On-site greywater treatment and reuse

applications, quality requirements,

treatment solutions

5th June 2013

Beirut, Lebanon

I am…

Markus Sellner

Degreed engineer of Environmental protection

Living in Göttingen / Germany

Productmanager for decentralised water management

Employeed at DEHOUST since April 2008

1. What is on-site greywater reuse?

Definitions

Process water = water with different quality characteristics than drinking water

serving commercial, industrial, agriculatural or similiar purposes (DIN 4046).

Greywater = part of the household wastwater without faecal matter and urine (blackwater).

Greywater is the drain from bath tubs, shower trays, washbasins and washing machines.

It may also contain high-polluted kitchen wastewater.

(British standard 8525-1:2010)

1. What is on-site greywater reuse?

General flow schematic

decentralised greywater treatment system

1. What is on-site greywater reuse?

Ideal building types

1. What is on-site greywater reuse?

Distribution of water consumption in residential buildings

saving potential around 50 %

Drinking water Treated greywater

38 % body care

2 % drinking/cooking

7 % dish washing

33 % toilet

13 % laundry

5 % others

2 % garden irrigation

1. What is on-site greywater reuse?

Typical water consumption in buildings

sourcebuilding type

body care*[L/p*d]

toilet[L/p*d]

washing machine[L/p*d]

Green irrigation

residential building 50-90 20-35 15-25

Depending on green area60 – 200 L/m²*a

hotel complex 60-200 20-45 15-30

office building 15-50 10-30 5-20

sports facility 50-150 10-25 5-20

Existing information sheets and guidelines just give estimations/recommendations

• fbr information sheet H201

• British Standard 8525-1

• DIN 1989-1 about rainwater harvesting systems

*showers, bath tubs, handwash basins

L = litre; p = person; d = day; m² = squarmeter; a = year

Greywater Process water

1. What is on-site greywater reuse?

2. Quality requirements for reuse

Code of practice for general requirements

hygienical / microbiological safe

colorless and clear

particle free

free from unpleasant odour emission

• British Standard 8525-1: 2011

about greywater reuse

2. Quality requirements for reuse

• EU bathing water guideline 2006/7/EC

• DIN 19650

hygienic concerns of irrigation water

hygienical / microbiological safe

colorless and clear

particle free

free from unpleasant odour emission

• British Standard 8525-1: 2011

about greywater reuse

2. Quality requirements for reuse

name BS 8525-1 2006/7/ECDIN 19650

public green areas, sports area,

vegetables

turbidity [NTU] < 10 - -

pH 5 – 9,5 - -

coliform bacteria[cfu/100 mL]

1.000 10.000 -

Escherichia coli[cfu/100 mL]

250 1.000 < 200

comparing German limits about coliform bacteria:

raw milk: 10.000 cfu/100 mL

soft cheese: 1.000 cfu/g

minced meat: 5.000.000 cfu/g

Code of practice of general requirements

• EU bathing water guideline 2006/7/EC

• DIN 19650

hygienic concerns of irrigation water

3. Treatment technique

3. Treatment technique

collection/buffering

treatmentstorage/

reuse

General flow chart

3. Treatment technique

Membrane bioreactor

combination of aerobic biological sludge treatment and external submerged membrane filtration system.

Ultrafiltration flatsheet membranes separating activated sludge from biologically treated wastewater.

3. Treatment technique

Membrane bioreactor

• state of the art in Europe

• exceeding all guidelines

• 100% barrier for sludge/particles

• 99,9% barrier for germs

• absolut clear water

• small footprint

• eco-friendly without chemicals

• packaged system by system manufacturer

• high investment costs

• maintenance costs

3. Treatment technique

Sequencing batch reactor

combination of aerobic biological sludge treatment and UV-desinfection

batches: fill => react/aeration => settle => decant

3. Treatment technique

Sequencing batch reactor

with UV-desinfection

• state of the art in Europe

• exceeding all guidelines

• 99,9% barrier for germs

• eco-friendly without chemicals

• low maintenance costs

• low energy consumption

• not guaranteed clear water (e.g. foam)

• UV-efficiency depends on biological efficiency

• large footprint

3. Treatment technique

other treatment possibilities

• constructed wetlands with additional desinfection

• combined treatment systems

(sandfilter, carbon-filter, chlorine station)

• multi-layer-filters

- not common and proven in long-term-operation

- insufficient biological treatment => odour, foam,…

- mixed technology– no packaged and tested units

4. LEED-Certification

110 possible points

Simple certificate: 40 – 49 Points

Platinum certificate: 80 Points or higher

4. LEED-Certification

110 possible points

Simple certificate: 40 – 49 Points

Platinum certificate: 80 Points or higher

4. LEED-Certification

5. Audiance

Discussion

Time for questions

Thank you

for your attention !