How to construct, install and use Bio-sand filter for pure ... filter.pdfHow to construct, install and use Bio-sand Filter How to construct, install and use Bio-sand Filter 1. Introduction

NATIONAL AGRICULTURAL RESEARCH INSTITUTE

Copies can be obtained from:

The Publication Unit National Agricultural Research Institute

PO Box 4415 LAE

Morobe Province

Telephone: (675) 478 4000/01 Facsimile: (675) 475 1450

Email: [email protected]

How to construct, install and use Bio-sand filter for pure drinking water

NARI Extension Series

Booklet No. 13

March 2017

The National Agriculture Research Institute (NARI) was established by an Act of National Parliament of Papua New Guinea (PNG) in July 1996 as a public funded, statutory research organization, to conduct and foster applied and adaptive research into:

any branch of biological, physical and natural sciences related to agriculture;

cultural and socioeconomic aspects of the agricultural sector, especially of the smallholder agriculture; and

matters relating to rural development and of relevance to Papua New Guinea.

Besides, NARI is responsible for providing technical, analytical, diagnos-tic and advisory services and up-to-date information to the agriculture sector in PNG. The Institute’s purpose (strategic objective) is to accomplish enhanced productivity, efficiency, stability and sustainability of the smallholder agriculture sector in the country so as to contribute to the improved welfare of rural families and communities who depend wholly or partly on agriculture for their livelihoods. This is intended to be accomplished through NARI’s mission of promoting innovative agricultural develop-ment in Papua New Guinea through scientific research, knowledge creation and information exchange. In its vision for PNG, NARI sees “Prosperous PNG Agricultural Commu-nities”.

Information presented in this booklet was compiled by the Soils and Water Management Team under the NARI EU-ARD Project

EXTENSION BOOKLETS

1. How to Produce Home-made Pesticides, Extension Booklet No. 1, February 2001

2. Descriptive List of Selected Sweet Potato Varieties for Lowland Conditions, Extension Booklet No. 2, March 2001

3. Efficient Propagation Techniques for Taro Multiplication. Ex-tension Booklet No. 3, June 2001

4. NARI Recommended Taro Hybrids, Extension Booklet No. 4, December 2001

5. Wetiwa Gras, Extension Booklet No. 5, November 2003

6. Four Recommended Upland Rice Varieties for Lowland Cli-mates, Extension Booklet No. 6, November 2003

7. Sampela Toktok Bilong Lukautim Maskovi Pato, Extension Booklet No. 7, September 2004

8. Makot: Rot bilong kamapim nupela pikinini long wanpela han bilong mama diwai, Extension Booklet No. 8, May 2005

9. Aibika Genetic Diversity of Papua New Guinea, Extension Booklet No. 9, November 2006

10. Cassava Genetic Diversity of Papua New Guinea, Extension Booklet No. 10, November 2006

11. Produce your own Rice, Extension Booklet No. 11, December 2006

Page 13

How to construct, install and use Bio-sand Filter How to construct, install and use Bio-sand Filter

1. Introduction

A Bio-sand filter purifies unsafe water (dirty and contaminated) and make it safe to drink.

Two purification methods involved simultaneously in the BSF are:

1. Reduction of pathogens population between bio-layer,

2. Filtering of dirt and pathogens using filtration sand.

1. Filtration materials should be clean before installation.

2. Crusher site and river bank sand and gravel are recommended for BSF (due to low contamination level and presence of salts).

3. Continue to pour in water into the BSF for 30 days straight after installa-tion in order to grow the bio-layer.

4. BSF always uses the same water source, therefore use one source.

5. Leave the high turbidity water for the dirt to settle before pouring into the BSF (dirty water will clog the sand pores).

6. Pause pouring the water into the BSF for 1-2 hours purposely to give the bio-layer a rest.

7. The water poured into the BSF has to free from any other chemicals, be-cause it will kill the bio-layer.

8. Close the BSF lid at all time to prevent animal waste and dust from enter-ing into the reservoir.

An initial cost of construction is approximately K250.00, and once you have the mould, a litre of Loc-Crete and sieve, then several of the concrete box have to be built using a cement bag.

An image of a Bio-sand filter

Important rules to follow in order for the BSF to work effectively

Cost Involved

Page 12


Checking of flow rate Flow rate is checked to ensure that the BSF is correctly installed. It is checked as below;

If it is too fast or too slow, the filter is not correctly installed so it can be reinstalled.

The size of filtration sand is too small that prevent pathogen and dirt from pass-ing through, and only water to passes through.

The process is active after 30 days from installation .

The process of BSF during purification

The four stages of pathogen removal

Page 4

Frame for concrete BSF mould construction Tools and materials needed for the inner and outer mould frame are:

a 6mm plywood sheet, 2x2 size timber (8 pieces @ 1.5 m each), 6mm pipe (1m) and working tools (nail 2’ and 3’), saw, hammer, tape measure, and level


Completion of a BSF

Outer frame Inner frame

Both moulds with base closed and top open

Cross brace at the opening (should be level)

Drill a hole (top for the outer mould & lower end of the inner mould) and insert the pipe

Lubricate the inner frame and at-tach plastic to the base for easy re-moval of the frame afterwards

Pour cement mix

Wooden frame for BSF mould

30.5 cm 23 cm

87 cm 94cm

Page 10


Cement mixing and pouring Mixing Ratio : 1 bucket cement : 2 bucket sand (avoid bigger particles).

10 ml (1 lid full) of lok-crete for concrete wall reinforcement added to 1L water and it will take 15 –20 L of water with Lok-crete mix (100-150ml lok-crete for 10-15 L of water) to completely mix the cement mix for one BSF mould. Note: Shovel the mix several times to see that it can form ridge, and if then its ready for use. If ridge disappears quickly it is too wet (not good) and if no ridge is formed and crumble then it is too dry so add water. Pour the mix into the wooden frame and tap the frame for the mix to be equally distributed into the mould to avoid hollow.

Use a tie wire to tie around the mould frame to prevent it from dislocat-ing or breaking.

Leave it to dry for two days and remove the frame for installation.

BSF Installation

Step by step process to install the BSF

Page 9


Preparation for BSF Installation Fill the concrete mould with water to see any leakage. If there is leakage, patch it with cement mix or silicon and clean the BSF. 1. Prepare filtration material (sand and gravel) Take sand from the river bank or crusher site (low in contamination), beach sand with sand in the river bed are not recommended. The BSF needs 96% filtration sand for purification.

4. construction of diffuser and BSF lead The diffuser protects the top level of filtration sand and it is the reservoir that holds water. To avoid corrosion, the diffuser is normally constructed using galvanized metal sheet or corrugated plastic. The hole of the diffuser is 3 mm in diameter (size of 3 inch nail) and

spacing is 2.5 cm in grid pattern. The dimension of a diffuser is given below.

A simple lid can be constructed using timber or other available materials as shown below.

The lid have to be closed at all time to prevent dust and animal waste from entering the reservoir.

Page 8


2.Preparation for BSF Installation 1. Sieving of sand to get good filter materials for BSF

3. Washing of filter materials

Jar Test is carried out to wash the filtration sand to its recommended stage. The process is described below;

Test each round of washing to correctly get the required sand and dry the washed ones in a clean and safe area for installation.

How to construct, install and use Bio-sand filter for pure ... filter.pdfHow to construct, install and use Bio-sand Filter How to construct, install and use Bio-sand Filter 1. Introduction

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