Resource Recovery from Wastewater Opportunities and

Achievements

Water (x 100)

Organics Nutrients

Salts

What can we get from Wastewater?

Water Reuse

Bio-Energy (Organic) Fertiliser

Vision

Wastewater treatment plants become resource recovery plants

Future hub for key resources

Should be energy neutral or negative

Should be public and private sector orientated

Products should not be directly linked to source

Optimal integration of sources and users

AND: Always ensure public health protection

Water Use Reduction & Efficiencies

SEQ Water Strategy, QWC

2010

2011/2012

Operating Cost ~ $0.85 / kL

Savings:

$1.5-2.5 / kL fresh water intake

$2 - 3 / kL effluent (trade waste) discharge

Water Recycling in Industry (Brewery)

Future Water Supply Concepts

Sources

Processes

Uses

Domestic

Wastewater

Industrial

Wastewater

Stormwater/

Run-off

River/ Dam/

Sea Water

Drinking

Water

Non-potable

Domestic

Industrial

Uses

Irrigation/

Farming

Centralised Decentralised Specialised

Physical Chemical Biological Disinfection etc.

Resource Efficient Recycling Options

Stage 1

Carbon Removal

Nutrient Recovery

Stage 2

Nitrogen

Removal

Stage 3

Water Polishing/

Disinfection

Agricultural irrigation

Low-quality industrial Environmental flows

Industrial reuse

Restricted irrigation

Non-potable domestic

Industrial reuse

Unrestricted irrigation

Potable domestic

Resource Efficient Recycling Options Stage 1

Carbon Removal

Nutrient Recovery

Stage 2

Nitrogen

Removal

Stage 3

Water Polishing/

Disinfection

Novel & Existing Processes Options

Anaerobic membrane bioreactor (AnMBR)

Granular high rate anaerobic (UASB/IC, EGSB, Baffled Anaerobic Reactor)

High-rate aerobic (activated sludge) process

Temperature phased anaerobic digestion (TPAD)

Nitritation/anammox combined Moving Bed Biofilm Reactor

Nitritation/anammox combined Sequencing Batch Reactor

Denitrifying anaerobic methane oxidation (DAMO)

Biologically activated carbon (BAC)

Low pressure (membrane) filtration

Sta

ge 1

S

tag

e 2

S

tag

e 3

Anaerobic MBR Concept

Veolia/Biothane

Key Challenges:

- Low flux large membrane areas - Energy for membrane cleaning

- Fouling potential to be determined

Energy Self-suffient Process WWTP Strass (Austria, A/B Process)

200,000 EP

Nutrient Removal Plant

Courtesy Bernard Wett

High Rate Aerobic Processes

Wett & Alex, (2003) WST 48(4)

HRT = 0.25h

SRT = 0.5 d

High-rate Aerobic Treatment of Industrial WW Laboratory scale SBR optimisation

(Feed COD: 2000 mg/L, HRT: 0.5 day, SRT: 2-4 days)

COD removal > 85%, 20-25% oxidised

Total Nitrogen removal 50-60%

Total Phosphorus removal > 80%

Sludge degradability > 80%

Temperature-Phased Anaerobic Digestion

Thermophilic

Reactor

T > 55C, 2d HRT

Mesophilic

Reactor

T 35C, 10-14d HRT

Damien Batstone, Paul Jensen, AWMC

Peak Phosphorus limited resource

Rise in P prices due to increasing

fertilizer demand

Nitrogen/urea price fluctuations

linked to energy/LPG prices

N and P are major challenges for

waste and wastewater management

Pipe blocked due to struvite precipitation

Nutrient Recovery - Motivation

Works well in concentrated streams eg. digester effluent

but not in dilute solutions

Mg feed often beneficial as concentrated magnesium

hydroxide or MgCl2 solution

Increasing pH improves performance

Precipitation/crystallisation conditions critical for success

N & P Recovery as Struvite

Struvite recovery unit at sewage

treatment plant in Brisbane, QLD

Feed Effluent P-PO4 (ppm)

110 -150 0.5 2 N-NH4 (ppm) 950-1000 800 850 pH 7.5 7.7 8.5 8.7

Chirag Mehta, Damien Batstone, AWMC

Primary

Treatment

Secondary

Treatment

P

removal

Waste

Water

Secondary

effluent

FeCl3

RO

Treatment

Drinking

water

FePO4

P recovery from Iron Phosphate Sludge

NaCl V

e-

Fe3+, S0

Fe2+, S2-

HS-

S0

ANODE CATHODE

e- PO4

3- in

solution

FeSx

Na2S

NaHS

Stage I: FeS

precipitation

process

Stage II:

Electrochemical

process

Elena Likosova, Stefano Freguia, AWMC

N, K Recovery using Electrodialysis

An

od

e (+

)

Cat

ho

de

(-)

Concentrate

Wastewater

NH+

K+

NH+

K+

NH+

NH+

K+

NH+

K+K+

Anion ExchangeMembrane (AEM)

K+

NH+

Cation ExchangeMembrane (CEM) AEM AEMCEM CEM

Chirag Mehta, Damien Batstone, AWMC

Resource Efficient Recycling Options Stage 1

Carbon Removal

Nutrient Recovery

Stage 2

Nitrogen

Removal

Stage 3

Water Polishing/

Disinfection

What is Anammox?

NH4+

NO3-

0.5 N2

2 O2 (100%)

C-Source (e.g. methanol:

2.2 kg/kgN; COD: >5kg/kgN)

Nitrification

Denitrification

NH4+

0.55 NO2-

0.44 N2 + 0.12 NO3-

0.84 O2 (42%)

Partial Nitritation

Anaerobic ammonia oxidation

0.45 NH4+

Conventional Nitritation/Anammox

A. Joss, EAWAG

Anammox-type process scale-up

Wett & Dengg (2006)

Approximately 18-24 month process for first full-scale installation

Much shorter (0-6 months) for subsequent installations

Full-scale plants in operation

Austria Strass, plus others

Switzerland Zrich, Thun, Glarnerland, Limmattal, Niederglatt, St. Gallen. In

planning: Bazenheid, Bern, Geneva

Germany Several plants

The Netherlands Rotterdam, Lichtenvoorde, Olburgen, Mie (others?)

Rest of the world

Biggest plant: Industrial in China, 11,000 kgN/d

A. Joss, EAWAG

25

ANAMMOX granules

The key for continuous & successful operation:

Simple and compact one step process

Stable and robust operation

Tolerant to peak nitrite levels

Tolerant to peak Suspended Solids levels

SRT Control - Cyclone for selecting for DEMON Granules

MLSS Overflow Underflow

Nitritation/anammox Combined in Moving Bed Biofilm Reactor (MBBR)

ANITATM-Mox

Dewatering Liquor Treatment in Zurich

Two SBR tanks; 2800m3 total volume; 1800m3/d flow; 1200 kgN/d load

Denitrifying anaerobic methane oxidation (DAMO)

Still under development at lab-scale, very slow bacterial growth but could have

good potential in conjunction with anaerobic and anammox processes

Shihu Hu, Zhiguo Yuan, AWMC

Resource Recovery Options

Stage 1

Carbon Removal

Nutrient Recovery

Stage 2

Nitrogen

Removal

Stage 3

Water Polishing/

Disinfection

Agricultural irrigation

Low-quality industrial Environmental flows

Industrial reuse

Restricted irrigation

Non-potable domestic

Industrial reuse

Unrestricted irrigation

Potable domestic

Concluding Thoughts

Water recycling justified by economics and supply security

but needs to improve environmental footprint

---

Energy recovery valuable for WWTP operation, plus

economic in industrial situations and/or for (bio-)products

---

Nutrient recovery needed for supply security (P) and

increasingly economics (N & K)