Converting Waste Agricultural Biomass into a Resource - UNEP

Job Potential: 231
Preparing the solid waste materials in usable form—perforating plastic bottles,
processing biomass residues, and generally constructing the DEWATS—
proved to be painstaking tasks for the project team. “But for small
communities, where processing areas for waste materials can be established,
the DEWATS can be easily replicated and could become a source of
community livelihood,” the project team recommends.
Social Considerations 232
1. Establishing of multi-stakeholder networks to combat water pollution
2. Building up implementation capacity on various levels
3. Providing treatment for both, domestic and industrial wastewater at
affordable price
4. Fulfillment of discharge standards and environmental laws
5. Wastewater pollution reduced by up to 90%
6. Providing treatment for wastewater flows up to 1000 m3 / day
Economic Instruments for Overcoming Barriers 233
The project, under the ASEAN University Network-South East Asia
Engineering Education Network (AUN/SEED NET), is funded by the Japan
International Cooperation Agency (JICA).
Advantages to Developing Countries 234
The state-of-the-art technology at reasonable costs, resulting from the use of
local materials, has made DEWATS applications popular in the developing
world.
The system costs less than conventional septic tanks, and can last for many
years. It can be used for both centralized and decentralized systems, as it can
easily be reinstalled in other sites. More importantly, it solves both the
wastewater management problem and the problem of solid waste disposal.
Disadvantages to Developing Countries 235
One drawback of the DEWATS is that it is not large enough. The pilot-scale
system could only treat one cubic meter of wastewater at a time. The septic
tank would also require de-sludging every two or three years. While the
technology is sound, low-cost, and durable, however, there is another
downside to the DEWATS.
Example of Real Life Applications 236
The project aims to solve sanitation problems and environmental pollution
caused by improper sewage disposal using a low-cost decentralized
wastewater treatment system (DEWATS). DEWATS treatment efficiency for a
hospital wastewater is found below.
231 Ibid.
232 http://www.borda.de/conrat/Dewats_Mai05_72.pdf
233 http://www.adb.org/water/actions/PHI/using-solid-waste.asp
234 Ibid.
235 Ibid.
236 http://www.up.edu.ph/upnewsletter.php?issue=28&i=414
412