| Abstract: |
The excessive growth of water hyacinth is a common environmental problem in
tropical regions. The use of water hyacinth to remove nutrients from bodies of
water and to produce biogas is a technically feasible way of controlling water
hyacinth, but its environmental and economic performance are not well
understood. This study collected data from an experimental biogas plant to
develop a lifecycle analysis and a cost benefit analysis for the control of
water hyacinth in Dianchi Lake, a eutrophic lake in China. A comparison was
made between the proposed project and the current approach at Dianchi Lake of
disposing of water hyacinth via collection and landfill. The results revealed
that the proposed project is economically feasible with a desirable energy
gain. The results also showed that the project is not financially feasible
but, compared to the current landfill practice, the government would be able
to spend less on controlling water hyacinth if they implemented the proposed
project. The removal of water hyacinth to produce biogas can also contribute
to water quality improvement and GHG emission reduction; however, these values
depend on the scale of processing undertaken by the biogas plant. Since both
the current approach and the proposed project can remove nutrients from bodies
of water, the additional value resulting from the proposed project of an
improvement in water quality only becomes possible when the processing scale
of the biogas plant is greater than the amount of water hyacinth disposed of
by landfill. The proposed project can avoid methane emissions when the
processing scale is greater than the amount of water hyacinth currently
disposed of via landfill. The internalization of GHG emission reduction alone
is not sufficient to make the project financially feasible and therefore other
sources of compensation are needed in order to promote the production of
biogas from water hyacinth. The proposed project could be a potential
microeconomic option, which could respond to China’s macro water pollution
control policies, renewable energy development, and energy saving and
emissions reduction. However, institutional arrangements are required to
coordinate these diverse policies when they are applied to the proposed
project. |