Phytotechnology and Photosynthesis - Environmental Biotechnology: Theory and Application - page 172

CaseStudy7.2 SustainableEngineeredPhytoremediation
(Dhulikhel,Nepal)
Many practical applications of phytotechnology owe their success to the effective
simplicity of their design, a factor which makes them particularly useful in areas
short on resources, skilled labour or traditional infrastructure. As a result, engineered
phytoremediation in particular can enable reproducibly sustainable development
projects to be undertaken in regions where it would be difficult to provide more
conventional solutions.
After a series of public health incidents which were shown to be linked to the
existing largely ad hoc arrangements for sewage, the Dhulikhel municipality - the
smallest in Nepal - constructed a community-based wastewater treatment plant,
utilising constructed wetlands to return cleaned water to the Punyamata River. Built
at Srikhandapur, in the Kavre district, and said to be the first scheme of its kind in
Southern Asia, six 175 m 3 horizontal reed beds lie at its core, with two 75 m 3 biogas
reactors providing cooking gas for the population. The sludge solids produced are
returned to beneficial use as agricultural fertiliser to support the local economy.
The project was instigated as a co-operative venture between the United Nations
Human Settlements Programme (UN-HABITAT), the Environment and Public Health
Organization (ENPHO), the Dhulikhel municipality and the people themselves.
Crucially, in addition to providing direct technical assistance, ENPHO also undertook
local training, to ensure that the reed beds will be able to continue to function
effectively in future. The success of this approach has led Nepal's Ministry of
Physical Planning and Works to consider feasibility studies of the biogas/constructed
wetland model for other communities and cities.
It is a particularly good example of the simplicity, sustainability and potential for
easy replication that phytotechnology can offer. However, perhaps more importantly,
it makes the point very clearly that 'biotech' solutions do not automatically have to
be technologically complex, excessively engineered or prohibitively expensive
to implement.