Rehabilitation and Extension of the Zlín-Malenovice Wastewater Treatment Plant

Zlín, Česká republika

Year of completion:

Contracting Party, Client:
Vodovody a Kanalizace Zlín (Local water company)

Total project cost:
426 million CZK

Scope of services:
All design stages, supply of technology systems

Project description:
Mechanical and biological plant with a capacity of 207 000 PE (capacity of the biological treatment stage is 108 000 PE)
Mechanical stage:

  • flow regulating chamber
  • gravel pit with mechanical extraction system
  • coarse screens, flow measurement flume
  • pump station
  • screen room (mechanically cleaned screens – four pairs)
  • longitudinal aerated sand traps – 2 corridors (with separator and sand washer)
  • primary settling tank φ 27.5 m (1275 m3)

Biological stage

  • activated-sludge basin (new monoblock unit including existing tank) with a total volume of approx. 26000 m3 divided to anaerobic, denitrification and nitrification zone incl. sludge and wastewater return flows
  • secondary settling tanks – 4 units φ 25 m, with a total area of approx. 1950 m2 and a total volume of approx. 5000 m3
  • discharge of the plant effluent into the river with effluent flow measurement
  • return sludge and internal recycle pump station

Sludge processing system

  • primary sludge from the settling tank is delivered directly to the digester
  • excess biological sludge is thickened in a circular tank φ 27.5 m with mechanical raking and pumped to the digestion zone (alternatively, excess sludge can be separated together with primary sludge as mixed sludge)
  • trucked-in sludge receiving pit – pump delivery to the sludge digester
  • sludge digester φ 20.0 m – 2 units
    • * SD 1o: volume of 3830 m3
    • * SD 2°: volume of 3560 m3 with an attached gas holder including a plant room with sludge heating system and gas compressor plant
  • boiler plant (with boilers fired with biogas and natural gas)
  • dry gasholder (1100 m3)
  • dewatering of the digested sludge on belt filter presses or centrifuges (3 units)
  • installation of CHP units 2 x 125 KW with consistent energy utilization of biogas