2.3. Data collection
The study collected data to analyze the environmental performance,
and the costs and benefits from both private and social
perspectives. Under the biogas option, datawas collected according
to the lifecycle of products, starting from the collection of water
hyacinth to the consumption of biogas and organic fertilizer. In the
landfill option, data was gathered for the whole disposal process
starting from the collection to the decomposition ofwater hyacinth.
The data was collected using two methods: fieldwork and
a literature review. The fieldwork was conducted to get familiar
with the processes involved in the two options, and identify related
costs at different stages by visiting the Dianchi Lake and the DAB,
landfill field and experimental biogas plant in Yunnan. The major
fieldwork in the study area included interviews with key people at
the DAB and workers collecting water hyacinth. Data on the growth
rate of water hyacinth, capability of reducing pollutants, methane
emission rate from the anaerobic digestion of water hyacinth, prices
of biogas and organic fertilizer, and other related parameters
used in the study were gathered from secondary sources.
2.4. Environmental performance analysis
The environmental performance of the biogas option was evaluated
using a lifecycle analysis of according to the production process