Page 104 - HUDCO-BPA21

SANITATION
SANIT A TION

Ÿ To meet the water requirements of units coming up state-of-the-art GE Membrane Technology (ultra followed by Flocculation-Clarification in Claritube the Moving Bed Biological Reactor.
inside Mangalore SEZ, Mangalore SEZ Ltd (MSEZL) filtration) for re-use of Secondary Treated Sewage Flocculator (CTF). Claritube Flocculator (CTF):
was provided with the wastewater from 3 STPs as one Water from Kavoor STP during the year of 2011. Ÿ Filtration by Membrane-based Ultrafiltration system.
of the sources. Since the Netravathi river is being Ÿ State-of-the-art plant with process automation and the Ÿ The Sewage from MBBR flows to the Claritube
utilized for drinking purposes, drawing of additional plant is being controlled and monitored through PLC- Ÿ Disinfection using ClO2 with onsite ClO2 unit. Flocculator. At the inlet of CTF alum is dosed in the
flash mixer. The solids separated here are settled and
water was not allowed from the river hence the based SCADA system. Ÿ Sludge handling Filter Press Unit. the sludge formed is withdrawn from the Claritube
MSEZL had to settle with the wastewater from 3 STPs Ÿ The tertiary treated sewage is then stored in a tank,
Ÿ Plant is commissioned and MSEZL is supplying Flocculator which is taken to the sludge sump.
as one of the Sources. from where it is pumped to SEZ area.
treated water to MRPL/MSEZL from November Ÿ The Claritube Settler comprises of Tube settler formed
Ÿ Several meetings were carried out with MSEZL and
2012. Stilling Chamber: by specially designed Tube Modules. In tube settler
formed SPV-Mangalore STP Limited for reusing the
secondary treated sewage water. Ÿ Tertiary Treatment Plant is mainly designed for The treated sewage outlet from the existing STP is raw the effective surface area required for the separation of
removal of TSS, turbidity and for further reduction of water for Stilling Chamber (SC), where the turbulence is suspended solids is provided in relatively much less
Mangaluru City Corporation has provided the below reduced. The sewage pumped to Stilling Chamber with volume compared to conventional clarifiers.
BOD & COD from secondary treated sewage water.
mentioned civil & mechanical structures and handed over 1162m3/hr to the downstream units. The Tube settler is divided into four zones.
to SPV. Ÿ The designed parameter of TTP is given in the table Moving Bed Biological Reactor (MBBR):
1. Inlet Chamber below. Ÿ Distribution zone
Ÿ The main pollutants in the treated sewage are Ÿ Inlet zone
2. Screen Removal
Parameter of TTP represented in the form of Biochemical Oxygen Ÿ Settling zone
3. Grit Chamber Demand (BOD) and Chemical Oxygen Demand
Ÿ Discharge zone
4. Parshall Flume Sl. Parameter Unit Inlet Outlet (COD). Ultra filtration:
No.
5. UASB Ÿ The bio-reactions are carried out in the controlled
1. pH - 6.5-7.5 7.0-7.5 environment in the Moving Bed Bio-Reactor Ÿ The clear overflow from CTF gravitates through the
6. Preaeration UFC channel to UFMT. ZW-1000 UF Membrane
2. TSS mg/l 30 < 1 (MBBR). The bioreactor comprises of a tank, fitted
7. Aeration system is used for treating the clarifier outlet water.
0
3. BOD5 at 20 C mg/l 20 <2 with an aeration grid. The bacterial activity needs The basic purpose of the UF system is to remove the
8. Clarifier dissolved oxygen, to synthesize the organic matter.
4. COD mg/l 100 < 30 fine colloidal impurities and thereby removes BOD.
9. CCT- Let off natural drains This is supplied by passing air in form of small
5. Nitrogen mg/l 15 (Total < 5 bubbles. Ÿ The complete UF system is automated and processes
10. Thickener & Sludge Recirculation
Nitrogen) (Ammonical are typically operated in the following modes.
11. Drying Bed Nitrogen) Ÿ The air is passed at the bottom of the tank so that the
complete volume of the tank is utilized. Dissolved - Permeation
The treatment Process Involves: 6. Fecal Coliform MPN - <1/100ml
oxygen can be used by the bacteria. - Backwash
Tertiary Treatment Plant 7. Turbidity NTU - <0.5 - Maintenance Clean (MC)
Ÿ The bacterial population is present on the media,
Ÿ MSEZL has taken up the construction of 5 MGD which forms an integral part of the reactor system. The - Recovery Clean (RC)
Advantage of TTP water reuse
(22.7MLD) Tertiary Treatment Plant (TTP) using media is made of small plastic elements. Millions of - Stand-by
Ÿ Reduction in the dependency on natural water
such pieces are present in the reactor. - Shutdown
resources.
Ÿ A very large surface area is available for the bacterial Disinfection System:
Ÿ Reduction of financial burden on Mangalore City population to grow. The bacteria grow on the plastic Ÿ The treated filtered sewage is then added with ClO2
Corporation for O&M of STP. media by using the organic content in the raw sewage for Disinfection. Chlorine Dioxide is generated using
Ÿ Avoiding disposal of secondary treated sewage in and the dissolved oxygen available. Due to constant Acid Chlorite technology.
natural river body thereby minimization of pollution aeration, the media is set in whirling motion so that Sludge handling:
loads on freshwater sources and improving continuous mixing takes place.
Ÿ The sludge from the Claritube Flocculator (CTF)
Environmental quality. Ÿ The bacterial layer growth on the media surface
flows to Sludge Sump (SC) and then it is pumped to
Ÿ Employment generation. increases to a certain extent and then gets sloughed off Filter Press (PS) for Solid Liquid Separation.
after a specific period.
Tertiary Treatment process: Ÿ The dewatered sludge is further used for Green Belt
Ÿ Around 60% to 70% of the BOD is further reduced in
Ÿ Biological treatment comprising of Aerobic development.
Treatment in Moving Bed Bio-Reactor (MBBR) Final Storage Tank:
STP and TTP Flowchart
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