Make it so idea - waste disposal solutions for floating villages

The Tonle Sap Lake and river system is home to around 1.2 million Cambodians. A quarter of the residents live in floating communities scattered around the lake. Its role in the nation’s economy, culture and livelihood is significant, with 75% of the country’s fish-catch being sourced from the lake. However, the sanitation practices of residents on the lake are causing severely detrimental effects on the local environment and water quality. Engineers Without Borders (EWB) have been working with local NGOs in developing more sustainable and environmentally friendly waste disposal solutions for floating villages on the Tonle Sap. One potential solution being implemented is the installation of a floating biodigester, where waste is treated and becomes a useful fertiliser. A by product of this process is the formation of biogas.

Live and Learn: Environmental Education is a not for profit organisation that aims to educate communities on the appropriate management and reduction of waste to prevent human and environmental risk . In partnership with EWB, Live and Learn, have focused on the implementation of efficient and cost effective, floating waste management systems with the hope that the instigation of such systems provides a social, environmental and economical dividends that will motivate the community to manage waste effectively. Coordinating this program for EWB is Rob Hughes, EWB's in-country volunteer, who is working with Live and Learn on this sanitation project.

Engineering students at the University of Melbourne are working with EWB on a project aiming to capture, treat and store the useful biogas created from the biodigestion process. This gas can then be used for cooking and lighting applications throughout communities. The FAO has reported that Cambodia has the third highest deforestation rate in the world. It is imperative that the reliance on wood-fuelled cooking is alleviated. The use of biogas has proven a popular replacement in many other developing countries due to its low cost and easy sourcing.

This project is unique in that biogas is most commonly used at its source (and not on a floating barge!). The team’s solution aims to treat and compress the biogas such that is can be transported throughout the community. The main design constraints are based on cost, local availability of materials and safety. A significant challenge is designing a manually operated reciprocating compressor which ensures the biogas remains entirely oxygen-free.

A University of Melbourne Dreamlarge Grant has allowed the team to travel to the local community in Cambodia to conduct in field research and testing of their prototype. While in Cambodia, the team will spend time in the capital, Phnom Penh, sourcing parts and ensuring the prototype can be successfully constructed before travelling to Phat Sanday, a community of 3000 residents on the Tonle Sap Lake. While in Phat Sanday, the team will assist with the installation of the first prototype biodigester while also evaluating their biogas capture and storage device for the local environment.

Student Team Project Timeline:

March 2011 – started project

September 2011 – travel to Cambodia

October 2011 – Final report due, presentation to fellow students and industry representatives

Team Members:

We are all final year students completing 5 year degrees. Our details are as follows:

Matthew Andrews (Mechanical Engineering/Science)

Henry Craig (Mechanical Engineering/Commerce)

Toray Altas (Mechanical Engineering/Computer Science/Music)

Alexander Thompson (Mechanical Engineering/Commerce)

Project supervisor:

Dr Colin Burvill