The biogas option can remove nutrients from a eutrophic water
body and reduce GHG emission, but, as compared to the current
landfill practice, the additional values depend on the processing scale
of biogas plant. When the process scale is less than or equal to the
current amount of removed water hyacinth at status quo, i.e.,
164,000 tons, the biogas option has no additional value of water
quality improvement but can avoid the economic loss of methane
emission from the current landfill practice. If the processing scale is
greater than 164,000 tons, then the processingof each additional unit
of water hyacinth has a corresponding additional value of water
quality improvement but no more additional avoided loss from
methane emission. To achieve the same level of control over water
hyacinth proliferation by the current practice, the project should
have a scale of processing 164,000 tons of water hyacinth. Considering
the annual growth of water hyacinth of around 250,000 tons,
there is a high possibility of expanding the scale of biogas production