Updated on January 3, 2024


Created on August 27, 2015

Lotus Water Chlorine Dosing Device


A chlorine dispenser to attach to flowing water systems.

Developed By
  1. Stanford Researchers and the International Centre for Diarrhoeal Disease Research, Bangladesh
Tested By
  • International Centre for Diarrhoeal Disease Research, Bangladesh
Content Partners
  1. Siemens | Stiftung


Product Description

The Lotus Water Project aims to reduce the transmission of water-borne diseases through the implementation of community-level water disinfection throughout urban slums. This chlorination device (currently a prototype) utilizes basic principles of fluid mechanics to dose water exiting a hand pump with the necessary amount of chlorine, making it safe to drink and store for later use. The chlorinator relies on pressure differences created by the device’s geometry to inject a dose of chlorine proportional to the amount of water flowing through the hand pump without using electricity (i.e. venturi effect). <sup> Interview with representative</sup>

Target SDGs

SDG 6: Clean Water and Sanitation

SDG 3: Good Health and Well-Being

Market Suggested Retail Price


Target Users (Target Impact Group)


Distributors / Implementing Organizations

As a prototype, Stanford Researchers and the International Centre for Diarrhoeal Disease Research, Bangladesh are deploying the product. Lotus Water is developing a strategy for scaling its approach to water disinfection, one option being establishing an independent organization with full-time employees and a distribution network. Interview with representative

Manufacturing/Building Method

The key parts are currently manufactured using 3D printers. All parts were purchased in Dhaka, Bangladesh with exception for the regulator and constant head tank. Interview with representative.  Interview with representative

Intellectural Property Type


User Provision Model

Landlords lease the device from Lotus Water company for the community’s water source. The landlord pays Lotus Water directly, and increases rent slightly to disperse the cost of the chlorination system evenly to each tenant; tenants pay the increased rent each month.

Distributions to Date Status

40 units

Active Chemical and concentration (%)

Sodium Hypochlorite (4%)



Dosing method: Batch or flow-through


Dosing method: Automatic or manual


Dosing quantity

0.4-0.6 mg/L

Contact time (min)


Target free disinfectant residual (mg/L)


Bacteria reduction


Virus reduction


Protozoa reduction


Heavy metals and/or arsenic reduction


Treatment lifespan (days)


Maximum recommended influent turbidity level (NTU)

Water should be low turbidity (<5 NTU) for best disinfection.

Design Specifications

The chlorinator is comprised of three core components—a venturi, a chlorine reservoir with a float valve (or constant-head tank), and a secondary chlorine reservoir. The venturi connects to the outflow of the hand pump and uses the venturi effect to draw in chlorine through an attached line.

Product Schematics

Technical Support

During prototype phase, support is provided by field staff based at the International Centre for Diarrhoeal Disease Research, Bangladesh; At maturity, Lotus Water Technicians will provide support. Interview with representative

Replacement Components

Not currently available for sale, but can be produced on a case-by-case basis.  Interview with representative


Technicians remove plastic chlorine bottles from each device site approximately once a month. The device is estimated to need full replacement every 2 years.  Interview with representative

Manufacturer Specified Performance Parameters

Lotus Water provides water that is not only safe when it comes out of the tap, but is safe in storage because of the residual chlorine.  Interview with representative

Vetted Performance Status

Field Testing ongoing. Within one three-month period, 1,100 samples were tested, of which 86% fell within WHO standards. Interview with representative


Plastic chlorine bottles to be removed from each device approximately once a month. The device is estimated to need full replacement every 2 years.

Complementary Technical Systems

Filtration prior to treatment can reduce the amount of chlorine needed, if source water is turbid.

Compliance with regulations

NSF / ANSI Standard 60: Drinking Water Treatment Chemicals: Lotus Water is not specifically listed as complying, but dozens other companies selling sodium hypochlorite products for drinking water treatment are approved. This certifies that chemicals are safe at the maximum dose and that any impurities are below the maximum allowable limit. US Environmental Protection Agency (EPA) Registration: Lotus Water is not registered with the EPA, sodium hypochlorite has been registered since 1957, and the EPA issued a registration standard in 1986 saying that sodium hypochlorite products (with 5.25% – 12.5% chlorine) do not need individual registration review. The document also states that, “widely used in disinfecting water supplies for nearly a century, the hypochlorites have been proven safe and practical to use. World Health Organization (WHO):The World Health Organization does not currently approve products for use to treat drinking water. However, the Guidelines for Drinking Water Quality list liquid NaOCl with concentrations between 0.5% and 1% as a point-of-use water treatment method.

Evaluation methods

WHO recommendations for chlorine dosing and contact times; Randomized controlled trial to evaluate impacts planned for Dhaka, Bangladesh.  Interview with representative

Other Information

Video on The Lotus Water Project. Please see Lotus Water's Gallery.

Leave a Reply

Explore similar solutions


May 27, 2024

DTW Lotus Biogas Burner

Read Solution

Implemented by

Development Technology Workshop


January 3, 2024

Zimba automatic chlorine dispenser

Read Solution

Implemented by

Suprio Das


January 3, 2024

MSR SE200 Community Chlorine Maker

Read Solution

Implemented by

Cascade Designers, Inc


February 21, 2024

Brilliance Phototherapy Device

Read Solution

Implemented by

Equalize Health


February 8, 2024

Firefly Phototherapy Device

Read Solution

Implemented by

Design That Matters (DtM)


November 24, 2023

Pumani Bubble Continuous Positive Airway Pressure (bCPAP) Device

Read Solution

Implemented by

Hadleigh Health Technologies, and Rice 360


November 22, 2023

SEA-PAP High Oscillation Continuous Positive Airway Pressure Device

Read Solution

Implemented by

The NeoRest team at the Seattle Children’s Hopsital


February 29, 2024

ShangRing Circumcision Device

Read Solution

Implemented by

Jian Zhong Shang


December 12, 2023

Sohum Hearing Screening Device

Read Solution

Implemented by

Sohum Innovation lab


October 30, 2023

Odon Device

Read Solution

Implemented by

Jorge Odón

All Solutions

Contribute to E4C's Library of Breakthrough Sustainable Development Technology Solutions

Suggest A Solution

Get more information about Solutions Library and its features.

Learn More

Have thoughts on how we can improve?

Give Us Feedback

Join a global community of changemakers.

Become A Member