Water Hyacinth Management - Eradication Through Utilization

Green Waste to Green Gold

Water hyacinth (Eichhornia crassipes) is a free-floating freshwater plant of the family Pontederiaceae. It can vary in size from a few inches tall to over three feet. This plant has blue-green leaves. It grows in mats up to 2 meters thick which can reduce light and oxygen, change water chemistry, affect flora and fauna, and cause a significant increase in water loss due to evapotranspiration.

Water hyacinth is native to South America and originated from the Amazon Basin and was introduced into many parts of the world as an ornamental garden pond plant due to its beauty. It has proliferated in many areas and can now be found in all continents apart from Europe. It is common in lakes across many sub-tropical and tropical regions of the world especially South America, Africa, and South & South East Asia.

Water hyacinth has been called the world's worst aquatic weed and has proven to be a significant economic and ecological burden to local communities. Water hyacinth is extremely difficult to eradicate once established. The goal of most management efforts is to minimize economic costs and ecological change. Many methods have been used to completely eradicate the Water hyacinth from the water bodies which include mechanical/physical removal, biological control, and chemical control but none of these has been able to eradicate it completely.

This article, therefore, endeavored to determine the economically viable method for water hyacinth management and control with community involvement. The approach suggested in the paper has been deployed across the world differently and is based on the fact that Water hyacinth contains significant amounts of chemical components. These are Chlorine, Nitrogen, Phosphorous, Sulphur, Copper, Calcium, Magnesium, and Lead.

Economical Value of Water hyacinth

The use of Water Hyacinth to produce different consumables as suggested in this concept-note involves a community in their production and will empower the community economically and help rid the water bodies of the weed.

Compost

Trichoderma viride and Pleurotus sajor-caju consortia along with urea can be used to prepare the compost using weeds such as Water hyacinth (Eichornia crassipes rpt Eichornia crassipes), parthenium, cyperus (Cyperus rotundus)’ and ‘cynodon (Cynodon dactylon). An elevated shaded place easily accessible from all sides with dimensions 5m by 1.5m should be selected and marked. 100 KG of water hyacinth should be cut to 10 to 15 cm in size and spread over the marked area. About 50 grams of microbial consortia should be sprinkled over this layer. 100 KG of water hyacinth is spread on this layer. 1 KG of urea is sprinkled uniformly over this layer. This process is repeated until the level rises to one meter. Water is sprinkled as necessary to maintain a moisture level of around 50%. Thereafter, the surface of the heap is covered with a thin layer of soil. The pile is turned thoroughly on the 21st day. The compost is ready in about 40 days.

Paper

Paper can be produced from the stalk of the hyacinth. The stalk is used in the process in which it is chopped into pieces 3-5 CM long and then cooked with chemicals in a stainless steel autoclave at temperatures of 120 to 130 degrees centigrade for about two hours. The cooked material is washed with water and the pulp bleached with hypochlorite in two stages with an intermediate alkali wash. The pulp is then beaten into paper. The paper with high water resistance shows appreciable strength, appearance, and smoothness suitable for writing and printing. Besides this, other varieties of papers and boards for use as file covers and cards can also be made satisfactorily in handmade paper units.

Biofuel

Water hyacinth has high cellulose and hemicellulose content in its biomass hence can be used for bioethanol production. Water hyacinth can be saccharified with diluted sulfuric acid and fermented to ethanol by yeast obtained from different hydrospheres.

Other Commercially Viable Consumables

Water hyacinth can be used to produce briquettes and bedding material for cultivating mushrooms and as a hydroponic medium.

It can also be used to produce cellulase enzyme which is used by industry in a large number of activities including but not limited to improving the quality of cotton textile, increasing the tensile strength of paper, and convert fiber to sugar to name a few.

Harvesting of Water hyacinth

Plants like Water hyacinth growing in water require special techniques to harvest them and transport them to the bank for whatever processing is needed for their ultimate utilization or disposal. The material is wet, it may be muddy, and in some circumstances may harbor dangerous micro-organisms or even animals.

Various mechanical techniques have evolved, yet for most of the people living in developing countries, to whom aquatic weeds may be a dangerous nuisance as well as a potential crop, harvesting must be done by hand from the bank, or by using small boats, and with conventional or specially designed hand tools.

Mechanical harvesting of water hyacinth is carried out with machines known as “Aquatic Scavengers”. These boats combine both cutting and carrying the weeds. They can cut normally to a depth of 1.5 m if necessary. To deliver the collected weed onshore the conveyor is run in the opposite direction. A standard unit can remove 100 MT each week. These machine units can be programmed to work in shallow water near the shore as well as in deeper water. A large variety of such machines with different capacities, capabilities, and costs are available and the selection of the most appropriate depends on various aspects including the economic viability of capital cost.

Way Forward

Each water body and its surrounding communities and economic environment is unique. To create a viable Water hyacinth management program needs a multidimensional study and this study can create a blueprint of the way forward.

About Author

DEEPAK PAREEK

https://www.dhirubhai.net/in/dpareek/

Managing Partner, HnyB, Pioneer & Expert – Digital Transformation, World Economic Forum  

Deepak is a serial social entrepreneur who created some of the most respected AgriTech companies, DigiAgri, MyCrop, and AgriChain. These companies use cutting-edge technologies for improving profitability and productivity of small and marginal farmers on one hand and providing valuable insights to agriculture ecosystem participants on the other. Deepak was honored as Technology Pioneer 2018 by World Economic Forum and is currently a member of various World Economic Forum communities and is also a member of the Expert Panel of World Economic Forum on Digital Transformation. He was awarded as top 10 Agropreneur by Future Agro Challenge and was also amongst the top 100 Social Entrepreneur listed by the National University of Singapore and DBS Foundation.

Deepak is a regular speaker across the globe and a well-published author. He has also moderated and Chaired many events related to Agriculture, Digital Transformation, and Global Business. He is also the host of the web series “Fire Side Chat with Champions” in which we interview global business leaders. He has been profiled by reputed publications/media including Forbes, Nikkei, Channel News Asia, YourStory, Nasscom Research, Inc42, Business Insider to name a few.