evaluation of low cost water purification systems for humanitarian assistance and disaster relief...

ORIGINAL PAPER

Evaluation of low cost water purification systemsfor humanitarian assistance and disaster relief (HA/DR)

Chittaranjan Ray • Ashish Babbar •

Bunnie Yoneyama • Lukas Sheild • Benjamin Respicio •

Cheryl Ishii

Received: 16 May 2012 / Accepted: 13 September 2012 / Published online: 27 September 2012

� Springer-Verlag Berlin Heidelberg 2012

Abstract Following a natural disaster, access to safe

drinking water by the affected population is a high priority.

Low cost water purification systems, which can be used for

both short-term (immediate) and long-term (sustainable)

response to serve the needs of the affected communities,

are ideal for these scenarios. The University of Hawaii has

developed three low cost water purification technologies

for use during humanitarian assistance and disaster relief

(HA/DR) missions. A UH team participated in joint USA

and partner nation training exercises, such as Crimson

Viper 2010 and 2011, organized by the Marine Corps

Forces Pacific Experimentation Center (MEC) in Sattahip,

Thailand, to demonstrate the effectiveness of these tech-

nologies to purify water from local sources. Three tech-

nologies were selected for Crimson Viper 2010: (1) a

backpack filter unit, (2) a bicycle pump powered reverse

osmosis (RO) unit, and (3) a model slow sand filtration

unit. For Crimson Viper 2011, improved versions of the

backpack and RO units were deployed. This article dis-

cusses and evaluates the results obtained during the dem-

onstration of the three technologies at these exercises.

Keywords Water purification � Humanitarian assistance �Disaster relief � Slow sand � Reverse osmosis

Abbreviations

APIX Asia Pacific Information Exchange

DSTD Defense Science Technology Division

DR Disaster relief

FHA Foreign humanitarian assistance

HA Humanitarian assistance

HTDV Hawaii Technology Development Venture

LED Light emitting diode

MEC Marine Corps Forces Pacific

Experimentation Center

NADESCOM National Development Support Command

ONR Office of Naval Research

PFC Perfluorochemicals

PICHTR Pacific International Center for High

Technology Research

RO Reverse osmosis

UH University of Hawaii

USPACOM United States Pacific Command

UV UltraViolet

C. Ray (&)

Water Resources Research Center and Civil & Environmental

Engineering, University of Hawaii at Manoa, 2540 Dole Street,

Holmes Hall 286, Honolulu, HI 96822, USA

e-mail: [email protected]

A. Babbar

University of Hawaii at Manoa, 2800 Woodlawn Drive,

Suite 163, Honolulu, HI 96822, USA

B. Yoneyama

University of Hawaii at Manoa, 2540 Dole Street,


L. Sheild



B. Respicio

University of Hawaii at Manoa, 2540 Dole Street,


C. Ishii



123

Clean Techn Environ Policy (2013) 15:345–357

DOI 10.1007/s10098-012-0530-1

Introduction

The Asia Pacific Information Exchange (APIX) water

purification project is designed to develop and evaluate

cost-effective water purification technologies in support of

Foreign Humanitarian Assistance (FHA) operations. The

water purification project focused on two FHA missions:

humanitarian assistance (HA) and disaster relief (DR). Clean

drinking water is one of the first requirements for sustaining

human life and health in case of a natural disaster. In such an

event there are many poor communities that are unable to

support a community type water purification system in

locations where adequate treatment is either impractical or

unaffordable. A safe, clean and low cost drinking water

source is a must in the global strategy to provide potable

water in a disaster scenario that disrupts local water supplies.

In this regard, the APIX program is intended to benefit both

the USA and its partner nations such as Thailand and the

Philippines by developing low cost water purification sys-

tems. The University of Hawaii (UH) demonstrated their

water purification systems for HA/DR at a technology

exchange exercise (i.e., Crimson Viper) organized by the

Marine Corps Forces Pacific Experimentation Center

(MEC), United States Pacific Command (USPACOM).

Technology requirements

The selected technology for water purification was expec-

ted to meet the following criteria:

1. Technology should be applicable to the humanitarian

phase of HA/DR and should also support development

activities. The proposed technology should cover at

least 60–70 % of possible scenarios.

2. Equipment designed for the proposed technology

should be easily transportable by air and have the

capability to be distributed with ease.

3. Proposed technology should be ‘‘low tech’’ and

require minimal expertise to operate.

4. Technology should be easy to use so that the local

population can be trained quickly and efficiently on its use.

5. Technology should be weight and volume efficient.

6. Recipients of the water purification technology should

have confidence the drinking water is suitable for

consumption based on taste, appearance, packaging,

and the purification process.

Technology categories

The HA/DR technologies for this effort were divided into

two broad categories:

1. Rapid and immediate response. These technologies

can be deployed at short notice and serve the needs of

the communities soon after a disaster. The systems

under this category should have the following features:

a. Portable

b. Low cost

c. Light weight

d. Easy to use or requiring minimal training

e. Requiring minimal or no external power

2. Long-term and sustainable response. These technologies

can be deployed after a disaster to provide long-term

support to the community. The systems in this category

can also be used in HA scenarios. The features for these

systems include:

a. Ability to support a community or large population

b. Able to purify a large volume of water

c. Parts do not require frequent replacements

d. Does not require complex training to operate

e. Uses easily available power sources

Technology exchange exercises

Under the APIX program, UH developed water purification

systems for demonstration at the following joint military

exercises (i.e., Crimson Viper and Balikatan).

1. Crimson Viper. A Thai-US technology collaboration

experimentation event, jointly sponsored by the

USPACOM and the Royal Thai Defense Science and

Technology Division (DSTD). The mission of Crimson

Viper is to provide technology developers access to

Thailand’s unique operational environment to conduct

experiments and to test their technologies.

2. Balikatan. A joint exercise between USPACOM and the

Philippines National Development Support Command

(NADESCOM) to conduct experimentation and testing

of partner technologies.

UH water purification systems

UH developed the following three water purification

technologies, which were demonstrated at the Crimson

Viper 2010 exercise:

1. Slow sand filter system

2. Soda bottle-based reverse osmosis (RO) system for

fresh water

3. Backpack-based multi-level filter system

The following two technologies were demonstrated at

the Crimson Viper 2011:

346 C. Ray et al.

123

1. Portable RO system for fresh water

2. Modified backpack-based multi-level filter system

At Balikatan 2012, UH will demonstrate the following

two technologies:

1. Modified slow sand filter

2. Portable RO system for fresh water

Crimson Viper 2010 demonstration systems

The UH water purification system demonstration was

conducted at Sattahip Royal Navy Base, Sattahip, Thai-

land. For the Crimson Viper 2010 exercise, two fresh water

sites within the base were selected for the system demon-

stration. Site #1 was a small pond inside the base. The

water from the pond was purified for drinking by the water

plant located on base. Site #2 was a small lake surrounded

by plants near the Utapao Airbase where a slow sand filter

was set up. Figure 1 shows the two demonstration sites at

Crimson Viper 2010.

Slow sand filter system

A slow sand or ‘‘biosand’’ filter is a water filtration sys-

tem that uses biological activity in the sand to improve

water quality without the addition of chemicals to the

water (Logsdon et al. 2002; Huisman and Wood 1974;

Haarhoff and Cleasby 1991). A slow sand filter can

operate as a self-sustainable technology without use of

electricity or fuel. The UH slow sand filter consisted of a

cylindrical container 0.90 m high, packed with *0.15 m

of gravel, and about 0.70 m of silica sand (particle size

between 0.20 and 0.35 mm). The source water to be

purified was supplied at the top of the column and was

allowed to flow slowly down (due to gravity) through the

sand and gravel to the pipes on the bottom. The sand bed

was kept saturated by the continuous flow of source water

through the system.

Slow sand filters work by the formation of a gelatinous/

bio layer called ‘‘Schmutzdecke’’ on the top few millime-

ters of the sand layer (Huisman and Wood 1974). Patho-

gens in the water were captured in the filter media and

acted upon by the microorganisms present in the biolayer

(Oasis Design 1991).

The advantages of the slow sand filter included the

following:

• Requires no electro/mechanical power or chemicals,

minimal operator training, and only periodic

maintenance.

• Has a simple design and easy to construct from locally

available materials.

• Removes over 99 % of harmful bacteria from the water

(Haarhoff and Cleasby 1991).

• Capable of removing viruses and improving water

clarity (Haarhoff and Cleasby 1991).

The slow sand filter developed by UH for the Crimson

Viper exercise had an average flow rate of 27 L/day.

Figure 2 shows the bench-scale slow sand filter demon-

strated at Crimson Viper 2010. This system was a demo

unit and was used to train the Thai counterparts on set up

and maintenance of such a system. No data were collected

from this system. The sand column for this system was an

acrylic cylinder. This system was easily scalable if a

greater volume of finished water was required. UH has also

developed a scaled-up version of this system capable of

filtering *750 L/day, which will be demonstrated at the

Balikatan 2012 exercise in the Philippines. Figure 3 shows

the prototype of this scaled-up system. The UH system

consists of two parts:

1. Front-end system. This section consisted of a slow

sand filter that relies on the Schmutzdecke to filter out

Fig. 1 Demonstration sites at Crimson Viper 2010

Evaluation of low cost water purification systems 347

123

particles of foreign matter that were then metabolized

by the bacteria, fungi, and protozoa in the Schmutz-

decke (Bellamy et al. 1985).

2. Tail-end system. This section consisted of a system

that can help improve the quality of water obtained

from the sand filter by further removing pathogens and

volatile organic compounds. A UV light disinfection

system was used to achieve these results.

Soda bottle-based reverse osmosis system

This system was based on a multiple stage RO procedure

and demonstrated at Crimson Viper 2010. Plastic soda

bottles with a 2-L capacity, which can withstand pressures

up to 689.47 kPa, acted as both the feed and pressure

vessel. Provisions were made for air to be pumped into the

bottle for pressurization. The pressurization pump created

enough pressure to force the water through the filters and

the outlet for collection.

In this system, the source water, poured into a plastic

soda bottle, was pressurized to 482.63 kPa using a bicycle

pump. Due to the pressure, the source water was forced out

from the soda bottle to run through a series of filters. The

source water passed through a sediment filter followed by a

carbon filter. Water from the carbon filter then passed

through an RO membrane filter. The filtered water was then

collected in a third soda bottle. The RO filter was washed at

periodic intervals to remove any sediment that may have

been attached to the RO membrane. Figure 4 shows the

soda bottle-based RO system demonstrated at Crimson

Viper 2010.

The advantages of the soda bottle filter system were as

follows:

• Easy to assemble and maintain by the local populace.

• Required minimum training to operate.

• Cost per liter of water produced was very low and the

process required no power input.

• Easily transportable and could be used in DR scenarios.

• Depending on the source water quality, this system was

capable of operating for an extended duration without

the need of filter replacements.

This system consisted of three different filters:

1. First stage: polypropylene sediment filter

• Osmonics 5-lm rating, Model #1-SED10

• Size: 10 in.

• Removed sediments and particles, including dust,

rust, and organic matter

• Cost: $9

• Procured from APEC Water Systems Inc.

Fig. 2 Slow sand filter demonstrated at Crimson Viper 2010 and

2011

Fig. 3 Slow sand filter to be demonstrated at Balikatan

348 C. Ray et al.

123

2. Second stage: carbon block filter

• KX Extruded 5-lm rating, Model #23-CAB10

• Size: 10 in.

• Removed chlorine, taste, odor, cloudiness, and

color

• Cost: $15


3. Third stage: thin film composite RO membrane filter

• Dow Filtec Tw30-1812-75 RO membrane

#114731

• Size: 11.75 in.

• Removed perfluorochemicals (PFC), bacteria and

viruses (Olsen and Paulson 2008)

• Cost: $75

• Procured from WaterFiltersOnline.com

Backpack-based multi-level filter

Demonstrated at Crimson Viper 2010, this system was a

portable, lightweight multiple filter system that could be

used to purify water in several stages using separate

methods of purification. This system was a portable unit

that could be supplied and easily used in DR scenarios. The

system consisted of modular, interchangeable filters that

can be combined to provide water filtration. The three

stages of the filter included: a 5-lm spun polypropylene

filter, a 0.5-lm carbon block filter, and a UV light disin-

fection system. This was a modified version of the Adap-

tive Water Treatment for Education and Research

(WaTER) laboratory system developed by Rice University

(Boyle and Houchens 2008).

As the source water flowed through the filter stack, each

filter acted to remove specific contaminants such as large

particulates, odor, and bacteria. The UV light disinfection

system operated on Li-ion batteries that were charged using

solar panels. Figure 5 shows the backpack-based multi-

level filter system demonstrated at Crimson Viper 2010.

The advantages of using a backpack filtration system

included the following:

• One of the simplest and cheapest means of producing

potable water.

• Used a hand pump to produce sufficient water for

human survival.

• Did not require any external power source for

operation.

• As a modular system, the filters can be assembled based

on the water quality of the different source waters.

Fig. 4 Soda bottle-based RO

filter demonstrated at Crimson

Viper 2010

Fig. 5 Backpack-based multi-level filter demonstrated at Crimson

Viper 2010


123

The backpack system consisted of three stages:

1. First stage: Pentek spun polypropylene filter

• 5-lm rating, Model #P5-478

• Flow rate: 7.56 L/min at 2.07 kPa

• Temperature range: 4–62 �C

• Reduced particulates such as sand, dirt, rust, and

sediment

• Cost: $3

• Procured from Filter Fast LLC

2. Second stage: Pentek carbon block filter

• 0.5-lm rating, Model #CBC-5

• Reduced bad taste, odor, and chlorine taste

• Cost: $10


3. Third stage: AquaStar Plus UV treatment system

• Weight: 85 g (including batteries)

• Battery: 2 9 type 123 batteries

• Reduced bacteria, protozoa, and viruses

• Cost: $79

• Procured from Meridian Design Inc.

The backpack-based system used three solar panels,

each capable of producing a peak power of 1.3 W. The

solar panels were used to charge the batteries that operated

the UV light filtration system. The solar panels had the

following specifications:

• Dimensions: 188 mm 9 85 mm 9 5 mm

• Weight: 120 g

• Substrate type: 3 mm aluminum/plastic

• Cell type: monocrystalline

• Cell efficiency: 17 %

• Open circuit voltage: 12 V

• Peak wattage: 1.3 W

• Cost: $6 per panel

• Procured from Voltaic Systems

Separate housings enclosed each filtration system used

in the backpack system. The housings can be pressurized

using a hand pump. The design allowed water to be poured

into the top of the stackable housings and dispensed at the

bottom into outlet cups.

Crimson Viper 2011 demonstration systems

For Crimson Viper 2011, the demonstration was also

conducted at the Sattahip Royal Navy Base, Thailand. Site

#1 was a stream located within the base, which received the

base runoff as well as the ‘‘gray’’ water from the sur-

rounding buildings. Site #2 had a rainwater catchment

system composed of a concrete tank, which was previously

used to wash parachutes. Figure 6 shows the two demon-

stration sites at Crimson Viper 2011.

Portable reverse osmosis system for fresh water

Based on the lessons learned from Crimson Viper 2010, a

modified version of the soda bottle-based RO system was

fabricated and tested for demonstration at Crimson Viper

2011. To serve the needs of a larger number of end users,

an RO system capable of filtering 170 L/day of water

was selected, with the addition of a Steripen UV disin-

fection unit as the final stage of water purification.

Although the RO system provides sufficient potable

water, UH included the UV disinfection stage based on

feedback received from the Thai military during Crimson

Viper 2010. The comments from the local population

indicated they felt it was safer to drink UV-treated water.

Figure 7 shows the portable RO system demonstrated at

Crimson Viper 2011.

Fig. 6 Demonstration sites at Crimson Viper 2011

350 C. Ray et al.

123

This system used RO to filter fresh water for HA/DR

scenarios. The six stages of filtration used to obtain purified

water were

1. First stage: polypropylene sediment filter

• Osmonics 5-lm rating, Model #1-SED10

• Size: 10 in.

• Removed sediments and particles including dust,

rust, and organic matter

• Cost: $9


2. Second stage: carbon block filter


• Size: 10 in.

• Removed chlorine, taste, odor, cloudiness, and

color

• Cost: $15


3. Third stage: carbon block filter


• Size: 10 in.

• Removed residual chlorine, taste, and odor;

improved RO membrane efficiency and extended

RO membrane life

• Cost: $15


4. Fourth stage: high rejection thin film composite RO

membrane

• Filmtec 0.0001-lm rating, Model #MEM-45

• Size: 10 in.

• Maximum operating temperature: 45 �C

• Maximum feed flow rate: 7.6 L/min

• Removed Giardia cysts and Escherichia coli (E.

coli) bacteria

• Cost: $65


5. Fifth stage: total polishing carbon filter

• Omnipure coconut shell refining carbon 5-lm

rating, Model #5-TCR

• Removed any residual tastes and odors

• Cost: $15


6. Sixth stage: Steripen UV disinfection system

• Weight: 471 g

• Battery: none; hand powered

• UV Lamp: 8,000 1 L treatments

• Removed bacteria, viruses, and protozoa

• Cost: $100

• Procured from Hydro-Photon Inc.

Figure 8 shows the filters used for this system. This

system had two modes of operation. If there was no

external power source available, the source water can be

fed through the system using a bicycle pump, which was

included as part of the system. The bicycle pump can be

attached to the source water bottle and used to pressurize

the system to 344.73 kPa, which would allow the source

water to pass through the system. Alternatively, the system

can be operated using a water pump that draws power from

a 12 V car battery. The car battery could then be charged

using a solar panel. This allowed the end user the flexibility

to choose the mode of system operation based on the

available power source. The source water would flow

through the first five stages of filters, and the output water

could then be obtained at the faucet connected to the fifth

stage. The water was then transferred to the Steripen UV

disinfection unit that was operated for 1.5 min using the

crank handle. The LEDs in the UV unit turned from red to

Fig. 7 Portable RO system

demonstrated at Crimson Viper

2011


123

green after 1.5 min to indicate the water was ready for

consumption.

The RO system is a compact system packaged in a

Pelican carrying case, which can be easily transported to

the source water. The system was capable of producing

water at 136–170 L/day. This system could easily be

scaled-up to produce around 340 L/day of water to serve

the needs of a group of families (small village). The peak

production of 340 L could only be achieved if the unit was

operated continuously for a period of 24 h. To accomplish

this, sufficient manpower is required to operate the system,

perform batch UV disinfection, and store the treated water.

The specifications for the system included:

• System capacity: 136–170 L/day at 344.73–413.68 kPa

• Feed water pH: 2.0–11.0

• Feed water pressure: 275.79–689.47 kPa

• Feed water temperature: 4–38 �C

• Maximum total dissolved solids: 2,000 ppm

• System dimensions: 19 in. 9 24 in. 9 15 in.

• System package weight: *18 kg

• Sediment filter replacement: 15,000 L

• Carbon filter replacement: 15,000 L

• RO membrane replacement: 60,000 L

Modified backpack-based multi-level filter system

The lessons learned from Crimson Viper 2010 were used as

a basis to modify and fabricate the next iteration of the

backpack-based multi-level filter. The stacked design of the

backpack system described earlier caused leaking of water

over time from one filter compartment to the other. The UV

disinfection unit was also replaced with a hand cranked

system to eliminate the need for batteries. The current

iteration of the backpack system was designed while

keeping these issues in mind.

This system was a portable and lightweight water puri-

fication unit that used different filters for each stage of

water purification. Two different filters were used in this

system:

1. First stage: Pentek spun polypropylene filter with the


• 5-lm rating, Model #P5-478

• Flow rate: 7.56 L/min at 2.07 kPa

• Temperature range: 4–62 �C

• Reduced sand, dirt, rust, and sediment

• Cost: $3


2. Second stage: Pentek carbon block filter with the


• 0.5-lm rating, Model #CBC-5

• Removed bad taste, odor, and chlorine taste

• Cost: $10


3. Third stage: Steripen UV disinfection unit with the


Fig. 8 Filters used for portable

RO system

352 C. Ray et al.

123

• Weight: 471 g

• Battery: none; hand powered

• UV lamp: 8,000 1 L treatments

• Removed bacteria, viruses, and protozoa

• Cost: $100

• Procured from Hydro-Photon Inc.

Figure 9 shows the filters used in the modified backpack

system. This system can be operated using a bicycle pump

to pressurize the system to 48.26–68.94 kPa. Alternatively,

the source water can be gravity fed to the system using a

3 ft head. Hence, this system required no external power to

operate.

The backpack system was a self-contained unit where all

the components, including filters, can easily fit in the

backpack so the end user could carry the technology to

remote areas for deployment. The weight of the backpack

system was around 6.8 kg. This system would be ideal

for providing potable drinking water to an individual or a

small group. This system was capable of producing 1 L of

drinking water in 5 min. Figure 10 shows the modified

backpack-based multi-level system demonstrated at Crim-

son Viper 2011.

Results and discussion

Water samples, both source water and output from the

purification systems, were tested at the Royal Thai Navy

water laboratory at Sattahip Navy Base in Thailand for

both the Crimson Viper 2010 and 2011 exercises.

Total coliform bacteria and E. coli were simultaneously

assayed using the IDEXX Colilert 18/Quanti-tray 2000 sys-

tem. Colilert 18 is a commercial most probable number assay

using a defined substrate technology for total coliform and

E. coli in drinking water. The colilert reagent is mixed with

100 mL of undiluted or diluted sample, placed in a Quanti-

tray and sealed. The tray is incubated for 18 h at 35 �C.

If total coliforms are present in the sample, they have a

b-galactosidase enzyme that can metabolize ONPG, caus-

ing the release of o-nitrophenol which changes the media

from colorless to yellow. If E. coli are present, they have a

b-glucuronide enzyme that can act on the MUG in the

media with a release of 4-methylumbelliferone which

causes a blue fluorescence under long wave UV.

The Quanti-tray 2000 is based upon the same statistical

model as the traditional 15 tube MPN. The 100 mL of

sample is distributed by the sealer into 97 wells of two

different sizes. This allows the Quanti-tray 2000 a counting

Fig. 9 Filters used for modified

backpack-based multi-level

filter

Fig. 10 Modified backpack-

based multi-level filter

demonstrated at Crimson

Viper 2011


123

range of 3 logs (on an undiluted sample this means a range

of 1–2, 419 MPN/100 mL).

IDEXX Colilert 18 is an EPA approved 18-h test and is

included in standard methods for the examination of water

and wastewater.

Standard wet chemistry methods were used for testing

parameters such as turbidity, pH, total dissolved solids,

hardness, nitrate, sulfate, and specific conductance.

Crimson Viper 2010 results

Soda bottle-based reverse osmosis filter

Water from two sources within the Sattahip Navy Base

(Thailand) was used to test the system performance. Tables 1

and 2 show the quality of source water as well as the output

water from the soda bottle-based RO filter demonstrated at

Crimson Viper 2010. Nine water quality parameters were

tested for at Crimson Viper 2010. The acceptable standards

(set by the Thai military) for these parameters are also shown

in Tables 1 and 2. The data from the two sites using the soda

bottle-based RO system showed that the product water met the

acceptable drinking water standards set by the Thai military.

Backpack-based multi-level filter system

The results from testing the backpack system at Crimson

Viper 2010 are shown in Tables 3 and 4. The product water

did not meet the coliform standard for Site #1. UH assessed the

reason for this and found that the stacked filter had some

design flaws. When the system was pressurized using a

bicycle pump with too much air space above, the source water

overflowed from one compartment to the other, and did not

allow enough contact time with each filter. Also, the UV unit

used in this system was in the bottom compartment, and after

extended use, when the water reached this compartment it

penetrated into the electrical system of the UV unit and caused

malfunctioning. These drawbacks were used as the basis to

redesign the backpack system for Crimson Viper 2011.

Crimson Viper 2011 results

Portable reverse osmosis filter for fresh water

The RO unit was modified to eliminate the need for plastic

soda bottles. The entire system was enclosed in a pelican

case for easy transport. As noted earlier, a batch UV dis-

infection unit was added as the sixth stage based on feed-

back from the Thai military personnel during Crimson

Viper 2010. They suggested that the local population

would trust the product water as potable if a UV disin-

fection stage were added to the system.

The Royal Navy Water Lab personnel, at Sattahip Navy

Base (Thailand), analyzed the water samples, and the Thai

military water quality standards were used as a baseline to

evaluate the system performance. Tables 5 and 6 show the

Table 1 Soda bottle-based RO

system results at site #1 (pond

water), Crimson Viper 2010

NTU nephelometric turbidity

units, MPN most probable

numbera Refers to Thai military

drinking water standard

Parameter Standarda Pond water baseline RO system

Turbidity (NTU) \5 13.4 0.29

pH 6.5–8.5 7.4 6.0

Total dissolved solids, TDS (mg/L) \500 385 235

Hardness (CaCO3) (mg/L) \100 120 50

Nitrate (NO3) (mg/L) as N \4 0.7 0.5

Sulfate (SO4) (mg/L) \250 51 7

Specific conductance (lS/cm) – 924 496

Total coliform bacteria (TCB) MPN/100 cm3 \2.2 2,420 1

E. coli colonies/100 cm3 None 2 0

Table 2 Soda bottle-based RO

system results at site #2 (lake

water), Crimson Viper 2010





Parameter Standarda Lake water baseline RO system

Turbidity (NTU) \5 12 0.14

pH 6.5–8.5 7 6.0

Total dissolved solids, TDS (mg/L) \500 111.8 123.7





Total coliform bacteria (TCB) MPN/100 cm3 \2.2 [2,420 0


354 C. Ray et al.

123

results for 13 water quality parameters for the source as

well as the product water. These 13 parameters were

selected by the Thai military for testing during the Crimson

Viper 2011 exercise.

The data from the portable RO filter show that the

product water from this system met all 13 standards set by

the Thai military whether the source was stream water or

rainwater.

Table 3 Backpack-based

multi-level filter results at site

#1 (pond water), Crimson Viper

2010





Parameter Standarda Pond water baseline Backpack system


pH 6.5–8.5 7.4 6.5

Total dissolved solids, TDS (mg/L) \500 385 285



Sulfate (SO4) (mg/L) \250 51 45


Total coliform bacteria (TCB) MPN/100 cm3 \2.2 2,420 45


Table 4 Backpack-based

multi-level filter results at

site #2 (lake water), Crimson

Viper 2010





Parameter Standarda Lake water baseline Backpack system

Turbidity (NTU) \5 12 1.75

pH 6.5–8.5 7 6.5

Total dissolved solids, TDS (mg/L) \500 111.8 118.2





Total coliform bacteria (TCB) MPN/100 cm3 \2.2 [2,420 1


Table 5 Portable RO system results at site #1 (stream water), Crimson Viper 2011

Parameter Standarda Stream water baseline RO system

Color \20 74 0

Odor None None None


pH 6.5–8.5 7.7 6.8

Total dissolved solids (TDS) mg/L \500 1,064b 51.34

Hardness (CaCO3) (mg/L) \100 256.7b 0

Chloride (Cl) (mg/L) \250 268.5b 14.7


Sulfate (SO4) (mg/L) \250 76.09 0

Iron (Fe) (mg/L) \0.3 0.09 0

Specific conductance (lS/cm) – 1,504 81.42

Total coliform bacteria (TCB) MPN/100 cm3 \2.2 [200c 0

E. coli colonies/100 cm3 None [200c 0

NTU nephelometric turbidity units, MPN most probable numbera Refers to Thai military drinking water standardb The stream water had high salt content, because of this the TDS, hardness, and chloride results for backpack did not meet the standard as the

backpack system is designed to purify fresh water only and is not designed to remove salts or ionsc The testing of product water samples was conducted locally in Thailand. UH had to rely on equipment used at the water quality laboratory at

the Sattahip Navy Base that had its detection limits


123

Modified backpack-based multi-level filter system

UH modified the stacked backpack filter design after the

demonstration at Crimson Viper 2010 revealed design

flaws. In the modified backpack system, each filter com-

partment was separated to ensure water from one com-

partment did not overflow and contaminate water in the

compartment below. This also encouraged more uniform

pressurization. Tables 7 and 8 show the results for 13 water

quality parameters that were tested as part of this exercise

for both the stream water and rainwater.

The three water purification systems and their modifi-

cations discussed in this article presented a subset of low

cost water purification systems that could be used for HA/

DR scenarios. Since HA/DR situations are unique, a single

or combination of these systems may provide temporary

Table 6 Portable RO system results at site #2 (rain water), Crimson Viper 2011

Parameter Standarda Rain water baseline RO system

Color \20 7 0

Odor None None None


pH 6.5–8.5 7.2 6.5

Total dissolved solids (TDS) mg/L \500 38.76 24.90


Chloride (Cl) (mg/L) \250 4.9 9.8



Iron (Fe) (mg/L) \0.3 0.01 0.02

Specific conductance (lS/cm) – 61.20 39.27

Total coliform bacteria (TCB) MPN/100 cm3 \2.2 [200b 0

E. coli colonies/100 cm3 None [200b 0

NTU nephelometric turbidity units, MPN most probable numbera Refers to Thai military drinking water standardb The testing of product water samples was conducted locally in Thailand. UH had to rely on equipment used at the water quality laboratory at


Table 7 Modified backpack-based multi-level filter results at site #1 (stream water), Crimson Viper 2011

Parameter Standarda Stream water baseline Backpack system

Color \20 74 2

Odor None None None


pH 6.5–8.5 7.7 7.9

Total dissolved solids (TDS) (mg/L) \500 1,064b 1,021

Hardness (CaCO3) (mg/L) \100 256.7b 257.5

Chloride (Cl) (mg/L) \250 268.5b 255.7


Sulfate (SO4) (mg/L) \250 76.09 77.01

Iron (Fe) (mg/L) \0.3 0.09 0.02

Specific conductance (lS/cm) – 1,504 1,449

Total coliform bacteria (TCB) MPN/100 cm3 \2.2 [200c 0

E. coli colonies/100 cm3 None [200c 0

NTU nephelometric turbidity units, MPN most probable numbera Refers to Thai military drinking water standardb The stream water had high salt content, because of this the TDS, hardness, and chloride results for backpack did not meet the standard as the

backpack system is designed to purify fresh water only and is not designed to remove salts or ionsc The testing of product water samples was conducted locally in Thailand. UH had to rely on equipment used at the water quality laboratory at


356 C. Ray et al.

123

solutions in obtaining potable drinking water until capacity

is rebuilt. UH is currently exploring replacing the hand

cranked UV unit with an inline UV system for the portable

RO system. This will allow continuous production of water

instead of a system behaving as a batch operation unit.

Conclusions

UH successfully tested its first and second-generation

backpack and RO water purification systems. The UH

systems are portable lightweight units that can support HA/

DR missions and with some modifications can be deployed

for small tactical US military missions. Being small por-

table units, multiple UH systems can be deployed in a

disaster scenario to ensure same amount of water produced

by a single larger system while eliminating the single point

of failure. Deployment of multiple UH systems can reduce

logistics burden of water distribution by enabling multiple

water distribution sites thereby reducing the wait time in

queue for disaster victims.

UH will continue to assess the full-scale slow sand filter

and higher production capacity RO and backpack systems

at technology exchange exercises such as Balikatan and

Crimson Viper. This will provide UH an opportunity to do

a comparative review of the modified systems with their

predecessors and refine the final systems for field deploy-

ment. Low cost and portable water purification systems are

essential as part of the first response to disaster scenarios;

therefore, there is great potential in research and develop-

ment of these systems that should be consciously explored.

Acknowledgments Funding for this research was provided by

Pacific International Center for High Technology Research (PIC-

HTR)/Hawaii Technology Development Venture (HTDV) through

the Office of Naval Research (ONR). The authors would like to

acknowledge the United States Pacific Command (USPACOM) and

the Marine Corps Forces Pacific Experimentation Center (MEC) for

their support for this project.

References

Bellamy WD, Silverman GP, Hendricks DW, Logsdon GS (1985)

Removing giardia cysts with slow sand filtration. J Am Water

Works Assoc 77(2):52–60

Boyle PM, Houchens BC (2008) Hands-on water purification

experiments using the adaptive WaTER Laboratory for Under-

graduate Education and K-12 Outreach. In: Proceedings of the

2008 ASME Fluids Engineering Division Summer Meeting,

Jacksonville, FL, pp 107–116

Haarhoff J, Cleasby JL (1991) Biological and physical mechanisms

in slow sand filtration. American Society of Civil Engineers,

New York, pp 19–68

Huisman L, Wood WE (1974) Slow sand filtration. World Health

Organization, Geneva. ISBN 9241540370

Logsdon GS, Kohne R, Abel S, LaBonde S (2002) Slow sand

filtration for small water systems. J Environ Eng Sci 1:339–348

Oasis Design (1991) Slow sand filtration. http://www.oasisdesign.

net/water/treatment/slowsandfilter.htm

Olsen P, Paulson D (2008) Water science and marketing, LLC,

performance evaluation: removal of perfluorochemicals with

point-of-use water treatment devices, final report prepared for

the state of Minnesota, Minnesota Department of Health

Table 8 Modified backpack-based multi-level filter results at site #2 (rain water), Crimson Viper 2011

Parameter Standarda Rain water baseline Backpack system

Color \20 7 0

Odor None None None


pH 6.5–8.5 7.2 8.6

Total dissolved solids (TDS) (mg/L) \500 38.76 69.60


Chloride (Cl) (mg/L) \250 4.9 18.6



Iron (Fe) (mg/L) \0.3 0.01 0

Specific conductance (lS/cm) – 61.20 109.5

Total coliform bacteria (TCB) MPN/100 cm3 \2.2 [200b 0

E. coli colonies/100 cm3 None [200b 0

NTU nephelometric turbidity units, MPN most probable numbera Refers to Thai military drinking water standardb The testing of product water samples was conducted locally in Thailand. UH had to rely on equipment used at the water quality laboratory at



123

http://www.oasisdesign.net/water/treatment/slowsandfilter.htm

http://www.oasisdesign.net/water/treatment/slowsandfilter.htm

evaluation of low cost water purification systems for humanitarian assistance and disaster relief...

Documents