Tettau Waterworks of the Lusatian water and wastewater association

Project description

As a result of a planning competition in which 36 planning agencies took part, 2 engineering firms were commissioned with the parallel preparation of a rehabilitation concept for the treatment plants of the largest public waterworks in the Federal State of Brandenburg. As well as reconstruction of the water treatment, the concept and implementation also contained the process measurement and control technology.
The main function of the drinking water treatment at the Tettau waterworks is deacidification, deferrisation and demanganisation. Given iron contents between 15 and 25 mg/l, deferrisation is performed by mechanical and chemical deacidification by means of coarse sedimentation treatment and grit filtration.

We investigated 2 different process options, each with 4 structural sub-versions, which differed mainly in the ratio of new construction to rehabilitation. As well as detailed calculation and comparison of investment and operating costs, we additionally carried out a comparative cost analysis according to the LAWA guideline.

As a result of this study, we recommended a version that exhibited clear process parallels to the previous treatment while envisaging major technological innovations. A combination of rehabilitation and replacement construction of various plant components was recommended for the constructual implementation.

The version recommended in our study formed the basis for the further planning development, with which we were subsequently commissioned.

In 1999/2000, process engineering tests were carried out at the waterworks under our supervision, which served principally to study the following aspects more closely:

• optimising the flocculation sedimentation for coarse deferrisation with regard to investment (building) and operating costs, taking into account the parameters of pH value, flocculation aid dosing volume (polyelectrolyte), surface feeding, dwell time and energy feed of the flocculation plant,
• optimising the flocculation sedimentation with the aim of co-precipitation of organic components (humic acids) taking into account the parameters of pH value, flocculation agent dosing volume (FeCl3), flocculation aid dosing volume,
• improving humin removal by additional flocculation (FeCl3 dosing) prior to filtration,
• long-term testing of different systems for mechanical deacidification/aeration of the ferriferous untreated water with comparison of energy and maintenance costs.

These semi-technical tests were supplemented by laboratory tests for humin removal by means of activated carbon adsorption and ozonisation. The treatment and implementation concept was adapted to the findings of the tests as well as to the concrete calculation parameters. The treatment plant has a capacity of 23,000 m³/d.

In the field of process measuring and control technology, a transformer and distribution station with 2,000 kVA and 10/0.4 kV and low-voltage switchboards for three group master control levels were constructed. Connection to the telecontrol system of the Association is via the Tettau waterworks control room.

Client

WAL Wasserverband Lausitz

Capital expenditure

15m EUR

Period of project

1998 - 2007