The removal of water hyacinth can contribute to reducing
nutrients in either of the two scenarios. According to Zheng et al.
(2008), the contents of nitrogen and phosphorus in dry water
hyacinth are 3.07% and 0.46%, respectively. That is, one ton of fresh
water hyacinth can absorb 2.01 kg nitrogen and 0.30 kg phosphorous.
A biogas plant with a capacity of processing 11,004.2 kg of
fresh water hyacinth can remove 22.16 tons of nitrogen and
3.32 tons of phosphorous out of a eutrophic water body. However,
both the biogas and landfill options can achieve the same result in
nutrient reduction as long as the amounts of disposed water
hyacinth are the same in the two options. As compared to the
current landfill approach and level of water hyacinth control, the
biogas option can have an additional contribution to water
improvement if the processing scale is greater than 164,000 kg of
water hyacinth