04-05-2025
Experts ‘peel away' Pirana's leachate threat
Ahmedabad: The mountain of waste at dumping sites like Pirana poses a constant environmental threat, none more insidious than leachate, the toxic liquid that the waste oozes. Packed with toxic carcinogenic pollutants and heavy metals, treating this complex cocktail remains a major challenge for every city. However, new research from the Institute of Advanced Research (IAR), Gandhinagar, and the Union MoEF's Indian Institute of Forest Management (IIFM) in Bhopal points to a surprisingly simple solution derived from kitchen scraps:
Garbage enzyme
.
Landfill leachate, formed as rain and moisture filter through decaying waste, carries a heavy load of inorganic ions like ammonium, nitrates, and heavy metals, as well as pathogens, posing serious risks to soil and water resources. Researchers Dharni Parekh, Sachin Vaidh, Dhara Patel, Shuvomoy Banerjee of IIAR, and Gajendra Vishwakarma from IIFM prepared two types of garbage enzymes (GE) for
landfill leachate treatment
testing: citrus and non-citrus. The process involved mixing organic waste peels, sugar, and water in a 1:3:10 ratio in an airtight container, followed by three months of fermentation with regular gas release. The final step was filtering the brownish liquid to obtain the enzyme solution.
"Biochemical analysis revealed GE to be a complex mixture. It was found to be predominantly acidic with pH ranging between 3.1 and 4.2," states the research paper. The mix contained several key compounds, including flavonoids, alkaloids, quinones, saponins, and cardenolides, in both citrus and non-citrus GE samples, states the research recently published in Elsevier's Waste Management Bulletin's April edition.
Researchers tested citrus and non-citrus garbage enzyme (GE) on the blackish
Pirana landfill leachate
, which had high total dissolved salts (TDS). Electric conductivity tests, chemical oxygen demand (COD) indicated a high presence of toxic chemicals, and ammoniacal nitrogen. After 21 days, both GEs turned the leachate from blackish to bright brown, indicating colour removal. The GE prepared using non-citrus vegetable peels reduced COD by 60%, and GE prepared using citrus peels by 47%. Ammoniacal nitrogen (NH3-N) decreased by 45% with non-citrus GE and 40% with citrus GE, suggesting enzyme breakdown of organics and bacterial nitrogen treatment.
The main bacterium found was Acetobacter senegalensis, important for bioremediation. This bacterium was stable, could handle heat, and produced a lot of acetic acid, which makes pollutants dissolve better and become more available for other microbes to break down.
