I am working for big tender at Qatar and I need your quote for Walk way bridges (Aeration + Settlement tanks) and scrapper mechanism urgently with lowest and best price
Please find below project details FYR
Client : PUBLIC WORKS AUTHORITY
Project Status: Tender
Project Name: PACKAGE TREATMENT PLANT (PTP)
UPGRADES AT EXISTING AL SHAMAL PTP
& AL DHAKIRA PTP SITES
1- Al Dhukira Site:
- Odour control will be required for sludge holding tank The volume of the empty tank is 477.33 m3
- Diameter: 11.95 m
- Height: 4.256
- The tank will hold treated sludge mixed with water
2- Al shamal
- Odour control will be required for lift station The volume of the empty tank is 160 m3
- Length: 8 m
- Width: 6.7 m
- Height: 3 m
- The tank will hold raw sewage water
The odour control system should comply with QCS 2007 (attached)
General specs:
ODOUR CONTROL
A Odour control units (OCU) may be a single central unit or a number of units located
locally to the odour source.
A OCU(s) shall reduce hydrogen sulphide levels at the treated gas outlet to less than
0.1mg/m3 (70 parts per billion) and in the case of sludge handling area off gases
additionally, to an odour concentration not exceeding 5000ou/m3. The Contractor shall
ensure that a minimum of 99% removal of hydrogen sulphide is achieved in the design and static H2S concentration not to be less than 500 mg/l
B All OCUs shall be designed to remove hydrogen sulphide and mercaptans. OCUs for
off gases from the sludge handling area shall also be designed to remove volatile
organic compounds (VOC), ammonia (NH3) and amines.
C OCUs shall be designed with the fans on the outlet end, drawing air through the unit, to
minimise leakage of odours from the unit and ductwork.
D Where granular activated carbon (GAC) or similar units are supplied, sufficient capacity shall be provided to limit the frequency of regeneration to 6 months intervals.
E The Contractor shall design the Works to minimise turbulence and the release of
hydrogen sulphide and other odourous compounds. Process transitions shall be
smooth and large free-falls of liquid shall be avoided to prevent gaseous stripping
unless it is essential for the process or hydraulic design.
F Confined spaces that require routine access shall be ventilated at Twelve (12) air
changes per hour. Confined spaces that do not normally require access but contain
sewer gasses shall be ventilated at a rate of Six (6) air changes per hour.
G Covers to areas that require odour control shall be of marine quality aluminium of
suitable grade for the atmosphere that will be encountered below the cover. Access
covers, walkways, gangways, platforms, etc. that are to be walked upon shall be
designed for a serviceable uniformly distributed load (UDL) of 750kg/m2 and a drop
load of 50 kg from 1m. Areas that are not designed to be walked on shall have safety
gates/chains to prevent unauthorised access and warning signs shall be clearly
displayed stating that the areas are not permitted for man access. All access covers
shall be easily removed to gain entry to the areas below them requiring inspection
and/or maintenance.