School of Civil Engineering FACULTY OF ENGINEERING

Phosphorus recovery from wastewater by biological algal uptake

Miller Alonso Camargo-Valero WASH and Resource recovery

Phosphorus Removal from Catchments: Technology or Source Control Nottingham Conference Centre 24th February 2015, Nottingham

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Algae-based technology for sewage treatment

WSP – pilot plant at Esholt, Bradford

Algae-bacteria symbiosis

Waste Stabilization Ponds (WSP) are natural

wastewater treatment systems based on the

symbiotic relationship between algae and

heterotrophic bacteria.

Matthew E Verbyla (University of South Florida). Location of Waste Stabilization Ponds systems in the United States (2014)

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WSP: UK design criteria

SECONDARY FACULTATIVE POND

e.g., 500 p.e.

Pre-treatment: septic tank (100m3)

lBOD = 80 kg ha-1 day-1

Area: 3.75 m2 p.e.-1

Waste Stabilization Ponds in the UK

A primary facultative pond

receiving 80 kg ha-1 day-1 of BOD

loading is able to produce an

effluent which complies with the

requirements for WSP effluents in

the Urban Waste Water Treatment

Directive – i.e., 25 mg filtered BOD

per litre and 150 mg SS per litre.

However, they require further

treatment (polishing units) to meet

ammonium and phosphorus

discharge requirements.

Primary facultative ponds perform even better when baffles are added.

Pilot primary facultative pond

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Wastewater Pond

System

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Yorkshire Water’s Ecological Wastewater Treatment Plant at Scrayingham, North Yorkshire

Winter/Spring Effluent EA consent

BOD, mg/L 15 40

SS, mg/L 31 60

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Yorkshire Water’s Ecological Wastewater Treatment Plant at Scrayingham, North Yorkshire

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Outdoor microalgae cultivation in the UK

Algal biomass cultivated in sewage ponds in the UK contained up to 10% N and 1% P (dry weight).

Experiments conducted with 15N

stable isotopes in facultative and

maturations ponds, revealed the

potential for nitrogen recovery from

sewage via biological algal uptake

under UK weather conditions.

Further research in this field has

gathered evidence supporting the

feasibility to incorporate algal

photo-bioreactors in sewage works

for both N and P control and

recovery.

M1 and M2 are maturation ponds in series

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Outdoor microalgae cultivation in the UK

Algal biomass cultivated in sewage ponds in the UK contained up to 10% N and 2% P (dry weight).

0,0

0,2

0,4

0,6

0,8

1,0

0,0 1,0 2,0 3,0t/qo

C/C

o

15N-Ammonium 15N-Suspended Organic Nitrogen Rhodamine WT

Tracer experiments in maturation ponds: summer conditions –

15N Ammonium spike

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Outdoor microalgae cultivation in the UK

Tracer experiments in maturation ponds: summer conditions –

15N Ammonium spike

Accumulative 15N mass balance Recovery, %

M1 effluent Suspended organic – N 48.9

Soluble organic – N 4.9

Ammonium – N 8.8

Oxidised nitrogen – N 0.2

Accumulation Water column 24.8

Sludge layer 7.4

Volatilisation 0.0

Total recovery after 3 q 100

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Nitrogen load removal in maturation ponds M1 and M2

Total nitrogen load removal, %

Unfiltered effluent Filtered effluent Season

M1 M2 M1 + M2 M1 M2 M1 + M2

Autumn 2004 16 21 36 29 35 45

Winter 2005 19 18 34 25 25 39

Spring 2005 31 30 52 54 68 78

Summer 2005 13 20 30 82 79 82

Autumn 2005 9 8 18 70 72 74

Winter 2006 11 14 23 38 45 51

Spring 2006 19 24 39 63 38 49

Summer 2006 12 14* 6

* 51 41 48

Autumn 2006 18* 27

* 45

* 19 0 19

Winter 2007 24 5* 25 32 2 25

Spring 2007 21 13 31 70 59 68 * Negative values () correspond with periods reporting sludge feedback.

Outdoor microalgae cultivation in the UK

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Maturation pond M1

Algal biomass: 9.8% (d. w.)

Sludge: 5.1%

Maturation pond M2

Algal biomass: 10.0%

Sludge: 3.9%

Outdoor microalgae cultivation in the UK

M1 and M2 are maturation ponds in series

Nitrogen content in algal biomass and sludge

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Nutrient control in large WWTW

Most popular biological nutrient removal configurations

Source: Manyumba et al., 2008. Meeting the phosphorus consent with biological nutrient removal under UK

winter conditions. Water and Environmental Journal, 23, 83-90.

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Current global challenges

Source: Budget 08, GCP-Global Carbon Budget Consortium (2009)

[1 Pg = 1 Petagram = 1 Billion metric tonnes = 1 Gigatonne = 1x1015g]

Growth rate of CO2 emissions

2000-2008 = 3.4% per year

1990-2000 = 1.0% per year

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6CO2 + 6H2O → C6H12O6 + 6O2

Light energy

chlorophyll

Natural carbon fixation through photosynthesis

Typical algal cell “formula”

C106H181O45N16P

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The nitrogen cycle is also out of balance

The reactive forms of nitrogen

are accumulating in

environmental reservoirs

Reactive forms of nitrogen in terrestrial

and marine environments (Tg N/y)*

1860 Early –

1990’s 2050

125 163 221

*Galloway et al., 2004. Biochemistry, 70, 153-226

250 -

200 -

150 -

100 -

50 -

Glo

bal

Nit

roge

n F

ixat

ion

(Tg

/y)

"Natural" biological N fixation

Lightning

Fossil Fuel Combustion

Legume Crops and Green Manures

Synthetic N Fertilizer

An

thro

po

gen

icB

ackgrou

nd

1920 1940 1960 1980Year

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The nitrogen cycle is out of balance

The industrial production of

nitrogen fertilizers has

increased almost tenfold in the

past seven decades.

The UK farming industry

consumed 1,506 kt of

fertilisers in 2010:

• 1,021 kt of N-fertiliser

• 198 kt of P2O5

• 287 kt of K2O,

90% of P- and 58% of N-

fertilisers were imported

0

20

40

60

80

100

120

0

20

40

60

80

100

120

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

N e

xc

reti

on

by h

um

an

s,

Mt

N

N f

ert

iliz

er

co

ns

um

pti

on

, M

t N

Time in Years

World Developed countries

Developing countries N excretion by humans

The equivalent to 50% of

imported N fertiliser in the UK

is present in domestic sewage

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Potential for P recovery from sewage

Cooper J and Carliell-Marquet C (2013). A substance flow analysis of phosphorus in the UK food

production and consumption system. Resources, Conservation and Recycling, 74, 84-100.

31% of imported

P fertiliser

71% of

imported

P fertiliser

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Sustainable urban metabolism

http://circulareconomy.wikispaces.com/file/view/Circular%20linear%20economy.jpg/344676144/800x413/Circular%20linear%20

economy.jpg

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Re-Engineering the activated sludge process

The activated sludge process (Edward Ardern and W.T. Lockett, 1913)

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P recovery through microalgae biological

uptake

light

biomass production

specific products

polyphosphate

CO2

Algae can easily grow in CO2 enriched environments

nutrient Algae are versatile in adapting to nutrient requirements

water Algae can grow in freshwater, saline water and wastewater

Luxurious P uptake

Typical level of phosphate 1% P (dry-weight)

Luxury uptake > 1% P (dry-weight)

Source: Yulistyorini A., Camargo-Valero M. A. and Horan N. (2015)

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Biological nutrient recovery using algae

Microalgae has the capacity to take up

nutrients from wastewater (up to 10% N and

4% P in dry biomass

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Biological nutrient recovery using algae

Microalgae has the capacity to take up

nutrients from wastewater (up to 10% N and

4% P in dry biomass

Source: Yulistyorini A., Camargo-Valero M. A. and Horan N. (2015)

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Bioenergy generation from algal biomass

Source: Adewale O., Camago-Valero M. A. and Horan H. (2015)

0

100

200

300

400

500

600

700

1 4 7 10 13 16 19 22 25 28 31

Cum

m. C

H4 @

ST

P (

Nm

l)

Time (Days)

0:100 25:75 50:50 75:25 100:0

Cumulative methane yield from a blend of thermally hydrolysed

algae and sewage sludge.

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Water

security

Food

security Energy

security

Adaptation to climate

change

Current global challenges

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Resource recovery and reuse from wastewater

Wastewater

reuse

Nutrient

recovery Renewable

Energy

Wastewater

treatment

School of Civil Engineering FACULTY OF ENGINEERING

UK Nutrient Platform The Royal Society of Chemistry, Burlington House, London

29 April 2015

The European Regional Development Fund, INTERREG, NW Region

co-funded this work under the project ‘BioRefine’: Recycling Inorganic

Chemicals from Agro- and Bio-Industry Waste streams.

School of Civil Engineering FACULTY OF ENGINEERING

Institute of Public Health and Environmental Engineering

Miller Alonso Camargo-Valero Lecturer in Water and Environmental Engineering

Resource Recovery and WASH

Room 4.04, School of Civil Engineering University of Leeds, Leeds LS2 9JT E: M.A.Camargo-Valero@leeds.ac.uk T: +44 (0) 113 3431580

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iPHEE