2.2. Delineation of scenarios
The study considered two scenarios, representing two
approaches of dealing with water hyacinth after it is collected. One
is the status quo (hereafter referred to as the landfill option), while
the other scenario will use water hyacinth for biogas production
(hereafter referred to as biogas option).
(1) Landfill option
The landfill option represents the current approach used to
control water hyacinth proliferation, where water hyacinth is
collected for disposal in a landfill. In this scenario, water hyacinth is
viewed as an aquatic weed and its proliferation is a nuisance to the
aquatic system. Despite other methods, mechanical removal is
presently the most effective method for the control of water
hyacinth bloom. The current average annual growth of water
hyacinth is 250 thousand tons. From 2005 to 2010, Dianchi
Administration Bureau (DAB), the authority of Dianchi Lake, has
financed eight companies to remove 820 thousand tons of water
hyacinth out of the lake.
The collected water hyacinth is disposed by simple landfill. As it
is disposed by landfill, water hyacinth will generate landfill gas,
which is mainly composed of methane and carbon dioxide, and will
eventually be released to the atmosphere because there is no
landfill gas capture system.