fix it with fixed film: the details of ifas/mbbr design and
TRANSCRIPT
OBG PRESENTS:
OBG PRESENTS:
Fix it with Fixed Film:The Details of IFAS/MBBR Design and Construction
Kristin Waller, PE 2016 TriCon – August 31, 2016
Agenda
2
Massillon Martinsburg Olean
IFAS/MBBR Overview
Process Overview
Important Design Details
Case Studies (3)
Summary and Questions
3
Overview
MMoving
BBed
BBiofilm
RReactor
Fixed Biofilm / IR / TN Removal Fixed Biofilm + SS / IR + RAS / TN + TP Removal
IIntegrated
FFixed-Film
AActivated
SSludge
Protected biomass on plastic media expands capacity
Nutrients, peak flows, cold temps
Tank configuration
Minimize approach velocity (~30-35 m/hr max)
Fail safes to contain media
Physical and operational
4
Important Design Details
Variation between vendors
Pre-purchase / selection (akin to Progressive Design Build)
5
CASE STUDY #1: MASSILLON, OH
Existing 15.8 MGD secondary
Expand to 17 MGD (22 MGD peak)
1 mg/L TP effluent limit - future 10 mg/L TN
Project Goals
Demo roughing filters
Meet milestone deadlines
Maintain existing footprint
6
IFAS for Massillon
Benefits Obstacles
7
Mid-TankScreen WallsDeep An/Ax
Mid- Tank IR Wells
SQUARE RECTANGULAR
TWO OPTIONS FOR RETROFIT
Replace screw pumps with VTSH
Deep An/Ax, no media
Hydraulic drop barrier
Deadline – January 2019
Pre-purchased IFAS and VTSH pumps
Suez (formerly IDI): square zones
Kruger: rectangular
Pre-Purchase Selection
8
Kruger: lowest capital and life-cycle costs
9
ADDITIONAL PHYSICAL PROTECTION
Provided walkway access
Overflows between tanks
Air scour cleaning
10
Stop flows sequentially
IR
RAS
Forward Flow
Mixing
De-clogging
Increases process and air scour blower air
ADDITIONAL OPERATIONAL FAIL SAFES
High water level sensor and alarms
Guided wave radar and level switches
Status: in construction
Contract 2 Construction NTP Delay
Delayed Contract 1 delivery
No-cost change order
Media stored onsite
12
CASE STUDY #2: MARTINSBURG, WV
3 MGD (10 MGD peak to bio)
5 mg/L TN effluent limit
0.5 mg/L TP effluent limit
Project Goals
Demo:
Trickling filters
Nitrification tower
Add:
New headworks
Operations building
Solids handling and storage
13
MBBR for Martinsburg
Benefits Obstacles
14
NEW TANKS
Allow for “ideal” reactors
Square
3-4 ft freeboard
Overflows between reactors
15
Pre-Anoxic
Effluent Channel
Swing
Internal Recycle
Post-Aeration
Nitrification
Post-Anoxic
Tank 1
IR
Tank 2
INTERIM TREATMENT
Keep 1 trickling filter online
Site / size restrictions
Build MBBR in 2 stages
Can also bypass Tank 1
Maintenance
Or, if media blockage
Pre-Purchase Selection
16
Suez (IDI) Kruger Biowater Technology Headworks
Operational deadline – June 2016
Pre-purchased MBBR
Lowest life-cycle, capital costs
Potential change to IFAS in future
17
New 5 mm screens and gritPHASE 1 (INTERIM) Headworks
Tricking FilterNit. Tower
Tank 2
18
Headworks
Status: construction near completion
PHASE 2 (FINAL) HeadworksTank 1 + 2
Solids HandlingOperations
19
LESSONS FROM CONSTRUCTION
IR zone flap gates
High mixing velocity
Media back into IR zone
Flat screen replacement
Still - mixing is good!
Keeps media from blocking
Square tanks, air scour facilitate roll
Warranty lengths
Tank 2 end near performance test
20
CASE STUDY #3: OLEAN, NY
Existing 4 MGD ADF, 7 MGD peak
Expand peak to 12 MGD
New winter NH3-N - 10.7 mg/L
Project Goals
Respond to consent order
Add SC to meet 10 states SOR
SPDES violations, wet weather
21
Initial Approach
3rd Final Clarifier
4th Aeration BasinDigester Complex
All new infrastructure
Difficult subsurface conditions
Reduces open space
22
Approach 2
3rd Final Clarifier
Convert 3 Aeration Basins to IFAS / MBBRDigester Complex
MBBR + IFAS
Less excavation
MBBR < 4 MGDIFAS > 4 MGD
23
Approach 3IFAS
Rebuild Existing Digester Complex
Convert 2 Aeration Basins to IFAS
Convert Aeration Basin 3 into SC
Benefits Obstacles
Pre-Selection (x2)
24
IDI Kruger Biowater Technology Evoqua
First try – Bidders determine tank configuration
Two “lowest bids” – capital vs. life-cycle
Owner wanted to select on capital
Restructured evaluation and re-bid
Biowater BWT-X
Lowest capital, life-cycle costs
Described more detail of tank segmentations (1 wall) and life cycle calcs
Existing eff trough and retention screen wall with air scour
FRP baffle wall 70/30 split
IFAS zone
MLSS Zone
RETROFITTING TANKAGE
Carved tanksMLSS + IFAS
No mid-tank screens required
Status: in construction. GC Inherited Pre-Selection Contract
Summary and Lessons Learned
26
Expand treatment within existing tanks or small footprint
Square reactors or mid-tank IR wells
3-4 ft freeboard, overflows
Hydraulic drops, screens contain media
Air scour cleans screens, encourages mixing
Level sensors / switches add operational fail safes
Pre-purchase/selection to streamline design coordination
Akin to Design Build
Clearly state selection criteria – translate client goals into installed product
Keep vendors abreast of schedule changes
28
CONVERSION OF AERATION TANK TO THIRD FINAL CLARIFIER
Existing clarifiers limited by surface overflow rate for
single stage nitrification
Resolved by converting rectangular
concrete tank to final clarifier
Chain and flight collector system installed in two
channels
Includes scum and WAS removal
Increases plant capacity from 9.1
MGD to 12.7 MGD (Design Peak)