Treatment of sewage using water hyacinth biomass

Water hyacinth and need for its removal

Water_hyacinthWater hyacinth (Eichhornia crassipes) is one of the most intransigent weeds of the world. It has successfully resisted all attempts of eradicating it by chemical, biological, mechanical or hybrid means. Wherever water hyacinth is not controlled, it rapidly covers all the water-bodies and surrounding marshy areas. At an average annual productivity of 50 dry (ash-free) tonnes per hectare per year, water hyacinth is one of the most productive plants in the world. Such colonization of wetlands leads to rapid decline of the quantity and the quality of water (DO depletion and aging of water bodies) through addition of dead biomass. It also affects aquatic ecosystems health and biodiversity of the water bodies.

Uses of water hyacinth

Water hyacinth is used in treating biodegradable wastewaters. Also, volatile fatty acids (VFAs) has been extracted which can be used as feed supplement in slurry biogas digesters and solid-feed digesters to generate fuels.

Need for other technology for disposing water hyacinth

But the quantity of the aquatic weed that can be utilized in above methods is very low. Even if these options are gainful, the problem of disposal of ‘spent’ weed (left over water hyacinth biomass) still remains. There is a need of novel technology (or combination of technologies), which is ecologically sound and economically viable, to solve the problem of aquatic weed management along with treatment of sewage.

Sewage treatment using water hyacinth

It is estimated that in cities and rural areas of India many million tonnes of organic waste is generated annually which is either burned or land filled. Also, organic contamination necessitates sewage treatment prior to disposal into natural water bodies. Otherwise, the water bodies can be eutrophicated and polluted. The conventional treatment technologies are not that successful, at least in developing countries. Use of aquatic plants, like water hyacinth, in the sewage treatment, apparently, holds the key for the problem.

Spent water hyacinth biomass for growing mushrooms

Mushroom (which falls under the category of healthy, medicinal organic foods) is one of the most delicious food ingredients. Also, demand for organic and healthy foods is increasing world over due to the change in consumer’s preference. So, spent water hyacinth (water hyacinth biomass after the sewage treatment) can be used as substrate for growing mushrooms.

Spent mushroom compost for vermicomposting

Mushroom production results in generation of large quantities of spent mushroom compost (spent substrate). 1 kg mushroom production results in the generation of about 5 kg spent mushroom compost (SMC). So, when water hyacinth biomass is used as substrate for mushroom production, disposal of spent biomass will continue to remain a haunting problem. In the past decades, potential of earthworms for breaking down organic waste has been explored in depth and many large scale vermicomposting have been developed all over the world with varying success. It is a viable, cost-effective and rapid technique for the efficient management of the spent mushroom compost. Vermicompost is considered as an excellent product since it is homogenous and tends to hold more nutrients over a longer period, without impacting the environment.

Summary

Water hyacinth biomass (harvested from water bodies after treatment of sewage), can be used as substrate in mushroom culturing and the spent water hyacinth biomass can be transformed into compost through vermicomposting route and used in agricultural fields to close the nutrient circulation loop.

Reference

Priyanka Anand

E-mail: priyanka210287[at]gmail[dot]com

Image Credit: By Ted Center, Agriculture Research Service, USDA

8 thoughts on “Treatment of sewage using water hyacinth biomass

  1. I think that the energy market is capable of absorbing it all as fuel gas. It digests pretty well on its own or in combination with manure. In Kenya, friends of mine make biomass briquettes of it, burn them in the new low-pollution stoves that produce charcoal for a byproduct, and use the charcoal as biochar.

    1. I know that water hyacinth can be utilized for generating fuel gas. But even then, the quantity of water hyacinth utilization in above mentioned uses is very less. So, there is a need of some other technology that can utilize water hyacinth in an efficient manner. One method is the one I have posted. Also, if this method is successful, then it can utilize water hyacinth in an efficient manner along with many benefits like treatment of sewage, mushroom production & vermicompost production.

      1. hi,i am doing chemical engineering final year in erode. Iam going to start the project regarding the waste water treatment.I have a doubt that by using Water hyacinth (Eichhornia crassipes) as an adasorbent in fenton oxidation process we can treat the textile effluent or not and how much its efficiency will be?

  2. i am also interested in studying water hyacinth as it has been a nuisance especially in the flood prone areas… im studying now on the use of water hyacinth as substrate in floating garden… but i have a question in mind… since this plant is a good absorber of heavy metals, would it transmit the heavy metals to the mushroom?

  3. Water hyacinth is a good absorber of heavy metals.
    The heavy metals may or may not be transmitted to the mushroom. For this, we have to do analysis of mushroom when water hyacinth is used as substrate.

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