Mieczyslaw Metzger, Dariusz Choinski

The modern neutralisation pilot plant has been designed and worked out at the laboratory of the CSCE group. The installation itself is a scale model of a real industrial neutralisation plant with two neutralisation reactors (stirred mixers) and with flexible connections of the injection pipes. There is also a possibility to carry out the in-line neutralisation process with the application of the in-line injection. The design features allow this installation to be considered as a first stage of the complete neutralisation and biological wastewater treatment plant that will be developed in the future at our laboratory.

The simplified scheme of the neutralisation pilot plant is presented in Fig. 1. Three real-world industrial dosing systems with metering pumps from Milton Roy were chosen to dose the reactants (acid and base) into the reactors. The especially designed system of two reactors was manufactured by Hydro-Eco-Invest. The three-input, three-output selector allows us to distribute the liquids into three separately chosen points of installation. The system of two stirred reactors is the main part of the plant. Each reactor has two injection points and is equipped with industrial pH-meter from Hydro-Eco-Invest. The remote pH measurement system consists of the pipeline, the peristaltic pump from Masterflex, the flow meter from Cole-Parmer and flow-through cell manufactured especially for this plant. Injection T-connector allows us to provide the in-line injection (in-line neutralisation process). The flexible pipeline system allows us to obtain different structures of the plant.

Neutralization pilot plant

Figure 1a. Neutralization pilot plant.

 

Computer-based visualization and control system

Figure 1b. Computer-based visualization and control system.

 

The possible structures cover (but are not limited to) the following:

  • Neutralisation process in the reactor 1L,
  • Neutralisation process in the reactor 2L,
  • Two-stage neutralisation process in two reactors (1L and 2L),
  • Neutralisation process in the reactor 2L with controlled (pH - controlled) disturbation in the reactor 1L,
  • Two-stage process of the neutralisation (in the reactor 1L) and the stabilisation (in the reactor 2L),
  • Neutralisation process in the reactor 2L with remote pH measurement,
  • Two-stage neutralisation process in two reactors (1L and 2L) with remote pH measurement,
  • Neutralisation process in the reactor 2L with pH-controlled disturbation in the reactor 1L and remote pH measurement,
  • Two-stage process of the neutralisation (in the reactor 1L) and the stabilisation (in the reactor 2L) with remote pH measurement,
  • In-line neutralisation process,
  • In-line neutralisation process with pH-controlled disturbation in the reactor 2L,
  • Two stage neutralisation process (in the reactor 2L and in-line neutralisation),
  • Three-stage process of the neutralisation (in the reactor 1L), the stabilisation (in the reactor 2L) and the in-line neutralisation.

The monitoring and control equipment consists of the FieldPoint™ modular distributed I/O system and of the specialised software: LabVIEW™ and LabWindows/CVI™ - both from the National Instruments. The pilot plant was in full operating conditions and ready for research experiments at the end of the 2000.

View of the pilot installation

Figure 2. View of the pilot installation.

 

View of the system of two neutralisation reactors

Figure 3. View of the system of two neutralisation reactors.