Modelling of physical, chemical and biological processes in Polish lakes and reservoirs

1993 ◽  
pp. 99-118 ◽  
Author(s):  
J. Uchmański ◽  
W. Szeligiewicz ◽  
M. Loga
Keyword(s):  
Biological Processes ◽  
Physical Chemical ◽  
Lakes And Reservoirs

Controlling chemical dosing for sulfide mitigation in sewer networks using a hybrid automata control strategy

2013 ◽  
Vol 68 (12) ◽  
pp. 2584-2590 ◽  
Author(s):  
Yiqi Liu ◽  
Ramon Ganigué ◽  
Keshab Sharma ◽  
Zhiguo Yuan
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Biological Processes ◽  
Control Performance ◽  
Hybrid Automata ◽  
Sewer Pipe ◽  
Physical Chemical ◽  
Iron Salts ◽  
Pumping Stations ◽  
Sewer Networks

Chemicals such as magnesium hydroxide (Mg(OH)2) and iron salts are widely used to control sulfide-induced corrosion in sewer networks composed of interconnected sewer pipe lines and pumping stations. Chemical dosing control is usually non-automatic and based on experience, thus often resulting in sewage reaching the discharge point receiving inadequate or even no chemical dosing. Moreover, intermittent operation of pumping stations makes traditional control theory inadequate. A hybrid automata-based (HA-based) control method is proposed in this paper to coordinate sewage pumping station operations by considering their states, thereby ensuring suitable chemical concentrations in the network discharge. The performance of the proposed control method was validated through a simulation study of a real sewer network using real sewage flow data. The physical, chemical and biological processes were simulated using the well-established SeweX model. The results suggested that the HA-based control strategy significantly improved chemical dosing control performance and sulfide mitigation in sewer networks, compared to the current common practice.

scholarly journals Biological activity of soils cultivated with yacón (Smallanthus sonchifolius Poep. & Endl) H. Robinson, inoculated with Azospirillum brasilense and native mycorrhizal fungi

2021 ◽  
Vol 38 (1) ◽  
pp. 125-133
Author(s):  
María Gabriela Di Barbaro ◽  
Horacio Enrique Andrada ◽  
Eleodoro Eduardo Del Valle ◽  
Celia Inés Brandán
Keyword(s):  
Biological Activity ◽  
Mycorrhizal Fungi ◽  
Azospirillum Brasilense ◽  
Microbial Consortium ◽  
Soil Samples ◽  
Biological Processes ◽  
Smallanthus Sonchifolius ◽  
Physical Chemical ◽  
Promote Plant Growth ◽  
Time Of Harvest

The soil is influenced by the roots of plants because the exudate radicals affect its physical, chemical, and biological processes. The aim of this research was to evaluate the microbial activity of soils cultivated with yacón (Smallanthus sonchifolius Poep. & Endl) H. Robinson and inoculated with microorganisms which promote plant growth. The experimental design used was randomized blocks with three repetitions per treatment. Each repetition corresponded to a 3m x 3m plot with 25 plants, in 5 cultivation lines with a distance of 70 cm apart. Four treatments were applied at the time of plantation. These consisted of yacón propagules inoculated with Azospirillum brasilense (T1) and native mycorrhizal fungi (T2) inoculated with the microbial consortium (T3). In the control treatments, the propagules were not inoculated with these microorganisms (T0). Soil samples were collected in lots cultivated with yacón located in the Province of Catamarca, in the northwest of Argentina. The samples were collected at the time of implantation and harvest during three agricultural cycles. The total Biological Activity (TBA) of the collected samples was determined by Fluorescein Diacetate Hydrolysis. The TBA of the soil was affected by the different crop treatments, which rose in the analyzed soils and was statistically different from the control treatments. Significant differences were also observed between the TBA of the soils at the beginning of the crops in comparison with the recorded values of the crop at the time of harvest. The inoculation of yacón propagules with A. brasilense and native mycorrhizal fungi affects the TBA of the cultivated soils marking a significant increase.

The three types of liquid water in the surface of present Mars

2009 ◽  
Vol 9 (1) ◽  
pp. 45-49 ◽  
Author(s):  
D. Möhlmann
Keyword(s):  
Solid State ◽  
Liquid Water ◽  
Bulk Water ◽  
Pure Liquid ◽  
Interfacial Water ◽  
Biological Processes ◽  
Undercooled Liquid ◽  
Liquid Bulk ◽  
Physical Chemical

AbstractThermodynamics teaches that pure liquid bulk water cannot stably exist on the surface of Mars. However, it is shown by thermodynamic arguments that liquid water can exist, at least temporarily, in the upper surface of Mars, in form of: (a) undercooled liquid interfacial water (ULI water); (b) undercooled liquid water in cryo-brines; and (c) liquid bulk water (due to solid-state greenhouse subsurface melting) in the subsurface of ice areas, which are covered by a lid of solid ice only. The presence of these forms of liquid water on present Mars is discussed in detail and in view of the possible consequences for physical, chemical and eventual biological processes.

Kinetic Hydrate Inhibitor Removal by Physical, Chemical and Biological Processes

2014 ◽  
Author(s):  
Samer Adham ◽  
Samir Gharfeh ◽  
Altaf Hussain ◽  
Joel Minier-Matar ◽  
Arnold Janson
Keyword(s):  
Biological Processes ◽  
Physical Chemical

Experimental reedbed systems for the treatment of airport runoff

1997 ◽  
Vol 36 (8-9) ◽  
pp. 385-390 ◽  
Author(s):  
D. M. Revitt ◽  
R. B. E. Shutes ◽  
N. R. Llewellyn ◽  
P. Worrall
Keyword(s):  
Pilot Scale ◽  
Surface Flow ◽  
Pollutant Removal ◽  
Biological Processes ◽  
Metal Concentrations ◽  
Physical Chemical ◽  
Flow Systems ◽  
Total Ammonia ◽  
Removal Efficiencies

The relative efficiencies of pollutant removal from airport runoff by three different designs of pilot scale reedbed treatment systems located at Heathrow airport are described. The sub-surface flow and surface flow systems generally performed more effectively than the rafted systems for reduction of BOD, COD, total ammonia, nitrate, phosphate and metal concentrations. The variable removal efficiencies are explained in terms of the physical, chemical and biological processes which are relevant to each reedbed system.

Physical, Chemical and Biological Processes for Optimizing Decentralized Composting

2003 ◽  
Vol 11 (4) ◽  
pp. 330-336 ◽  
Author(s):  
William Hogland ◽  
Torleif Bramryd ◽  
Marcia Marques ◽  
Sven Nimmermark
Keyword(s):  
Biological Processes ◽  
Physical Chemical

Lessons learned from injection into sedimentary geothermal aquifers

2020 ◽  
Author(s):  
Maren Brehme ◽  
Abel Marko ◽  
Santiago Aldaz ◽  
Guido Blöcher ◽  
Ernst Huenges
Keyword(s):  
Biological Activity ◽  
Large Scale ◽  
Lessons Learned ◽  
Biological Processes ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Physical Chemical ◽  
Sustainable Operation ◽  
Aquifer Properties ◽  
Flow Pathways

<p>Reasons for injectivity decline were investigated at different geothermal sites in Europe. Due to low injectivities, production rates have to be reduced and the site faces negative commercial implications. In addition to historical operation data, fluid and rock samples were investigated in the laboratory. Analysis and experiments focus on physical, chemical and biological processes and their interaction. Results show different processes being responsible for injection-triggered occlusion of flow pathways, e.g. fines migration, precipitation, micro-biological activity, aquifer properties, corrosion or O<sub>2</sub> inflow.</p><p>Lessons learned will be shown, from preparation of large-scale projects, from monitoring programmes towards sustainable operation.</p><p>Activities are taking place in the frame of the DESTRESS project. The DESTRESS project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 691728.</p>

Study of an A+2B--->C Reaction-Diffusion System with Initially Separated Components

1994 ◽  
Vol 366 ◽  
Author(s):  
Andrew Yen ◽  
Raoul Kopelman
Keyword(s):  
Reaction Front ◽  
Reaction Rate ◽  
Reaction Diffusion ◽  
Biological Processes ◽  
Local Production ◽  
Kinetic Behavior ◽  
Acetate Trihydrate ◽  
Physical Chemical ◽  
Global Reaction ◽  
Front Dynamics

ABSTRACTThe presence of a reaction front is a characteristic feature of a variety of physical, chemical and biological processes. A chemical reaction exhibits a front (spatially localized region where concentration of product is non zero), provided the diffusing reactants are separated in space. We study the reaction front dynamics of a termolecular A+2B--->C reaction with initially separated components in a capillary. The reaction tetra+2Ni2+--->1:2 complex is used, where ‘tetra’ is disodium ethyl bis(5-tetrazolylazo) acetate trihydrate. We measure and compare with theory the dynamic quantities that characterize the kinetic behavior of the system: the global reaction rate R(t), the location of the reaction center xf(t), the front's width w(t), and the local production rate R(xf,t). The non-classical nature of this dynamical system is confirmed.

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