Water Hyacinth and Water Cabbage: Multi-Purpose Solutions for Wastewater Cleaning, Composting, and Biochar Production
The beauty of water hyacinth and water cabbage hides its potential—from becoming an excellent source of nitrogen for plants to fodder for fuel, to destroying the natural habitats of lakes. At first glance, water hyacinth (Eichhornia crassipes) and water cabbage (Pistia stratiotes) might seem like harmless, even beautiful aquatic plants. However, their rapid growth and invasive nature make them formidable challenges for aquatic ecosystems. These plants thrive in nutrient-rich waters, forming dense mats that block sunlight, reduce oxygen levels, and disrupt native biodiversity. Yet, despite their notoriety as invasive species, both water hyacinth and water cabbage hold untapped potential for addressing environmental challenges.
Floating Water Hyacinth Lake cleaning Solutions
In 2021, I relocated to Bangalore and became involved with the water conservation group in the Bangalore Environment Trust. I voluntered to help map water pollution across lakes in Bangalore and its outskirts. Here, I learned that water hyacinth and water cabbage can indeed be a cruel invasives, but could also represent the cure these lakes so desperately needed.
As I began recording lake TDS data, my cook excitedly shared stories about his hometown in Bihar. He talked about people getting entangled in water hyacinth and having to be rescued while pulling it out. He also described the practice of drying water hyacinth by spreading it on roads, where it is crushed by passing vehicles, and its subsequent use as cooking fuel. At Organo an organic villa community, as well as Diyabubula, Sri Lanka, I saw their swimming pool being cleaned by duckweed, WH, and more. These stories added a deeply human perspective to my understanding of these plant.
Turning Problems into Compost
My observations of water hyacinth and water cabbage in Bangalore’s lakes revealed their ability to clean polluted water. Their dense root systems absorb pollutants like nitrogen, phosphates, and even heavy metals. These properties make them excellent candidates for use in constructed wetlands or as natural bio-filters for wastewater treatment. While their overgrowth is problematic, harnessing their natural filtering abilities could offer a cost-effective solution to water pollution. I began to incorporate WH and WC as nitrogen-rich greens in my composting experiments. They decompose quickly and enrich the compost with nutrients, balancing the carbon-heavy browns like dried leaves and straw.
Step-by-step guide to using WH & WC, with challenges
- Chopping the plants into smaller pieces.
- Dry them and mixing them well with dry materials.
- Turning the pile regularly while drying ensured better aeration and minimized pest problems and odour problems.
I learned the hard way that I will use WH and WC only in hot composting, and as browns. They can attract pests like slugs if not handled carefully. Green WH and WC have a high moisture content levels. This resulted in soggy piles with anaerobic conditions, slowing down the rate of decomposition and foul odors. Furthermore, their “nitrogen-rich” content requires a greater balance of the browns.
Thermophilic Composting or Biochar
Hot composting, also known as thermophilic composting, maintains temperatures between 131°F and 160°F (55°C–70°C), accelerating the breakdown of organic material while effectively destroying pathogens, weed seeds, and pests.
WH and WC can carry water based pathogens. This method is particularly effective for managing water hyacinth and water cabbage, as it mitigates challenges like their high moisture content and the risk of spreading viable seeds. By achieving and sustaining these elevated temperatures, thermophilic composting transforms these invasive aquatic plants into nutrient-rich compost that supports sustainable agriculture.
Personal Reflections on the Environmental and Economic Impact
Reflecting on these observations, I’ve realized that water hyacinth and water cabbage are more than just weeds. They’re symbols of how we can turn environmental challenges into opportunities. From cleaning wastewater to enriching compost and producing biochar, these plants offer a range of sustainable solutions. The practices I’ve witnessed in Bangalore and Bihar show that effective management and innovative thinking can transform invasive species into resources that benefit communities and ecosystems alike.
What are your experiences with water hyacinth and water cabbage? I’d love to hear your thoughts and ideas. I can be reached at [email protected]