Pulp & Paper Industry — Effluent Treatment Solutions

The pulp and paper industry is one of India's most water-intensive manufacturing sectors — and one of the most heavily regulated from an effluent discharge perspective. India has approximately 800 operating paper mills, ranging from small agro-residue-based units (50–200 TPD) to large integrated kraft pulp and paper mills (500–2,000 TPD). Each mill type generates a distinct wastewater profile: integrated kraft mills produce high-COD effluent with dark colour and chlorinated organics from the bleaching plant; recycled fibre (waste paper) mills produce effluent dominated by high suspended solids, ink, and de-inking chemicals; newsprint and packaging mills generate moderate-strength effluent with high TSS from whitewater.

The CPCB has progressively tightened effluent discharge standards for the pulp and paper industry, and the National Green Tribunal (NGT) has issued orders mandating ZLD for mills located along the Ganga and its tributaries, as well as mills in several other notified river basins. Compliance failures in this industry are treated seriously — several large mills have received closure orders from the NGT for non-compliance with ETP operation and effluent quality standards. For paper mill operators, a fully functional and compliant ETP is not optional; it is a prerequisite for continued operations.

Spans Envirotech has been engaged in the pulp and paper sector through our existing client base in the industrial wastewater segment, building on our core capabilities in physio-chemical primary treatment, biological secondary treatment, and advanced tertiary treatment and ZLD systems. Our paper mill ETPs are designed to address the complete effluent challenge — screening and fibre recovery from paper machine whitewater, primary clarification for fibre and filler removal, biological oxidation of dissolved COD and BOD, advanced colour removal using chemical oxidation or adsorption, and ZLD using RO membranes and MEE/MVR evaporation where mandated.

Water reuse is a critical economic driver for paper mill ETP projects — large mills consuming 30–100 m³ of water per tonne of paper can significantly reduce freshwater costs and wastewater discharge fees by recovering treated water from the ETP for reuse in whitewater circuits, cooling towers, and utility applications. Spans designs paper mill water recovery systems that integrate with existing mill water balance and can recover 70–90% of treated effluent for in-plant reuse.