Construction
of Municipal Wastewater Treatment and Collection System in Niš
Lot 1- Construction of
WWTP Ciganski Ključ and Wastewater treatment at WTP Mediana
The
overall objective of this project is to protect environment from communal
wastewaters and wastewaters from water treatment plant Mediana by construction
of main collectors and wastewater treatments.
The works
covered under this Project include two components:
Component
1: Construction of WWTP Ciganski Ključ (including the Access Road to WWTP
Ciganski Ključ)
The
specific aim of this section is to establish a wastewater treatment plant for
wastewaters collected by the public sewerage system which will have a capacity
of 286.000 PE. The process will include Primary and Secondary treatment with
tertiary treatment in phase II, Conventional activated sludge treatment,
Anaerobic digestion of sludge, Solar drying of digested sludge prior to
disposal at landfill.
The Works
will include the following process lines:
Wastewater
Treatment Line:
• Preliminary Treatment
• Primary Treatment
• Secondary / biological treatment with
nutrient removal in Phase II
• UV disinfection of part of treated
effluent and re-use as technical and firefighting
Sludge
Line:
• Sludge Thickening
• Anaerobic digestion
• Dewatering of stabilized sludge
• Solar drying of dewatered sludge to
50% DS content
Construction
under this section will be in two phases, whereas this Contract covers design
of both phases but the construction of only Phase I:
Phase I –
Bio-aeration comprises organic reduction.
Phase II
– Treatment line upgraded to tertiary treatment, comprising process units for
nutrients (N and P) biological removal.
Component
2: Wastewater treatment at WTP Mediana
The
specific aim of this section is to provide treatment of filter backwash water
and sludge from tube settlers at WTP Mediana and the construction of a process
line for wastewater treatment at the WTP Mediana location, on the left bank of
the river Nišava.
Seven captured karst springs provide sufficient water quantity for Niš during
most of the year. In case of increased needs for drinking water, it is replaced
by surface water from the river Nišava, which is treated at the WTP Mediana.
Water streams generated during the process of preparation of drinking water at
WTP Mediana, sludge from tube sedimentation tanks and water from filter
backwashing, are combined and currently discharged into river Nišava without
prior treatment.
The Works
will include the following:
• Design raw water flow – 600 l/s
• Treatment of settled sludge and
backwash water
• Design sludge flow – 10 m3/d per
settling tank
• Design sludge flow – 177 m3/d per
filter tank
• Process include chemical dosing,
settlement, sludge thickening and dewatering.