Research & Development Section of National Water Supply and Drainage Board has been established to innovate new technologies on water supply activities in the organization.

Research & Development Departments are common in many larger organizations, especially those working with newer products or technologies.  At present the government target is to meet 100% safe drinking water coverage in the country and increase pipe born water supply coverage to 60% by year 2020 where as at present safe water coverage is 85% and the pipe born coverage is about 45%.

Due to human activites, water quality is deteriorating day by day and water supply is becoming challenging task with climate change.

Therefore task of the R&D section is to selection of appropriate technologies and optimization of cost.  R&D section is actively involved in monitoring of Reverse Osmosis Plants installed in North Central Province where Chronic Kidney Disease patients are present.

Vision

Identify and implement economic sustainable means of providing potable water to people of Sri Lanka while minimizing environmental pollution.

Mission

Exploit Local expertise and material as far as possible to succeed with application oriented research activities

 

Postal Address : Research & Development Section
National Water Supply & Drainage Board
Telawala Road, Ratmalana
Telephone
: +94 11 2625196
Fax
   
Name & Designation Telephone Fax Mobile E-mail
Eng. N.Athmarajah
Assistant General Manager (R&D)
 +94 11 2625196
0714910697
                         076 1809760

This email address is being protected from spambots. You need JavaScript enabled to view it.This email address is being protected from spambots. You need JavaScript enabled to view it.">
This email address is being protected from spambots. You need JavaScript enabled to view it.

        This email address is being protected from spambots. You need JavaScript enabled to view it.
Eng. N.P. Goonawardena
Chief Engineer
+94 11 2625196     This email address is being protected from spambots. You need JavaScript enabled to view it.
Eng. S.K.L.S. Rupasinghe
Chief Engineer
+94 11 2625196      

 

 

 

National Water Supply and Drainage Board welcome professionals' assistance to intervention of following research areas where extensive studies are needed.

  1. Durability analysis of Domestic Water Meters
  2. Premature failure of Domestic Water Meters
  3. Low Cost technologies on Algae removal in water

 

Water Treatment with Reverse Osmosis Systems Click Here.........

 

Manual(English) for the Package Treatment Plant Click Here.........

Manual(Sinhala) for the Package Treatment Plant Click here........

 

 

1. Study on risk assessment of pumping wells and groundwater vulnerability of aquifers in the Buttala Divisional Secretariat Area in Monaragala District 

2. Research on Ground Water Dynamics of the Murunkan basin.  An environmental isotropic study for effective management of Murunkan well field.

3. Study on the historical evidences on chronic kidney disease (CKD) based on life pattern with respect to environmental and social factors.

3. Research on evaluation of adequacy and effectiveness of CBO tariff system for sustainability and diversification.

4. Analysis of Organochlorine and Organophosphate pesticide residues in drinking water sources in Nuwara Eliya, Welimada and Bandarawela areas

5. Recovery and reuse of Alum from water treated sludge.

6. Study on defective water meters.

7. Model water treatment plant.

8. Iron exchange for reducing hardness and fluoride in water.

9. Design and handling issues related to package treatment plants with the support of workshop for fabrications, as per requests from RSCs.

10. Study and monitoring of RO plants and carrying out measures to improve the system

11. Sanitation problems in the plantation sector with special reference to Demodara Estate, Southam Division in Badulla District, Sri Lanka.

12. Social survey on new connections to analyze the customer satisfaction for upgrading the NWSDB service.      

Proposed Projects - 2016

Analysis of the status of Groundwater quality which is contaminated with waste oil in Chunnakum area, Jaffna District – Stage II

 

Completed Researches

 

Item

Topic

Collaboration

1

Air Release Valve (PVC) to be installed before water meter

NWSDB 

2

Package plants Pugoda 500 cum/d & Manganese removal at Mahiyangana 2000 cum/d 

NWSDB 

3

Research on impact of the water pollution on water study supply from Kelani River

NWSDB, JICA 

4

Package water treatment plant 500 cum/d for Alawwa WSS 

NWSDB NW Region and
Central Workshop 

5

Sociological research on pipe water supply Sri Lanka

University of Colombo, NWSDB 

6

Well water quality, Werahera 

University of Sri Jayawardhanapura, NWSDB 

7

Maha Oya pollution study

University of Sri Jayawardhanapura, NWSDB 

8

Contamination sources of Bomburu Ella reservoir at Nuwara Eliya 

University of Sri Jayawardhanapura, NWSDB 

9

Pebble matrix filter, Kataragama

PNG University of Tech, World Bank, NWSDB 

10

Sand seiving machine 

NWSDB 

11

Research studies on coastal towns of Ampara district (ECTAD) WSS

NWSDB 

12

Konduwatuwan Alage problem study with respect to treatment plant performance and recommendations 

University of Moratuwa, NWSDB 

13

Proposal to improve treatment processes as using water from irrigation tanks taking Konduwatuwan Alage study as a case study

University of Moratuwa, NWSDB 

14

Hardness removal study for Puttlam WSS

NWSDB, NW Region, CLS 

15

Research on hydro geological and geochemical study on the natural springs the Matale District 

NWSDB, GW 

16

Assessment of Tri Halomethane formation in Chlorinated water supplies of Greater Colombo WSS of NWSDB

ITI and NWSDB 

17

Islandwide algae identification and screening of Microsistin study 

University of Sri Jayawardhanapura, NWSDB 

18

Water Pollution due to Pesticide residues and Toxic metals i Drinking water Bodies of Sri Lanka 

NWSDB and CEA

19

Point of use water treatment study, Clay filter and Domestic Slow Sand Filter

Red Cross, NWSDB

20

Water Treatment Plant index (WTPI) Study 

Open University, NWSDB

21

Preliminary study on Alge removal efficiency of Microstrainer at Polonnaruwa Water Treatment Plant 

University of Sri Jayawardhanapura, NWSDB 

22

Health risk (Oesophageal and stomach cancer) due high Nitrate in Jaffna ground water

Universit of Ruhuna, North Region, NWSDB 

23

Study on algal and cynobacteria identification in selected drinking and irrigation water bodies in Sri Lanka

Universtiy of Sri Jayawardhanapura, NWSDB 

24

Analysis of water quality in selected locations of Kaluganga

University of Sri Jayawardhanapura, NWSDB 

25

Water Safety Plan 2011-2012, 2012-2013 Biennium

NWSDB, WHO 

26

Projection of population for the Western Province metropolitan area 2012-2030

Department of Demography, University of Colombo 

27    Analysis of the status of Groundwater quality which is contaminated with                    NWSDB

waste oil in Chunnakum area, Jaffna District

28   Study of proper oxidizing agent as pretreatment to Kalatuwawa raw water                 NWSDB

29   Provision of safe water for drinking and cooking purposes for Chronic Kidney              NWSDB

       Disease affected areas in Girandurukotte and Polpithigama

30  Research on Use of Rain Water Harvesting to Mitigate Chronic Kidney Disease              NWSDB

      in North Western   Province in Sri Lanka.

 

 

Item No. Project
1 Reseaerch on Rain Water Harvesting to Mitigate Chronic Kidney Disease in North Western Province in Sri Lanka.
2 Provision of Safe Water for Drinking and Cooking Purposes for Chronic Kidney Disease Affected in Polpithigama.
3 Model Treatment Plant
4 Bottling of Liquid Chlorination 
5 Study of proper oxidizing agent as pretreatment to Kalatuwawa raw water. 
6 Jaffna 
7 Research Study on study of risk assessment on pumping wells and groundwater vulnerability of aquifers in the Buttala Divisional Secretary area, Monaragala District 
8 Research Proposal on Ground Water Dynamics of the Murunkan basin.  An environmental isotropic study for effective management of Murunkan well field.
9 Environmental and Social Factors 
Proposed Projects  
1 Facters affect for Domestic Water Meter defects 
2 Study on Water Meter Errors (After 8 years) 
3 Perception of Users 

Completed Research

Item Topic Collaboration
1 Air Release Valve (PVC) to be installed before water meter NWSDB 
2 Package plants Pugoda 500 cum/d & Manganese removal at Mahiyangana 2000 cum/d  NWSDB 
3 Research on impact of the water pollution on water study supply from Kelani River NWSDB, JICA 
4 Package water treatment plant 500 cum/d for Alawwa WSS  NWSDB NW Region and
Central Workshop 
5 Sociological research on pipe water supply Sri Lanka University of Colombo, NWSDB 
6 Well water quality, Werahera  University of Sri Jayawardhanapura, NWSDB 
7 Maha Oya pollution study University of Sri Jayawardhanapura, NWSDB 
8 Contamination sources of Bomburu Ella reservoir at Nuwara Eliya  University of Sri Jayawardhanapura, NWSDB 
9 Pebble matrix filter, Kataragama PNG University of Tech, World Bank, NWSDB 
10 Sand seiving machine  NWSDB 
11 Research studies on coastal towns of Ampara district (ECTAD) WSS NWSDB 
12 Konduwatuwan Alage problem study with respect to treatment plant performance and recommendations  University of Moratuwa, NWSDB 
13 Proposal to improve treatment processes as using water from irrigation tanks taking Konduwatuwan Alage study as a case study University of Moratuwa, NWSDB 
14 Hardness removal study for Puttlam WSS NWSDB, NW Region, CLS 
15 Research on hydro geological and geochemical study on the natural springs the Matale District  NWSDB, GW 
16 Assessment of Tri Halomethane formation in Chlorinated water supplies of Greater Colombo WSS of NWSDB ITI and NWSDB 
17 Islandwide algae identification and screening of Microsistin study  University of Sri Jayawardhanapura, NWSDB 
18 Water Pollution due to Pesticide residues and Toxic metals i Drinking water Bodies of Sri Lanka  NWSDB and CEA
19 Point of use water treatment study, Clay filter and Domestic Slow Sand Filter Red Cross, NWSDB
20 Water Treatment Plant index (WTPI) Study  Open University, NWSDB
21 Preliminary study on Alge removal efficiency of Microstrainer at Polonnaruwa Water Treatment Plant  University of Sri Jayawardhanapura, NWSDB 
22 Health risk (Oesophageal and stomach cancer) due high Nitrate in Jaffna ground water Universit of Ruhuna, North Region, NWSDB 
23 Study on algal and cynobacteria identification in selected drinking and irrigation water bodies in Sri Lanka Universtiy of Sri Jayawardhanapura, NWSDB 
24 Analysis of water quality in selected locations of Kaluganga University of Sri Jayawardhanapura, NWSDB 
25 Water Safety Plan 2011-2012, 2012-2013 Biennium NWSDB, WHO 
26 Projection of population for the Western Province metropolitan area 2012-2030 Department of Demography, University of Colombo 
     
     
     
     
     
     
     
     
Write comment (0 Comments)

In recent past years, National Water Supply & Drainage Board had constructed several package water treatment plants in the capacities of 500, 1000 and 1500 cum per day. Mega plants are most suitable for urban areas where the population is concentrated. Compared with the package water treatment plants the investment for mega plant is very much high. The cost of a 500 cum per day treatment plant only is around SL Rupees 12-13 million according to 2012 calculations, which includes the cost of material, fabrication, transportation & installation from Aerator to Filter exclusive support piers, back wash pumps, chemical dosing, concrete foundations and ancillary buildings etc. The price variation is depends on the site location & the condition.

By the initiative of the Research & Development Section the first 500 cum package plant was constructed in year 2005 in Pugoda. In recent past year with continuous improvements Research & Development section has designed 500, 1000 & 1500 cum treatment plant with tray & cascade aerators with the options of mechanical, hydraulic flocculation. This is a product of team work of NWSDB, the design by the Research & Development Section, drawn by Planning & Design Section, fabrication & installation by Central Work Shop. Finally, the relevant regions take the field adjustments, construction, supply and installation of pumps, chemical dosing and necessary building, supervision, operation & maintenance.

Plant Location Plant Capacity (Cum/day) Status/ Year Remarks
Pugoda 500 Completed in 2005  
Mahiyangana 2000 Completed in 2007  
Alawwa 500 Completed in 2008  
Oyamaduwa 1500 Completed /Year 2012  
Thanthirimale 1000 500 cum plant year 2012 Balance 500 cum/day to be completed
Kilinochchi 500 90% completed  
Anuradhapura sacred city 1000 75% completed  
Thmbuththegama 1000 Fabrication is in progress  
Sithulpawwa 500 Fabrication is in progress  

In Kilinochchi plant is with new feature of ZIG-ZAG cascade aerator. In Kilinochchi 500 cum package water treatment plant is constructed in the area of appr. 107 square meters land. Where in Pugoda it was 400 square feet.

Around the world there are number of household water treatment techniques in practice. In South Asia Plain sedimentation, cloth filter, boiling, solar disinfection and chlorination are the five most commonly used HWTS options. Boiling, cloth filter and plain sedimentation are widely used traditional household water treatment options in Sri Lanka. Solar disinfection is used by few households.

The disinfection of drinking water and municipal wastewater provides critical public health protection. Disinfection destroys bacteria and viruses, helping to protect ecosystems and prevent the spread of waterborne disease such as cholera, typhoid, dysentery and hepatitis ‘A’.

The main objective of this research was to produce commercially available liquid chlorine [Sodium Hypochlorite (NaOCl)] disinfectant for household water treatment and for emergencies in Sri Lanka. Thereby reduce the mortality & mobility of water borne disease.

Research & Development section has made a household disinfectant solution (NaOCl). As an initial step, Research & Development Section has planned to conduct a field survey for households to get their perception on pilot basis. The survey will be conducted among, who take only well water for drinking purposes.

Around the world there are number of household water treatment techniques in practice. In South Asia Plain sedimentation, cloth filter, boiling, solar disinfection and chlorination are the five most commonly used HWTS options. Boiling, cloth filter and plain sedimentation are widely used traditional household water treatment options in Sri Lanka. Solar disinfection is used by few households.

The disinfection of drinking water and municipal wastewater provides critical public health protection. Disinfection destroys bacteria and viruses, helping to protect ecosystems and prevent the spread of waterborne disease such as cholera, typhoid, dysentery and hepatitis ‘A’.

The main objective of this research was to produce commercially available liquid chlorine [Sodium Hypochlorite (NaOCl)] disinfectant for household water treatment and for emergencies in Sri Lanka. Thereby reduce the mortality & mobility of water borne disease.

Research & Development section has made a household disinfectant solution (NaOCl). As an initial step, Research & Development Section has planned to conduct a field survey for households to get their perception on pilot basis. The survey will be conducted among, who take only well water for drinking purposes.

Provision of Safe Water for Drinking and Cooking Purpose for the Chronic Kidney Disease Affected in Polpithigama

Chronic Kidney Disease of unknown etiology (CKDu) has been prevalent in the North Western Province of Sri Lanka over the past decade or so. According to Health Ministry, in certain areas of this province fairly large number of population is affected by KDu inclusive of children.

At present, few pockets of the identified CKDu areas are not covered under NWSDB pipe born water supply, but those areas are covered by piped water supply systems provided by NGO’s and CWSSP. These systems supply almost untreated water from groundwater source such as dug wells & tube well.

This study covers the water supply provided by NGOs’ to around 500 families from 30 dug wells, 4 tube wells and one spring.

The aim of this research study is to study the water quality and social survey of the above mentioned 35 groundwater sources. The water quality tests include Physical, Chemical, Biological, Pesticides, Heavy metals, Arsenic and Sodium etc. At present the social survey is in progress.

Collecting water samples from ground water source Social Survey

Rainwater Harvesting to Mitigate Chronic Kidney Disease in North Central / Western provision

Chronic Kidney Disease of Unknown Etiology (CKDu) has been prevalent in the North Central and North Western provinces of Sri Lanka over the past decade. The number of cases has been steadily rising since the inception of the disease. In certain areas 5 to 10 % of the population of all age groups including children is affected. CKDu has grown to epidemic level in Kurunegala & Anuradhapura districts. Many research groups including a specialist team of WHO are involved in studies to identify the cause of this disease. Naturally available water in the district is not a major cause of disease according to WHO report (year 2013) but statistics reveal that treated water from NWSDB piped water schemes have very low contribution to it. Considering this situation NWSDB concludes that drinking safe water could control the disease.

As it is not practically possible to cover the entire district with pipe borne water, NWSDB proposes rain water harvesting and provision of treated water via bowser supplies could help the un served communities to avoid this deadly disease. With the lessons learnt from provision of ferro-cement tanks, NWSDB has initiated in year 2010 to provide 154 nos of a capacity of 2000L plastic tanks to identified dwellings of the patients in Polpithigama area. The houses in the respective areas were selected giving weightage for the following.

  • Houses where there is a kidney patient
  • Houses where there had been a fatality due to CKD
  • Number of children below 18 years of age
  • Willing to accept rain water for consumption

The Salient features of the facility provided include of a cloth filter, automatic first flush facility and introduction of a smaller capacity poly ethylene tank. The pilot project contains 154 rain water tanks and a follow up monitoring program scheduled to ensure the sustainability of the project.

Girandurukotte

The following areas (Shown in Figure 1) were inspected by R&D section after the discussion with Manager (Bandarawela) and OIC (Girandurukotte) to provide bowser supply for CKD affected areas close to the Girandurukotte Water Supply Scheme (WSS).

  • Haguranketha Yaya
  • Theldeniyaya

Figure 1


The Water Treatment Process includes Aeration, sedimentation and rapid sand filatration to purify the raw water. Further, the WSS was designed to cater 3200 house holds. However, NWSDB has provided 1800 connections at present under Gamidiriya programme in Girandurukotte area. Hence, OIC (Girandurukotte) has revealed that there is a possibility to distribute excess water trough bowser to other areas which are not covered by the existing water distribution network. Based on this the pilot project area Haguranketha Yaya village was selected. The details of PE storage tanks are as shown in Table1 and Figure 2 shows the placing of PE tank at site.
Figure 2

 

Project Area No of Houses Tank Capacity No of Tanks Coverage / Tank
Haguranketha Yaya 97 1000L 20 5 house hold

*Theoretical tank filling frequency: 7 Days

The post survey was carried to investigate project performance and it revealed 87% of the total population (Figure 3) is adapted to the introduced system. Further, Figure 4 shows the percentage of the CKDu patient in the Haguranketha Yaya village

Figure 3 Figure 4

This is a simple flow control device which was constructed and tested to get required flow rate by adjusting the water height. Flow rates between 6 and 30 l/min can be used to measure accurately with this simple device equipped with 1/2” nipple.

Discharge through nipple was measured for different equilibrium heights of water. A graph was drawn according to the test results. Then for each equilibrium water height the theoretical discharge and actual discharge were calculated.

[Discharge (Theoretical)/Discharge (Actual)] = 0.64

h (cm) Volume (l) Q Actual (l/min) Q average(l/min)
31.6 5.37 32.22 32.14
  5.37 32.22  
  5.33 31.98  

Practically measured discharge is shown above. Therefore from this device 30L/min flow can be obtained at 31.6 cm water height.

Similarly by adjusting height different flow can be measured using this device.

The graph of Height Vs Discharge for simple flow control device

If required flow = 0.5 L/S = 30L/min

Assuming discharge factor 0.64
30 = 0.64* Qth
Qth= 46.88 l/min

Using above theoretical graph

(40-30) /(52.85-45.77) = (40-h)/ (52.85-46.88)
1.41 =(40-h)/5.97
31.6 cm = h

Health impacts from long term use of fluoride bearing water have been summarized as;

<0.5 mg/L : Dental caries
0.5 - 1.0 mg/L : Promotes dental health
1.0 – 4 mg/L : Dental fluorosis
>4 mg/L : Dental & Skeletal fluorosis
>10 mg/L : Crippling fluorosis

In this research we will focus on removal of fluoride by a fluoride selective ion exchange resin. The fluoride selective ion exchange resin is a chelating resin loaded with aluminum ions. In the lab scale this research is carried out it show success results.

Fluoride concentration in feed water : 1.52 mg/L
pH : 7.43
Flow rate : 100 mL/min

In this trial a single ion exchange filter containing 200g of resin was used. A representative ion exchange curve is shown in figure 1. It can be concluded from the curve that the break through of fluoride at 1 ppm occurred after 18 L, which equal 3 hours of operation, the operating capacity of the ion exchange resin is therefore, about 4.68x10-5 grams of fluoride adsorbed per one gram of resin.

fluoride removable capacity
Chlorine is added as final treatment step to disinfect and to provide residual chlorine to maintain this status. Removal of residual chlorine using activated carbon at the point of use helps to improve the taste and reduce health risks. About one ppm chlorine gas is injected into water to produce free chlorine that destroys and deactivates pathogenic and other organisms through oxidation. The residual free chlorine of 0.2ppm (WHO 2011) provides continued disinfection as water piped to homeowners, but another practical circumstance cause undesirable taste and odor. residual chlorine removal

For four months interval this filter can effectively reduce residual chlorine. Research continuous further.

Activated carbon dechlorinates drinking water through a chemisorption process whereby residual chlorine catalytically reacts with the carbon surface and is transformed into ionized hydrochloric acid. The process is increase pH levels typically found in drinking water. The reaction is as follows;

reactionC* and CO* represent activated carbon and the surface oxide on the carbon, respectively.

Tap the activated carbon filter to water line test for residual chlorine properties of filter and results as follows.

Dimension of the filter  Length - 50 cm
Diameter- 5 cm
Particle size distribution   1.70mm =Max: 05%
1.70 x 0.60mm=Min: 90%
0.60mm=Max: 05%
Flow rate 150 mL/min
filter

Research and Development Section has developed a demonstration model of Water Treatment plant, to understand the basic treatment process in Conventional Water treatment plant.

The processes indicate in this model is given as below.

basic treatment process

Aeration : Water from raw water source, will contain little or no dissolved oxygen. Hence, oxygen is added here. Also this step removes dissolved gases such as CO2, H2S and Ammonia from water thus improving the taste. Also dissolved iron is oxidized
Coagulation : The water contains very small particles less than 1 μm (Colloidal solids). They cannot settle out of suspension naturally because of their smaller size and negative charge. Coagulants such as Alum{[Al2(SO4)3. 18H2O] – Hydrated Aluminium Sulphate} are added to neutralize and destabilize these particles to induce them to aggregate into bundles known as flocs. This flash mixing with Alum is done with correction of pH to around 6.8. Sometimes Lime is used for this pH correction. About 60 seconds is enough for this Flash mixing step.
Flocculation : The bundling of destabilized particles is termed flocculation which is based on particle collisions. Flocculation is done practically in three steps termed “Slow Mixing” which improves the chance of particle collisions.
Tube Settler : The flocs formed after flocculation are settleable and hence removed by settling in sedimentation tank. As the flocs settle, the clarified water at the surface overflows a simple weir on top to the filtration unit. Tube settler is one of the most efficient settling device. It needs only one fifth of land area compared to a plain sedimentation tank.
Filtration : After sedimentation, the remaining impurities in water are very fine solids. (<10 mg/L in concentration) and dissolved material. Some of these impurities are originally in the raw water, but some are formed during the coagulation process. The residual material is removed in the filtration process by passing settled water through a layer of fine sand.
Disinfection : Although the coagulation process can remove some viruses and filtration can remove bacteria up to certain extent, the finished water may still contains some pathogenic viruses and bacteria which need to be destroyed or kept at safe level. Hence chlorination is applied to disinfect the filtered water before distributing to the consumers.
Write comment (0 Comments)

Low Cost Water Treatment Studies

pmf viewPebble Matrix filter is identifiead as a low cost method for removing high turbidity in raw water and pilot project was carried out at Kataragama Water Supply Scheme, following pdf will give you more details of the project.

First Full-Scale Trials of Pebble Matrix filtration [PDF - 1.39 MB] [ZIP - 1.35 MB]
Write comment (0 Comments)

This section will be available soon...

Write comment (0 Comments)