Reactor Design for Electrochemical Water Treatment

Increasing volumes of wastewater combined with limited space availability and progressively tightening European standards promote the development of new intensive biotechnologies for water treatment. Fixed biomass processes offer several advantages compared with conventional biological treatments: higher volumetric load, increased process stability and compactness of the reactors. The purpose of this paper is to present a new concept of gas-lift mobile bed, the circulating floating bed reactor (CFBR). The reactor design is simple and does not require any complex technical devices (easier effluent and air-flow distribution, no primary settling, no back-washing). This new process is studied and developed in an industrial-scale prototype. The optimum hydrodynamic characteristics of the CFBR (liquid circulation velocity 0.3-0.4 m s−1, kLa 50-300 h−1, average mixing time 85 s) were not deteriorated by the high solid hold-ups (up to 40% v/v) of the floating media. On the contrary, three-phase operating improves the local gas hold-up in the downcomer. Improved hydrodynamics in the CFBR guarantee high nitrification rates and operation stability either in tertiary (up to 2 kgN m−3 d−1) or secondary (up to 0.6 kgN m−3 d−1) nitrification. The results show that nitrification is the limiting step in simultaneous C+N treatment. The negative effect of the increasing C/N ratio is more pronounced than stepwise decreasing of the temperature. The study of the biofilm composition and activity shows an effective control of the attached biomass growth by the high liquid circulation velocity. It is concluded that this new three-phase bioreactor ensures not only an enhanced process stability and biological reaction rate through an effective biofilm control but also guarantees an excellent synergy between hydrodynamic and biological performances. These advantages are highlighted by the simplicity of the reactor design. Thus, this innovative technology will be an attractive solution for intensive wastewater treatment for nitrogen and carbon removal.

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Plasma-based water treatment: Conception and application of a new general principle for reactor design

Chemical Engineering Journal ◽

10.1016/j.cej.2015.03.059 ◽

2015 ◽

Vol 273 ◽

pp. 543-550 ◽

Cited By ~ 53

Author(s):

Gunnar R. Stratton ◽

Christopher L. Bellona ◽

Fei Dai ◽

Thomas M. Holsen ◽

Selma Mededovic Thagard

Keyword(s):

Water Treatment ◽

General Principle ◽

Reactor Design

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Interface Science in Drinking Water Treatment - Theory and Application

10.1016/s1573-4285(06)x8069-9 ◽

2006 ◽

Keyword(s):

Drinking Water ◽

Water Treatment ◽

Drinking Water Treatment ◽

Interface Science ◽

Treatment Theory

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Modeling and Control of a Chemical Waste Water Treatment Plant

Computers & Chemical Engineering ◽

10.1016/s0098-1354(97)00171-3 ◽

1997 ◽

Vol 21 (1-2) ◽

pp. S947-S952 ◽

Cited By ~ 2

Author(s):

R Miller

Keyword(s):

Waste Water ◽

Water Treatment ◽

Waste Water Treatment ◽

Treatment Plant ◽

Water Treatment Plant ◽

Waste Water Treatment Plant ◽

Chemical Waste ◽

Modeling And Control ◽

And Control

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Optimization of Residence Time Distribution in Small Water Treatment Systems

Computational Fluid Dynamics ◽

10.1061/9780784415313.ch15 ◽

2019 ◽

pp. 123-130

Keyword(s):

Water Treatment ◽

Residence Time ◽

Time Distribution ◽

Residence Time Distribution ◽

Small Water

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To the issue of water treatment by hydrocyclone on the systems of the combined irrigation

Melioration and Water Management ◽

10.32962/0235-2524-2019-2-21-25 ◽

2020 ◽

Vol 0 (2) ◽

pp. 21-25

Author(s):

Nikolay Dubenok ◽

Andrey Novikov ◽

Sergei Borodychev ◽

Maria Lamskova

Keyword(s):

Water Treatment ◽

Organic Compounds ◽

Irrigation Water ◽

Irrigation System ◽

Petroleum Products ◽

Cylindrical Part ◽

Agricultural Landscapes ◽

Treatment Unit ◽

Drain Pipe ◽

Irrigation Network

At the stage of water treatment for irrigation systems, the efficiency capture coarse and fine mechanical impurities, as well as oil products and organic compounds affects the reliability of the equipment of the irrigation network and the safety of energy exchange processes in irrigated agricultural landscapes. The violation of work irrigation system can cause disruptions in irrigation schedules of agricultural crops, crop shortages, degradation phenomena on the soil and ecological tension. For the combined irrigation system, a water treatment unit has been developed, representing a hydrocyclone apparatus with a pipe filter in the case. For the capacity of 250 m3/h the main geometrical dimensions of hydrocyclone have been calculated. To organize the capture petroleum products and organic compounds, it has been proposed a modernization of a hydrocyclone unit, consisting in dividing the cylindrical part of the apparatus into two section. The first is section is for input irrigation water, the second one is for additional drainage of clarified irrigation water after sorption purification by the filter, placed on the disk and installed coaxially with the drain pipe and the pipe filter.

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