Paques Environmental Technology India Private Limited is helping the pulp and paper industry to close the loop on water use and greatly reduce their environmental footprint by providing advanced solutions to lower freshwater dependency, recycle wastewater and replace fossil fuel use in boilers with biogas. Mr. Mani Elanchezhiyan, Associate Vice President (AVP) – Process & Proposals (Emerging Market), Paques Environmental Technology India Private Limited, revealed this and much more during a freewheeling chat with Paper Mart.
Paper Mart: How has your understanding or approach to water circularity evolved over time? How are you helping mills move closer to achieving it?
Mani Elanchezhiyan: Over time, our understanding of water circularity has moved from basic treatment and discharge systems to integrated, closed-loop designs that aim for maximum reuse with minimal freshwater intake. Initially, our focus was on anaerobic treatment and biogas recovery. Now, we integrate this into a full circular loop, combining technologies like DAF units, aerobic polishing and final clarifiers, enabling mills to recycle water directly back into the pulp process. By commissioning multiple BIOPAQ IC and ICX reactors, especially in OCC-based paper mills, we’ve enabled clients to not only meet discharge norms, but to close the loop on water use, greatly reducing their environmental footprint.
PM: How widely are circular water systems (such as ZLD, membrane filtration, biological treatments, or AI-based monitoring) being adopted in paper mills? What adoption trends are you noticing?
ME: Adoption of biological treatments is now widespread in the Indian paper industry, especially anaerobic systems due to the dual benefit of pollution load reduction and biogas recovery. ZLD systems are gaining ground, especially in regions with strict water abstraction limits or high-water stress. Membrane technologies are being evaluated, but fouling and operational costs are still a concern. AI-based monitoring is in its early stages, though some large mills are piloting predictive maintenance and process optimization tools. Overall, the trend is towards integrated systems that combine proven biological processes with smart monitoring and controls.
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PM: Based on your experience, which current technologies are having the greatest real-world impact in improving water circularity in paper mills?
ME: Anaerobic digestion (BIOPAQ IC/ICX) for high-load wastewater is the most impactful, providing COD reduction and renewable energy (biogas). DAF systems for primary solids and fat/oil removal help protect downstream units and recover usable water early in the process.
Aerobic polishing systems paired with secondary clarifiers ensure the treated water meets reuse standards for the pulp process. Biogas purification, like the project at Sainsons Paper, adds a monetary value to circularity through fuel sales.
By commissioning multiple BIOPAQ IC and ICX reactors, especially in OCC-based paper mills, we’ve enabled clients to not only meet discharge norms, but to close the loop on water use, greatly reducing their environmental footprint.
PM: What are the key challenges your clients face in improving water management or achieving circularity?
ME: Our clients majorly face space constraints for adding new treatment stages in existing facilities; sludge management, especially post-aerobic treatment; and operational reliability, especially with varying influent loads in OCC-based systems. Several mills, especially the small and mid-sized mills, have major concerns over capacity enhancement. Skilled manpower to operate and maintain complex biological & integrated systems is another area of concern for customers.
PM: How are environmental regulations influencing demand for circular water systems? Are you seeing more compliance-driven innovation?
ME: Yes, regulations are a strong driver. CPCB norms on discharge quality and local pollution control board directives are pushing mills to adopt more advanced treatment and reuse systems. This has led to compliance-driven innovation, where mills are not only meeting the norms but also turning waste into value (for example, biogas purification and sale). We’re seeing increased interest in modular systems that can be easily upgraded as norms tighten.
PM: Can you share examples of cost or efficiency gains achieved by mills using your systems for water recycling or ZLD?
ME: At multiple OCC-based paper mills, our systems have helped achieve up to 85-95 percent water reuse, significantly lowering freshwater dependency. Biogas generation has replaced fossil fuel use in boilers, saving costs and improving carbon footprint. At Sainsons Paper, purified biogas is sold to a nearby HPCL station, turning waste into a new revenue stream.
Reduced sludge generation in anaerobic systems has also helped lower disposal costs.
Overall, the trend is towards integrated systems that combine proven biological processes with smart monitoring and controls.
PM: How do you co-create solutions with mills? Are there examples of partnerships that led to better water management outcomes?
ME: At one large OCC-based mill, we co-developed a DAF+ICX+aerobic polishing+water reuse system that met both production expansion needs and zero liquid discharge compliance.
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PM: Looking ahead, which emerging technologies or innovation models (such as digital twins, decentralized systems, or AI/IoT platforms) could radically improve water circularity in the next 5–10 years?
ME: Digital twins of water treatment plants can help simulate and optimize performance before real-world deployment. IoT-enabled monitoring and AI analytics will improve predictive maintenance, energy efficiency, and process control, while decentralized modular systems will allow smaller mills to implement circular solutions without massive infrastructure. Advanced anaerobic technologies like low-footprint ICX/IC reactors and biogas upgrading systems will further enhance energy recovery and water reuse.
