Fabric Enhanced

Ceramic Candle Filters

Pete Crosthwaite Yr. 4 MEng Civil Engineering

What’s Coming Up

Point of Use (Household) based treatment

Problems with ceramics candle filters

Fabric Enhancement?

Simple engineering improvement

Millennium Development Goals

Goal 7, Target 10:

“Halve, by 2015, the proportion of people without

sustainable access to safe drinking water and basic

sanitation”

WHO:

“1.1 billion people have no access to any type of

improved drinking source of water”

Mama Abungu

Photographer: Douglas Tooth

Mama Abungu

Photographer: Douglas Tooth

Water Supply in Bar-Agulu

Photographer: Douglas Tooth

Water Supply in Bar-Agulu

Photographer: Beth Crosthwaite

Obama’s Grandma’s Water Supply!

Photographer: Douglas Tooth

Back to Statistics

Contaminated water responsible for:

4 billion cases of diarrhoea each year

Causing 2.2 million deaths

Mostly children under 5 years old(WHO 2000)

Definitions

Point of Source Point of Use

(Household Water Treatment)

Treatment at Point of Source

Household connection

Public standpipe

Borehole

Protected well or spring

Rainwater collection

Treatment at Point of Source

(Clasen T.F. and Bastable A. 2003)

Proportional number of faecal bacteria

Problem at Point of Use

(Clasen T.F. and Bastable A. 2003)

Proportional number of faecal bacteria

Why? Look back at the picture of the well…

Treatment at Point of Use

Ceramic water filters

Biosand filters

Boiling

Solar disinfection (SODIS)

Chlorination (with tablets or liquid)

Ceramic Filters are the Best!

“By contrast [to other interventions] the

clear effectiveness of the ceramic filterin this analysis would make further controlled trials unethical.

Research should focus primarily on how to

increase uptake and sustainability

of the intervention.”

Paul R. Hunter

Ceramic Candle Filters

Advantages:

Filters 99.9% of bacteria

Inexpensive & cost effective

Incorporates storage

Viewed as an asset by

household

Candles

Top Bucket

Top Lid

Middle Lid

Bottom

Bucket

Plastic Spigot

Ceramic Candle Filters

Disadvantages:

Fragile and easily cracked

Requires frequent

cleaning (scrubbing)

Low flow rate 1-2 l/hour

Or even lower!

Overall Aim

The overall aim is to enhance ceramic candle

filter systems using fabric to:

reduce the frequency of cleaning required

simplify the cleaning process

maintain sufficient flow rate.

Initial Concept

“Fabric Enhanced Filters”

Initial concept from research on slow sand filters – layers of fabric

Applied to ceramic candle – like a sock!

Experimental Set-Up

Fabric

“sock”

pre-filter

Constant Head

Pump

Filters

ResultsCandle Flow Rates

0.00E+00

1.00E-07

2.00E-07

3.00E-07

4.00E-07

5.00E-07

6.00E-07

01/02/2010

12:00

02/02/2010

00:00

02/02/2010

12:00

03/02/2010

00:00

03/02/2010

12:00

04/02/2010

00:00

04/02/2010

12:00

05/02/2010

00:00

Date and Time (dd/mm/yyyy hh:mm)

Flo

w R

ate

(m

^3

/s)

Candle 1

Candle 2

Candle 3

Candle 4

Candle 5

Candle 6

Candle 7

Candle 8

Expected Avg. Q

Expected Max

Expected Min

Measured Avg.

Summary

Fabric Enhanced Ceramic Candle Filters:

Point of Use based treatment has a big impact

Simple & Creative engineering improvement to

ceramic filters

Real problem...affecting real people

I represent a small step….

Any questions?

…I hope it leads to giant leaps.