Waste Water Recycling,

Reclaim, and Reuse

GBI Professional Series

14th June 2014

Waste Water Recycling, Reclaimation,

and Reuse

• Waste Water

• Grey Water and Black Water

• Water Balancing

• How much Waste Water can be reclaimed/recycled?

• How much Potable Water can be Saved

• Waste water recycling and Reclaim Methods

– Centralised

– Decentralised –

• What are the risks?

Waste Water – Statistics (SPAN)

Waste Water Flow Rates

Type of Establishment Population Equivalent

Residential 5 per house

Commercial :

Includes offices, shopping complex, entertainment / recreational centres,

restaurants, cafeteria and theatres

3 per 100m2 gross area

School / Educational Institutions :

- Day schools / Institutions

- Fully residential

- Partial residential

0.2 per student

1 per student

0.2 per non-residential student

1 per residential student

Hospitals 4 per bed

Hotel with dining and laundry facilities 4 per room

Factories, excluding process water 0.3 per staff

Market (Wet Type) 3 per stall

Market (Dry Type) 1 per stall

Petrol kiosks / Service stations 15 per toilet

Bus Terminal 4 per bus bay

Taxi Terminal 4 per taxi bay

Mosque / Church / Temple 0.2 per person

Stadium 0.2 per person

Swimming Pool or Sports Complex 0.5 per person

Public Toilet 15 per toilet

Airport0.2 per passenger/day

0.3 per employee

Laundry 10 per machine

Prison 1 per person

Golf Course 20 per hole

Population Equivalent (Indah Water)

Population Equivalents (PE)

In order to design pipe network, pump stations and sewage treatment plants, estimates need to be

made of the volumetric flow rate which will be expected to be carried, pumped and treated.

Such flow rates are measured in cubic metres per second and need to be calculated for both existing

land use and for expected future development.

There are many methods for calculating expected flow rates. One method is to calculate a design

parameter called the "population equivalent" (PE) of a catchment and convert this to a flow rate.

The PE is an estimate of the usage made of sewage facilities. It is not a measure of population.

For residential areas the population equivalent is calculated as five per dwelling and is a direct

measurement of the population in an area.

However for commercial areas it is calculated from the floor area, which is considered to be

proportional to the number of people using a premises during the day. In this case it does not reflect

the population living in an area.

The PE may be converted to a flow rate using a simple formula such as set out in Malaysian

Standards 1228 (MS1228).

Waste Water Influent Design Values

• Depends on What We Use

• Depends on What We Eat

Waste Water Effluent Discharge Quality

Parameter Unit Standard A B

(1) (2) (3) (4)

(i) Temperature °C 40 40

(ii) pH Value 6.0 - 9.0 5.5 - 9.0

(iii) BOD5 at 20°C mg/l 20 50

(iv) COD mg/l 50 100

(v) Suspended Solids mg/l 50 100

(vi) Mercury mg/l 0.005 0.05

(vii) Cadmium mg/l 0.01 0.02

(viii) Chromium, Hexavalent mg/l 0.05 0.05

(ix) Arsenic mg/l 0.05 0.10

(x) Cyanide mg/l 0.05 0.10

(xi) Lead mg/l 0.10 0.5

(xii) Chormium, Trivalent mg/l 0.20 1.0

(xiii) Copper mg/l 0.20 1.0

(xiv) Manganese mg/l 0.20 1.0

(xv) Nickel mg/l 0.20 1.0

(xvi) Tin mg/l 0.20 1.0

(xvii) Zinc mg/l 1.0 1.0

(xviii) Boron mg/l 1.0 4.0

(xix) Iron (Fe) mg/l 1.0 5.0

(xx) Phenol mg/l 0.001 1.0

(xxi) Free Chlorine mg/l 1.0 2.0

(xxii) Sulphide mg/l 0.50 0.50

(xxiii) Oil and Grease mg/l Not detectable 10

PARAMETER LIMITS OF EFFLUENT OF STANDARDS A AND B

Grey Water & Black Water

• Greywater is wastewater with the exception of wastewater from

toilets, which is known as blackwater. Greywater is waste water from

washing machine, bathroom sinks, and showers.

• Not all greywater is equally "grey". Kitchen sink water laden with

food solids, laundry dicharge, and floor traps within WC cubicles are

more of a deeper shade of grey when compared to greywater from

ablution and bathroom basins. Greywater from these sources

contains less pathogens than blackwater

• Blackwater is wastewater from WCs, Urinals

•

• To reuse/reclaim blackwater treatment is required for the water to

the quality which suit the reclaim purpose.

Typical Composition of Grey Water

National Water Quality Standard

PARAMETERS UNITCLASSES

I IIA IIB III IV V

Ammoniacal

Nitrogenmg/l 0.1 0.3 0.3 0.9 2.7 ›2.7

BOD mg/l 1 3 3 6 12 ›12

COD mg/l 10 25 25 50 100 ›100

DO mg/l 7 5-7 5-7 3-5 ‹3 ‹1

pH 6.5-8.5 6-9 6-9 5-9 5-9 -

Colour TCU 15 150 150 - - -

Elec.

Conductivity*umhos/cm 1000 1000 - - 6000 -

Floatables N N N - - -

Odour N N N - - -

Salinity (%) % 0.5 1 - - 2 -

Taste N N N - - -

Total Dissolved

Solidmg/l 500 1000 - - 4000 -

Total Suspended

Solidmg/l 25 50 50 150 300 300

Temperature (C) °C -Normal

+2°C[] @

Normal

+2°C- -

Turbidity (NTU) NTU 5 50 50 - - -

Faecal Coliform

**counts/100mL 10 100 400

5000

(20000)ª

5000

(20000)ª-

Total Coliform counts/100mL 100 5000 5000 50000 50000 ›50000

Water Class and Uses

CLASS USES

Class I Conservation of natural environment.

Water Supply I - Practically no treatment

necessary.

Fishery I - Very sensitive aquatic species.

Class IIA Water Supply II - Conventional treatment.

Fishery II - Sensitive aquatic species.

Class IIB Recreational use body contact.

Class III Water Supply III - Extensive treatment required.

Fishery III - Common,of economic value and

tolerant species;livestock drinking.

Class IV Irrigation

Class V None of the above.

Source : EQR2006

Water Classes And Uses

Water Balancing

Why is this important?

• Identify the required water usage

• Identify sources of waste (Potable Water, Rainwater Harvesting, Waste

Water)

•Encapsulates cost of water & water treatment

How to do it?

•Capture incoming & outgoing flow capacities for every water consuming component for operation

•Classify entity under a category and sum up all entities under category

•Return of Investment

Reclamation and Reuse of Waste Water

WASTE

WATER

INFLUENT

TREATMENT

RECLAIMED

EFFLUENT

REUSED

Reclamation and Reuse of Grey Water

GREY WATER TREATMENT

RECLAIMED

EFFLUENT

REUSED

BLACK

WATERTREATMENT

DISCHARGED

EFFLUENT

Typical Office Building Water Use

% Black Water and Grey Water Discharge

Total Waste Water 24.5%

Grey Water 9.9%

Black Water 14.6%

Total Waste Water 24.5%

Grey Water/T. Waste 40%

Black Water/T Waste 60%

Grey Water Reclaim Potential Reuse

Overall Strategy with Grey Water Reclaim

and Rainwater Harvesting

Potable Water 12.3%

Grey Water 4.2%

Rain Water 82.5%

Water Balancing Diagram

University with STP Discharge Reclaim

Water Balancing Diagram

Factory with Effluent Reclaim

GBI Credit for Water Recycling

Use of Waste Water Reclaimation

• Irrigation - public parks, schools, any

landscaped areas, golf courses

• Commercial - vehicle washing facilities, laundry

facilities, window washing, mixing pesticides and

herbicides

• Construction - dust control, concrete production

• Toilet and urinal flushing

• Fire protection

• Drinking water

Typical Household Waste Water (IWK)

Residential Wastewater Reuse

Commercially available greywater treatment &

recycling

Residential Wastewater Reuse

Greywater treatment & Reclaim

Residential Wastewater Reuse

• Why reuse wastewater at home?

– Conserve precious drinking water supply

• Droughts

• Low Water Level In Dams

• Overuse or population overwhelming supply

– Save money

– Reduce environmental impact associated with

wastewater treatment & disposal

Residential Wastewater Reuse

• Greywater:

– Wastewater from sinks, bathtubs, showers, dish

washer, laundry (anything except toilets)

– May contain pathogens, likely to contain other

microbes, detergents, bleach, hair, food particles,

suspended solids

– Not for potable reuse unless tertiary treatment

Typical Sewage Treatment Process (IWK)

Urban Waste Water Reclaim and Reuse

Urban Wastewater Reuse

• Recycled urban wastewater or reclaimed water?

– Urban wastewater that has undergone

additional treatment following secondary

treatment in order to be reused rather than

discharged into the environment

• Can reduce strain on potable water supply

Urban Wastewater Reuse

• Retrofitting reclaimed water system in existing

Buildings can be expensive

• BUT can be cost-effective if:

– Water supply is of poor quality

– Water supply does not meet demand

– Advanced wastewater treatment already

required

– Rainwater Harvesting is not Viable

Wastewater Reuse

• Major considerations are public health and

reliability of the system

– Water must be of acceptable quality for intended uses

– System must be maintained and operated properly

– Reclaimed water pipes must be clearly marked

Risks

• Health risk from associated pathogens

• Health risk from other contaminants (e.g. metals,

chemicals, pharmaceuticals)

• Decrease in soil quality from accumulation of

metals and acidification

• Infiltration of groundwater

Thank You