratamiento de aguas mediante programación matemática. Un caso de estudio

2020 ◽  
Vol 20 (1) ◽  
pp. 37
Author(s):  
María Colomina ◽  
Modesto Pérez-Sánchez ◽  
Raquel Sanchis ◽  
Manuel Díaz-Madroñero

One of the main problems of the water treatment plants is the high energy consumption they have to face. Therefore, reducing energy consumption is an imperative objective for these facilities. This work proposes a mathematical programming model for the capacity planning and the management of water treatment plants using dilution process that will reduce the energy consumption in the aeration phase. This model presents, as a novelty, the inclusion of the time variable, generating a quasi-stationary model that has been applied to a real case study.

2012 ◽  
Vol 12 (2) ◽  
pp. 200-211 ◽  
Author(s):  
G. Venkatesh ◽  
Helge Brattebø

This paper studies the trend in the consumption of energy and chemicals and the associated environmental impacts, for water treatment plants (WTPs) in Oslo, over the years between 2000 and 2009. The Norwegian Drinking Water Regulations stipulate that supplied water should comply with over 50 quality criteria. Abiding by the regulations and improving the water quality has its costs – economically and environmentally. Quality improvement entails, inter alia, the consumption of more chemicals, both in terms of quantity and variety, and a rise in energy consumption. In order to determine the environmental impacts of the consumption of chemicals and energy, an environmental life cycle assessment (LCA) was carried out. It was observed that the impacts of chemicals have increased dramatically after 2007, courtesy of a process upgrading at one of the WTPs. Except in the years 2004 and 2007, the impacts attributable to chemicals consumption have exceeded those due to energy consumption. Global warming is the key impact in both cases, though in the case of energy consumption, abiotic depletion and acidification are also significant.


1993 ◽  
Vol 28 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Y. Suzuki ◽  
S. Miyahara ◽  
K. Takeishi

Gas-permeable film can separate air and water, and at the same time, let oxygen diffuse from the air to the water through the film. An oxygen supply method using this film was investigated for the purpose of reducing energy consumption for wastewater treatment. The oxygen transfer rate was measured for the cases with or without biofilm, which proved the high rate of oxygen transfer in the case with nitrifying biofilm which performed nitrification. When the Gas-permeable film with nitrifying biofilm was applied to the treatment of wastewater, denitrifying biofilm formed on the nitrifying biofilm, and simultaneous nitrification and denitrification occurred, resulting in the high rate of organic matter and T-N removal (7 gTOC/m2/d and 4 gT-N/m2/d, respectively). However, periodic sloughing of the denitrifying biofilm was needed to keep the oxygen transfer rate high. Energy consumption of the process using the film in the form of tubes was estimated to be less than 40% of that of the activated sludge process.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 198
Author(s):  
Sabrina Bochicchio ◽  
Gaetano Lamberti ◽  
Anna Angela Barba

Some issues in pharmaceutical therapies such as instability, poor membrane permeability, and bioavailability of drugs can be solved by the design of suitable delivery systems based on the combination of two pillar classes of ingredients: polymers and lipids. At the same time, modern technologies are required to overcome production limitations (low productivity, high energy consumption, expensive setup, long process times) to pass at the industrial level. In this paper, a summary of applications of polymeric and lipid materials combined as nanostructures (hybrid nanocarriers) is reported. Then, recent techniques adopted in the production of hybrid nanoparticles are discussed, highlighting limitations still present that hold back the industrial implementation.


Nature ◽  
1978 ◽  
Vol 273 (5664) ◽  
pp. 587-587
Author(s):  
L. G. BROOKES

1994 ◽  
Vol 29 (10-11) ◽  
pp. 1-11 ◽  
Author(s):  
M. Boller ◽  
W. Gujer ◽  
M. Tschui

The variables affecting nitrification in biofilms are identified on a theoretical basis. The influence of various design and operational parameters which affect the resulting substance fluxes into and out of the biofilm and the biomass activity regarding nitrification are illustrated with the help of experimental investigations with plastic media trickling filters, rotating biological contactors and different aerated biofilters. The results of experiments with these systems in tertiary nitrification applications reveal process limitations and technical measures to enhance nitrification performance in each system. In a case study, a comparison between the different biofilm processes and activated sludge alternatives showed that biofilm systems may lead to remarkably smaller reactor volumes, but high energy consumption due to unfavorable oxygen utilization.


ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 61
Author(s):  
Giuseppe Sutera ◽  
Dario Calogero Guastella ◽  
Giovanni Muscato

<p>In recent years, drones have become widely used in many fields. Their vertical flight capability makes these systems suitable for carrying out a variety of tasks. In this paper, the delivery service they provide is analysed. The delivery of goods quickly and to remote areas is a relevant application scenario; however, the systems proposed in the literature use electromagnets, which affect the duration of the flight. In addition, these devices are heavy and suffer from high energy consumption, which reduces the maximum transportable payload. This study proposes a new lightweight magnetic plate composed of permanent magnets, capable of collecting and positioning any object as long as it has a ferromagnetic surface on the top. This plate was developed for the Mohamed Bin Zayed International Robotics Challenge 2020, an international robotics competition for multi-robot systems. Challenge two of this competition required a drone capable of picking up different types of bricks and assembling them to build a wall according to an assigned pattern. The bricks were of different colours and sizes, with weights ranging from 1 to 2 kg. In light of this, it was concluded that weight was the most relevant specification to consider in drone design.</p>


2021 ◽  
Vol 248 ◽  
pp. 02058
Author(s):  
Kaitai Hua

Considering the problems such as long duration of defrosting, low working reliability and high energy consumption of refrigerated containers, this paper put forward a new defrosting method combining air and electro-thermal energy, and designed a new defrosting structure system based on the structural features of refrigeration modules of refrigerated containers. The two-variable method of wind pressure change and temperature difference change on both sides of the evaporator was used to detect frosting, and the specific controlling strategy supporting the new defrosting system was provided to realize the effect of intelligent defrosting. It can provide references for fast defrosting, intelligent defrosting and low energy consumption defrosting of refrigerated containers.


2008 ◽  
Vol 58 ◽  
pp. 83-89
Author(s):  
Ning Chang Liu ◽  
Zhao Feng Li

In cement industry, many grinding up systems are on operating now. The tradition process of tube mill grinding system is high energy consumption, so it’s low efficiency, especially in the final cement grinding process. The value and advantage of slag is recognized more and more, but it’s difficult to be grinded up. Furthermore, the disadvantage and shortages to grind up clinker compounded with slag to produce cement are obvious and adopted. The best process is to grind up slag, clinker separately. Then, these two kinds of powder are compounded by a mixer. Hereby, it introduces a design of the process to grind up clinker, slag by one roller mill.


2012 ◽  
Vol 52 (No. 2) ◽  
pp. 51-66 ◽  
Author(s):  
P. Havlík ◽  
F. Jacquet ◽  
Boisson J-M ◽  
S. Hejduk ◽  
P. Veselý

BEGRAB_PRO.1 &ndash; a mathematical programming model for BEef and GRAssland Biodiversity PRoduction Optimisation &ndash; elaborated for analysis of organic suckler cow farms in the Protected Landscape Area White Carpathians, the Czech Republic, is presented and applied to the analysis of jointness between several environmental goods. In this way, the paper complements recent studies on jointness between commodities and non-commodities. If these goods are joint in production, agri-environmental payments must be carefully designed because they do not influence only production of the environmental good they are intended for but also the production of other environmental goods. If jointness is negative, any increase in the payment for an environmental good leads to a decrease in production of other environmental goods.


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