Plant Coagulants Clean Dairy Wastewater, Study Shows
India, the world’s leading milk producer, generated an estimated 239 million tonnes of milk in 2024—about 25% of global output—and consequently, 2.5 times more wastewater than the milk processed . Dairy processing—especially for products like yoghurt, butter, and cheese—demands large volumes of water, resulting in wastewater rich in organic matter, fats, suspended solids, and industrial cleaning chemicals such as benzene, zinc, and chromium. If released untreated, this wastewater poses serious risks including oxygen depletion in aquatic environments, algal blooms, groundwater contamination, and increased vector-borne diseases like malaria and dengue .
A recent study by Lipsa Mishra and team proposes plant-based coagulants—specifically papaya seeds, sweet lemon (Citrus limetta) peels, and Moringa oleifera (drumstick) powder—as eco-friendly alternatives to conventional chemical coagulants like aluminium and ferrous sulphate. These natural options achieved impressive results: lemon peels removed 94% of BOD, while papaya seeds and mora powder delivered 94% turbidity removal and 68% reduction in dissolved solids, all with biodegradable sludge outputs .
The use of these natural materials also helps maintain pH balance and reduce both biochemical oxygen demand (BOD) and chemical oxygen demand (COD)—vital parameters for preventing aquatic hypoxia and preserving ecosystem health . The authors emphasize the need for broader adoption of such eco-friendly solutions to address India’s growing water scarcity and environmental pollution challenges.
Industry Insight
Plant-based coagulants point to a sustainable shift in dairy wastewater management—combining high treatment efficiency with minimal environmental impact and supporting potential water reuse strategies, such as irrigation. This approach aligns with the industry's broader move towards green processing and regulatory compliance.
Source : Dairynews7x7 Aug 20th 2025 Read full story here