Detailed Sampling for Process Modeling of Nitrogen and ... · Activated Sludge Model -Process...

Detailed Sampling for Process

Modeling of Nitrogen and

Phosphorus Removal

OWEA 2013 Annual Conference

June 19, 2013

Will Martin

Alyssa Mayer

SWOWEA YP Award

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• Biological Process Models Overview

• Process Sampling Overview

• Sampling Plans – Overview and Preliminary Steps

• Sampling Plans – Development

• Case Study #1: Upper Mill Creek WRF

• On-site Coordination

• Case Study #2: Sycamore Creek WWTP

• Summary

Presentation Overview

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Process Model Whole plant models

Anaerobic Zone

Influent Anoxic Zone Aerobic

Zone

Secondary

Clarifier

Temperature Model

Gas Transfer Model

Activated Sludge Model -Process Stoichiometry

-Process Kinetics

Reactor Model

Hydrodynamic Mixing Model (eg CSTR, Plug

Flow, etc)

Influent Wastewater Characterization Model

Sedimentation/ Clarification Model

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Process Model Uses and Benefits

• Planning / Design Capacity Analysis

Alternative Evaluation

Design Optimization

• Process Optimization Nutrient Removal

Wet Weather

Aeration

• Training

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Benefit of Process Sampling

• Junk in = Junk out - ANY inputs can be simulated

• OBJECTIVE – calibrate model so results are representative of observed plant performance

Highlight process issues

Confidence for scenarios outside historical data

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Benefit of Process Sampling

Example Process Issue

• WWTP with floating sludge issues

• Detailed process model sampling

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Model Inputs and Variables What Usually Changes?

From WERF 2003 “Methods for Wastewater Characterization in Activated Sludge Modeling”

Highly

Variable and

Plant Specific

Plant Specific

Default Values

Recommended

Typically

Constant

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Influent Characteristic Sampling Why?

• NPDES Sampling

cBOD5

TKN

TSS

TP

• COD Driven

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Influent Characteristic Sampling Why?

• Sensitive to Nutrient fractions

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Influent Characteristic Sampling Site Specific

From WERF 2003 “Methods for Wastewater Characterization in Activated Sludge Modeling”

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Influent Characteristics BNR Plants

• Special Emphasis for BNR Plants – Denitrification

Denitrification is driven by carbon consumption • Influent COD fractions

Denitrification must have anoxic conditions – DO Profiling

• Special Emphasis for BNR Plants – BioP

Phosphorous Release driven by rbCOD (VFAs) • Influent or sidestream COD fractions

• Special Emphasis for BNR Plants – Both

Sidestream sampling – up to 20% of Nitrogen and 30% of Phosphorous loads

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Sampling Plans Overview

• Guidelines apply to WWTPs of all sizes and configurations - tailor accordingly

• Sampling plans vary in size from 100 to 2,500 analyses

• H&S Cincinnati Office Sampling Experience

1.5 MGD to 55 MGD WWTPs

Traditional Activated Sludge, Bio-P Process (VIP and A2O), Counter Current Aeration

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Sampling and Sampling Plans Good vs. Bad

• Well executed sampling is like a surgeon’s scalpel:

Minimally invasive

Highly informative

“According” to plan – first try on most things

• Poorly executed sampling is like a machete:

Highly disruptive to WWTP operators and lab staff

Lots of unnecessary data is collected or critical data is missed

Significant rework

LONG days

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Sampling Plans – Preliminary Steps Compile Plant Historical Data

• Physical Plant Data

Tank dimensions and configurations

Blower and pump sizes

• Water Quality Data

Influent & Effluent – MOR

Nutrient profiles, sludge disposal data

• Operational Data

Flow measurements

SRT, DO set-points

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Sampling Plans – Preliminary Steps Review Trends and Data Quality

• Develop Trends

• Perform Mass Balances

• Calculate Yields

• Preliminary Modeling

• Identify Gaps and

Data Quality Issues

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Sampling Plans – Preliminary Steps Site Visits and Meetings with Operators

• Determine:

Flow paths

Recycle streams

Chemical usage

Wet weather operation

Dewatering operations

Aeration strategy

Temporary on-site lab location

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Sampling Plan Development Duration and Timing

• Representative Dry Weather Period

• Capture Typical Variation

Throughout the day

Throughout the week

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Sampling Plan Development Sample Types

COMPOSITES

DIURNAL GRABS

PROCESS GRABS

SIDESTREAM GRABS

•Flow-Weighted, 24 hour Average

•Collected by an automatic composite sampler

•Collected each day of sampling period

•Comparison to plant-collected samples

•Collected using automatic samplers at discrete time periods

•Collected once every 1-2 hours, over 24 consecutive hours

on at least 2 separate days (one weekday and one weekend day)

•Collected manually at several time periods throughout the day

•Composited together to obtain a daily average

•Collected each day of sampling period

•Collected using “dippers” at discrete time periods

•Collected during peak and low loading periods

on at least 2 different days ( one weekday and weekend day)

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Sampling Plan Development Where and What?

• Select Locations

Influent

Recycles

Solids Train

Unit Process Input/Outputs

BNR Tank Profiles

Parameters

TSS/VSS NO2-N

COD Total P

BOD5 PO4-P

cBOD5 Ca

TKN Mg

NH3-N Alkalinity

NO3-N pH

• Choose Parameters for Analysis

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Sampling Plan Development Parameter Guidelines

Typical Plant Critical Sampling Locations and Parameters (Partial List)

Plant Area Solids COD VFAs Nitrogen Phosphorous Other

Influent TSS,VSS

XX, XG, XF,

XM

Bio-P

Only TKN, NH3 TP, PO4

Alk, pH,

Mg, Ca

Primary Effluent TSS,VSS

XX, XG, XF,

XM

Bio-P

Only TKN, NH3 TP, PO4

Primary Sludge TSS,VSS

Aeration Basins -

MLSS TSS,VSS NH3, NO2, NO3 TP, PO4

RAS TSS,VSS NH3 TP, PO4

Secondary Effluent TSS,VSS

XX, XG, XF,

XM

TKN, NH3, NO2,

NO3 TP, PO4

Return Streams TSS,VSS XX, XG

Bio-P

Only

TKN, NH3, NO2,

NO3 TP, PO4 Alk, pH

Abbreviations: TSS = Total Suspended Solids, VSS = Volatile Suspended Solids, XX = Total Fraction, XG = 1.2 um

filter Fraction, XF = Floc Filter Fraction, XM = 0.45 um filter Fraction, TKN = Total Kjehldahl Nitrogen, NH3 =

Ammonia-N, NO3 = Nitrate-N, NO2 = Nitrite-N, TP = Total Phosphorous, PO4 = Ortho Phosphate, Alk =

Alkalinity, Mg = Magnesium, Ca = Calcium

Note: Refer to Table 21-1 in WERF Sampling Guidelines for Full Detailed List

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Sampling Plan Development Case Study #1: Upper Mill Creek WRF

Plant Sampler

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Sampling Plan Development Case Study #1: Upper Mill Creek WRF

Influent Pump Station

West Influent East Influent

Filter

Backwash Centrate

Combined

Influent

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Sampling Plan Development Case Study #1: Upper Mill Creek WRF

• Calculating “True” Influent

By Addition

By Subtraction

• Developed correction factors to use historical data

West East +

Centrate & Filter BW

Combined

Influent -

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Sampling Plan Summary

~1,700 analyses

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• What?

On-site Coordination Cost Effective Distribution of Labor

• Who?

Consultant

Plant Operators

Plant Lab Staff

Contract Lab Operational

Data

Sample Collection

Sample Prep

Analysis

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On-site Coordination Guidelines for Sample Collection

• Well-mixed, representative locations

• Test everything before event

• Time constraints • pH measurement right away

• Immediate MLSS removal from any sample measured for soluble parameters

Sample Collection

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On-site Coordination Flow meters, probes etc.

Operational Data

• Coordinate operational data collection

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On-site Coordination Typical Sample Breakdown

Sample Prep

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• Contract Lab or Plant Lab

Bottle order (size, preservatives)

Chain of Custody Development

Coordinate picks-ups to meet hold time requirements

On-site Coordination Splitting Samples for Analysis

Sample Prep

• Temporary Lab On-Site (Consultant)

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On-site Coordination On-site Capabilities

Analysis

• Hach TNT+ kits

• COD

• TKN, TN, NH3, NO3

• TP, PO4

• pH

• Duplicates run by multiple labs

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On-site Coordination Case Study #2: Sycamore Creek WWTP

~350 Samples Collected and

~2,000 Total Analyses

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On-site Coordination Case Study #2: Sycamore Creek WWTP

• N and P Removal at Sycamore

1 anaerobic zone

2 anoxic zones

2 aerated passes

Anoxic 2 Anoxic 1

A

B

C EFF

Anaerobic

INF

ARCY

RAS

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On-site Coordination Case Study #2: Sycamore Creek WWTP

• Nutrient profile results

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Keys to a Successful Sampling Event

• Detailed understanding of plant layout and operations

• Planning, Planning, Planning

• Realistic assessment of capabilities (equipment, man power, budget)

• Good communication with all parties

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Acknowledgements

• Upper Mill Creek WRF, Butler County Water and Sewer:

• Todd Madden (Plant Supervisor), Jeremy Hamel and the rest of the UMC operations staff.

• Sycamore Creek WWTP, Metropolitan Sewer District of Greater Cincinnati:

• Dave Wilson (Plant Supervisor), Barb Browne (Area Supervisor), Joe Baer, Jason Grooms and the rest of the SCWWTP operations staff.

36 amayer@hazenandsawyer.com

wmartin@hazenandsawyer.com

Questions?