Wastewater Treatment Plant Specification...
Transcript of Wastewater Treatment Plant Specification...
Compagnie Sucrière de Bel Ombre Ltée Second Golf Course at Bel Ombre
Environmental Impact Assessment
CSBOL/EIA/01 | Issue | 5 October 2016
J:\CURRENT PROJECT\250379-00 - EIA 2ND GOLF COURSE AT BEL OMBRE\4.5 - REPORTS AND MEMOS\INFRA\BEL OMBRE GOLF EIA REPORT (ISSUE, 2016-09-30)\BEL
OMBRE GOLF EIA REPORT (ISSUE, 2016-10-05).DOCX
Page L1
L1 Wastewater Treatment Plant Specification
Sheet
This appendix contains the wastewater treatment plant specification sheet as
provided by Solutions Eau et Environnement Ltée, SEE.
Solutions Eau et Environnement Ltée - The Junction Business Hub - Calebasses - Mauritius
Tél : +230 243 18 20 – Fax : +230 243 12 20 - Mail : [email protected] - Web : www.see.mu – BRN : C12107657 - VAT : 27129077
WASTE WATER
TREATMENT PLANT
BEL OMBRE
GOLF CLUB HOUSE
SEE 2016-09-08
22 September 2016
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1. PRESENTATION
The project consists in the construction of wastewater treatment plant for Golf CLUB
HOUSE in BEL OMBRE.
The technical solution proposed is very well-adapted for small and medium water treatment
plant reaching an outlet water quality in accordance with the Mauritian and European reject
standards.
Many installations are already in service in Mauritius with this technology, which have been
controlled and validated by the Wastewater Management Authority.
For your perusal, following clients have already chosen the proposed technology:
- Medine Student Flats
- Decocity Bagatelle
- Choisy-Les-Bains
- Residential complexes developed by 2Tribes/2Future: Cape Bay, Element Bay,
The Residence, Element Bay 2
- Be Cosy Hotel / Terrasses du Barachois Residence / RES Trinidad (Trimetys)
- RES La Tourelle de Tamarin (Bhunjun group)
- Shopping Center Le Barachois in Tamarin (Trimetys)
- Shopping Center Riverside in Rivière-du-Rempart (IOREC)
- Les Jardins de Chantenay elderly house (Ideco)
- Residences Cap Ouest and Latitude (DLB Construction)
- IRS Matala in Black River
- Residence Rose des Sables (Davyland)
- And many others independant promoters/developers
These references show that it is a very well adapted and efficient solution and also cost
effective.
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Underground STP in Bain-Boeuf
Underground STP in Black River
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Underground STP in Wolmar
Underground STP in Flic en Flac
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2. TREATED WATER OBJECTIVES
Objectives for treated water are the Mauritius Irrigation Standards:
Main parameters are:
Parameters Outlet value
BOD5 ≤ 40 mg/l
COD ≤ 120 mg/l
SS ≤ 45 mg/l
Fecal Coliforms ≤ 200/100ml
- On a 24h composite sample.
- For a temperature ≥ 12°C and ≤ 30 °C and pH between 6 and 8.5.
- And as long as the above mentioned wastewater characteristics are respected.
Treated water quality
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3. TECHNICAL SOLUTION
3.1. THE CONTEXT
The project consists in the construction of a wastewater treatment plant for daily volume of
12m3 of wastewater.
Effluent characteristics:
BEL OMBRE GOLF CLUB HOUSE
Hydraulic loads
Daily volume Vd m3/d 12.0
Average daily waterflow m3/h 0.8
Peak flow coefficient 3.0
Peak waterflow m3/h 2.3
Pollution loads
BOD5 kg/d 4.2
COD kg/d 8.4
TSS kg/d 5.4
TKN kg/d 0.6
Oil, Grease and Fat kg/d 0.1
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Specificities of the treatment plant:
The plant will treat wastewater coming from the project.
Hydraulic and pollution loads will fluctuate according to the occupancy.
The wastewater treatment plant must be adaptable to these variations all other
the year.
As the plant is installed near the habitations, it has to be fully integrated site wise
regarding visual, noise and odour aspects.
Available area is limited: the plant has to be compact and easy to install.
Treated water quality has to be fully in compliance with the environmental
standards 365 days/year.
3.2. SOLUTION PROPOSED
The water treatment technology proposed is a different solution based on aerobic biological
treatment on fixed immerged support.
The bacteria fixed on an immerged support will promote the biological oxidation of the
wastewaters. Active air incorporation into the system allows bacteria to grow.
The advantage of this technology is the complete control of the treatment, guarantying the
water outlet quality in all circumstances.
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CHARACTERISTICS SOLUTION PROPOSED
Adaptation to different
pollution concentration
The « fixed bacteria » technique is the only technique allowing an easy
adaptation to pollution peaks and variable pollution concentration in waters,
guarantying a good usage of the treatment plant throughout the year.
Reject quality Irrigation reuse with a tertiary step of treatment
Process evolution and
extension
Compact and adjustable, the process is easily extensible by adding a compact
module in parallel
Site integration Compact and invisible : can be adapted in various environment
Installation Simple and quick installation
Site topography In major case, a few centimeters slope is enough and the system does not need
any lifting station
Fiability Process and equipment control
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3.3. PRINCIPLE
The water treatment technology is a different solution based on aerobic biological treatment
on fixed support.
Autonomous and semi collective water treatment plants have to deal with regular pollution
concentration changes:
“Tub effect” (rapid « tub » emptying)
Low usage periods
It is therefore important that the bacteria responsible for the water treatment are present within
the system in all circumstances: it is the reason why fixing the bacteria is a key principle in
this system.
In the aerobic system, the bacteria will grow in presence of air on a specific support.
The support has been designed to optimize bacteria activity.
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3.4. FUNCTIONNING
The treatment takes place in 3 phases, requiering 3 cells:
CELL A : PRIMARY CLARIFIER
A: Polluted water is received in the first cell called primary decanter. The suspended
materials will decant in the lower part of the cell and will be “pretreated” by anaerobic
bacterias (bacteria which do not need air). Through this first anaerobic bacterial
action, most solid materials will be liquefied.
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CELL B: BIOLOGICAL REACTOR
B: Pre-treated water flows by gravity into Cell B « Biological reactor ». In this tank,
pollution matters will be eliminated by aerobic bacteria.
E: Organism and bacteria of the biological reactor fix and grow on an immerged
polypropylene support. This support is constructed with recycled polypropylene, in a
sustainable development concept. Its shape allows an optimal development and growth
of bacteria, resulting in optimal conditions for elimination of pollution matters never
reach in that kind of small wastewater treatment plants.
D: Air blower diffuses oxygen for aerobic bacteria which grow on surface of the
immerged support.
F: Air is diffused at the bottom of the tank via fine air bubbles diffusers.
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CELL C: CLARIFIER
C: Water enters in third tank (clarifier) by gravity. Aerobic bacteria which are
eliminated pollution matters become in suspension and are able to settle. In the
clarifier, bacteria (called sludge) and treated water are separated. Treated water is able
to flow to the outlet directly to reject point and be reused in irrigation.
H Sludge settles to the conic bottom of clarifier.
G: Sludge is evacuated by pumping and re-circulated into Cell A (primary clarifier).
There, it is mixed with primary settled sludge and partially digested with time.
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3.5. INDICATIVE DIMENSIONAL CHARACTERISTICS
Plant can be installed totally below ground level.
Dimensional characteristics are:
Golf Club House
Dimensions
Dimensions L (m) w (m) H (m)
Primary settling tank 2.2 1.8 2.8
Aeration tank 3.0 1.8 2.8
Clarifier 2.0 1.8 2.8
Pre-filtration 0.4 1.8 2.8
Irrigation storage tank 3.4 1.8 2.8
A technical room of 3 x 2 m will have to be built for filtration / disinfection unit and electrical
board.
All tanks will be made with concrete on site and are excluded of our scope of works.
Tertiary step of treatment (filtration and disinfection) for re-use in irrigation is described
below
A grease trap (not included) must be built upstream of the STP.
Treated water storage tank can be connected to rain water network.
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4. COMPONENTS DETAILS
4.1. AIR PIPES AND MANIFOLD SYSTEM
Air pipes and manifold system are made with PVC pressure pipes PN16 according to the
standards NBN EN 1452. Components assembly is performed by gluing. Air pipes are fixed
to the concrete side walls with synthetic corrosion-proof clamps.
4.2. AIR DIFFUSERS
Aeration tank is equipped with «fine bubbles» diffusers which ensure proper aeration and
mixing.
4.3. BLOWER
One air blower will be supplied and placed in a correctly ventilated machine room. This
machine room will be able to host the blower and the instrument control cabinet.
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The blower will be equipped with a sound enclosure to protect the machine and to decrease
the sound level pressure with insulated pipes. The blower is provided with the following
fittings:
Inlet filter
Oil level control
Filter pressure differential gauge
Sound enclosure
Check valve
Safety valve
4.4. SLUDGE RECIRCULATION
One submersible pump will be installed.
Manufacturer KSB or similar
Number 1
Head 6 m
4.5. BIOFILM CARRIER
Biofilm carriers (packing medium) are easily removed from the tank to allow anytime a
maintenance work in the biological reactor.
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Biofilm carrier specifications
Material Recycled polyethylene/polypropylene
Shape Polygonal
Void percentage +/- 90 %
Volume weight +/- 105 kg/m³
Specific surface
area +/- 195 m²/m³
Packaging +/- 85 L rot proof bags
4.6. FILTRATION AND DISINFECTION
In order to re-use the treated water for irrigation, it is necessary to install a tertiary step of
treatment.
It will be composed of 1 filtration pump, 1 sand filter and 1 chlorination dosing pump.
Submersible Filtration pump:
Manufacturer KSB or similar
Type Amaporter
Number 1
Flowrate 5 m3/h
Sand filter:
Manufacturer ASTRAL POOL or similar
Type CANTABRIC or JUPITER
Number 1
Diameter 600 mm
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Example of sand filtration unit
Chlorination dosing pumps:
Manufacturer ASTRAL POOL or similar
Number 1
Flowrate 1 - 10 l/h
Pressure 2-4 bars
Example of chlorination dosing pump