1.3 Physical Resource Flows

From where do resources come, and where do they end up?

versus

Learning objective: to grasp how resource

flows are created and manipulated, and to

become familiar with methods of analysing

resource flows and the challenges they pose .

Linear flow

Lo

op

Loop

What comes in ……

Water 20-200 kg/p/day

Food 2 kg/p/day

Energy > 1 kg/p/day

Consumer goods

1- ? kg/p/day

Jan-Olof Drangert, Linköping University, Sweden

house- hold

… must go out

Greywater 20-200 kg/p/day

Solid waste1 - ? Kg/d/p

Faeces 0.3 kg/d/p

Urine1.5-3 kg/d/p

Jan-Olof Drangert, Linköping University, Sweden

house- hold

pollutants

The trick is to bend today´s many linear resource flows

• Solid waste is the most visible output. It may be discarded or sorted and recycled. Scavengers perform an important service

• Faecal matter is very small in volume, but is a major health threat unless treated and used wisely

• Urine (urine) volumes are small. Smells may be a problem unless urine is returned to the soil

• Grey water is voluminous and a major challenge in dense areas but can be a useful product if handled well

• Storm water may be a serious problem or it can augment household and irrigation supplies

• Energy is invisible but heat may be recovered Jan-Olof Drangert, Linköping University, Sweden

Water and nutrient ’kretslopp’

Rural home

City with linear flows

Sorting

city

food

Wastewater = (grey water, urine, and faeces)

WWTPwastewater

food

chemicals

J-O Drangert, Linköping University, Sweden

Leaking pipes

water

Three examples of ’kretslopp’ thinking

Fraction:

Solid ‘waste’

Organic ‘waste’

Faecal matter

Urine (urine)

Grey water

Storm water

In Stockholm

sorted in 8 fractions, collected and reused

organics composted together with hygien-ised dry faecal material

collected and trucked to farm

in situ after biological treatment

infiltration (no heavy rains)

In Kimberley

No sorting, collected and put on landfills

dried and composted

used in situ or by truck to council gardens

Grey water to pond after biological treatment, and rainwater to the same pond. Little rain.

In Kampala

No sorting, burnt in situ, the rest to landfill

banana peels etc to animal feed

dried and composted

in situ or collected

Infiltrated in situ and to drains

In drains but flooding due to heavy rains

Jan-Olof Drangert, Linköping University, Sweden

Provides heating/energy

Provides soil conditioner

Liquid fertiliser

Irrigation water and biogas

Groundwater recharge

Soil conditioner

Liquid fertiliser

Soil conditioner

Liquid fertiliser

Soil conditioner

Material Flow Analysis for human settlements

MFA uses the principle of balance:

input = output + accumulated stock in the system

and provides a systematic description of the flow of goods, materials or substances through various processes and out of the system.

Process 1

Process 2

input Process 3

output

output

Jan-Olof Drangert, Linköping University, Sweden

A resource flow model for a hamlet

8

Courtesy of Jenny Aragundy, Ecuador

9

The Stockholm model to improve sustainability

Courtesy of Stockholm Water Company

food

hydrosphere

wastehandlingconsumption

deposit/ landfill

livestockagriculture

urinefaeces

Modelling the situation (MFA)

• Select the material, product or chemical you are interested in

• Include all the flows, uses, losses and disposals

• Find estimates for all flows and stocks

4 STEPS in modelling:

(1) Description of the system (2) Formulation of model equations, (3) Calibration, and (4) Simulation incl. sensitivity and uncertainty analysis

• Decide the boundaries of your system (dashed line)

Jan-Olof Drangert, Linköping University, Sweden

Example 1: Actual reuse of nutrientsfrom households in urban agriculture

100%

50%

1870 1910 1950 2000waste pits +urine diversion +WC only WC +WWTP stop

Jan-Olof Drangert, Linköping University, Sweden

Proportion being reused

Heavy metals

Glass, tins, ceramics

Table 1: Data for the primary and secondary waste treatment for Linköping, 1870-2000

Sources:

Year No of inhabitants

Primary waste treatment/ toilet system

Comments Secondary waste treatment or storage

Comments

1870 7 300 0% WC 10% water-tight buckets 90% dug pit/outhouse

Level 3 based on (1)

70-90% to soil 10-30% to animal

fodder

1885 10 700

2% WC 5% urine separation 30% water-tight buckets 63% dug pit or equiv.

Level 3 bases on (1)

80-100% to soil 0-20% to animal

fodder

1900 14 500

8% WC 16% urine separation 76% water-tight buckets 0% pit latrine or equiv.

Level 3 based on (1)

80-100% to soil 0-20% to animal

fodder

1920 26 900 20% WC 10% urine separation 70% water-tight buckets

Level 3 based on (2)

95-100% to soil 0-5% to animal

fodder

1940 38 650 50% WC 0% urine separation 50% water-tight buckets

Level 2 (3)

40-60% to soil 40-60 % to landfill

1950 54 500 90% WC 10% water-tight buckets

Level 2 (4)

wastewater treatment plant (WWTP), no P

reduction unit

60% of W C connected to WWTP

1975 78 000 100% W C (6), (7) WWTP with 90% of

P to sludge; 0-20% to plant/soil

All W C connected to WWTP

1990 82 600 100% W C (5), (6), (9)

WWTP with 95% of P to sludge;

20-30 % reused (of which 2/3 to

energy forest and 1/3 to farmers)

70-80% to landfill

same assumptions as for the year 2000

2000 94 000 100% W C (5), (8), (9)

WWTP with 97% of P to sludge;

21% reused (10-40%) (of which 2/3 to

energy forest and 1/3 to farmers)

79% to landfill

Ex. 1 con´t Examples of ranges for parameters

Neset and Drangert, 2010

Ex. 1 con´t Sensitivity analysis

The filled curves represent calculated averages, while coloured areas between the dotted curves indicate uncertainty ranges due to estimated input data(in kg phosphorus per capita per year)

Source: Neset and Drangert, 2010

Phosphorus reuse and phosphorus losses 1870-2000

Example 2: Eutrophication of Lake Dianchi, China

55% of TP

45% of TP

Kunming city

Farmland P leakage

river downstream

385 tonnes

33 tonnes

Jan-Olof Drangert, Linköping University, Sweden

Dianchi

faeces flush

urine flush

laundry

kitchen

bath

industrialdischarge

HH

denitrificationstreet runoffroof runoff

runoff

comb. sewer

infiltration incl. river water

exfiltration

wrong connection

storm sewer

separate storm water drainage

treated wastewater

overflow out of CSO tank

overflow out of combined sewer

WWTP

sludge

CSO tank

Ex. 2 Cont Urban P flow to Dianchi Lake, China

Source: Huang et al., 2007

Ex 2 Con´t Outcome to guide a new strategy

1. Even with the best available treatment technology (BAT with 98% P removal etc.) the discharge would still be twice what the lake can accommodate.

2. A major problem is that during heavy rains the wastewater bypasses the WWTP and washes all wastewater straight into the lake.

3. Groundwater and stormwater enter the poor-quality sewers and make up a large portion of the water coming to the WWTP

4. Source-control measures such as urine-diversion toilets and P-free detergents and body care products are necessary to avoid discharging untreated wastewater downstream the lake and just moving the environmental problems.

Source: Huang et al., 2007

Example 3 : P flows through Hanoi City

Source: Montangero et al., 2004

Ex. 3 con´t Phosphorus flows in Hanoi City

Courtesy of Agnes Montangero, 2007

CompostingAgricultureMarket

Sewerage & drainage

Landfill

Organic wastecollection

On-sitesanitationHouse-

holds

Watersupply

Ex. 3 cont Feeding the people of Hanoi - a sensitivity analysis

Source: Montangero et al., 2007

2007(3 M)

Business as usual

2015 (5 M residents)

No septic tanks

No-meat diet

Example 4: Nutrients and food security – a global view

Only 1/5 of the P in mined rock reaches the food on our forks!

Ex 4 cont. Securing a sustainable phosphorus future

The future is not all dark!

Source: Cordell, N

eset, White &

Drangert 2009

Principle:

• Organic ≠ other solid waste

• Stormwater ≠ sewage

• Industrial ≠ household wastewater

• Black toilet water ≠ greywater

• Faeces ≠ urine

Strategies for sanitation improvements

Jan-Olof Drangert, Linköping University, Sweden